A total of 382 dentists completed the questionnaire. The main reasons for antibiotic prescribing were for abscesses (39.6%), extractions (24.5%), and pulpitis (14.1%). The majority of participants (85.3%) reported prescribing macrolides in the case of a penicillin allergy. Most dentists (98.9%) were aware of the antimicrobial resistance phenomenon, but only 7.4% of them consulted the guidelines for prescribing antibiotics. This study demonstrates that the same trend exists in Italy as in other countries in terms of the high prevalence of misuse and overuse of antibiotics, and that Italian dentists utilize a range of antibiotic management strategies.Antimicrobial resistance is a growing phenomenon, often associated with the improper prescription of antibiotics, prescribed by those who do not follow the guidelines for antibiotic stewardship. The aim of this study was to evaluate the current attitude towards antibiotic prescribing and antimicrobial resistance awareness among Italian dentists. An online questionnaire was distributed to Italian dentists from September to December 2021. The questionnaire was composed of three main sections. The first part was focused on demographic characteristics, the second part on prescription habits, and the third part on the dentists’ knowledge regarding the phenomenon of antimicrobial resistance. A chi-square test was used to find associations between different variables. The level of significance was set at  The discovery of antibiotics is considered to be one of the most important of the twentieth century . It revoAntimicrobial resistance (AMR) is a global health problem that increases antibiotic treatment failure and, consequently, mortality and healthcare costs . This phHowever, systemically delivered antibiotics were also found to be frequent and excessive in a 2018 Italian survey . Consist® .The present cross-sectional study was conducted by sending an online survey questionnaire to Italian dentists from 1 September to 31December 2021. The survey was created using an online survey development cloud-based software product called SurveyMonkeyThe participants were approached via Facebook, WhatsApp, and mailing lists, and the sample size was estimated from similar studies .Participation was voluntary and did not involve compensation. No personal health information was collected, the personal information of participants was protected, and there were no inhumane questions or investigations. All participants gave authorization to use their data, which were collected anonymously.Participants’ demographic features (their age and gender) and dental practice characteristics, concerning their working experience (in years), dental setting , or whether they were a public employee, or a private employee), and their main practice ;The antibiotic prescription habits of Italian dentists, for prophylaxis  and for therapy , as well as their prescription frequency and the most frequent cause of prescribing systemic antibiotics;Dentists’ attitudes towards antibiotics and AMR awareness, asking how often Italian dentists consult the guidelines for prescribing antibiotics, what the antibiotic resistance phenomenon is, dentists’ awareness of antibiotic resistance, prescribing behavior regarding antibiotics and the development of antibiotic resistance, the main reason why antibiotics are prescribed without indication or wrongly, and dentists’ main source of reference to access information on the topic of antibiotic resistance and antibiotic therapy.The questionnaire, developed after a literature review by a group of dentists with different dental specialties, consisted of 23 multiple-choice questions and two open questions, which were sorted into three main sections, specifically investigating:p < 0.05.Frequencies and percentages for categorical data were computed. A chi-square test was used to assess the association between the general frequency of antibiotic prescription and gender, years of experience, and main activity; between the frequency of antibiotic prescription in the treatment and prophylaxis of various dental conditions and years of experience; and between knowledge of the antibiotic resistance phenomenon and years of experience. The main outcome was considered to be the association between wrong antibiotic prescription (for pulpitis) and the experience of the respondents. The effect size w and posthoc power of the study was calculated using G*Power software . A standard statistical software package  was used. The level of significance was set at Out of the 655 dentists that participated in the study, 382  completed the questionnaire.Out of the 655 dentists that participated in the study, 382  completed the questionnaire, giving a response rate of 58.32%. Participants’ demographic features and dental practice characteristics, detailed in The antibiotic prescription habits of Italian dentists, investigated in the second section of the web-based survey and shown in p = 0.007, effect size w = 0.32, power = 99%). Moreover, 66/382 dentists (17.3%) always prescribed antibiotics as prophylaxis in simple tooth extractions. Most dentists (266/382) prescribed antibiotics “daily” (16.7%) or “weekly” (52.6%). Among the dentists with more than 20 years of experience, 72/86 (83.7%) prescribed antibiotics most frequently (“daily” or “weekly”) (p = 0.007). The dentists who most frequently prescribed antibiotics were those who mainly practiced oral surgery  and prosthetics/implantology , while those who less frequently  prescribed antibiotics were orthodontists  (p < 0.001). Antibiotics were prescribed “monthly”, “annually”, or “never” by 64/148 (43.2%) of female dentists compared to 54/236 (22.9%) of male dentists (p < 0.001). Men  made up a significantly higher proportion (p < 0.001) of oral surgeons and prosthetists/implantologists compared to women .In particular, 136/382 dentists (35.6%) prescribed antibiotic therapy in the case of pulpitis. The majority of those who prescribed antibiotics for pulpitis treatment  were dentists with less than 20 years of experience (The majority of dentists (326) prescribed macrolides in the case of an allergy to penicillin, although 18 (4.7%) participants did not know which type of antibiotic to prescribe in such a scenario .The final section of the questionnaire assessed dentists’ attitudes towards antibiotics and antimicrobial-resistance awareness, respectively .The majority of dentists  reported being aware of the antibiotic resistance phenomenon, but only 28 (7.4%) of them consulted the guidelines for prescribing antibiotics.p = 0.002).Less than half of the participants  believed that their prescribing behavior could influence the development of antibiotic resistance. Less experienced dentists were more aware that their behavior had worsened the phenomenon of antibiotic resistance (The three main reasons as to why antibiotics were prescribed without indication or with an incorrect indication were as follows: to avoid capable litigation (34.8%), in the proximity of the weekend or a holiday when it was difficult to predict the evolution of the pathology (23.5%), and with non-compliant patients (23%).Regarding behaviors that could favor the development of antibiotic resistance, 164 participants (42.9%) reported consulting the updated clinical guidelines, 88 (23%) reported obtaining the information from scientific magazines and/or scientific journals, and 36 (9.4%) reported reading forums on the internet.This cross-sectional web-based survey study aimed to investigate the current antibiotic prescribing habits for prophylactic use based on dental procedures, and for therapeutic purposes according to dental diagnoses, in relation to dentists’ working experience, usual setting, and main practice. The secondary aim was to assess the sources and frequency of the consultation of the relevant guidelines, awareness and knowledge about antimicrobial resistance, and related antibiotic prescribing behaviors among Italian dentists.Among the study participants, female dentists tended to prescribe antibiotics less frequently, prescribing antimicrobials “monthly”, “annually”, or “never” in 43.2% of cases, compared to male participants. Similarly, 73.9% of the orthodontists selected “monthly”, “annually”, or “never” with regard to antibiotic prescription in their ordinary practice. Conversely, those dentists mainly practicing prosthetics/implantology and oral surgery reported higher rates of antimicrobial administration, with 85.7% and 97.3% reporting “daily” or “weekly” prescriptions, respectively. Such findings may be explained by the fact that, among the respondents who were prosthetists/implantologists and oral surgeons, men made up a significantly higher proportion than women. In addition, the highest frequency of antibiotic prescription was recorded among dentists with >20 years of dental practice, excluding for prophylactic purposes in simple tooth extractions and for therapeutic use in the case of pulpitis, in which less experienced dentists prescribed antibiotics at a higher frequency. This was probably because they are less confident in their ability to deal with possible complications.The presented results show that many dentists prescribed antibiotics for both prophylactic purposes and therapeutic use in several clinical situations, even if not indicated in the guidelines. However, a general overuse of antibiotics, both for prophylactic and therapeutic purposes, was noted in the present study. This is in line with findings from other countries that also attest to an increase in dental antibiotic use, such as France , the CzeProphylactic antibiotic administration to healthy patients was reported by approximately half of the participants, in cases of dental implant placement (57.1%), regenerative surgery (52.4%), and surgical tooth extractions (47.6%). It is worth noting that 17.3% of dentists in the present survey reported administering antimicrobials to healthy patients in cases of simple tooth extractions. Similar findings were described in several other studies, indicating that dentists often overprescribe antibiotics for prophylaxis, even in healthy patients undergoing invasive dental procedures, such as surgical extractions, dental implant positioning, and endodontic procedures, without observing the relevant guidelines ,25. It sAntibiotic administration for therapeutic use in healthy patients was reported by 84.3% of dentists, specifically in cases of dental abscesses, followed by pericoronitis (58.6%), periodontitis 31.9%), and pulpitis (19.4%). In particular, 35.6% of the participants prescribed antibiotics for therapeutic use in cases of pulpitis, despite the evidence being considered insufficient to support the use of antibiotics for the treatment of irreversible pulpitis and periapical abscesses %, and pu. AnalogoItalian dentists often reported ignoring the guidelines, which is one of the main reasons underlying inappropriate antibiotic prescription. In this study, only 7.4% of dentists reported always consulting the current antimicrobial prescription guidelines, while the majority consulted the guidelines “seldomly” (48%) or “never” (5.3%). From this perspective, it is crucial to raise awareness of AMR among Italian dentists, as it is a serious global public health problem and is directly related to increased healthcare costs and poorer clinical outcomes. Awareness-raising programs should focus on understanding how important it is to consult the updated guidelines in order to combat this phenomenon . The maiThe participants in the present study reported prescribing antibiotics to avoid capable litigation (34.8%) or in cases of patients with poor compliance to dental treatments (23%). In this respect, the COVID-19 pandemic probably increased antibiotic prescriptions due to the impossibility of making an accurate diagnosis during the lockdown and patients’ subsequent fear of returning to a dental practice .Similar to our results, overuse and misuse of antibiotics in dentistry was registered in France , the USATo avoid the overuse and misuse of antibiotics, several factors should be considered before commencing treatment. These include clinical indications for antibiotic administration, the patient’s oral health status, comorbidities, current medication status, and, if possible, a microbiological test to correctly determine the risk/benefit ratio related to systemically delivered antibiotic administration . MoreoveAlong with appropriate short-term antibiotics prescriptions in dentistry, timely management of oral, dental, and periodontal dysbioses is strongly advocated, with adequate dental procedures and antiseptic use which may enhance the control of infections ,14. IndeTherefore, multiple combined strategies are needed to counteract antimicrobial resistance in dental settings, improving awareness and knowledge of AMR, optimizing antibiotics use, and strengthening surveillance ,44.The present study has various limitations, for example, the questionnaire was self-administered, and so specific questions may have been improperly interpreted, although it may be conceivable that self-administration permits more authentic answers that are truly representative of the respondent’s beliefs. In addition, an exact response rate could not be computed. However, this study assessed antibiotic administration among Italian dentists not only for prophylactic purposes , but alsThis study, conducted among Italian dentists, showed a similar trend to that seen in other countries that have a high prevalence of overuse and misuse of systemic antibiotics in dental practice. In addition, it highlights the need to enhance antimicrobial-resistance awareness among Italian dentists.Antimicrobial stewardship should be deeply integrated in dental practice and oral health care. Moreover, through education and training, practitioners’ antibiotic administration should be improved in order to reduce the number of unnecessary prescriptions, and patients’ adherence to antimicrobial treatment should be enhanced in order to limit non-medical prescriptions.


Antibiotics are essential medications for treating life-threatening infections. However, incorrect prescribing can lead to adverse events and contribute to antibiotic resistance. We sought to develop a utilization quality measure that could be used by health insurance plans to track overall prescribing for respiratory conditions.A consensus-based process that included evidence review, testing, and stakeholder input was used to develop a measure and assess its usefulness for the Healthcare Effectiveness Data and Information Set (HEDIS), a national quality measurement tool.Guidelines and literature were reviewed to establish the rationale for the measure. The measure was tested in claims data for commercial, Medicaid and Medicare Advantage enrollees to assess feasibility of collecting and reporting needed information. The measure was vetted with multistakeholder advisory panels and posted for public comment to solicit wide input on relevance and usability.Respiratory conditions are frequent reasons for outpatient care in the data assessed. On average, across all lines of business, the measure revealed that approximately one-third of outpatient visits for respiratory conditions are followed by antibiotics. Stakeholders supported the measure as a tool for monitoring antibiotic prescribing across health plans alongside existing measures that assess inappropriate prescribing for specific conditions. The final measure assesses the number of antibiotic prescriptions dispensed across all outpatient respiratory-related encounters at a health-plan level.The measure on antibiotic prescribing for respiratory conditions was relevant, feasible, and useful. Stakeholders strongly supported the newly developed measure and recommended its integration into HEDIS. The consequences of antibiotic resistance include limited treatment options for certain conditions, healthcare-system strain from longer hospitalizations, and an inability to produce new antibiotics at a pace to match emerging infections. Furthermore, the coronavirus disease 2019 (COVID-19) pandemic prompted increased use of telemedicine, which merits attention given physical examination limitations and other potential impediments to antibiotic stewardship strategies.Antibiotics are essential medications for individuals with life-threatening infections. However, any time they are prescribed, they can lead to adverse events and contribute to antibiotic resistance, including >2.8 million antibiotic-resistant infections occurring in the United States. Thus, health insurance plans are uniquely positioned to establish antibiotic stewardship programs. Health plan administrators have access to data on their enrollees’ healthcare encounters, diagnoses, and treatments. The ability of health plan administrators to leverage those data across various settings is particularly beneficial for antibiotic stewardship efforts.Ambulatory settings account for a large proportion of antibiotic prescriptions, with marked variation across primary, retail, urgent-care and emergency-care providers. Quality measures facilitate prospective auditing of prescribing trends and can assess the impact of interventions such as provider education or prior-authorization processes. National quality measures related to judicious antibiotic use are available in the Healthcare Effectiveness Data and Information Set (HEDIS). HEDIS is used to evaluate the quality of care for >200 million individuals covered by commercial, Medicaid, and Medicare managed-care plans. HEDIS is used to assess whether health plan administrators ensure that their members receive recommended services, treatments, and care management.Measurement is 1 of the 4 Core Elements of Outpatient Antibiotic Stewardship. The performance of these measures has shown modest improvement between 2010 and 2019. However, more information may assist health plan administrators to discern whether improvement is due to better antibiotic treatment decisions or whether it is a reflection of factors unrelated to judicious prescribing, such as misdiagnosis or overdiagnosis. Although assessing antibiotic prescribing for targeted conditions is important, understanding prescribing within a health plan across a broader range of respiratory conditions can complement stewardship efforts.In HEDIS, quality measures assess appropriate antibiotic prescribing for 3 targeted clinical diagnoses: bronchitis, upper respiratory infection, and pharyngitis. These conditions, along with all other respiratory conditions, account for >30% of inappropriate antibiotic prescribing. Pairing data on condition-specific antibiotic prescribing with data on antibiotic prescribing across all respiratory conditions may provide the additional context to advance antibiotic stewardship. Given the prevalence of antimicrobial resistance, high antibiotic prescribing rates, and an increased emphasis on antibiotic stewardship, we sought to develop a utilization measure that provides additional information to complement the existing portfolio of HEDIS antibiotic prescribing measures. Here, we describe the process undertaken to develop, test, and achieve stakeholder consensus for a measure assessing overall utilization of antibiotics for respiratory conditions.Measuring antibiotic utilization for all respiratory conditions presents an opportunity to further analyze prescribing practices and the factors that may contribute to high antibiotic prescribing in outpatient settings. These trends may be influenced by patient desire for antibiotics, provider diagnosing, and coding practices. The process is designed to ensure that any resulting measure exhibits desirable attributes of relevance, scientific soundness, and feasibility. Relevance refers to the importance of the measure to its potential users. Scientific soundness refers to how closely the measure reflects evidence-based guidelines. Feasibility refers to whether the measure can be reported without undue burden. To ensure that a wide range of perspectives were considered, a multistakeholder panel was convened and served as the advisory group to the process.A development process that considers clinical evidence, data analysis and multistakeholder input was used.The process begins with conceptualizing a measure using scientific evidence and input from the advisory panel. Representatives from health plans, clinicians, public health, and the scientific community were identified by the project team based on the individual’s expertise in the field and were recruited for the panel. In some cases, recruited individuals were participants of prior antibiotics-related measure development projects. As a condition of appointment, potential conflicts of interest were assessed for all panel members.The panel provided feedback on key measurement characteristics, including how to define the population to be measured, the range of respiratory conditions to be assessed, and other characteristics that could affect the measure’s usefulness to clinicians, health plan administrators and policy makers. In addition, a separate technical panel composed of quality measurement experts was consulted. This group is a standing advisory panel maintained by the National Committee for Quality Assurance, which stewards HEDIS; the group comprises representatives from health plans, measure auditors, and federal and state measurement program leads. The panel provided input on the feasibility of a respiratory-condition–focused antibiotic prescribing measure based on data sources and analytic capabilities available to health plan administrators.International Classification of Disease, Tenth Revision (ICD-10) and Systematized Nomenclature of Medicine (SNOMED) codes was produced.Defining respiratory conditions. Respiratory conditions were defined as viral or bacterial infections and other illnesses of the upper and lower respiratory tract. These conditions served to identify episodes eligible for the measure.Defining competing diagnoses. Competing conditions were defined as a non–respiratory-antibiotic–indicated diagnosis, such as urinary tract infection, present on the same day as the respiratory condition encounter or ≥3 days after. These are conditions outside respiratory conditions that may warrant treatment with antibiotic medications and therefore should result in the encounter being removed from the measure.Defining comorbid conditions. Comorbid conditions were defined as diagnoses in the 12 months prior to the respiratory-condition encounter for immunocompromising conditions  that may be managed with unique clinical discretion .Key features of the draft measure were developed and specified for testing. The lists of respiratory conditions, competing diagnoses, and comorbid conditions were primarily developed by reviewing and aligning them to the existing antibiotics-related measures in HEDIS. The lists were vetted by the advisory panels. A value set using standardized Once the measure was conceptualized, testing was conducted to provide empirical evidence of the measure’s feasibility and performance rates, as well as to inform other technical features of the measure. Specifically, analyses examined the following: (1) the volume of outpatient visits for respiratory conditions ; (2) the frequency of potential conditions that would exclude an encounter from the denominator; (3) the volume of antibiotic prescriptions dispensed for respiratory conditions ; and (4) performance rates according to proposed measure specifications. The testing was conducted from June through October 2020 using data from the National View that represented healthcare utilization occurring in calendar years 2018 and 2019. The data included index outpatient visits (denominator events) occurring from January 1, 2019, through December 31, 2019, and antibiotic dispensing dates (numerator events) occurring from January 1, 2019, through January 3, 2020. All analyses for the Medicare and commercial populations were conducted using R software.Analyses for Medicare and commercial lines of business were conducted using deidentified administrative claims data from the Optum Labs Data Warehouse, which includes medical and pharmacy claims, laboratory results, and enrollment records for commercial and Medicare Advantage (MA) enrollees. The database contains longitudinal health information on enrollees and patients representing a mixture of ages, ethnicities, and geographic regions across the United States. A unique enrollee identifier was assigned to each individual consistent across years. To maintain patient confidentiality and to adhere to data use agreements, results were not available at the health-plan level. The testing was conducted from October through December 2020, using data on index outpatient visits (denominator events) occurring from January 1, 2018, through December 31, 2018, and antibiotic dispensing dates (numerator events) occurring from January 1, 2018, through January 3, 2019. All analyses for the Medicaid population were conducted using WPS Analytics (a SAS-like platform).Medicaid testing was conducted using the IBM MarketScan Multistate Medicaid Database, which contains medical, surgical, and prescription drug claims for >47 million Medicaid enrollees from multiple states.Descriptive analyses for all lines of business were performed at the population level to determine counts and proportions of outpatient visits based on member age and respiratory condition diagnosis. At the health-plan level, the distribution of outpatient visits for respiratory conditions was also calculated for the Medicare and commercial lines of business. Performance rates for the measure were calculated for each product line. The denominator assessed was the count of eligible outpatient visits for respiratory conditions; the numerator assessed was the number of visits for which an antibiotic dispensing event occurred within 3 days. Because data were based on completed claims, numerator events were measured as antibiotics dispensed. This method produced a rate expressed as the percentage of episodes for members ages 3 months and older with a diagnosis of a respiratory condition that resulted in an antibiotic dispensing event. Also in line with the existing HEDIS measures, members who used hospice services were excluded.Visits were excluded if they resulted in an inpatient stay, if they were associated with a member who had a history of the defined comorbid conditions or competing diagnoses, or if they were dispensed an antibiotic in the 30 days prior to the qualifying event. The impact of excluding these visits was assessed by examining the reduction in frequency and proportion of total visits that occurred after implementing the exclusions. Visits qualified for inclusion if they were conducted among members who were continuously enrolled in a health plan from 30 days prior to the visit date through 3 days after the visit date, for a total of 34 days. For members who had >1 visit in a 31-day period, only the first eligible visit was counted. This method of deduplicating visits aligns with the 3 existing HEDIS measures assessing antibiotic use for bronchitis, upper respiratory infection, and pharyngitis.The draft technical specifications, measure rationale and testing summary were posted for a 30-day public comment period between February and March 2021. Broad feedback was sought to understand the measure’s relevance, perceived feasibility, and usefulness to stakeholders. All comments were reviewed and discussed with the advisory panels.Event characteristics for respiratory conditions. Results indicate that respiratory conditions are frequent reasons for outpatient care in the databases assessed , if overall antibiotic utilization for respiratory conditions more broadly is rising simultaneously, then further examination may be warranted. The advisory panel concluded that inclusion of both types of prescribing ensures that the measure is less vulnerable to variations in coding and diagnostic practices.This study had several limitations. First, testing was conducted using 2018 and 2019 data. This period preceded the COVID-19 pandemic, which was declared in March 2020. After testing was complete, and based on stakeholder input, COVID-19 diagnosis codes were added to the measure. Analyses of 2021 performance data showed that while the rate of antibiotic utilization was lower compared to 2019, the age and sex distribution of the eligible population and the variation in measure performance across plans were similar to those shown in 2019. Related to COVID-19, it is possible that some stakeholders who would otherwise have commented on the draft measure during the public comment period may not have done so due to the overwhelming burden of the pandemic. However, the number of comments received was similar to numbers observed in previous public comment periods for past measure development projects. As the COVID-19 pandemic continues to challenge stewardship efforts across conditions, improved quality metrics will be an important tool to ensure high-quality care for patients.The measure pertaining to antibiotic prescribing for respiratory conditions received support from health plan administrators and leaders in antibiotic stewardship as a tool for monitoring antibiotic utilization and as a flag for further analysis into the organization’s prescribing practices. Stakeholders indicated strong support for the new measure and encouraged improved antibiotic stewardship at the health-plan level, including the integration of the new measure into quality reporting programs. Given their financial role in the provision of health care and the data available to them, health plan administrators are well positioned to monitor antibiotic stewardship efforts across various outpatient settings. As such, the Centers for Disease Control and Prevention released a tool kit of strategies that health plan administrators can employ to improve outpatient antibiotic prescribing.


To show that iFAST  can give accurate susceptibility results for urinary tract infection (UTI) samples in less than 5 h.UTIs are one of the most common forms of infection and reasons for antibiotic prescribing. Empirical prescribing without reference to antimicrobial susceptibility tests (ASTs) is common due to the high incidence, burden of symptoms and the length of time needed for an AST (24–48 h). However, untreated UTIs can lead to complications and in severe cases to bacteraemia and death. In addition, resistance to frontline antibiotics is increasing, leading to increased treatment failure. There is, therefore, a need for a fast, accurate and cost-effective AST for urine samples.Bacterial impedance cytometry can measure the opacity and electrical size of individual cells by measuring the change in the electrical current as single cells flow between micro-electrodes. Bacteria treated with antibiotics change their electrical size and opacity compared with untreated cells. This change is visible on the iFAST within 2 h of exposure to above MIC of antibiotics, thereby enabling detection of cells susceptible to breakpoint concentrations of antibiotics. The iFAST technology and workflow can fit into current diagnostic laboratory practice.Escherichia coli and Klebsiella pneumoniae strains were streaked onto standard agar plates and incubated at 37°C. After 2 h a streak of cells was inoculated into 0.9% saline. Cell count was measured using the iFAST and adjusted to 5 × 105 cfu/mL. 100 μL samples were exposed to EUCAST susceptibility breakpoint concentrations of frontline UTI antibiotics in MH2: co-amoxiclav (2/8 mg/L), amoxicillin (8 mg/L), ceftazidime (1mg/L), cefalexin (16mg/L), ciprofloxacin (0.25mg/L), gentamicin (2 mg/L), nitrofurantoin (64mg/L), trimethoprim (4mg/L) or a no antibiotic control and incubated at 37°C. After 2 h, 60 μL of each culture were measured in the iFAST for 2 min and compared with the no antibiotic control, using percentage cell count and a 50% population contour. In parallel, a gold standard microbroth dilution MIC was carried out, according to EUCAST guidelines, on the cultures.Fifty-eight E. coli treatment and was therefore disregarded for K. pneumoniae), overall concordance with the gold standard microbroth dilution MIC method was 95.2% for total cell count metric and 94.9% for cells in the population contour. The highest concordance was seen for ceftazidime (100% for both metrics) and amoxicillin (100 and 99% respectively), the lowest for trimethoprim (92% and 89% respectively). All non-concordances, except one strain with trimethoprim, showed an MIC of ±1 log2 (doubling dilution) different to the breakpoint concentration, which was used for iFAST. This is the normal technical variability of the gold standard method.For the 441 tests conducted (58 strains in 8 antibiotics, nitrofurantoin is only recommended for iFAST has up to 100% concordance with current gold standard MIC methods and delivers the results in less than 5 h compared with 24–48 h for current ASTs. This novel, fast, accurate and cost-effective AST could increase evidence-based antibiotic prescribing, thereby improving patient treatment, decreasing risk of UTI complications and overall decreasing antimicrobial resistance development.


Prevotella secretes beta-lactamases, which may influence recovery of lung function. We hypothesize that sub-therapeutic and broad spectrum antibiotic exposure leads to decreasing microbial diversity. Our secondary aim was to evaluate the concerted association of beta-lactam pharmacokinetics (PK), antibiotic spectrum, microbial diversity, and antibiotic resistance on lung function recovery using a pathway analysis. This was a retrospective observational study of persons with CF treated with IV antibiotics for PEx between 2016 and 2020 at Children’s National Hospital; respiratory samples and clinical information were collected at hospital admission for PEx (E), end of antibiotic treatment (T), and follow-up (F). Metagenomic sequencing was performed; PathoScope 2.0 and AmrPlusPlus were used for taxonomic assignment of sequences to bacteria and antibiotic resistance genes (ARGs). M/W Pharm was used for PK modeling. Comparison of categorical and continuous variables and pathway analysis were performed in STATA. Twenty-two PwCF experienced 43 PEx. The study cohort had a mean age of 14.6 years. Only 12/43 beta-lactam courses had therapeutic PK, and 18/43 were broad spectrum. A larger decrease in richness between E and T was seen in the therapeutic PK group  and those receiving broad spectrum antibiotics . We did not detect differences in the increase in percent predicted forced expiratory volume in one second (ppFEV1) at end of treatment compared to PEx based on beta-lactam PK (sufficient 13.6% vs. insufficient 15.1%) or antibiotic spectrum (broad 11.5% vs. narrow 16.6%). While both therapeutic beta-lactam PK and broad-spectrum antibiotics decreased richness between PEx and the end of treatment, we did not detect longstanding changes in alpha diversity or an association with superior recovery of lung function compared with subtherapeutic PK and narrow spectrum antimicrobials.Persons with cystic fibrosis (PwCF) suffer from pulmonary exacerbations (PEx) related in part to lung infection. While higher microbial diversity is associated with higher lung function, the data on the impact of short-term antibiotics on changes in microbial diversity is conflicting. Further,  Pseudomonas aeruginosa and other Gram negative organisms are frequent opportunistic pathogens in this population3, and unfortunately beta-lactam antibiotic therapy directed against these pathogens is underdosed about 50% of the time6. Understanding the potential impact of insufficient beta-lactam antibiotic exposure on lung function is important to guide clinical use of beta-lactams10, especially in light of unclear evidence regarding the impact of antimicrobial resistance in persons with CF12.There are more than 70,000 children and adults with living with cystic fibrosis (CF) worldwideP. aeruginosa or other Gram-negative pathogens and clinical outcomes is often evaluated as a single entity or in combination with a single pathogen18, it is important to consider that these pathogens exist within a microbial community20. Prior studies have repeatedly demonstrated an association between low microbial diversity and low lung function22. However, the contribution of antibiotics to changes in microbial diversity remains unclear. Long-term and large cross-sectional studies have demonstrated an association between increased antibiotic exposure and decreased microbial diversity24. Short-term studies of antibiotic treatment of PEx have shown short-term changes in diversity but this was not sustained at follow up25. Importantly, these prior studies did not include the variables of beta-lactam antibiotic exposure27, antibiotic spectrum29, nor the impact of anaerobes30 or community level antibiotic resistance32, such as the ability of Prevotella species to secrete beta-lactamases34.While the relationship between Prevotella relative abundance) and beta-lactam antibiotic resistance, on recovery of pulmonary function.Our overarching study hypothesis is that insufficient beta-lactam pharmacokinetics/pharmacodynamics  and broad-spectrum antibiotic exposure leads to decreasing microbial diversity over time by fostering an environment for select bacteria to dominate the microbiome. Our secondary study aim was to evaluate the concerted association of beta-lactam PK and antibiotic spectrum, through impacts on microbial diversity  antibiotics for PEx between 2016 and 2020 at Children’s National Hospital in Washington DC  was used for PK modeling36.Sputum, oropharyngeal (OP) swabs, and BAL specimens were collected and processed according to standard procedures as previously described  using a Mid-Output 2 × 150 cycle kit. For analysis of the bacterial load, the run was considered successful if the cycle threshold (CT) of the sample run in triplicate was within one cycle. The mean bacterial load of the sample in triplicate was used for subsequent analyses. A log reduction between time points was used to analyze the change in bacterial load between samples.Bacterial DNA extraction, sequencing and PCR were performed as previously described 41. The taxonomic and antibiotic resistance gene count tables were filtered to bacterial species and antibiotic class, respectively, and were imported into Rstudio v3.6.1 for subsequent analyses. The Rstudio packages used for analysis included DESeq2 v.1.24.042, ggplot2 v3.2.043, phyloseq v.1.28.044, and vegan v.2.5-645. Permutational analysis of variance (PERMANOVA) was also performed in Rstudio using the adonis function for analysis and portioning sums of squares using Bray–Curtis dissimilarities. Repeated patient samples were controlled for using the strata function. For comparative analyses taken into STATA, the Morisita–Horn index, observed species, Shannon index, and the inverse Simpson’s index were calculated using Explicet v2.10.546.FastQC and Flexbar were used to evaluate sequences for quality and for sequence trimming prior to putting sequences into downstream applicationsxtreg) and controlling for repeat participant samples (xtset) using robust standard errors. Structural equation modeling for pathway analysis was also performed in STATA/IC ; richness and alpha diversity between groups were compared using random-effects GLS regression  while 25 courses were considered narrow spectrum .A total of 47 beta-lactam agents were administered for the 43 PEx events Table . AntibioS. aureus (mean relative abundance 20.1%), followed by Rothia mucilaginosa (12.5%) and P. aeruginosa (8.5%). Sample specific bacterial relative abundance, richness and alpha diversity are shown in Supplemental Figs. p = 0.848, Shannon p = 0.960, inverse Simpson p = 0.533). Similarly, we checked for an association with the most commonly received inhaled antibiotics, tobramycin  and aztreonam . We did not find an association with inhaled antibiotic use and richness or alpha diversity at PEx . We also evaluated the differential abundance of bacterial species between time points based on sequencing data. We found that the traditional CF pathogens P. aeruginosa, S. aureus, and H. influenzae significantly decreased after antibiotic treatment  were significantly decreased at follow up compared to PEx onset  or antibiotic spectrum . Likewise, there were no differences in the duration of antibiotic therapy based on beta-lactam PK  or antibiotic spectrum . When comparing the change in the number of species observed between end of antibiotic treatment (T) and PEx onset (E) between beta-lactam PK sufficient and insufficient, we found a greater reduction in the richness of the PK sufficient group  time between respiratory sample collection for the PEx (E) and end of treatment (T) sample was 11.8 (5.01) days. There were no differences noted based on beta-lactam PK . In the multivariate model, both beta-lactam PK and antibiotic spectrum were significantly associated with the change in microbial richness observed .While there were no differences appreciated in the time between sample collection based on beta-lactam PK or antibiotic spectrum in our study cohort, it has been shown in other studies that the timing of sample collection during antibiotic therapy can affect outcomesp = 0.446). The time between sample collection was longer in those receiving broad spectrum antibiotics compared to those receiving narrow spectrum antibiotics . However, no differences were noted in the change in richness or alpha diversity or the reduction in bacterial load based on beta-lactam PK  time between respiratory sample collection between for the PEx (E) and follow-up (F) sample was 68.8 (35.1) days. There were no differences noted based on beta-lactam PK . This was not sustained in the comparison between PEx (E) and follow up (F) samples. When using the multivariate model as described for alpha diversity above, the impact of beta-lactam PK remained non-significant (p = 0.411), and the impact of antibiotic spectrum still approached significance (p = 0.060). When looking at the change in microbial composition, we used both Bray–Curtis distances in a non-metric multidimensional scaling (NMDS) plot and the Morisita–Horn index Fig. . The Brap < 0.001), the mean ppFVC increased from 77.6 to 90.2% (p < 0.001), and the mean ppFEF25-75 increased from 46.7 to 61.9 (p < 0.001). Additionally, there were no significant differences in the end of treatment measures compared to the best in the prior 6 months . For our pathway analysis, recovery of pulmonary function was measured as the increase in ppFEV1 from PEx onset (E) to end of treatment (T) and the ratio of the ppFEV1 at end of treatment (T) to the best ppFEV1 in the 6 months prior to PEx onset. Six separate structural equation models were run to incorporate the three different alpha diversity measures  as well as the two outcome measures. All models underwent several goodness of fit tests and all indices suggested good fitting models. Specifically, no model had a significant chi-square goodness of fit test, all RMSEA values were < 0.05, no pclose values were significant, and all comparative fit index values and Tucker–Lewis index values were > 0.95. The Z-score and p value for all of the model components are shown in Table p = 0.028), which was consistent with our baseline analyses using linear regression  and the inverse Simpson index (p = 0.015). Lastly, there was a trend toward an inverse relationship between recovery of pulmonary function and the presence of antibiotic resistance genes in both recovery of baseline ppFEV1 (p = 0.083 for the Shannon diversity model and p = 0.068 for the inverse Simpson index model) and increase in ppFEV1 (p = 0.088 for the Shannon diversity model and p = 0.080 for the inverse Simpson index model).Overall, the study participants had a significant improvement in their pulmonary function from PEx onset to end of treatment. Using a paired t-test, the mean ppFEV1 increased from 64.3 to 78.9% (p = 0.026). Vancomycin was the next most frequently used antibiotic (n = 6 of 43 courses) and was found to be significantly associated with both the change in species observed and inverse Simpson index between PEx and follow-up . Aztreonam was used in 5 courses and had a significant impact on the change in Shannon diversity from PEx to end of treatment . Lastly, trimethoprim/sulfamethoxazole use in 5 courses was associated with a significant change in species observed from PEx to follow-up .We also examined the role of other antibiotics received during PEx treatment on the change in richness and alpha diversity measures from PEx to end of treatment and from PEx to follow up , whereas the other changes noted above did not remain significant. In the multivariate analysis, it was interesting that most of the significant variables were typically agents that would be used in MRSA infection .As each PEx was treated with multiple antibiotics, we attempted a multivariate analysis to explore if any specific antibiotics remained as significant variables associated with changes in richness and alpha diversity  between PEx onset and the end of antibiotic therapy compared to those receiving narrow-spectrum antibiotics. While we found short-term changes, we did not find sustained changes when we compared PEx onset to follow-up after PEx resolution, suggesting the impacts in this study cohort were transient. We also did not find an association between beta-lactam PK or antibiotic spectrum and recovery of lung function in a model that incorporated microbial diversity, the relative abundance of 26. This is in direct contrast to the findings of this study, where insufficient beta-lactam PK was associated with a greater short-term decrease in microbial diversity. However, the prior study was limited by study participants in the insufficient PK group starting out with lower diversity and having more advanced lung disease; thus, the conclusion was they had less ability to decrease their diversity further. Additionally, this study incorporated NGS as opposed to 16S sequencing, which allowed for better refinement of the microbial community to the species level and increased the effect size our study had the power to detect. Another study of persons with CF using NGS found an association between sufficient beta-lactam PK and reduced microbial diversity similar our current findings, although the prior study found the change to be demonstrated in the comparison between the PEx onset and follow-up time points27. Together, these studies support the notion that the cumulation of individual antibiotic courses likely affect microbial diversity, but that the effect size is small enough that it would require a very large study to be powered sufficiently to detect these changes on a course-by-course basis. The association of antibiotic spectrum on intra-person beta-diversity found in this study confirms prior work in our lab28. This is not surprising, as broad-spectrum antibiotics by their definition have activity against Gram-negative, Gram-positive, and anaerobic organisms in the airway and thus are more likely to affect the microbial community at large.In prior studies evaluating the association between beta-lactam PK, our lab found that insufficient beta-lactam PK was associated with reduced short-term decreases in microbial diversity compared to sufficient beta-lactam dosingBurkholderia pseudomallei and B. ubonensis to be differentially abundance in PEx samples compared to end of treatment samples based on sequencing data. B. pseudomallei has previously been reported as a global pathogen in persons with CF, albeit more common in norther Australia or southeast Asia47. However, it should be noted that B. pseudomallei only contributed to 0.05% of all reads , whereas the other Burkholderia species  were found to contribute more overall . Additionally, only B. cepacia and B. gladioli were identified in associated clinical cultures.We also noted a few interesting findings regarding bacterial species that were differentially abundant between time points. We found 48, as well as beta-lactam PK28 and antibiotic spectrum29. We sought to develop a model that wound incorporate these features, as well as microbial diversity since it has also been strongly associated with lung function24. Our model did not demonstrate an association with beta-lactam PK nor antibiotic spectrum with lung function recovery around the time of a single pulmonary exacerbation.Studies to understand the nuances of antibiotic treatment on recovery of lung function have been limited by the complexity of the study population, the differing microbial pathogens that are targeted, and the variability in the antibiotics that are selected for treatment. Numerous articles have been published with contrasting results on the impact of antibiotic resistance on pulmonary outcomes24, and the knowledge that bacteria frequently adapt to antibiotic exposure by developing mechanisms of antibiotic resistance50, it would be reasonable to assume that this would be an expected outcome. The potential association between antibiotic resistance genes and pulmonary function is interesting, given the lack of association between antibiotic resistance detected via conventional methods and lung function recovery48 and the paradox this presents for clinical practice12. Our prior work and others33 have suggested the importance of incorporating community level resistance into an assessment of antibiotic resistance, and this study supports the need for more research in this area.While not the primary or secondary outcomes of our study, we did identify associations between the relative abundance of antibiotic resistance genes detected by NGS and alpha diversity, as well as potential association between antibiotic resistance and recovery of pulmonary function. Because of the associations previously described between microbial diversity and antibiotic exposureLastly, we also examined the role of other antibiotics and the impact on changes in microbial diversity over time. Tobramycin was used in 63% of treatment courses, and its use was associated with a decrease in Shannon diversity at end of treatment. Changes were also noted with the use of vancomycin, aztreonam, and trimethoprim/sulfamethoxazole, but as they were much less frequently used (11–13% of courses), their true impact is less clear. In a multivariate analysis, vancomycin remained a significant variable in the change in species observed between PEx and follow-up. Other agents that also were also significant in the multivariate model were primarily anti-MRSA therapies . This suggests that the link between MRSA infection, antibiotic treatment, and microbial diversity should be an area of future study.52 and emerging data suggesting changes in the microbial ecology of the airway53, there may be differences in persons with CF on this treatment. Second, as this was a single center study and limited to children and young adults who could spontaneously produce sputum, the total number of study participants is small and skews toward those with more symptomatic disease, which may impact the generalizability of these results. However, almost two thirds (64%) of the study participants were considered early disease stage based on their ppFEV1 prior to their first PEx. Our a priori power analyses were based on the estimation that 50% of study participants would be beta-lactam PK insufficient, but in this study 72% of study participants met that criterium. This affects our power to detect changes in both microbial diversity and lung function and may have impacted our findings. We also attempted to further parse out the concerted versus individual impact of all antibiotics that were used for treatment of PEx. This again was limited by the sample size of our study. Lastly, there are a few points about sequencing data that should be noted. We found many bacterial species within the sequencing data that were not present in clinical cultures. This is likely due to several factors, including the culture conditions within the clinical lab  or due to misalignment of sequencing data to the representative clades. We should also note that while we had excellent sequencing depth to explore bacterial species and thus diversity, our assessment of antibiotic resistance genes is more limited.There are several limitations to note in the interpretation of our results. First, the study was performed based on PEx occurrence before the widespread use of highly effective CFTR modulators, and no study participants were on elexacaftor-tezacaftor-ivacaftor at the time of PEx. Given the known impacts of elexacaftor-tezacaftor-ivacaftor on pulmonary functionPrevotella species, and the presence of beta-lactam antibiotic resistance genes, neither beta-lactam PK nor antibiotic spectrum were associated with differences in the recovery of pulmonary function. The impact of community level antibiotic resistance on clinical outcomes should be explored in future studies.In summary, both sufficient beta-lactam PK and broad antibiotic spectrum were associated with short-term reductions in bacterial species richness at the end of antibiotic therapy, but these differences were no longer apparent at follow up. Similarly, changes in beta diversity as measured by the Morisita–Horn index were increased by broad antibiotic spectrum, but those differences were not apparent at follow up. In a model incorporating microbial diversity, the relative abundance of Supplementary Information 1.Supplementary Information 2.


Hybrid alkali-activated cements (HAACs), also known as cements with high percentages of alkali-activated supplementary materials, are alternative cements that combine the advantages of ordinary Portland cement (OPC) and alkali-activated systems. These cements are composed of a minimum of 70% precursor material and a maximum of 30% OPC mixed with an alkaline activator. This article evaluates the corrosion performance of reinforced HAAC concrete based on fly ash (FA) under exposure to chlorides . Its performance is compared with that of a binary alkali-activated cement (AAC) based on FA and granulated blast furnace slag (GBFS) . The tests performed on the concrete matrix correspond to the compressive strength and permeability to chloride ions. Using accelerated corrosion techniques (impressed voltage) and electrochemical tests after immersion in 3.5% NaCl, the progress of the corrosive process in the reinforcing steel is evaluated. The FA/OPC exhibit a better corrosion performance than the FA/GBFS concrete. At the end of the exposure to chlorides, the FA/OPC hybrid concrete presents the best performance, with a 49% lower corrosion rate than that of the FA/GBFS. Note that according to the polarization curves, the values of the proportionality constant B in the alkaline-activated concretes differ from the values recommended for concrete based on OPC. Howevermissions ,4,5. Formissions ,7.2O3 can be incorporated as an alternative to replace thermal curing [AAMs are produced through the chemical reaction of precursor material, an aluminosilicate source, and an alkaline activator. The precursor materials commonly used are fly ash (FA), metakaolin, natural pozzolans, granulated blast furnace slag (GBFS), and construction and demolition waste, among others ,9,10. Thl curing . From thl curing , and is l curing ,17.2O3 content not exceeding 10%, reactive silica content between 40% and 50%, and less than 5% loss on ignition (LOI)) [As mentioned above, FA is one of the most commonly used precursor materials for the production of AAMs. Regarding the use of FA in AAMs, certain specific characteristics have been recommended ) ,19. Howen (LOI)) , previouOne of the main durability problems faced by the components of civil infrastructure that has a great influence on their useful life is the corrosion of steel in reinforced concrete structures. To maintain the structures in a safe and functional state, high-cost repairs and maintenance are necessary. OPC-based concretes provide the necessary pH conditions to promote the passivation of the reinforcing steel; however, when they are exposed to chloride ions, the ions can diffuse through the cementitious matrix, and upon reaching a critical concentration, they can degrade the passive layer and initiate corrosive processes in the reinforcing steel that can result in a rapid deterioration of the structure ,22,23. Icorr), polarization resistance (Rp) and corrosion current (Icorr) for the steel embedded in the geopolymer concrete during the first three months showed that the passivation of the reinforcing steel was slightly lower than that of concrete made with OPC. Other studies have shown opposite results, stating that alkali-activated mortars or concretes based on FA have a protection similar to or better than that of reinforcing steels embedded in materials manufactured with OPC, achieving similar Icorr and Ecorr [Monticelli et al.  studied nd Ecorr ,30,31. Ond Ecorr ,32 evalund Ecorr  stated tnd Ecorr , who repcorr) lower than those of OPC concrete after 20 months of exposure to accelerated carbonation . Note that there are no reports on the corrosion performance of these hybrid concretes  in the presence of chlorides.Studies of these hybrid materials have mostly been carried out on pastes and mortars and focus on the mechanisms of hydration and the mechanical performance ,36,37,38This article evaluates the corrosion behaviour of the reinforcing steel of an HAAC based on FA  in the presence of chlorides. As a reference, binary AAC . To evaluate the corrosive process, two exposure methodologies were used: the accelerated technique known as impressed voltage and electrochemical tests , and Tafel slopes) after immersion in a 3.5% NaCl aqueous solution.To produce alkaline-activation systems, FA, GBFS and OPC for general use were used. The chemical compositions of the FA, GBFS, and OPC were determined with the X-ray fluorescence (XRF) technique using a Phillips MagiX-Pro PW-2440 spectrometer, and the results obtained are shown in The micrographs obtained by scanning electron microscopy (SEM) for each of the materials are presented in 2SiO3·nH2O with chemical composition of 32.34% SiO2, 11.81% Na2O and 55.85% H2O) and industrial grade sodium hydroxide  was used to obtain the appropriate molar ratios for each concrete produced.As an activator solution, a mixture of commercial sodium silicate  and relative humidity (RH) above 90%.To prepare the concretes, river sand with a fineness modulus of 3.1 and crushed gravel with a maximum particle size of 12.7 mm were used according to the ASTM specifications . Two typAcronal acrylic primer) was applied on the lateral face of the specimen to make this face impermeable to direct the entry of water. The tests were performed on cylindrical specimens (76.2 mm diameter and 152.4 mm height) at curing ages of 28 and 360 days. The values reported of compressive strength and resistance to water penetration correspond to the average of three specimens.The compressive strength tests were carried out according to the ASTM C39 standard using an ELE International testing machine with a capacity of 1500 kN at a speed of 1 mm/min until breakage. The resistance to water penetration (m) was evaluated following the standard procedure described in EMPA SIA 162/1  and ASTMCylindrical specimens 76.2 mm in diameter and 50 mm thick were used to evaluate chloride permeability. The test was carried out based on the ASTM C1202 standard . The val2. Several methods were used to determine the susceptibility to corrosion of structural steels in reinforced concrete:For the evaluation of the electrochemical behavior of the reinforcing steel embedded in the studied concretes, cylindrical samples with a diameter of 76.2 mm and a height of 152.4 mm were made. The structural steel bar (AISI 1020) was placed in the central part of the specimen. This reinforcement was covered with an anticorrosive epoxy film so that the exposure area was 100 mmImpressed voltage—The procedure was carried out based on the NT Build 356 standard , using a-Polarization curves (Tafel). At exposure times of 0, 180 and 360 days of exposure, the polarization curves were carried out to evaluate the electrochemical process and to determine by means of the Tafel slopes, the constant of proportionality B, according to Equation (1).a and βc correspond to the anodic and cathodic Tafel slopes, respectively.Immersion test—In this case, the reinforced concretes after curing for 28 days were exposed to two environments, immersion in drinking water and immersion in 3.5% NaCl aqueous solution, and the following tests were carried out to evaluate the corrosive process:-corr corrosion rate was calculated using the Stern-Geary equation Equation (2):Linear Polarization Resistance (LPR). Linear polarization resistance was determined at the end of each month of exposure, and the test was carried out for a total period of 12 months. The LPR test was performed following the ASTM G59 standard . The thrp corresponds to the linear polarization resistance. For the specific OPC, the recommended value B = 26 mV was used [A three-electrode electrochemical cell was used, where the working electrode corresponds to reinforcing steel, an Ag/AgCl reference electrode and a stainless-steel counter electrode located around the concrete. Overpotentials of −250 to +250 mV were applied. A Potentiostat/Galvanostat brand Autolab Instrument PGSTAT128N was used in the test.was used .7 s/m2. At 360 days of curing, the best behaviour is exhibited by the FA/GBFS concrete, which reaches a compressive strength of 62 MPa and a resistance to water penetration of 4.77 × 107 s/m2. On the other hand, the FA/OPC concrete exhibit compressive strengths of 41 MPa at 360 days of curing and a resistance to water penetration of 3.14 × 107 s/m2, surpassing by 100% the results obtained at the 28 days of curing.The compressive strength of the concretes FA/GBFS and FA/OPC at ages of 28 and 360 days of curing, as well as the resistance to water penetration (m), are included in In + and OH− [+ ions present in the pores of the material are expected to diffuse in the direction opposite that of the Cl− ions through the pore network, which can lead to a greater charge transfer during the test. Therefore, a greater ionic strength in the pore solution of the samples is expected to lead to higher charge values, which means that the values observed in the evaluated AACs could be higher than the chloride permeability in reality.In the interpretation of the data obtained by RCPT, it is important to take into account that this test is fundamentally a measure of the electrical conductivity of the concretes. Ionic transport depends to a large extent on the structure of the pore network in the cementitious matrix, while the electrical conductivity in the concrete is affected both by the structure of the pore network and by the chemical composition of the solutions in the pores ,54,55. I and OH− ,57,58. TTo analyze the corrosion susceptibility of the FA/GBFS and FA/OPC concretes, impressed voltage tests were carried out, through which the behavior against corrosion was rapidly evaluated. During the test, the electrical potential applied to the reinforcing bars attracts the negatively charged chloride ions from the aqueous solution of 3.5% NaCl to the concrete and towards the positively charged steel bars, thus initiating the diffusion process of chloride ions in the matrix and inducing the corrosive process . Due to + and OH− present in the pore solution of the alkaline activation concretes [oncretes ; coincidoncretes . The subThe FA/OPC concretes present a higher current intensity than the FA/GBFS at the appearance of the first crack, reaching values of 20 mA, as is presented in It is well known that the most reliable method for determining the degree of corrosion in reinforcing steel is a mass loss measurement. Therefore, to determine the mass loss of the corroded reinforcing steel, the concrete samples were transversely broken to extract the reinforcing bar. corr, the current density Icorr and the proportionality constant B were obtained by the extrapolation method from the polarization curves obtained in the Tafel test. These results are presented in corr values.+, OH−), this can cause a higher conductivity and therefore more negative potentials and higher corrosion densities. The electrical conductivity generated by these ions is related to moisture since it increases their mobility. Bastidas et al. [corr of mortars activated with FA in humid environments are more negative than those in dry environments. It is important to mention that the RH at which these tests were performed is on the order of 70% (corresponding to the atmospheric humidity of the region). Another factor mentioned in the literature that can affect the values of corrosion potentials and rates in alkaline activation systems is the pH of the pore solution; however, more studies are necessary to corroborate this effect [corr decrease, which indicates that the ionic conductivity is reduced. This behavior coincides with that observed in the impressed voltage test  and the cathodic curve (βc) Equation (1). The technical committee RILEM TC154 [corr calculations by means of the LPR technique for OPC concretes. According to corr by means of the LPR technique, the average of the B values obtained at exposure ages of 180 and 360 days of the FA/OPC and FA/GBFS concretes was calculated for the two environments evaluated. A B value of 14.6 mV ± 1.6 is obtained.The proportionality constant B was calculated from the slopes of the anodic curve . At the end of the exposure, the values of IThe visual inspection of the steels after exposure to chlorides for a period of 12 months does not reflect the severity of the conditions indicated by the results of the electrochemical measurements for the activated concretes, suggesting the need to modify the ranges used to evaluate the severity of corrosion in this type of concrete is needed.


Background: To aid in oncology drug development, we investigated MET proto-oncogene receptor tyrosine kinase gene aberrations in 2,239 oncology patients who underwent next-generation sequencing (NGS) in clinical practice.Materials and methods: From November 2019 to January 2021, 2,239 patientswith advanced solid tumors who visited oncology clinics underwent NGS. The NGS panel included >500 comprehensive NGS tests using archival tissue specimens. Programmed death-ligand 1(PD-L1) 22C3 assay results and clinical records regarding initial chemotherapy were available for 1,137 (50.8%) and 1,761 (78.7%) patients, respectively for overall survival (OS) analysis.Results: The 2,239 patients represented 37 types of cancer. The NGS panel included >500 genes, microsatellite instability status, tumor mutational burden, and fusions. The most common cancer types were colorectal (N = 702), gastric (N = 481), and sarcoma (N = 180). MET aberrations were detected in 212 patients. All MET-amplified tumors had microsatellite stable status, and 8 had a high tumor mutational burden. Of 46 patients with MET-amplified cancers, 8 had MET-positive protein expression by immunohistochemistry (2+ and 3+). MET fusion was detected in 10 patients. Partner genes of MET fusion included ST7, TFEC, LRRD1, CFTR, CAV1, PCM1, HLA-DRB1, and CAPZA2. In survival analysis, patients with amplification of MET gene fusion had shorter OS and progression-free survival (PFS) than those without. Thus, MET aberration was determined to be a factor of response to chemotherapy.Conclusion: Approximately 2.1% and 0.4% of patients with advanced solid tumors demonstrated MET gene amplification and fusion, respectively, and displayed a worse response to chemotherapy and significantly shorter OS and PFS than those without MET gene amplification or fusion. MET proto-oncogene receptor tyrosine kinase plays a pivotal role in multiple cellular processes such as carcinogenesis and tumor progression in several solid tumor types ,2,3. StuMET amplification has been reported in 5%–26% of cases to be implicated in the acquired resistance to epithelial growth factor receptor TKIs . MoreoveThis study aimed to investigate the incidence of MET aberrations, including copy number variations (CNVs), especially gene amplification, and/or fusions using a 500-gene NGS panel as real-world, pan-cancer data. Furthermore, we analyzed the impact of MET alterations on response to chemotherapy and survival.This retrospective study was approved by the Institutional Review Board of Samsung Medical Center (IRB File No. 2021-09-052). All patients who participated in this study provided written informed consent prior to NGS, and additional informed consent was waived by the IRB. This study was performed in accordance with the principles of the Declaration of Helsinki and Korean Good Clinical Practice guidelines.Tumor regions were micro-dissected for most tumor tissues, except for the samples used in genomic DNA extraction. Genomic DNA was isolated from formalin-fixed paraffin-embedded (FFPE) tissue fragments and purified using AllPrep DNA/RNA FFPE Kit . DNA concentration was measured using a Qubit dsDNA HS assay kit , and 40 ng DNA was used as the input for library preparation. The DNA integrity number, a measure of DNA fragment size and quality, was determined using the Genomic DNA ScreenTape assay on an Agilent 2,200 TapeStation system .The DNA library was prepared using a hybrid capture-based TruSight Oncology 500 (TSO 500) DNA/RNA NextSeq Kit according to the manufacturer’s protocol. During library preparation, enrichment chemistry was optimized to capture nucleic acid targets from FFPE tissues. Unique molecular identifiers were used in TSO 500 analysis to determine the unique coverage at each position and reduce any background noise caused by sequencing and deamination artifacts in the samples. This technique enables thxe detection of variants at low variant allele frequencies while simultaneously suppressing errors, thereby providing high specificity.Sequence data were analyzed for clinically relevant classes of genomic alterations, including single nucleotide variants (SNVs), small insertions and deletions (indels), CNVs, and rearrangements/fusions. Results of SNVs and small indels with a variant allele frequency of <2% were excluded. Average CNVs of more than four were considered as gain and those less than one were considered as loss. Only gain (gene amplification) was analyzed in the TSO 500-CNV analysis, and RNA translocation-supporting reads of >4–12 were considered as translocation, which was dependent on the quality of the sample. Data outputs exported from the TSO 500 pipeline  were annotated using the Ensembl Variant Effect Predictor Annotation Engine with information from databases, such as dbSNP, gnomAD genome and exome, 1,000 genomes, ClinVar, COSMIC, RefSeq, and Ensembl . The prohttp://www.graphpad.com/). Statistical significance was set at p < 0.05. All statistical tests were two-sided. Correlations between clinicopathologic features were analyzed using a t-test, Fisher exact test, or one-way analysis of variance, as appropriate. Overall survival (OS) was defined as the time from the first treatment to the date of death. Progression-free survival (PFS) was defined as the time from the first treatment to the date of disease progression or death from any cause. The Kaplan-Meier method was used to analyze all survival events, and the 95% confidence interval for the median time to each event was computed. All statistical analyses were performed using Prism 8  or R for windows . RStudio desktop 1.4 was used for drawing all graphics .Data are presented as the mean ± SD. All statistical analyses were performed using GraphPad Prism 8.0  in a total of 2,239 patients with advanced cancer . By gendN = 2) of cases had a high TMB status (≥13 mut/Mb) (TMB ranged from 0.8 to 15.7 with median of 7.0). In the pan-tumor analysis of patients with PD-L1 IHC data available, no correlation between PD-L1 expression and MET amplification was observed. The overall genomic landscape including known oncogenes in the MET-amplified patient cohort is provided in We specifically investigated MET gene amplification in MET aberration involving copy number and structural changes as well as nucleotide variants. In this case, we collected the cases more than 4 copies of MET gene. The patients’ age ranged from 30 to 82 years with a median of 58 years, and no gender bias was observed. Of the 47 patients with MET amplification, 14 had GC , 10 (1.4%) had colorectal cancer, 7 (6.3%) had melanoma, 6 (3.8%) had cholangiocellular carcinoma (CCC), 2 each had sarcoma (1.1%); hepatocellular carcinoma (HCC) (4.3%); pancreatic cancer (1.6%); and non-small cell lung cancer (1.7%), and gallbladder cancer (4.1%). In addition, we investigated tumors with a high incidence of MET amplification. The incidence of MET amplification among melanoma patients was 6.3%, which showed a high expression rate within the group. Furthermore, 4.3% of HCC patients, 3.8% of CCC patients, and 3.1% of GC patients showed a high incidence of MET amplification . We analN = 24) and A1381T (N = 19). Finally, most patients had concurrent mutations in TP53, KRAS, and ARID1B  of the patients in this study had MET fusion including cooccurrence of amplification and fusion cases . The pard ARID1B .N = 49), 25.1% had GC (N = 43), 10.5% had sarcoma (N = 21), 8.8% had NSCLC (N = 15), and other tumors (n = 61) were detected mainly in the semaphorin (Sema) domain (E168D) . And, MET exon 14 juxtamembrane splicing mutations (N = 7) were detected . SNV alterations were identified in the MET IPT/TIG  domain (exon 5-9). In addition, mutations were detected in the intracellular tyrosine kinase domain of MET  in 19.7%  and PFS (p = 0.007). Finally, we compared patients with CNV amplification in the MET gene to those with amplification in any gene. In this comparison, MET-CNV patients showed significantly shorter OS (p = 0.0039) and PFS (p = 0.016) than patients with amplification in any gene, suggesting that MET amplification is an influential factor for survival following first-line chemotherapy (We established the genomic landscape of patients with MET aberrations . In an aotherapy .N = 46) and that of MET fusion to be 0.4% (N = 10), while 0.1% of patients (N = 3) had both MET amplification and fusion, simultaneously. Additionally, MET amplification was found in nine types of cancer. The range of copy numbers varied from 3.1 to 52.2. While most samples demonstrated <10, many samples displayed ≥10 copy numbers. Additionally, we observed a correlation between high copy number and probability of progressive disease. Furthermore, patients with MET aberrations demonstrated a shorter OS and PFS compared to those without. Finally, because patients with MET amplification showed a worse response to chemotherapy and no improved response to immuno-oncology therapy, a new targeted therapy was warranted for such patients.In this study, we comprehensively investigated the incidence of MET alterations  in a consecutive series of 2,239 patients with cancer who were candidates for palliative chemotherapy. Our cohort represented 37 different types of cancer. We found the incidence of MET amplification to be 2.1%  or MET-negativity (according to IHC) respond to MET inhibitors warrants further investigation in future trials .N = 11) were confirmed by IHC, and approximately one-third of the patients with MET fusion had MET overexpression at the protein level , and CCC . MET amplification and fusion occurred concurrently in patients with colorectal cancer and CCC. Additionally, patients with MET aberration (amplification or fusion) demonstrated significantly shorter OS and PFS. Based on our data, NGS panels, particularly TSO 500, may be a feasible, real-world practice for identifying MET aberrations in the clinic. Our data can be used as a guideline for the design of future clinical trials of MET inhibitors.We identified MET gene aberrations in a cohort of Korean patients at the Samsung Medical Center Precision Oncology Clinic. NGS screening identified 46 patients (2.1%) with MET amplification, 10 (0.4%) with MET fusion, and 3 (0.1%) with concurrent amplification and fusion. Aberrant MET genes appeared in various cancers in the following order: gastric cancer , colorectal cancer (


The dolomite crystals in the samples containing 50% fly ash and metakaolin are relatively complete.In this paper, the dolomitic limestone determined as alkali–carbonate-reactive by various methods is used as an aggregate. Inhibition experiments were carried out on the basis of the concrete microbar method (RILEM AAR-5 standard), in which 10%, 30%, and 50% fly ash and metakaolin were used to replace cement. Thermogravimetric–differential scanning calorimetry (TG-DSC), X-ray diffractometry (XRD), mercury intrusion porosimetry (MIP), and scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS) were used to analyze the inhibition mechanism of fly ash and metakaolin on ACR. The results show that the expansion of samples at the age of 28 days are less than 0.10% when the fly ash contents exceed 30% and the metakaolin contents exceed 10%, which proves that the ACR is inhibited effectively. Meanwhile, the Ca(OH) The alkali–aggregate reaction (AAR) includes the alkali–silica reaction (ASR) and the alkali–carbonate reaction (ACR), ACR is a reaction that occurs between the carbonate components of the aggregate and the alkaline solution, resulting in anomalous expansion and disintegration of the concrete. In 1957, Swenson  first di+, Na+) in the pore solution and the dolomite (CaMg(CO3)2) in the aggregate , and the reaction equation is as follows:+, Na+, or Li+Since the ACR was proposed, there has been a relatively consistent view . The ACR2CO3 continues to react with Ca(OH)2 to form calcite and regenerate MOH.Reaction Formula (1) is the dedolomitization reaction; Formula (2) indicates that MMeasures commonly adopted to mitigating AAR include selective quarrying of aggregates, use of low-alkali cements, incorporating chemical admixtures or mineral admixtures such as pulverized fly ashes and granulated blast furnace slag, and limiting the alkali content of concrete. Unfortunately, nonreactive aggregates are not always supplied. Other measures are necessarily recommended to mitigate expansion caused by AAR.Mineral admixtures such as silica fume, pulverized fly ash, and granulated blast furnace slag are widely used to inhibit ASR expansion ,5,6. The2O equivalent is used [Mineral admixtures are not as effective in controlling ACR as it is to conduct an ASR when Portland cement with 0.43% Na is used ,9,10,11. is used .Granulated blast furnace slags (GBFS) lend to reduce the hydroxyl ion concentration in pore solutions and restrict the transportation of water and ionic species to reaction sites when blended with Portland cement . It was 3 and Li2CO3 were chosen as admixtures to control the expansion of concrete made with the highly reactive dolomitic limestones from Kingston and a high-alkali Portland cement. The expansion of the concrete was reduced by 50% and the effectiveness of the additives in mitigating expansion was not enough to prevent the concrete from cracking [- concentrations in the pore solutions due to the formation of Fe(OH)3 may be involved in the reducing the expansion of the concrete.FeClcracking ,13. The In research on the chemical resistance of concrete, it was noted that newly formed magnesium hydroxide can react with silica gel to form magnesium silicate hydrate, which tended to block pores and hindered penetration of ions . The expIt is generally accepted that low-alkali Portland cements, mineral admixtures, and lithium salts cannot be used to effectively mitigate the expansion of highly reactive dolomitic limestones from Kingston, Canada. Neither may limiting alkali content of concrete effectively control the expansion of highly reactive dolomitic limestones from Kingston, Canada. Data on the effectiveness of measures on preventing ACR are almost completely based on the highly reactive dolomitic limestones from Kingston, Canada. Not enough data can be obtained on preventing the expansion of moderately reactive dolomitic rocks. Nowadays, alkali–carbonate reactive rocks are not allowed to be used as coarse aggregates of concrete in specifications globally.The main purpose of this study is to examine the inhibition and mechanism of fly ash and metakaolin on the ACR. Therefore, in this paper, concrete microbars were prepared by using alkali–carbonate reactive dolomitic limestones as aggregate, and fly ash and metakaolin were used to inhibit the ACR of dolomitic limestones. Thermogravimetric–differential scanning calorimetry (TG-DSC), X-ray diffractometry (XRD), mercury intrusion porosimetry (MIP), and scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS) were used to analyze the inhibition mechanism of fly ash and metakaolin on ACR. The study will guide the practical application of dolomite in concrete structures.P·II 52.5 Portland cement (OPC) from Jiangnan—Onada Cement Co. Ltd. Nanjing, China was used in this experiment. Its alkali content was 0.56%. The chemical composition of the cement was analyzed by X-ray fluorescence (XRF) in Metakaolin (MK) is produced by Super Kaolin Co. Ltd. Inner Mongolia, China. It is calcined and ground from kaolin ore. Class F fly ash (FA) from Nanjing Pudi, The aggregate is Ordovician dolomitic limestone S1# derived from Baofuling, Shandong Province, China. The concrete microbars method (RILEM AAR-5) , accelerAccording to the standard of RIELM AAR-5, the experiment used dolomitic limestone S1# as aggregate (around 5 mm–10 mm) and Portland cement  to prepare concrete microbars (40 mm × 40 mm × 160 mm), the cement to aggregate ratio is 1:1, and the water–cement ratio is 0.32. Fly ash and metakaolin replaced 10%, 30%, and 50% of cement quality respectively. 2 content in the concrete.Thermogravimetric–differential scanning calorimetry (TG-DSC) and X-ray diffractometry (XRD) were used to determine the change of Ca(OH)2 atmosphere, and α-Al2O3 was used as the reference to analyze the heat and mass changes of the samples during the heating process.Cement pastes containing 10%, 30%, and 50% fly ash and metakaolin were made into about 2–3 mm cubes. The TG-DSC test used the STA 449 F3 thermal analyzer from NETCSZH Company, Bayern, Germany. Samples were heated from 0 to 600 °C at a heating rate of 10 °C/min in a NThe cement pastes containing 10%, 30%, and 50% fly ash and metakaolin were dried, ground with an agate mortar, the particle size was controlled below 80 μm, and the samples filled into a 20 × 20 × 0.5 mm quartz sample tank. The XRD test used the SmartLab (3) X-ray diffractometry  from Rigaku Company, Tokyo, Japan.A cube about 2–3 mm in the center of the concrete microbars containing 10%, 30%, and 50% fly ash and metakaolin was cut and PoreMaster-60 mercury porosimeter was used to analyze the pore structure of the selected samples. The test has two phases—low pressure from 0 psi to 25 psi (0.172 MPa) and high pressure from 20 psi (0.138 MPa) to 50,000 psi (344.738 MPa).Ultra55 field emission scanning electron microscopy from Zeiss Company Jena, Germany was used to observe the morphology of the ACR products in concrete microbars.In order to study the effect of fly ash on inhibiting ACR, 10%, 30%, and 50% fly ash was used to replace cement. The expansion rates of concrete microbars at the age of 28 days are shown in In order to study the effect of metakaolin on inhibiting ACR, 10%, 30%, and 50% metakaolin was used to replace cement. The expansion rates of concrete microbars at the age of 28 days are shown in 2 has been recognized by many scholars for its role in maintaining the alkalinity of the cement system and promoting AAR.As one of the important hydration products of cement, Ca(OH)2 content in cement paste. 2 in the XRD pattern also decreases, which indicates that the content of Ca(OH)2 in the cement paste decreases with the increase of the content of fly ash and metakaolin.X-ray diffraction analysis can semi-quantify the change of Ca(OH)2 in cement paste, which can be accurate to less than 0.1%.TG-DSC can accurately determine the content of Ca(OH)2 endothermic peak in the cement pastes decreases significantly with the increase of the fly ash content, which indicates that the content of Ca(OH)2 in the cement paste decreases with the increase of fly ash content. According to the TG-DSC curve, the content of Ca(OH)2 in cement paste can be calculated. The contents of Ca(OH)2 in cement paste containing 0%, 10%, 30%, and 50% fly ash were 12.3%, 11.5%, 9.0%, and 7.4% respectively.2 endothermic peak in the cement pastes decreases significantly with the increase of the fly ash content, which indicates that the content of Ca(OH)2 in the cement paste decreases with the increase of fly ash content. According to the TG-DSC curve, the content of Ca(OH)2 in the sample can be calculated. The contents of Ca(OH)2 in cement paste containing 0%, 10%, 30%, and 50% fly ash were 12.3%, 8.2%, 0%, and 0% respectively, which indicates that the Ca(OH)2 in cement pastes containing 30% and 50% metakaolin has been completely reacted.2 generated by cement hydration also decreased. On the other hand, the secondary pozzolanic reaction of Ca(OH)2 with fly ash and metakaolin resulted in the decrease of Ca(OH)2 content in the system. With the hydration of cement, the fly ash and metakaolin react with hydration products Ca(OH)2 and C-S-H gel for secondary pozzolanic reaction, further producing C-S-H gel with low Ca/Si. The reduction of the content of Ca(OH)2 weakens the regeneration of alkali metal ions  and the secondary pozzolanic reaction produces a large amount of C-S-H gel with low Ca/Si, which has a stronger adsorption effect on alkali metal ions .There are two main reasons for this result. On the one hand, the content of cement decreased after the fly ash and metakaolin partially replaced the cement, and the content of Ca(OH)+ and Na+ to the active aggregate and inhibit ACR.The pore structure of concrete microbars cured in 80 °C, 1M NaOH solution for 28 days was analyzed. (1)Four methods were used to determine that the dolomitic limestone S1# is alkali-carbonate reactive aggregate.(2)In the concrete microbars test, metakaolin and fly ash can effectively inhibit the ACR of reactive aggregate, and the more the content of fly ash and metakaolin, the more efficient the effect of inhibition. Less fly ash cannot effectively inhibit the alkali–aggregate reaction of active aggregate. When the content of fly ash and metakaolin is the same, metakaolin is more effective than fly ash.(3)The products of ACR calcite and brucite can be clearly observed in the SEM image, but no ASR gel was found, which indicates that the expansion of dolomitic limestone S1# was caused by ACR.(4)2 of Portland cement and reduces the alkalinity of the cement hydration product, so the ACR be inhibited. The pore structure of concrete containing fly ash and metakaolin becomes denser, which prevents the diffusion of K+ and Na+ to the active aggregate.Metakaolin and fly ash participate in the secondary hydration of cement, which consumes a large amount of the hydration product Ca(OH)The most significant conclusions of this paper are summarized as follows:


To optimize antibiotic treatment and decrease antibiotic resistance, national treatment guidelines are available for urinary tract infections (UTIs) in general practice. The usefulness of these guidelines in risk areas for antimicrobial resistance such as cross border regions or areas with dense agriculture, is unknown.Midstream urine samples from women with symptoms of acute UTI visiting general practitioners (GPs) in the Westland area, a dense agriculture area, were microbiologically analysed, and patient characteristics, symptoms, previous and present antibiotic treatment were collected. The National Nivel data were used as reference for antibiotic resistance.E. coli UTI. Empirical antibiotic therapy was prescribed to 148 patients (48%) in total; in 7% of women with a negative and 52% with a positive urine culture. Having more than one symptom was associated with the prescription of antibiotics; travel history or previous antibiotic use for UTI were not. The isolated uropathogens were susceptible to the empiric antibiotic therapy in 98% of patients. Resistance to co-amoxiclav was higher (22%) than reported in the national data of 2004 (12%), 2009 (13%) and 2014 (9%), as was the prevalence of extended spectrum β-lactamase (ESBL): 3.4% in our study versus 0.1%, 1% and 2.2% in the national data respectively.Of 310 women with symptoms of uncomplicated UTI, 247 (80%) had a culture proven The presence of environmental and socio-demographic risk factors for antibiotic resistance did not influence the empiric choice nor susceptibility for antibiotics advised by the national guidelines in women with uncomplicated UTI.The online version contains supplementary material available at 10.1186/s12875-022-01840-6. Antimicrobial resistance (AMR) has been associated with the use of antimicrobial agents . In humaAntibiotics are not only prescribed in human health care, but also in livestock farming and in agriculture , 5. TranE. coli in irrigation water of vegetables for human consumption [Indeed, studies report the occurrence of antibiotic-resistant (including extended spectrum β-lactamase (ESBL) producing) sumption –12. The sumption . Travel,sumption , 15. Thisumption .Given the association between use of antibiotic drugs and AMR, the WHO advocates antimicrobial stewardship: to treat each patient with the most appropriate antimicrobial therapy, thereby minimalizing the risk of development of AMR . The DutTo explore the adherence and usefulness of the national guidelines for uncomplicated UTI, we investigated adherence to the guidelines for female patients with complaints of an uncomplicated UTIs in an area with sociodemographic (i.e. East European season immigrants) and environmental risk factors (i.e. presence of dense glasshouse agriculture) and determined whether the empiric therapy was in accordance with the culture results .Patient recruitment took place at eight general practices in the Westland area of the Netherlands from March 2018 to June 2018. The Westland area is an area with dense agriculture, situated in the West of the Netherlands and characterized by many green glasshouses: 40% of the total surface of agriculture under glass (3.850.000.000 m2) is concentrated in this part of the country . This reGeneral practitioners (GP) were asked to fill in a questionnaire upon presentation of women > 11 years with acute complaints of an uncomplicated UTI. Patient characteristics such as age and UTI symptoms such as pain/ burning, polyuria, urinary urgency, were collected as was information about, antibiotic therapy received for previous infections in the last 12 months and travelling abroad in the last 12 months. An uncomplicated UTI was defined as symptoms of pain or burning sensation, polyuria or urinary urgency without signs of tissue expansion like flank pain or fever. Furthermore, the actual empiric prescription was recorded. Exclusion criteria were pregnancy, fever (> 38 ℃), urological and nephrological problems, having a urinary catheter, diabetes mellitus and immunosuppression. Patients who received a prescription after laboratory culturing became available were not included. Also, patients with incomplete questionnaires were excluded. Included patients received care as usual for UTIs and the GPs did not have knowledge of the culture results at the moment of prescription or thereafter.Informed consent was waived by local ethics committee (MEC-2017–1167).3 cfu/ml was defined as an UTI [Midstream urine samples were collected and sent the same day for microbiological analysis to the department of Medical Microbiology of the Erasmus Medical Centre Rotterdam, the Netherlands. Bacterial growth of the urine samples on blood agar and MacConkey (Oxoid) agarplates of ≥ 10s an UTI . Presencs an UTI . For cons an UTI .E. coli was compared to the resistance from studies performed in 2004, 2009 and 2014 among GP of the Sentinel Stations Network of NIVEL [The antibiotic resistance of the of NIVEL –29. No dof NIVEL .2 test and Fisher test were performed for comparing percentages of the categorical data . A multivariate logistic regression was performed with as outcome variable the empirical prescription of an antimicrobial drug for this UTI episode and as variables age, number of symptoms, positive culture, UTI, antibiotic use and travelling abroad in the year before participating in this study. A p-value of < 0.05 was considered statistically significant.The XDuring the study period, 312 women visited eight practices of general physicians with symptoms of an uncomplicated UTI. Due to incomplete questionnaires, two patients were excluded. Of the remaining 310 patients , 247 (79.7%) had a culture proven UTI  of the 310 patients, and the most frequently given antibiotics were nitrofurantoin in 112 patients (36%), fosfomycin in 19 patients (6%) and trimethoprim in nine patients (3%). Twenty of the 310 patients (7%) were empirically treated with an antibiotic although their culture could not confirm an UTI  or three or more  symptoms were found to be more often prescribed antibiotics than patients with no or one symptom. Furthermore, patients with a culture proven UTI afterwards were more often prescribed empirical antibiotic therapy  than patients with a negative culture. Traveling abroad, either in or outside Europe, and previous use of antibiotics were not associated with prescription of antibiotics (Table n = 247) with one or two uropathogens were included resulting in 293 uropathogens analyzed. E. coli was the most frequently isolated uropathogen  followed by Enterococcus faecalis , Klebsiella spp. , Streptococcus agalactiae (Group B streptococcus)  and Proteus mirabilis . The remaining 67 (23%) uropathogens include among others Enterobacteriales and non-fermenters, see supplementary table Urinary samples  followed by amoxicillin-clavulanic acid (22%), trimethoprim (15%) and co-trimoxazole (15%). The resistance rates to amoxicillin, trimethoprim and co-trimoxazole were in line with the national data. Resistance to amoxicillin-clavulanic acid was higher than in the national studies 12%, 13% and 9% in 2004, 2009 and 2014 respectively as was the prevalence of ESBL 3.4% versus 0.1%, 1% and 2.2%  was susceptible to the empirically started therapy which was according to the NHG guidelines, i.e. nitrofurantoin as first choice and fosfomycin and trimethoprim as second and third choice. Traveling abroad or previous treatment for UTI were not associated with start of therapy  immigrant workers seems negligible. We found only a higher resistance to amoxicillin-clavulanic acid, 22% in the Westland, versus 9% on national level in our study of 2014 [Potential risk factors for a higher prevalence of resistance for Inhabitants of the Westland are exposure to pesticides due to a dense greenhouse agriculture and a high percentage of migrant workers –33, comp of 2014 . Also na of 2014 . This in of 2014 , 35.E. coli UTI. Use of other national data such as Nethmap [According to the guideline amoxicillin-clavulanic acid is not recommended for uncomplicated UTI and was indeed not prescribed for this indication in the present study. The higher prevalence of resistance might be due to prescriptions for other indications such as respiratory tract infections . Because Nethmap  was not An potential risk for antibiotic resistance in the Westland is the use of pesticides for agriculture –10. NoneE. coli did not substantially differ from the national antibiotic resistance rates, the influence on antibiotic resistance of (season) immigrant workers seems negligible.Next to antibiotic use another risk factor for the introduction and spread of antibiotic resistance is travelling to regions with a higher prevalence of resistance compared to the Netherlands , 37, 38.The increase in ESBL rates is recognized worldwide and many surveillance studies monitor the prevalence . The occWe found an antibiotic match of 98% between the choice of the agent and the susceptibility of the isolated uropathogen, which support the correct empirical treatment of UTI by the participating GP’s and the adherence to the national NHG guideline of UTI. These results are in contrast to studies of Ganzeboom et al. and Lugtenberg et al. where regional differences of resistant patterns were found and no adherence to the NHG guideline , 20.n = 119) patients with a proved UTI were not empirically treated. The NHG guidelines describe the possibility of a postponed prescription including educating patients about the natural course of an UTI, (i.e. 20% of the UTI resolve spontaneously) and shared decision making. Adherence to national guidelines will contribute to control the antibiotic resistance problem. A limitation is the number of participating GP and patients included and the lack of follow -up data to determine the effectiveness of the policy prescribed. The low number of patients limit the applicability of our results for other areas in the Netherlands.The strengths of the study is the careful control of the adherence and the usefulness of the NHG guidelines for the treatment of uncomplicated UTI in an area with socioeconomic and environmental risk factors. The adherence include not only the choice of the agent but also the decision when to start treatment. In our study 48%  and nearly all cultured bacteria were susceptible to the antibiotics given. The number of symptoms was associated with empirical antibiotic therapy, travel history and previous antibiotic use were not. When confirmed in larger studies, such factors may be included in guidelines for antibiotic therapy in women with uncomplicated UTI.Additional file 1: Supplementary Table 1. Percentages of uropathogens. Supplementary Table 2. Percentages of antibiotic resistance of E.coli in patients from the Westland area in comparison with data from studies of NIVEL 2004-2014 in the Netherlands