Background and objective: The increasing emergence and spread of drug-resistant pathogens resulting from inappropriate antibiotic usage have become more evident in recent years, particularly with the rising incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections. Since joining the Organization for Economic Cooperation and Development (OECD), Costa Rica can now compare its healthcare system with other countries, and similarities have been noted with Italy regarding health indicators. Both nations have universal healthcare systems, covering their entire populations, and hold similar positions in the Human Development Index (HDI). Consequently, the goal is to compare antibiotic prescribing and consumption patterns to collaboratively develop strategies against bacterial resistance.Methods: In order to compare antibiotic consumption between regions, a standardized contrast was utilized, specifically using the defined daily dose (DDD). An Orthogonal Contrast test was performed to test the means, followed by the application of the Student's t-test on these contrasts. This analysis aimed to assess the potential influence of regions on DDD values. Antibiotic consumption data were collected between January 2021 and December 2022 from the Local Health Authority of Naples 3 South (LHANS) in Italy and IMS Health, Q Quintiles, and VIA by way of (IQVIA) reports in Costa Rica.Results: LHANS shows a considerable disparity in gross expenditure compared to Italy's overall expenditure, while the private sector of Costa Rica exhibits even lower gross expenditure than Italy. Antibiotic consumption in Italy exceeds that of Costa Rica, with Costa Rica's consumption amounting to 47.70% of Italy's total consumption. Additionally, LHANS exhibited a 22.43% higher gross expenditure compared to the Campania region, emphasizing the variability in antibiotic usage within the same country The results indicated no statistically significant differences in antibiotic consumption between the regions, as none of the null hypotheses were rejected.Conclusions: The study provides valuable insights into expenditure patterns and antibiotic consumption, highlighting the need for improved prescribing practices and awareness campaigns to address the issue of antibiotic resistance. The findings emphasize the importance of implementing international guidelines to combat the growing threat of antibiotic resistance and ensure the effective management of infectious diseases. The spread of drug-resistant pathogens has only become apparent in recent years. In the last three decades, improper or discontinuous intake of antibiotics has led to the emergence of antibiotic-resistant microorganisms. The overuse and misuse of antibiotics are the main causes of this critical issue, as bacteria have had the chance to adapt and overcome the drugs effective for bacterial infections -3. AntibNowadays, antimicrobial resistance (AMR) represents a global health threat and makes bacterial infections difficult to treat. In 2019, AMR was associated with over 1.27 million deaths worldwide ,11. AMR In addition, AMR infections can raise the risk of developing new health threats such as pandemics -17. WhenBy 2025, a decade would have elapsed since the implementation of the World Health Organization (WHO) Global Plan of Action (GPA) to combat AMR, in which five strategic objectives are proposed to reduce this global problem ,20,22. OIn Costa Rica, these programs have been shown to improve the consumption of antibiotics such as first-generation cephalosporins, third-generation cephalosporins, and fluoroquinolones, as well as changes in the prescription habits of medical specialists in surgery and intensive care -26. On tThe objective of this study is to evaluate the prescribing trends of antibiotics in two countries that differ in geographic area and socioeconomic development to contrast the data collected. A direct comparison of data from a Western Europe country with one in Latin America can provide new and important evidence, useful in enriching the existing literature since lower respiratory infections are the leading causes of death in both income groups ,30.Study designThis is a retrospective comparative analysis, conducted between January 2021 and December 2022, of antibiotic consumption between Italy and Costa Rica. In Italy, the search has been conducted via the Local Health Authority of Naples 3 South (LHANS), an authority characterized by providing healthcare to a population of over one million inhabitants, which comprehends 10 health districts and five hospitals. In Costa Rica, the study has been conducted by extracting information from the IQVIA reports , an American multinational company serving as a global provider of healthcare data and analytics, and their reports are highly relevant when it comes to understanding drug consumption trends per country. IQVIA collects and analyzes vast amounts of data from various sources, including pharmacies, hospitals, and healthcare providers, to provide comprehensive and representative insights into the pharmaceutical market. The research study strictly adhered to the established guidelines known as Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). These guidelines ensure comprehensive and transparent reporting of observational studies, enhancing the overall quality and credibility of the research findings.Data collectionData compilation for this study involved accessing specific sources to gather comprehensive information on drug consumption in different countries. For instance, in Italy, the “Tessera Sanitaria” (TS) database was consulted to analyze all antibiotic prescriptions and dispensations during the studied period in the LHANS and Campania Region. The TS database, a national healthcare system, served as a valuable resource by storing healthcare data for the Italian population.Similarly, in Costa Rica, IQVIA collects data from multiple sources, including pharmacies, hospitals, and healthcare providers. Additionally, they may obtain data on drug sales and prescriptions directly from pharmaceutical companies. By leveraging this diverse range of data sources, IQVIA can generate representative insights into drug consumption patterns in the private sector of this country.ConsumptionConsumption has been analyzed by calculating the DDD of the antibiotics used in the studied period, the calculations were conducted using consumption reports obtained directly from the mentioned databases to create tables to compare regions and countries. The analysis of drug costs involved expressing them in gross euros as gross expenditure multiplied by 1,000 inhabitants/day. To ensure comparability, the drug prices in Costa Rica were converted to net euros using the current exchange rate in May 2023.Sales or prescription data expressed as DDDs per 1,000 inhabitants per day can offer an approximate estimation of the proportion of the study population receiving daily treatment with a specific drug or group of drugs. For instance, a value of 10 DDDs per 1,000 inhabitants per day signifies that, on average, in a representative group of 1,000 individuals, 10 DDDs of the drug are used on any given day within the analyzed year.Data analysisThe data were collected, classified, and analyzed using Microsoft® Excel® for Microsoft 365 MSO  and IBM® SPSS Statistics version 28 . Descriptive statistics, such as frequencies and percentages, were calculated.Subsequently, a standardized antibiotics consumption comparison between Italy and Costa Rica was conducted using an Orthogonal Contrast test, broken down by sectors . This stThe following hypotheses are proposed. H0: The effect on the mean DDD of CR is the same as the others vs H1: The effect on the mean DDD of CR is smaller than the others. Then, H0: The effect on Italy's average DDD is equal to that of its region’s vs H1: The effect on the mean DDD of LHANS is smaller than that of the other regions. Finally, H0: The effect on the mean DDD of Campania is equal to that of LHANS vs H1: The effect on the mean DDD of Campania is less than that of LHANS to formulate a Student's t-test to the contrasts.Tables Compared to Italy, LHANS experienced a significant 107% change in antibiotic expenditure demonstrating a substantial difference between these regions. Furthermore, LHANS exhibited a 22.43% higher gross expenditure compared to the Campania region, underscoring the variability in antibiotic cost within the same country.Table Table The gross expenditure for antibiotic usage showed a mixed pattern, with both increases and decreases observed. While some antibiotics demonstrated a rise in associated costs, including clarithromycin, cefixime, and ceftazidime, others experienced reductions in expenditure, such as cefditoren, fosfomycin, and sulfamethoxazole and trimethoprim.Table Additionally, as shown in Table Finally, the Student's t-test applied to the contrasts resulted in the following p-values; H1: p=0.8475, H2: p=0.8023, and H3: p=0.6382. None of the hypotheses raised is rejected, so it is concluded that the region has no statistically significant effect on DDD.Gross expenditureFirstly, the analysis reveals a difference in gross expenditure Table  between Moreover, the comparison between LHANS and the Campania Region reveals variations in both gross expenditure and antibiotic consumption. The 22.43% higher gross expenditure in LHANS indicates differences in healthcare resource utilization, emphasizing the importance of studying regional variations within a country ,33. ThesIn contrast, the private sector of Costa Rica exhibits lower gross expenditure compared to Italy's total. This indicates potential cost-effectiveness in the private healthcare system of Costa Rica, suggesting the presence of measures to control healthcare spending . HoweverAntibiotic consumptionThe comparison between LHANS and Costa Rica shown in Table Costa Rica has evidenced a significant improvement in antibiotic prescription practices since the implementation of the Stewardship Programs in an inpatient setting. This program, like initiatives in other countries, focuses on developing internal prescription protocols for the most common infectious diseases at the local level in various hospitals . Its priComparison of antibacterial drug expenditure and consumptionThe temporal analysis of antibiotic consumption and gross expenditure shown in Table LHANS experienced a significant increase in gross expenditure and DDD in comparison with Campania. This suggests a higher prevalence of antibiotic prescriptions or an increased dependency on antimicrobial treatments within LHANS. These findings raise concerns about the potential overuse of antibiotics within the region. It highlights the need for closer monitoring and appropriate interventions to promote responsible antibiotic prescribing practices and combat the growing issue of antibiotic resistance.Tables Notably, ceftriaxone generated a substantial total expenditure of 8.83, despite having a DDD of only 0.66. This emphasizes the importance of considering expenditure variations when selecting antibiotics in the region, as factors such as changes in drug pricing, prescribing patterns, and healthcare policies can influence these variations .In terms of changes between 2021 and 2022, ciprofloxacin usage decreased, while there was an increase in the usage of azithromycin, amoxicillin, and amoxicillin with beta-lactamase inhibitors. These changes align with the implementation of antibiotic stewardship in ambulatory prescriptions indicating a positive impact on prescribing practices in Costa Rica .A notable difference to highlight is the consumption of doxycycline, with the private sector of Costa Rica exhibiting the highest consumption rate , followed by Italy , LHANS , and Campania .Additionally, the study emphasizes the importance of implementing ambulatory antibiotic stewardship programs. These programs play a crucial role in promoting responsible antibiotic use, minimizing unnecessary costs, and addressing the emerging challenge of antibiotic resistance. By involving pharmacists in the process, these programs can leverage their expertise to optimize prescribing practices, educate patients and healthcare providers about appropriate antibiotic use, and monitor the outcomes of antibiotic therapies. This collaborative approach can enhance the effectiveness of interventions, ensure patient safety, and improve overall healthcare outcomes in the studied regions and countries .Based on the results presented in Table This direct comparison between Italy and Costa Rica provides novel evidence, considering their different geographic and socioeconomic backgrounds. As lower respiratory infections are the leading causes of death worldwide, the findings have relevance in addressing this global health issue. The study's methodology, utilizing national health databases and reputable sources, ensures reliable and representative data. Calculation of DDD and analysis of drug costs contribute valuable insights into consumption patterns and economic aspects .The results of this comparative study provide valuable insights into the patterns of gross expenditure and antibiotic consumption between two very different countries: Italy and Costa Rica. Understanding these variations can be helpful in identifying potential areas of improvement in each country and promoting the development of more responsible antibiotic prescribing practices.As illustrated in the results, when compared to 2021, the trend of antibiotic consumption in 2022 in both countries exhibited a steady rise, resulting in increased pharmaceutical expenditure and potentially contributing to the antibiotic resistance phenomenon. Although global campaigns aimed at raising awareness and reducing the use of antimicrobial agents have been conducted, they have not yielded the anticipated outcomes. The recent global action plan advocated by the WHO aims to address the issue of antibiotic prescriptions across all healthcare fields.To raise awareness among healthcare professionals and all stakeholders regarding the issue of antibiotic resistance, it is crucial for health authorities to develop information campaigns. These campaigns should aim to educate all stakeholders about the harmful effects of improper antibiotic use. Without access to effective alternative treatments, various projections indicate that the health risks associated with infectious diseases will increase. This retrospective analysis, conducted in two distinct geographical areas, underscores the need to address the issue of antibiotic resistance by sharing and implementing international guidelines.


Background: The AWaRe tool was set up by the World Health Organization (WHO) to promote the rational use of antimicrobials. Indeed, this tool classifies antibiotics into four groups: access, watch, reserve and not-recommended antibiotics. In The Democratic Republic of Congo, data on antibiotic dispensing (prescribing) by health professionals according to the AWaRe classification are scarce. In this research work, we aimed to explore antibiotic dispensing pattern from health professionals according to the WHO AWaRe classification to strengthen the national antimicrobial resistance plan. Methods: For this purpose, a survey was conducted from July to December 2022 in the district of Tshangu in Kinshasa. From randomly selected drugstores, drug-sellers were interviewed and randomly selected customers attending those drugstores were included in the study for medical prescriptions collection. The prescribed antibiotics were classified into the access, watch, reserve and not-recommended antibiotics group and by antibiotics number by prescription among pharmacies surveyed. Results: 400 medical prescriptions were collected from 80 drugstores and among which, 301 (75.25%) contained antibiotics. Out of 301 prescriptions, we noticed 164 (54.5%) containing one antibiotic, 117 (38.9%) containing two antibiotics, 15 (5%) containing three antibiotics and 5 (1.6%) containing four antibiotics. A total of 463 antibiotics were prescribed and distributed as 169 (36.5%) were from the access group, 200 (43.2%) from the watch group and 94 (20.3%) from not-recommended antibiotics group, respectively. This can explain the fact of emerging bacterial strains, as, according to the WHO recommendations, the access group should be prioritized because of its activity against a wide range of commonly encountered pathogens and its showing low resistance susceptibility compared to antibiotics from other groups. Based on the anatomical, therapeutic and chemical (ATC) classifications, we observed that third generation cephalosporins represented 34.33% of the prescribed antibiotics, followed by penicillins (17.17%), macrolides (7.63%), aminoglycosides (7.36%) and Imidazole (7.36%), thus accounting approximately for 74% of the classes of antibiotics prescribed. Additionally, among them, the most frequently prescribed antibiotics were Ceftriaxone (21.38%), Amoxicillin (11.01%), Gentamycin (5.61%), Amoxicillin-clavulanic acid (5.61%), Azithromycin (4.97%) and Metronidazole (4.75%), thus accounting for approximately 54% of all the prescribed antibiotics. Conclusion: These results highlight the importance of strict implementation of the national plan to combat antimicrobial resistance and the need to train health workers in the correct application of the WHO AWaRe classification. Antimicrobials play a major role in the fight against infectious diseases around the world. Unfortunately, excessive and abusive use of antimicrobials is at the origin of the emergence and spread of resistance to a large number of antimicrobials, making them less and less effective against infectious diseases. Antimicrobial resistance (AMR) threatens the survival of all humanity and is, therefore, becoming a major public health problem worldwide ,2. Although AMR is a problem that affects all regions of the world, it remains more pronounced in Sub-Saharan African countries because projections made by the World Health Organization (WHO) show that if adequate provisions are not taken in time, the AMR would cause more than 4,150,000 deaths by 2050 . AMR is Several factors promote the development of AMR. We can cite, for example, on one side, the irrational medical prescriptions of antibiotics and other antimicrobials in humans, self-medication, inappropriate veterinary prescriptions in animals, the abusive use of antimicrobial on crops, as well as the dissemination of residues of these antibiotics in the environment ,5,6 and,Antibiotic resistance is an integral part of AMR; however, it is considered the most dangerous and urgent global risk that requires more than special attention from all health actors and political authorities worldwide ,2. AMR iIn Africa, in general, and in the Democratic Republic of Congo (DRC), in particular, a policy for monitoring antibiotic resistance and the rational use of antibiotics is still lacking. The absence of an adequate quality assurance system in the pharmaceutical sector facilitates the excessive and irrational use of substandard antibiotics in hospitals and in the population, in animal husbandry and in agriculture, which leads to the rapid selection of multi-resistant strains ,6,7.Staphylococcus aureus and extended-spectrum beta-lactamase-producing Enterobacteriaceae [Research work on antibiotic resistance initiated in the DRC showed a strong trend towards an increase in the rate of resistance to commonly indicated antibiotics by strains of eriaceae ,9,10,11.In its National Health Development Plan (NHDP) 2016–2020, the DRC set itself the general objective of contributing to the improvement of the health status of the population, in order to enable everyone to live in good health and promote well-being for all at all ages within the framework of universal health coverage by 2030 . NeverthTo deal with this phenomenon, more and more encouraging initiatives are being taken. Thus, in collaboration with the Ministry of Public Health and Hygiene, it was developed in support of the Project “Surveillance of antimicrobial resistance in the DRC, a University Reference Center for Research and Surveillance of Antimicrobial Resistance” (CURS-RAM), the missions of which are training and research on AMR, surveillance and service to society. Another project, the Interuniversity Innovation Center for the Implementation of a Green Approach to Combating Antimicrobial Resistance (PI-RAM), the mission of which is to develop technological innovations capable of combating AMR by green approach based on nanotechnology, works in collaboration with the CURS-RAM within the University of Kinshasa in the Faculty of Pharmaceutical Sciences.The global action plan to combat AMR aims to enable humanity to continue to have, for as long as possible, effective means of preventing and treating infectious diseases in the form of safe and effective drugs, guaranteed quality, used responsibly and accessible to all who need it ,13. BaseThe WHO defines the rational use of medicines as the prescription of the most appropriate product, obtained in time and at an affordable price for all, delivered correctly and administered at the appropriate dosage and for an appropriate period of time . This deThe WHO developed the access, watch, reserve (AWaRe) classification of antibiotics with the aim of combating the irrational use of antibiotics and curbing the growing resistance to antimicrobials. The AWaRe tool classifies antibiotics into four groups and specifies which antibiotics to use for the most common and serious infections, which should be always available in the healthcare system  and which should be used in moderation or stored (antibiotics to be used selectively) and those used only as a last resort (reserve antibiotics). The fourth includes combinations of antibiotics whose indications and efficacy were not proven .The primary objective of this classification was to bring to at least 60% of the proportion of the world’s consumption of antibiotics in the group of antibiotics whose accessibility is essential and to reduce the use of the antibiotics most exposed to the risk of resistance in the groups of antibiotics to be used selectively and reserved antibiotics. The use of antibiotics whose accessibility is essential reduces the risk of resistance because they are narrow-spectrum antibiotics. They also cost less because they are available in generic formulations .This tool represents hope for humanity in the fight against AMR, it aroused great interest among scientists, which explains the growing number of articles written to evaluate its use ,23,24,25In low-income countries such as the DRC, where any medicine, or even antibiotics, can be obtained without a medical prescription, the problem of the emergence of AMR cases is a permanent concern. Among them, we can mention the use of Amoxicillin (from penicillin family) and Tetracycline (Cyclines family) as part of the most used antibiotics without prescription. The public indulges in the misuse of antibiotics by practicing self-medication and health personnel over-prescribing antibiotics following the non-application of laws governing the pharmaceutical sector .To the best of our knowledge, no study was yet conducted on antibiotics prescribing pattern in the district of Tshangu, in the city of Kinshasa, according to the WHO AWaRe tool. Tshangu, as the largest district of the city, is located in the eastern part and gathers the largest popular mass (approximately 17.07 millions) in their multiculturalism. Additionally, it was subjected into this research because it is full of the majority of illegal pharmaceutical and medical establishments where illegal prescriptions and dispensing of pharmaceuticals are common. Additionally, under such conditions, we are almost reassured that the implementation of the WHO prescribing standards for antibiotics is bound to encounter enormous difficulties. It is in this context that this study to explore the adherence of prescribers to the WHO protocol on the rational use of antibiotics according to WHO AWaRe tool was initiated.The capital of the DRC, the city–province of Kinshasa, is made up of four districts, namely: Funa, Lukunga, Mont Amba and Tshangu. The district of Tshangu is located east of Kinshasa, it is by far the most extensive district of Kinshasa, but also the most rural (4°21′0″ S et 15°22′60″ E). There is a promiscuity ((high popular density with large number of pharmacies) that does not facilitate the application of laws related to the regulation of the health system, thus illustrating an ideal framework for studying the quality of care administered to the population. Targeted pharmacies (of interest) were randomly selected based on the availability of their drug-sellers to the conduct of this study. Those pharmacies were selected in the field due to their frequentation by patients. No geographic limit was set, as most of them are concentrated in areas of high population density. However, it should be pointed out that some of the 80 pharmacies we also worked on were isolated in certain parts of the district where there were few pharmacies open to the public.Authorization to undertake the study: first of all, the authorization to undertake this study was requested and obtained from the National Ethics Commission.Medical prescriptions: a photocopy of medical prescriptions was obtained from patients who gave their consent to participate in the study.A voluntary consent document, ensuring the anonymity of the various participants who agreed to participate in the study, was signed.Data collection form: a form was established for data collection following the WHO model .AWaRe list: document drawn up by WHO containing the classification of antibiotics into groups, access, watch, reserve and not-recommended antibiotics group.A retrospective and descriptive study was conducted from July to December 2022 in the district of Tshangu, with the aim of evaluating the adherence of prescribers to the WHO protocol on the rational use of antibiotics according to the WHO’s AWaRe tool.A total of 400 prescriptions were randomly collected to constitute the sample used in this study. Only prescriptions from the Tshangu district were retained, illegible prescriptions were excluded from this study. One out of three patients who came to obtain medication was approached to request their participation in the study.The Statistical Package for Social Sciences program version 20.0 (SPSS) from the University of Kinshasa was used to perform the statistical analyses.Frequencies and percentages were used to express the results.The models used were described according to the WHO 2019 AWaRe classification of antibiotics, in which antibiotics were classified into four groups: access, watch, reserve and not-recommended combinations . For medThis study revealed an overuse of antibiotics. Indeed, of the 400 prescriptions collected, 301 (75.25%) prescriptions contained antibiotics, 164  contained one antibiotic, 117  contained two antibiotics, 15  contained three antibiotics and 5  contained four antibiotics. These collections were carried out from 80 randomly selected pharmacies according to their frequentation frequency and the drug selling price. Comprising a large population, the majority of whom are poor, the district of Tshangu is characterized by the presence of pharmacies that are often unauthorized , so that for most of them, this is a lucrative business activity. Thus, the only concern of these shopkeepers is to sell and not to provide quality care.In the group of prescriptions containing one antibiotic, Ceftriaxone injectable, even if belonging to the watch category, was the most prescribed drug, accounting for 31.1% (51/164) of prescriptions containing an antibiotic, followed by Amoxicillin (access) 13.4% (22/164), Amoxicillin–Clavulanic acid combination (access) 12.2% (20/164), Azithromycin (watch) 10.4% (17/164) and Ciprofloxacin (watch) 7.4% (12/164). Of the 164 prescriptions containing one antibiotic, 54  prescriptions contained antibiotics of access group and 110  of watch group. These results are shown in Of the 117 prescriptions including two antibiotics per prescription, Ceftriaxone (watch) was once again the most prescribed antibiotic. Indeed, it was present on 43  prescriptions, followed by Amoxicillin (access) which was present on 27 , Gentamicin (access) which was present on 23  and Metronidazole (access) which was present on 16 . A total of 21  prescriptions contained access category antibiotics and 62  prescriptions contained watch category antibiotics, of which 54  were composed of one antibiotic from the access group and another from the watch group and 8  of two antibiotics from the watch group and 34  prescriptions contained fixed-dose combinations antibiotics in the not-recommended group. These results described above are presented in Of the 15 prescriptions containing three antibiotics each, 1  prescription was from the access group, 7  prescriptions from the watch group, of which 4  consisted of one antibiotic from the watch group and two from the access group and 3  of two antibiotics from the watch group and one access group, and 7  prescriptions containing not-recommended fixed-dose combinations; of which 3  were associated with an access group antibiotic and 4  with a watch group antibiotic .In the 5 prescriptions comprising four antibiotics, it can be noted that all 5 (100%) contained the not recommended fixed-dose combinations. All being associated with one antibiotic from the Access group and another from the Watch group .In addition to the three main groups of the AWaRe list, this list includes a fourth group of antibiotics not recommended by the WHO due to their unproven indication or efficacy. In this study, a total of 46  prescriptions contained antibiotics of the not-recommended group. The most prescribed combinations were Ceftriaxone/Sulbatam , Norfloxacin/Metronidazole , Ofloxacin/Ornidazole  and Ciprofloxacin/Metronidazole . There was even one  prescription containing together two fixed-dose combinations of antibiotics that were not recommended: Ceftriaxone/Sulbactam and Norfloxacin/Metronidazole .In Applying the ATC classification to the 463 antibiotics prescribed, it can be seen that 128  antibiotics were third generation cephalosporins (watch), followed by 63 (63/463 13.61%) which were Penicillins (access), 28  which belonged to Macrolides (watch), 27  which were Imidazoles (access), 27  Aminoglycosides (access), 26  Beta-lactamase inhibitors and 22  which were Fluoroquinilones (watch). A total of 169  antibiotics belonged to the access category, 200  to the watch category and 94  to the group of antibiotics not recommended see .As mentioned above, our study was conducted under authorization of the National Ethics Commission, taking into account the promiscuity resulting from high number of pharmacies in this district that do not comply with the limits set by the country’s pharmaceutical legislation authority, which recommends a distance of 500 meters in urban areas and around 1 kilometer in rural areas. Additionally, this leads to their concentration where there are high population movements. within the Tshangu population, number of unauthorized pharmacies and the lack of respect to the antibiotics prescriptions guidelines established by the WHO. This study demonstrated that antibiotics were over-used in the district of Tshangu because most of them are prescribed in a framework that does not take into account the characteristics of the infections involved, or even for the simple reason of suspicion of an unconfirmed infection. Additionally, above all, the majority of them are prescribed to patients without prior establishment of an antibiogram in accordance with the general rules. Indeed, the collected data showed that out of 400 prescriptions, 301  contained antibiotics, highlighting the frequency of use of these products compared to others for other therapeutic indications. Additionally, out of the 301 prescriptions containing antibiotics, 76  prescriptions contained antibiotics belonging to the access category, 179  those of the watch category and 46  of the not-recommended category. By developing the AWaRe tool, the WHO’s objective was to encourage the use of access group antibiotics, up to 60%, because these are antibiotics that target a limited number of germs and, therefore, would not easily favor AMR. However, in this study, we noted a lower use of antibiotics from the access group, i.e., 25.25%.Of the 301 prescriptions with antibiotics, 164  medical prescriptions contained one antibiotic, 117  contained two antibiotics, 15  contained three antibiotics and 5  contained four antibiotics.A total of 54.5% (164/301) of prescriptions had one antibiotic; this percentage is much lower than that found by Md. Ariful Islam et al. in Bangladesh, who noted 87.3% medical prescriptions containing one antibiotic . This maOf these 164 antibiotics prescribed, 32.9% (54/164) were from the access group while 67.1% 110/164) were from the watch group. We noted that prescriptions of watch group dominated, i.e., 67.1%. This result is similar to that found in a study conducted in West Asia (66.1%)  and Kaza/164 wereOf the 19 different antibiotics prescribed out of these 164 prescriptions, 5 antibiotics accounted for 74.5%. They were distributed as follows: Ceftriaxone (watch) was the most frequently prescribed 31.1% (51/164), followed by Amoxicillin (access) 13.4% (22/164), Amoxicillin–Clavulanic Acid (access) 12.2% (20/164), Azithromycin (watch) 10.4 (17/164) and Ciprofloxacin (watch) 7.4% (12/164). The watch group accounted for 48.9% and the access group only 25.6% of the top five. A similar finding on Ceftriaxone was noted in a study which focused on the prescription of antibiotics in the hospital sector in adults; the study concerned 69 countries, but with a slightly lower percentage of 24.8%. This, unfortunately, shows an overuse of watch group antibiotic on a global level, with a serious risk of favoring AMR towards Ceftriaxone over time.A total of 117  prescriptions contained two antibiotics. This percentage is much higher than the 11.2% found in Bangladesh . Indeed,Indeed, because of the lack of appropriate medical equipment  to carry out clinical examinations, prescribers tend to prescribe the same antibiotics already used, of which they are sure of the results. In addition, 21 prescriptions (17.94%) of prescriptions contained access category antibiotics, 62  prescriptions contained watch category antibiotics and 34  prescriptions contained not-recommended antibiotics. Indeed, the 29.06% of prescriptions containing not-recommended antibiotics could be explained by the fact that these combinations of antibiotics are considered to be the antibiotics of choice and are legal to use in the DRC while not recommended by the WHO. The AWaRe tool was set up to increase the use of access group antibiotics beyond 60%; the result found in our study (17.94%) showed that health authorities still have a lot to do to encourage prescribers to promote the rational use of antibiotics.A total of 15  prescriptions contained three antibiotics. The Bangladesh study found 1.4% of medical prescriptions containing three antibiotics, a much lower percentage than the 5% found in our study. Poly-pharmacy is a dangerous practice for drugs in general and antibiotics in particular because the risk of drug interactions and AMR is high. One (6.67%) prescription included antibiotics from the access category, seven  from the watch category, which is a lower percentage than the 87.9% found in Armenia and 84.4% found in Jordan , and sevA total of five  prescriptions contained four antibiotics each. The tendency to poly-pharmacy was even more accentuated in this case. With prescriptions containing four antibiotics, all combinations belonged to the not-recommended group, which greatly increases the risk of AMR and dangerous drug interactions for the patient.A total of 463 antibiotics were prescribed out of the 301 medical prescriptions. The most prescribed antibiotics were Ceftriaxone (watch) representing 21.81% (101/463), followed by Amoxicillin (access) representing 11.01% (51/463), the Amoxicillin–Clavulanic Acid combination (access) representing 5.61% (26/463), Gentamicin representing 5.61% (26/463), Azithromycin (watch) representing 4.97% (23/463), Metronidazole (access) representing 4.75% (22/463) and Ciprofloxacin representing 3.67% (17/463). A similar study was conducted by Yingfen Hsia et al, which covered 56 countries from different continents and the following results  were fouThe percentages of consumption for all these antibiotics were higher in our study than those found in these four continents except for amoxicillin–clavulanic acid in Europe (9.1%) and Southwest Asia (8.9 %), Gentamycin (10%) and Ciprofloxacin (3.8%) in Africa and finally Metronidazole 5.5% and 5% in Africa and Asia, respectively. Once again, Ceftriaxone (watch group) was the most frequently prescribed antibiotic. Ceftriaxone misuse is higher not only in DRC but also around the world, and so, appropriate decisions must be taken to avoid AMR by promoting Ceftriaxone rational use.Out of 463 antibiotics prescribed, 169 , 200  and 94  were from the access, watch and not-recommended antibiotics groups, respectively. These results clearly show that the WHO objective of achieving 60% use of access group antibiotics in the DRC is still an ideal , but it The AWaRe list includes a list of therapeutic fixed-dose combinations of a number of broad-spectrum antibiotics with unproven efficacy. They are, therefore, not recommended by the WHO for use in clinical practice . A totalA total of 42.30% of antibiotics used in prescriptions were from the watch group, including oral forms of third generation Cephalosporins (Cefixime and Cefpodoxime), Fluoroquinolones (Levofloxacin and Ciprofloxacin) and macrolides (Azithromycin). As well as their negative effect on the intestinal flora, these broad-spectrum antibiotics facilitate the development of antimicrobial resistance ,30,31,32Several strengths characterized this study. First, to the best of our knowledge, this is the first study to assess the antibiotic prescription pattern of health personnel in the district of Tshangu in the city of Kinshasa. Second, we established the profile of medical prescriptions containing one, two, three and four antibiotics, which demonstrated excessive use of watch group antibiotics and not-recommended antibiotics. Third, an overall assessment of all prescriptions according to AWaRe classification and the anatomical, therapeutic and chemical (ATC) classification was performed. The latter showed the overuse of certain therapeutic families  which are likely to promote AMR.However, some limitations should be considered when interpreting these results. Indeed, our work was limited only to the district of Tshangu, which is only one of four districts of the city of Kinshasa. In addition, only a few pharmacies in Tshangu district participated in the study, thereby providing a limited sample of 400 medical prescriptions. Finally, the study did not cover the whole year, thus not considering the possible influences of seasonal variation on the qualities of medical prescriptions.We found an irrational and exaggerated use of watch group antibiotics and non-recommended antibiotics. Certain classes of antibiotics such as third generation Cephalosporins, Penicillins, Macrolides, Aminoglycosides and Imidazoles alone constituted approximately 74% of the classes of antibiotics used. In addition to this, Ceftriaxone was the most prescribed antibiotic, accounting for 21.38% of the antibiotics prescribed. This finding underlines the need to popularize the use of the AWaRe tool among health personnel to encourage responsible use of antibiotics and, thus, combat the emergence of AMR. Unfortunately, our study was limited to a survey and collection of prescriptions arriving in pharmacies without knowing the problems for which they were prescribed exactly. As a tool to support antibiotic stewardship efforts at local, national and global levels, AWaRe classifies antibiotics into three groups , taking into account the impact of different antibiotics and their classes on antimicrobial resistance, to expand their rational use impact. In addition to DRC having a national plan to fight against antimicrobial resistance, it is time that the authorities with public health in their prerogatives can ensure the strict implementation of these objectives and the application of laws governing the health sector to limit the excessive use of antibiotics.


The permeability coefficient of construction materials plays a crucial role in engineering quality and durability. In this study, a microstructure model based on real aggregate shape and digital image technology is proposed to predict the permeability coefficient of concrete. A two-dimensional, three-component finite element model of cement concrete was established considering the interfacial transition zone (ITZ) between aggregate and mortar. The permeability coefficient prediction model was developed by the finite element method. The accuracy of the model was verified by experimental data, and the influence of the water−cement ratio on the permeability coefficient of concrete was analyzed. The results show that this method has good prediction accuracy with a relative error of 1.73%. According to the verified model, the influences of aggregate content, aggregate characteristics, aggregate location, ITZ thickness, and other factors on the permeability of concrete were explored. The higher the water−cement ratio, the higher the permeability coefficient. With the increase in aggregate content, the permeability coefficient decreases. Aggregate permeability has a significant influence on the effective permeability coefficient of concrete within a certain range. The greater the roundness of aggregate, the greater the permeability of concrete. On the contrary, the larger aggregate size causes lower permeability. The permeability coefficient of concrete with segregation is lower than that with uniform distribution. At the same time, the permeability increases with the increase of ITZ thickness. The impermeability of construction materials is a critical requirement for underwater and coastal structures, such as dams, tunnels, and piers. Besides, permeability significantly impacts the durability of concrete structures in cold climates. Lower permeability contributes to enhanced frost resistance and overall durability under such conditions ,2. The pEarly studies on the permeability coefficient generally adopted theoretical formulae and laboratory test methods for calculation and analysis. For instance, the typical Katz−Thompson equation  establisLaboratory testing is also a practical method to evaluate the permeability of concrete ,16,17. TAlthough laboratory testing provides direct and accurate data on concrete impermeability, there are some inherent limitations due to variations in testing methods and diversity in testing criteria. For concrete with low permeability, conducting tests often requires the application of high pressure, resulting in long test times. Moreover, it is often difficult to maintain long-term confinement under such high-pressure conditions. Consequently, considering the limitations of experimental testing, numerical simulation methods have been conceived. The advancement of computer technology has facilitated the utilization of CT scanning, digital imaging, nuclear magnetic resonance (NMR) imaging ,21, and The main objective of this study is to develop a virtual testing approach for evaluating concrete permeability based on the digital mesostructure of concrete. In this approach, the concrete was simulated as a random medium composed of continuous mortar, discrete aggregates, and an interfacial transition zone (ITZ) between mortar and aggregates. The refined digital aggregates with specific gradations were generated through image analysis and were randomly placed into a digital matrix of mortar. The ITZ between aggregates and mortar was then generated through a digital image processing (DIP) technique. The above digital mesostructure of concrete was imported into the finite element model to compute the permeability coefficient. The accuracy of the virtual testing approach was validated with experimental measurements. Additionally, the effects of ITZ, coarse aggregate content, and mesoscopic parameters of concrete on the permeability coefficient were analyzed with the validated virtual testing approach.From the available studies on permeability coefficients, aggregates were generally considered as simpler shapes, such as spheres or ellipsoids, in most finite element simulations of cement concrete ,28,29. HAt the microscopic scale, cement concrete is generally regarded as a nonhomogeneous material composed of three distinct components, namely, cement mortar, ITZ, and coarse aggregates ,33. In tTo begin, the aggregates with various particle sizes were divided into different groups; 80 representative aggregates were selected randomly to serve as the original aggregate templates. These aggregates were thoroughly washed and dried. After that, the geometry information of these aggregates was collected using the aggregate image system (AIMS), which generated 2-D projections of the aggregates in batches. The resulting projections were processed using image binarization techniques to produce the aggregate template. The experimental setup utilized for this process is shown in The aggregate template obtained above was imported into PFC 2D, a discrete element software, and random pellets were generated according to the specified grading using the command flow. Next, the aggregate template was replaced with circles of the same area to achieve a random distribution of coarse aggregate, as shown in It has been found in previous studies that the shape of ITZ is related to many factors, such as aggregate type, particle size, water−cement ratio, etc. ,35. ConsM × N, then the number of pixel points should be m × n, where M:N = m:n. Considering each pixel point as the basic unit of the model, the actual length x represented by each pixel point can be obtained through a simple operation, i.e., x = M/m or x = N/n. After discretization, the distance from the aggregate was converted to the ITZ thickness by assigning different colors to the pixels near the aggregate boundary using the dilate function. To generate ITZ in the digital model, the image files were imported into MATLAB and resized to fit the actual specimen size. The number of discrete pixel points should correspond to the size of the actual model to ensure the uniform thickness of the ITZ. If the size of the actual specimen is 3 in this paper. Therefore, Darcy’s law can be applied to calculate the seepage. The model was discretized into a finite number of cells with meshing, and the flow rate of each node on the water boundary was calculated. The overall flow rate (Q) of the concrete specimen can then be determined by summing the flow rate (Qi) at each node, as illustrated in K is the permeability coefficient of cement concrete, m/s; iQ represents the flow rate at each node, m3/s; ∆h is the hydraulic slope, m; L is the seepage path, m; A is the section area, m2. In this paper, A = 1 × the width of the specimen W.These FE models focused on the saturated seepage of cement concrete. It assumed the concrete skeleton to be completely rigid, and the water flow was characterized as an incompressible laminar flow. The density of water In the FE model presented in this paper, aggregates with particle sizes smaller than 4.75 mm were considered as part of the mortar, while coarse aggregates ranged in particle size from 4.75 to 25 mm. The aggregate gradation followed the Fuller curve, with cumulative sieve residual data presented in According to the characteristics of cement concrete, it was considered that no displacement or deformation occurs in the process of water penetration, and only the seepage field was considered in the numerical simulation. The steady-state analysis was conducted, and all degrees of deformation were constrained in the initial boundary condition, as shown in −4 m. Some models were partially encrypted , and limestone aggregate (apparent density of 2720 kg/m3). The fine aggregate used was river sand, and the coarse aggregate was limestone with a particle size greater than 4.75 mm. Tap water was added to the mixing process. The round table samples with a base diameter of 175 mm, top diameter of 185 mm, and height of 150 mm were cast. The samples were demolded and subjected to a 28-day curing period under controlled conditions. The curing environment maintained a relative humidity of greater than 95% and a room temperature of 20 °C. The materials used in this study included PC 42.5 cement, natural sand . The experimental results are presented in Km of cement mortar was set to the average value measured in the experiment at 5.724 × 10−12 m/s, and the permeability coefficient of ITZ Ki was equal to 30 Km [−10 to 10−14 [Ka was set at 1.0 × 10−12 m/s.In this study, the water−cement ratio was fixed at 0.5. In this case, the permeability coefficient to 30 Km . Accordito 10−14 ,38,39. IUndoubtedly, larger models result in more realistic numerical simulations. However, it is also necessary to consider the effect of the model size on the computation time when dealing with large quantities of models. Due to the significant size difference, it is impractical to model and compute the whole specimen. Consequently, cement concrete models of varied sizes were established to determine the optimal simulation size. The sizes considered include 60 mm × 60 mm, 80 mm × 80 mm, 100 mm × 100 mm and 120 mm × 120 mm. At the same time, based on the above concrete microstructure models, the permeability coefficient of concrete and the calculation time were calculated when the water−cement ratio was 0.5.−12 m/s, 3.411 × 10−12 m/s, 3.417 × 10−12 m/s, and 3.471 × 10−12 m/s, respectively. The mean value of the measured data was 3.359 × 10−12 m/s. The relative errors between the predicted and measured values were 4.61%, 1.55%, 1.73%, and 3.33%, respectively. In general, the accuracy of the permeability calculation model based on microstructure is acceptable. Besides, the computation time was calculated for each model. As shown in Five values were obtained from different models, and the average permeability coefficient values of the finite element models with different sizes were 3.514 × 10Based on the finite element microstructure model of cement concrete established with the above method, the permeability coefficients of cement concrete under different aggregate volume contents were calculated. For each content, five different values were obtained from different models. These values were averaged and shown in At the same time, a total of 25 models without considering ITZ thickness were established for comparison. When ITZ was not considered, the permeability coefficient of concrete was underestimated, especially when the aggregate content was high and the gap was more obvious, which was very unfavorable to the design and normal use of cement concrete with high impervious requirements.Some studies have concluded that the permeability coefficient of aggregate was very small, which was usually regarded as an impervious material . HoweverKa/Km was set from 0.001 to 100,000, and the permeability coefficients of 36 models were calculated. According to previous studies, the w/c ratio of concrete had a great influence on ITZ. Therefore, a fixed water−cement ratio of 0.5 was used when calculating the permeability coefficient of aggregates. The logarithmic coordinate system was drawn according to the above simulation results, as shown in Ka/Km is less than or greater than a certain threshold, Keff/Km basically converges to a constant value. However, within this range, the value of Keff/Km exhibits significant changes with varying Ka/Km values, which also reflects that the influence of the aggregate permeability coefficient on the effective permeability coefficient of concrete cannot be ignored within a certain range. The lower and upper limits of the permeability coefficients of aggregates in the sensitive region were determined by interpolating the fitted logarithmic curve, resulting in values of 1.1 × 10−13 m/s and 4.5 × 10−9 m/s, respectively. The selected parameter for the model in this paper was 1.0 × 10−12 m/s, which was located in the sensitive region, indicating the need to consider the permeability of aggregates.To encompass a wide range of aggregate permeability values in a compact manner, the ratio Kr represents roundness, A represents the aggregate area, and L represents aggregate contour circumference.The influence of aggregate shape on the permeability coefficient of cement concrete is an important consideration in practical production, as aggregates can take various shapes. The roundness of aggregates is a parameter that reflects the degree of approximation to a sphere and can affect the permeability of concrete . To evalKr decreases, the aggregate becomes flatter and longer, while aggregates with larger Kr values tend to be closer to circular in shape.Through Equation (4), the roundness was calculated based on 500 real aggregate templates obtained by AIMS, and five aggregates with different roundness values were selected from them  for subsIn this study, the numerical simulation method was adopted to calculate the permeability coefficient of the above samples when the aggregate content was about 40%, and the calculation results are shown in As can be seen from In cement concrete, coarse aggregates serve as a filler to reduce the amount of cement, and their particle sizes vary across a wide grading range. Previous studies ,39 have As shown in Studies ,43,44 haFour concrete specimens with identical material composition but different segregation conditions were generated, as illustrated in Five models of normal cement concrete and five models of segregated cement concrete were established with numerical simulation, and the permeability coefficients of these samples were calculated at an aggregate content of approximately 40%. The calculation results are presented in Ki = λKm [The determination of the permeability coefficient of ITZ through laboratory experiments presents challenges due to its particularity. Previous studies have suggested that the w/c ratio of cement concrete and aggregate content are closely related to the permeability coefficient of ITZ ,29. To cThe data presented in (1)The water−cement ratio of concrete greatly impacts permeability. The experimental results show that the lower w/c ratio leads to more impermeability. The proposed prediction method in this study shows acceptable accuracy, with a relative error of 1.73%.(2)The permeability coefficient of cement concrete gradually decreases with the increase in coarse aggregate content.(3)The permeability of aggregate significantly influences the effective permeability coefficient of concrete. The roundness of aggregates has little influence on the permeability coefficient of concrete. However, when the proportion of smaller-sized aggregates is higher, the ITZ increases, leading to a corresponding increase in the permeability coefficient.(4)The separation of cement concrete leads to the decrease of permeability coefficient. And the decrease is gradual in the 0–20% range, while it becomes more pronounced between 20% and 30%.(5)With the increase of ITZ thickness, the effective permeability coefficient of concrete increases.In this study, computer algorithms and digital image technology are used to establish a 2-D, three-phase microstructure model of cement concrete. The finite element model was used to calculate the permeability coefficient of cement concrete compared to experimental measurement. The following conclusions were drawn from the analysis:Future study is recommended to develop a 3-D microstructure of concrete and verify the findings of an effective permeability coefficient obtained from 2D models.


Antibiotic-associated diarrhea is one of the most frequent side effects of antimicrobial therapy. We assessed the epidemiological data of antibiotic-associated diarrhea in pediatric patients in our region.The prospective multi-center study included pediatric patients who were initiated an oral antibiotic course in outpatient clinics and followed in a well-established surveillance system. This follow-up system constituded inclusion of patient by the primary physician, supply of family follow-up charts to the family, passing the demographics and clinical information of patient to the Primary Investigator Centre, and a close telephone follow-up of patients for a period of eight weeks by the Primary Investigator Centre.p = 0.014), particularly higher in The Eastern Anatolia and Southeastern Anatolia. Though most commonly encountered with cephalosporin use, antibiotic-associated diarrhea is not a frequent side effect.A result of 758 cases were recruited in the analysis which had a frequency of 10.4% antibiotic-associated diarrhea. Among the cases treated with amoxicillin-clavulanate 10.4%, and cephalosporins 14.4% presented with antibiotic-associated diarrhea. In the analysis of antibiotic-associated diarrhea occurrence according to different geographical regions of Turkey, antibiotic-associated diarrhea episodes differed significantly (This study on pediatric antibiotic-associated diarrhea displayed epidemiological data and the differences geographically in our region. Helicobacter pylori infections found that gut microbiota were influenced for up to four years post-treatment. . The reasons for antibiotic treatment were acute tonsillopharyngitis , lower respiratory tract infection , acute otitis media , acute rhinosinusitis , acute lymphadenitis , soft tissue infection , and urinary tract infection . The most common antibiotic groups prescribed were aminopenicillins , cephalosporins (CEP) , macrolides  and phenoxymethyl penicillin .Figure p > 0.05). In terms of age distribution of participants with AAD, 14.7% were < 2 years of age, 14.9% were > 12 years, 8.8% were 2–7 years, and 6.9% were 7–12 years. A significant difference was evident among the participants with and without AAD episodes based on geographical location (p = 0.014). A sub-analysis of the regions showed that those from Eastern Anatolia and Southeastern Anatolia had significantly higher incidences of AAD, compared to the rest of the country (p = 0.04). Among the patients treated with amoxicillin-clavulanate (AMC) 10.4% presented with AAD; the same applied to 14.4% of those treated with CEPs, 10% of those treated with phenoxymethyl penicillins, and 6% of those treated with macrolides. Among the participants treated with the usual dose and a high dose of AMC, 8% and 12.3% had AAD in the follow-up, respectively.The characteristics of the participants according to AAD occurrence were displayed in Table n = 45) occurred during the 10 day-period of treatment. Figure n = 26) and 76% (n = 29) percentage of cases with AAD who displayed with a Bristol scale of 7 were 63% (n = 26) and 76% (n = 29) of those in the 10-day treatment period and in the following weeks, respectively.Among the AAD episodes, 56% (Two patients treated with AMC (dose: 60 mg/kg/d) needed hospitalisation because of AAD during the study period. They were analysed for other infectious causes of diarrhoea and diagnosed with AAD. One was an 18-month-old female admitted with diarrhoea at the fourth week of follow-up and treated with IV fluids for 3 days. The other patient was a 1-year-old male at the third day of antimicrobial treatment. He was hospitalised for 4 days and treated with IV fluids.In the present study, we analysed the occurrence of AAD in a paediatric outpatient population receiving antimicrobial treatment. The participants were followed up for eight weeks and 10.4% of cases had an AAD episode. There was a wide range of antibiotic classes included in the study and the most common types of antibiotics as the reason for AAD were CEPs and AMC. One of the intriguing findings in the analysis was the significant geographical difference in AAD occurrence.Antibiotics disarrange intestinal microbiota, thus changing the the diversity and numbers of bacteria in the gut, which leads to AAD. Resident microbiota cannot resist the invasion of pathogenic microorganisms, and endogenous opportunistic pathogens become overgrown –14. ThisClostridium difficile diarrhoea [Enterobacteria, whereas changes in the anaerobic population including Lactobacillus, Bifidobacterium and Bacteroides differed tremendously between studies from no change, to increases and/or decreases, as well as changes in diversity [Enterobacteria with divergent effects on anaerobic bacteria, Bifidobacterium sp, Lactobacillus sp and Bacteroides sp and a general decrease in diversity. Some studies have shown that these effects may last as long as 3–4 weeks [Enterobacteriacaea; however, a few have documented an increase [Bacteroides spp. increased with the use of first- and second-generation cephalosporins, but decreased with higher generation cephalosporins. An analysis of other antibiotics, such as ciprofloxacin, minocycline, clindamycin, paromomycin and clarithromycin plus metronidazol, revealed further devastating effects of antibiotics on bacterial diversity [In terms of risk factors for the occurence of AAD in outpatient clinics, Truck et al.  found thiarrhoea . In the iversity . Additio–4 weeks , 25. Manincrease . The abuiversity . The duriversity , 28.Akkermansia municiniphila and Lactobacillus which are related to healthy metabolic states [Bifidobacterium and decrease the amount of Clostridia. Non-digestible carbohydrates also increased the amount of Lactobacillus, Ruminococcus, Eubacterium and Roseburia, which displayed a healthy gut microbiome [An intriguing finding of our study was that the frequency of AAD differed significantly between the geographic areas in Turkey, which may be due to the well-known nutritional factors differ between regions. Nutritional habits differ between the east, south and west of the country. For example, food in east and southeast of Turkey comprises red meat and a high fat content. In contrast, on the south and west coasts, the food is mainly a Mediterranean style. Our study results bring to mind the question of the relationship between nutritional factors and AAD occurence. The recent data showed that a high fat high protein diet was associated with a dysbiotic microbiome and metabolome in the colon , 30, whic states . In a dic states . It is wc states . Similarcrobiome , 34–36. Antibiotics may cause gastrointestinal side effects following the cessation of treatment. In piglets that were given amoxicillin one day after birth, the microbiota remained substantially altered five weeks after treatment, which further emphasises the long-term effects of antibiotics on gut homeostasis . The theThis study had some limitations. First, we were not able to analyse the stools and define changes in microorganisms in the AAD cases. Second, the effects of probiotics were not tested in the study. Third, despite a quite reasonable time of follow-up period, the number of participants could have been higher if we had examined the impact of a wider range of antibiotic groups. Finally, we did not assess the rate of diarrhea with other causes among patients in different regions of the country who did not receive antibiotics as a comparator group. Accordingly, the baseline rates of diarrhoea were not evaluated in our study.In conclusion, the study presents the data on the occurrence of AAD in paediatric outpatient care with a valuable time of follow-up period. It provides some clues regarding the epidemiological differences in AAD occurence, which may inform clinicians for anticipating AAD in their own region. This may help them make more meticulous decisions regarding antibiotic prescriptions, even to the extent of performing better antimicrobial stewardship practices. Further analysis in conjunction with microbiata milieu may highlight the geographical differences in AAD occurence. Importantly, the our data revealed the potential duration of antibiotics’ gastrointestinal effects in a paediatric outpatient population, which may avoid from precribing antibiotics in unnecessary clinical states, especially in children.


Recently, utilizing solid mine waste to replace natural sand not only greatly reduces the 3D printing costs, but also contributes to an environmental sustainability development. However, most solid waste inevitably has an impact on the inherent mechanical strength and printability of concrete materials. It is an urgent requirement to expand the alternative materials and improve the overall property of 3D concrete materials. This paper reported an innovative concrete material that replaced natural sand with fine limestone powders for 3D concrete printing applications. The experimental measurements were performed including microstructures characteristics, flowability, buildability, shrinkability, layer-interface properties, mechanical properties and interlayer bonding strength. Besides, an effective method was proposed to characterize the printable properties of concrete materials and then the reasonable limestone powder replacement ratio was determined. Based on the investigation results, appropriate substituting limestone powder (40%) can effectively improve the grading of the concrete, thus promoting its printability and buildability. Moreover, the microstructures of the 3D printing concrete materials after curing were denser and their mechanical property improved by approximately 45%. With the further increase of replacement ratio, the reduction in the flowability led to a decrease of the printability. A large number of fine particles increased the shrinkage of the curing process and some bubbles were stranded inside the materials due to its increase in the viscosity, thereby reducing the mechanical properties of the hardened material. The produced concrete for 3D printing can be treated as an eco-friendly building material that contributes to the rational development and resource utilization of solid water, thus promoting the sustainable development of construction field. With the rapid growth of population, the solution to the contradiction between development and environment has become the focus of the world. In this context, the investigation of sustainable development technology becomes a global consensus. Especially, 3D printing based on concrete material is recently a novel and promising process technology in the building industry. Nowadays, 3D printing is capable of creating almost any complicated structures and has been confirmed as a promising and green manufacturing technology for various fields including aerospace, robotics, architecture and biomedical research, etc –3. In coAt present, the raw materials of 3D printing cement are mostly dependent on the large-scale mining. With the rapid development of Chinese economy, natural sand has become the largest, indispensable and irreplaceable raw materials because of an annual consumption of about 20 billion tons . HoweverAs a kind of common solid waste materials, the mass stack of limestone powders will seriously pollute the atmosphere and water, which brings severe threats to the safety of human beings –27. TherIn this paper, a novel concrete material that replaced natural sand with fine limestone powders was proposed for 3D concrete printing applications. The concrete materials with different replacement ratios of limestone powders to natural sand were investigated. Experimental measurements were performed to evaluate and compare the printable properties of above materials, including microstructures characteristics, flowability, buildability, shrinkability, layer-interface properties, mechanical properties and interlayer bonding strength, etc. And then the reasonable limestone powder replacement ratio was determined. This research explores an eco-friendly 3D printing concrete material, which not only significantly improves its mechanical strength and printability, but also effectively develops the current solid waste, thus contributing to an environmental sustainability development.2/g. And the chemical compositions of cement, limestone powders as well as fly ash have been measured and analyzed by the X-ray fluorescence (XRF) analysis, as displayed in The raw materials in this study were natural sand, Portland cement, limestone powder, fly ash and superplasticizer. Among them, the specific surface area of natural sand is 0.101 mParticle size distribution testing can be employed to help understand the dispersion degree of particles, including particle size, shape, density, and the gaps among particles, etc, which is of great importance for the subsequent processing and performance of the materials. Specially, 3D printing concrete materials are required to possess smaller and smoother particle grading to flow easily out of the printer and ensure the flowability and printability , 29. A pThe cumulative curve of particle volume percentage of limestone powder is shown in The fabrication processes, characterization and main measurement methods of the 3D printing concrete materials are shown in To achieve the flowability evaluation of the concrete materials, a series of experiments have been performed, including the slump test and the jumping table test. The slump test is most widely used in laboratories and fields . As showx and y  , as showx and y . SimilarH0 and ΔH were the initial height and height variations of the printed samples.H and w were the real-time height and width of the printed samples. Without loss of generality, the geometric factor hwA was adopted to estimate the stability of the structures. Meanwhile, Hε and hwA were used to synthetically analyze the buildability of concrete materials.Buildability is one of the critical parameters to estimate its printability, which is essentially the capability to maintain its extruded shape and resist deformation under external load for the concrete. In general, concrete materials were stored in a barrel and evenly extruded from the nozzle by screw rotation to generate multilayered structures , 33. In The fresh mixture was required to possess good water retention performance and no damage, separation, or blockage. The base was made of plastic plate, and the clean cling film was placed on the plate to ensure its free shrinkage. On this basis, the concrete strips extruded from the printer were cut into 5 pieces with a length of 100 mm. Initially, measurements were carried out every 2 min with a high-precision digital caliper, and then taken every 10 min after 10 min. The shrinkage test was carried out according to the Chinese national standard (GB/T 50082–2009) . The thrIn order to explore the differences between the layer-interface structures of 3D printing concrete materials with different limestone powders substituting ratios, the samples cured for 28 days were observed and studied by using a magnifying glass. Firstly, samples cured for 28 days were cut into small pieces near the interlayers and polished. Then, a magnifying glass with 100x was employed to observe their interlayer structures and compare the differences between the various samples.Besides, the microstructures of the optimum designed concrete materials were characterized by scanning electron microscopy . The printed samples were cut into small flakes with planarizing surface and vacuum dried at 55°C for 12h. After that, the samples were treated with gold plating and the SEM tests were carried out.Mechanical characteristics always play an important role in the printability. The samples were cured in a standard curing room for a certain period of time after being printed layer by layer, and then the samples were shaped in the dimension of 70mm×70mm×70mm. The printing direction is along the length direction, as shown in Interlayer bonding strength is closely related to the mechanical properties of printing concrete materials . To inveHε and aspect ratio hwA for different limestone powders replacement ratios were measured, as illustrated in Hε significantly increases. Besides, the aspect ratio hwA is highly dependent on the replacement ratios of limestone powders, which indicates that the structural or geometric stability of the printed structures are obviously varying with the dosage of limestone. Although all of the samples T2-T6 are capable of being shaped, it is obvious that the lower the vertical strain and the larger the aspect ratio, the better the buildability of the samples owing to the higher quasi-static shape retention. Among them, the aspect ratios of all samples are close, but the vertical strains of T2, T3, T4, T6 are quite different as well as the cracks appear on their surfaces compared to sample T5. Therefore, it is accepted that the sample T5 displays optimal buildability, which causes its preferable selection for the 3D printing.In order to quantitatively analyze the buildability of concrete materials, two important geometric factors including vertical strain Shrinkage results can provide supplementary for the evaluation of the stability of concrete materials. In general, the smaller shrinkage ratios at the specific time, the greater the deformation resistance of structure, indicating a better stability of the concrete materials. As shown in The extrusion-based 3D printing technology is stacked layer by layer during the actual printing, which inevitably leads to a weak interface between the layers, thus seriously reducing the mechanical properties of the printed samples. It is well known that the binding strengths between the layers are closely related to the characteristics of the layer interfaces . As showNevertheless, with the further increase of limestone powders replacement ratios (greater than 40%), the macroscopic voids begin to increase, and the natural sand particles that supported the framework are gradually decreased. The augment in the voids may be due to the increase of capillary pressure between fine particles as the amount of limestone powder contents increase, resulting in a plastic shrinkage of the materials and more microcrack on their surface. Additionally, some researchers consider that the increase of limestone powder contents leads to an increase in the viscosity of the slurry, and the bubbles in the slurry are unable to escape, thereby increasing their macroscopic voids. As shown in In order to further evaluate the properties of the sample T5, its microstructure is characterized and compared to the reference sample T1, as shown in Whereas, the mechanical properties of printing materials are reduced to a certain extent as the limestone powder contents are greater than 40%. When the limestone powders replacement ratios increase from 60% to 100%, their compressive strength after 3 days decreases by about 9.7% and 74.2% compared with sample T1. With the further increase of limestone powder and decrease of natural sand contents, a small number of natural sand particles are suspended in the limestone powder, which makes them insufficient to contact each other to require a stable skeleton structure and limits the improvement of mechanical strength. More importantly, the excessive limestone powder contents could not only weaken the framework effect, but also hinder the hydration of the cement, which blocks the sustainable development of the mechanical strengths . TherefoInterlayer bonding strength is a crucial parameter that assessing the structural strength of printed samples and closely connected with the buildability of the concrete materials. It may be attributed to the weaken interfaces and adhesion reduction problems between the adjacent layers caused by the retention of tiny bubbles as well as the increase of microcracks, which causes the loss of tensile strengths. Therefore, it is recommended to replace the natural sand with 40% limestone powders contents in the manufacturing process so as to enhance the structural strength and buildability of the printed structures.In conclusion, the sample T5 exhibits preferable comprehensive characteristics, including printability, buildability, mechanical properties and so on, demonstrating that the concrete material with the limestone powders replacement ratio of 40% has a broad promising in the field of 3D printing.In this paper, the concrete materials with different replacement ratios of limestone powders to natural sand were investigated and compared to evaluate the printability in the field of 3D printing. The experimental measurements were performed including microstructures characteristics, flowability, buildability, shrinkability, layer-interface properties, mechanical properties and interlayer bonding strength. Besides, an effective method is proposed to characterize the printable properties of concrete materials and then the reasonable stone powder replacement ratio is determined. By comparison, the sample T5  could effectively improve the grading of the concrete, displaying an optimal printability and buildability. Besides, its mechanical property significantly improved by approximately 45%. The produced concrete not only greatly reduced the 3D printing costs and expanded the alternative range of materials, but also improved its inherent mechanical strength and printability, which can be treated as an eco-friendly building material that shows promising application in the field of sustainable 3D printing.S1 Data(XLSX)Click here for additional data file.


Urinary tract infections (UTIs) are one of the most common adult bacterial infections. The global burden of UTIs has nearly doubled in the last 30 years with more than 400 million affected individuals in 2019 ,6. RecurDespite the growing financial and societal burden of rUTIs, there has been little innovation in prevention or treatment over the past decade . Both inMethenamine is a urinary antiseptic first introduced in 1895 . In an aMethenamine is available in 2 salt forms—methenamine hippurate (MH) and methenamine mandelate. Methenamine mandelate salt tabs, which have an enteric coating, are dosed 4 times daily at 1 g. MH is only available without an enteric coating and is dosed at 1 g twice daily, although higher doses can be used. As a result of these dosing schedules, MH is the more commonly used formulation. Methenamine has excellent oral bioavailability with 70% to 90% being renally secreted  and is sDue to its mechanism of action, concurrent treatment with MH and urinary acidifiers, such as ascorbic acid (Vitamin C), had been recommended to enhance methenamine efficacy. Urinary acidifiers, however, have not been found to have a significant mean effect on urine pH  and, in Despite its low side effect profile, methenamine fell out of favor in the late 20th century with the discovery and expansion in use of antibiotics. Given the growing crisis of antibiotic resistance, there has been a recent resurgence in methenamine use as a viable alternative to antibiotics for UTI prevention.In 2012, a Cochrane review analyzed the available trials evaluating the efficacy of methenamine for UTI prevention [p = 0.05). Six months after discontinuing preventive treatment, both groups exhibited similar, reduced proportions of resistant Escherichia coli isolates of 38% (15/39) in the antibiotic arm and 42% (19/45) in the MH arm (p = 0.73). Despite a lower proportion of antibiotic resistance, the MH cohort demonstrated higher rates of asymptomatic bacteriuria (14% versus 7%) at 12 months. Of participants with E. coli isolated at baseline and at least 1 postbaseline sample, similar proportions of participants (52% versus 36%) in the antibiotic and MH arms developed new resistance to at least 1 antibiotic (p = 0.1). The acquisition of E. coli MDR at any follow-up was also similar in both arms, at 17% (7/42) and 14% (6/42) of participants in the antibiotic and MH arms (p = 0.76), respectively. Six months posttreatment, however, a higher proportion of participants in the MH arm  demonstrated E. coli MDR than in the antibiotic arm . As fewer than half of participants were assessed at this time point, it is unclear if this difference reflects higher incidence of acutely treated UTIs throughout the study, the bacteriostatic nature of MH, or sampling bias.Since the Cochrane review, 2 randomized trials have evaluated the efficacy of methenamine compared to daily prophylactic antibiotics in preventing rUTIs. Both studies excluded patients with urinary tract abnormalities and/or neurogenic voiding dysfunction. The multicenter, randomized, open label, noninferiority ALTAR trial compared MH to low-dose antibiotic prophylaxis with either nitrofurantoin, trimethoprim, or cephalexin for 12 months . Their pBotros and colleagues conducted a single-center, randomized, open-label, noninferiority trial comparing MH to trimethoprim prophylaxis for treatment duration of 6 months . Their pLactobacillus spp. and the expansion of pathogenic species such as Gardnerella, which increases the risk of rUTI [Although previously considered sterile, sensitive molecular methods, such as next-generation sequencing (NGS) and multiplex polymerase chain reaction (PCR), have revealed that the urinary tract contains commensal microbial communities even in healthy, asymptomatic individuals ,24. Disr of rUTI . Shifts  of rUTI , with ch of rUTI . While uAs its mechanism of action is primarily bacteriostatic, methenamine may preserve protective microbial diversity. Recently, Acevedo-Alvarez and colleagues evaluated the longitudinal effect of MH on the urobiome of 6 postmenopausal women with rUTIs . From eaThe growing crisis of antibiotic resistance has led to a reintroduction of methenamine as a viable and efficacious nonantibiotic management strategy for UTI prevention. Methenamine is as effective in UTI prevention as prophylactic antibiotics with a low side effect burden in randomized, controlled trials. Despite over a century of use, no bacterial resistance mechanisms or increased carcinogenesis have been observed. Although methenamine is gaining ground for UTI prevention, future studies will need to evaluate its longitudinal effect on host microbiota, both in and outside the urinary tract, and long-term impacts of such changes on subsequent health and disease. Given a new appreciation of the collateral damage of repeated antibiotic use on human health, effective nonantibiotic therapies, such as methenamine, must be revisited as part of the armamentarium in UTI prevention.


Large engineering structures made of various materials, including concrete , steel , or others, are often subjected to severe vibration, dynamic, and cyclic loads, which lead to crack initiation, crack growth, and finally structural failure. One of the effective techniques to increase the fatigue life of such structures is the use of reinforced materials. In the meantime, environmental factors, such as corrosion caused by corrosive environments, also affect the fatigue behavior of materials. Therefore, the main purpose of this paper is to study the influence of corrosive environment on the high-cycle fatigue (HCF) behavior of concrete reinforced by epoxy resin. For this purpose, five corrosive environments with different intensities, including fresh air, water: W, sea water: SW, acidic: AC, and alkaline: AL, were considered and the laboratory samples of conventional concrete (CC) and polymer concrete (PC) were immersed in them for one month. Next, axial fatigue tests were performed under compressive–compressive loading with a frequency of 3 Hz on cylindrical specimens. Moreover, to achieve reliable results, for each stress amplitude, the fatigue test was repeated three times, and the average number of cycles to failure was reported as the fatigue lifetime. Finally, the stress–life cycle (S-N) curves of different states were compared. The results showed that polymer concrete can resist well in corrosive environments and under cyclic loads compared to the conventional concrete, and in other words, the epoxy resin has performed its task well as a reinforcer. The results of fatigue tests show that the load bearing range of 10 tons by CC has reached about 18 tons for PC, which indicates an 80% increase in fatigue strength. Meanwhile, the static strength of samples in the vicinity of fresh air has only improved by 12%. Most old building structures are made of conventional concrete, and are currently either at the end of their life, have been replaced with new structures according to the technological advancements, or need minor repairs ,2. ThereGolestaneh et al. studied the chemical resistance of PC samples in different solutions . In thisDespite the value and reliability of the experimental results, the two parameters of cost and time consumption of the tests lead to a reduction in the scope of various parameters. This fact shows itself colorfully when dealing with a complex system, including a test specimen with complex geometry or a complex testing process. Here, the subject of fatigue–corrosion is one of the most complex phenomena, which is very difficult and, in some cases, impossible to test in accordance with reality. On the other hand, the development of science and simulation software has made it possible to study the behavior of complex systems with a little simplification and at a much cheaper cost than performing tests . For exaAs is clear from the articles mentioned above, valuable studies have been conducted in the field of simulating the behavior of reinforced concrete and practical results have been published, which are not within the scope of this article, and in this research, the investigation is performed only in laboratory conditions. Furthermore, from the literature review, it is clear that most of the laboratory evaluations were performed on different types of concrete in the vicinity of fresh air. This is despite the fact that the use of this material, i.e., concrete, is not only for exposure to fresh air, and sometimes they are placed in harsh working conditions and corrosive environments, so the estimation of their service life in such environments should be conducted correctly. Hence, the author tried to evaluate the fatigue properties of conventional and polymer concretes exposed to various corrosive environments with different pH values in vitro.To make concrete as a composite material, two different sizes of rounded aggregates, i.e., fine and coarse, were used in both CC and PC modes. In this regard, the classification of aggregates in terms of appearance and geometry is shown in Another member of this composite material is adhesive, for which cement is used in conventional concrete. In the present research, Portland cement with specifications of Epoxy resin was also used to make PC. In this way, EI-413 resin and HA-94 hardener were mixed with a ratio of 1:0.6. Finally, the technical specifications of the obtained epoxy resin are listed in In construction standards, two types of concrete samples are defined, namely cylinder and rectangular cube, whose laboratory results can be converted to each other with specific coefficients. In this research, laboratory samples were made in the form of cylinders with dimensions according to the ISO 1920-3 standard . The diaAs mentioned in the previous sections, the main objective of this article is to investigate the high-cycle fatigue behavior of conventional concrete and polymer concrete under the effect of corrosive environments. Therefore, before performing any mechanical tests, it is necessary to immerse the samples prepared in the previous step in different corrosive environments with different pH values. Thus, in the following, each of these subsections will be discussed separately.To achieve the goals defined in this research, five different corrosive environments were considered. The first environment is the fresh air that most buildings are exposed to. Water was considered the second case. In this way, distilled water with pH of 7 was used to simulate rainy and foggy weather conditions. After that, sea water was considered. To simulate marine environments, making pH of 7.25 was attempted by adding different elements, such as calcium dichloride, magnesium dichloride, and sodium chloride, to distilled water. In addition, to simulate an acidic environment such as the behavior of acid rain, reducing the pH of distilled water from 7 to 2.5 was attempted by adding hydrochloric acid. And the last environment is dedicated to the alkaline environment. Normally, the pH of such environments is very high. Therefore, at first, increasing the pH value of distilled water was attempted by adding calcium hydroxide. As a result, the pH value became about 10. For further increase, sodium hydroxide was also added to the mixture to bring the pH value to 12.5. Despite the preparation of different environments, the pH values were checked weekly so that they did not lose their properties and remained within the defined range, otherwise the environment was changed. Ten samples of each type of concrete, i.e., CC and PC, were immersed in each of the environments for one month and then kept in the fresh air to dry. Now they are ready to perform various mechanical tests.In order to determine the appropriate range of cyclic loading in the fatigue test, a compression test was performed on the samples. This test was performed according to the ISO-1920-4 standard  on both Axial fatigue test was performed on 9 samples of each group of materials. All experiments were performed under constant amplitude and force-controlled conditions at room temperature. In this regard, the loading ratio, i.e., the ratio of minimum force to the maximum force, was considered equal to 0.1 and loaded with a frequency of 3 Hz. This means that the specimens are always under compressive load. Also, to apply force uniformly on the cross-sectional surface of the samples, 100 mm thick St52 plates were used at the beginning and end of the samples between the jaws of the testing machine. Moreover, to obtain the fatigue behavior in the high-cycle area and extract the coefficients of Basquin linear relationship, the tests were loaded at three different force levels, and the average number of cycles until the final failure of the sample and its collapse was reported as the number of fatigue cycles (each test was performed three times to check the repeatability of the response). During the tests, it was observed many times that a surface crack is initiated in the sample, and despite the long length of cracks even more than half the height of the sample, or the presence of deep cracks up to the depth of about 1/3 of the diameter of the sample, the sample can withstand cyclic load. Therefore, the test ends when the sample cannot withstand any force.The static test results are reported in As is clear from the results presented in From The static test results showed that the compressive strength of polymer concrete is about 12% higher than the compressive strength of conventional concrete (both samples were in the vicinity of fresh air). Also, the reduction rate of the static strength of polymer concrete was less than conventional concrete in all the studied corrosive environments.The fatigue resistance of polymer concrete is much higher than conventional concrete. This was proven in all corrosive environments. Also, in some cases, it has been shown that this increase in strength sometimes reaches 100%.The fatigue test results on conventional concrete samples indicated that the longest fatigue life is related to the samples in the vicinity of fresh air. Also, the lowest fatigue life is related to samples immersed in an alkaline environment.Fatigue test results on polymer concrete samples showed that the lowest fatigue life is related to the samples in the vicinity of water and alkaline environments.Fatigue behavior of conventional and polymer concretes considering the conditions stated in this research was qualitatively and quantitatively discussed. In future study, the author plans to perform more experiments and analyses using statistical tools such as data mining techniques and machine learning tools. In addition, attempts are made to remove the current laboratory limitations, including equipment, so that the fatigue behavior can be investigated in two separate areas, i.e., low-cycle and high-cycle.In this study, the author has tried to investigate the effect of various types of corrosive environments with different pH values on the fatigue properties, i.e., the life span under cyclic loading, of conventional and polymer concretes. In this regard, the research was completely experimental. To this end, different environments such as fresh air, water, sea water, acidic, and alkaline were used and the samples were evaluated by fatigue test after one month immersion in these environments. Finally, the S-N diagrams of different samples were compared with each other. Among the most important achievements of this research, the following can be mentioned:


Background: Handshake stewardship is a variation of prospective audit and feedback that entails the individual review of patient charts by a physician–pharmacist collaborative team followed by in-person feedback to primary teams to communicate recommendations regarding optimal antibiotic use. Handshake stewardship has been shown to have durable effects in reducing antimicrobial use in children’s hospitals, but data regarding this intervention in adult hospitals are scarce. In particular, no data are available regarding the impact of this type of stewardship intervention on adult surgical units. We examined the effect of a handshake stewardship intervention at a large academic medical center on adult trauma and acute- and critical-care surgery (ACCS) units. Methods: The antimicrobial stewardship program (ASP) at Barnes-Jewish Hospital launched a handshake stewardship intervention targeting surgical floor teams in January 2022. These teams included the ACCS teams and a number of other surgical services. The intervention consisted of once weekly reviews and in-person rounds with the surgical floor teams along with the establishment of a 7 day per week “hotline” in which the surgical teams could contact an ID physician or pharmacist with questions regarding antibiotic use. Patients with formal ID consultations were not reviewed. Recommendations were tracked including the type, the antibiotic targeted, and recommendation acceptance or rejection. Descriptive statistics were performed to analyze these results. At the end of 12 months, antibiotic use in the floors covered by the ACCS teams were pulled from the NHSN AU module to perform an interrupted time-series analysis 12 months before and after the intervention. Results: Overall, 3,127 charts were reviewed during the intervention period and 637 recommendations were made to all the surgical teams. Opportunities for antibiotic use optimization were identified in ~20% of antibiotic orders. The overall recommendation acceptance rate was 71%. In the ACCS units, 272 interventions were recommended, with an acceptance rate of 67%. The most frequent recommendations were for antibiotic discontinuation (37%), antibiotic de-escalation (17%), shortening duration (12%), and broadening coverage (12%). Antibiotic usage trends  on the ACCS floors, which were showing a nonsignificant increasing trend (P = .70) before and after the intervention, now show a nonsignificant decreasing trend (P = .20). Conclusions: There are numerous opportunities for antibiotic optimization on adult surgical floors. Although handshake stewardship is a labor-intensive intervention, preliminary findings after 1 year show that, on ACCS units, there may be a trend toward a sustained impact.Disclosures: None