Antibiotic resistance is a global public health issue, particularly in low- and middle-income countries (LMICs), where antibiotics required to treat resistant infections are not affordable. LMICs also bear a disproportionately high burden of bacterial diseases, particularly among children, and resistance jeopardizes progress made in these areas. Although outpatient antibiotic use is a major driver of antibiotic resistance, data on inappropriate antibiotic prescribing in LMICs are scarce at the community level, where the majority of prescribing occurs. Here, we aimed to characterize inappropriate antibiotic prescribing among young outpatient children and to identify its determinants in 3 LMICs.n = 2,639) nonetheless resulted in antibiotic prescription. This proportion was much lower in Madagascar (15.6%) than in Cambodia (57.0%) or Senegal (57.2%) (p < 0.001). Among the consultations determined not to require antibiotics, in both Cambodia and Madagascar the diagnoses accounting for the greatest absolute share of inappropriate prescribing were rhinopharyngitis  and gastroenteritis without evidence of blood in the stool . In Senegal, uncomplicated bronchiolitis accounted for the greatest number of inappropriate prescriptions (84.4% of associated consultations). Across all inappropriate prescriptions, the most frequently prescribed antibiotic was amoxicillin in Cambodia and Madagascar  and cefixime in Senegal (31.2%). Covariates associated with an increased risk of inappropriate prescription include patient age greater than 3 months (adjusted odds ratios (aOR) with 95% confidence interval (95% CI) ranged across countries from 1.91  to 5.25 , p < 0.001) and living in rural as opposed to urban settings . Diagnosis with a higher severity score was also associated with an increased risk of inappropriate prescription , as was consultation during the rainy season . The main limitation of our study is the lack of bacteriological documentation, which may have resulted in some diagnosis misclassification and possible overestimation of inappropriate antibiotic prescription.We used data from a prospective, community-based mother-and-child cohort  conducted across urban and rural sites in Madagascar, Senegal, and Cambodia. Children were included at birth and followed-up for 3 to 24 months. Data from all outpatient consultations and antibiotics prescriptions were recorded. We defined inappropriate prescriptions as antibiotics prescribed for a health event determined not to require antibiotic therapy . Antibiotic appropriateness was determined a posteriori using a classification algorithm developed according to international clinical guidelines. We used mixed logistic analyses to investigate risk factors for antibiotic prescription during consultations in which children were determined not to require antibiotics. Among the 2,719 children included in this analysis, there were 11,762 outpatient consultations over the follow-up period, of which 3,448 resulted in antibiotic prescription. Overall, 76.5% of consultations resulting in antibiotic prescription were determined not to require antibiotics, ranging from 71.5% in Madagascar to 83.3% in Cambodia. Among the 10,416 consultations (88.6%) determined not to require antibiotic therapy, 25.3% , particularly among children, who face a disproportionately large share of the global burden of bacterial disease.Antibiotic overuse, as a result of inappropriate prescribing, is a major driver of antibiotic resistance, but relevant data from LMICs are scarce at the community level, where the majority of antibiotic prescribing occurs.Data regarding the prevalence and risk factors of inappropriate prescribing among outpatient children in LMICs are needed to understand its extent and causes and to inform intervention.N = 2,719) having at least 1 outpatient consultation from birth up to 24 months of age.Using data from a mother-and-child cohort in urban and rural sites of Madagascar, Senegal, and Cambodia, the appropriateness of outpatient antibiotic prescribing was assessed among all children , disease with a higher severity score, consultation during the rainy season, and residence in rural areas.Inappropriate antibiotic prescribing is pervasive among outpatient children in LMICs, although there is great heterogeneity across countries in prescribing practices.Locally adapted antibiotic stewardship programs are needed to optimize pediatric antibiotic prescribing, while taking into account the specific contexts associated with high-risk populations across diverse LMICs. Antibiotic resistance is a leading global threat to public health . Over thInappropriate antibiotic prescribing is a primary factor underlying the emergence of antibiotic resistance. An antibiotic prescription may be deemed inappropriate if the chosen dose, molecule, or schedule is nonoptimal, or if the patient’s clinical indication does not necessitate antibiotic therapy. In this study, we focus on the latter. Inappropriate antibiotic prescribing has deleterious impacts on human health across scales. At the individual level, patients are unnecessarily exposed to potential side effects of antibiotic consumption, including allergic reactions and digestive symptoms related to microbiome dysbiosis, and may experience delays to appropriate care. Potential longer-term risks of pediatric antibiotic exposure, such as increased risks of asthma and autoimmune disorders, continue to be described . At the In the context of efforts to mitigate the burden of antibiotic resistance, reducing inappropriate antibiotic prescribing is a public health priority. However, the share of antibiotic prescribing that qualifies as inappropriate is poorly described in LMICs. Most studies estimating the magnitude of and risk factors for inappropriate antibiotic prescribing have been based in HICs –11. In pThe objectives of this study were to describe and quantify inappropriate antibiotic prescribing and to identify determinants of inappropriate prescribing among children enrolled in a community-based cohort in Madagascar, Cambodia, and Senegal.We used data from the BIRDY cohort , a prospective, multicentric, community-based mother-and-child cohort. The study took place across urban and rural sites in Madagascar (pilot phase: 2012 to 2014 and complete phase: 2014 to 2018), Senegal (2014 to 2018), and Cambodia (2014 to 2018). The primary objective of this cohort study was to estimate the incidence of antibiotic-resistant bacterial infections in children.The formal analysis plan for the BIRDY cohort was established in 2012 . There wThis BIRDY cohort has been described in detail elsewhere . BrieflyTo recruit study participants, a first phase of exhaustive identification of all pregnant women was carried out in the study areas. Women were enrolled, after having given written informed consent, during their third trimester of pregnancy and followed until delivery to include their newborns at birth.Inclusion criteria were the following for both the mother and her newborn: routine residence in the study area with no plan to move away during the follow-up period, and no opposition to the research being conducted, nor to the collection of epidemiological data and biological samples. Data regarding sociodemographic, medical, and obstetric characteristics of mothers were collected, as well as data regarding the delivery and health characteristics of newborns.After delivery, children were followed up for between 3 and 24 months, depending on the site and country. Duration of follow-up was 6 months during the pilot phase and 18 months during the complete phase in Madagascar and 24 months in Cambodia. In Senegal, children were followed up for 3 months in rural areas and 12 months in urban areas. Children were followed up by both active and passive surveillance according to the same schedule across all study sites. Active surveillance consisted of scheduled home visits within 3 days of childbirth, followed by weekly visits until the first month of life, fortnightly visits from the first to the third months of life, and finally, monthly visits until the end of the study period. During these visits, children’s health status was checked, especially for signs of infection. In case of a health event, the child was referred to an outpatient consultation or directly to hospital if the child’s condition was serious. Passive surveillance consisted of asking mothers to contact the investigation team whenever the child showed signs of infection in order to schedule an outpatient consultation. Thus, children were able to benefit from outpatient consultations whenever they were sick, whether identified by their guardians or by study investigators. Clinical decisions regarding antibiotic prescribing were not monitored or imposed, but were rather left to the attending physicians to decide according to local protocols.Importantly, epidemiological data collected during these consultations included children’s diagnoses, symptoms, and treatments received, including details of any antibiotics prescribed. Costs of consultation and antimicrobial treatment were covered by the study.For the present study, the population considered was all children from the BIRDY cohort who had at least 1 outpatient consultation during their follow-up. Only systemic antibiotics were taken into account . We did not consider local antibiotics  because their impact on antibiotic resistance is probably different from systemic antibiotics.For each consultation, diagnoses were categorized by the study team using data collected during children consultation. First, we ensured that all diagnoses made by the physician not of infectious origin were concordant with data collected on the signs and symptoms presented by the child. Then, all infectious diagnoses were determined using a syndromic algorithm based on the World Health Organization (WHO) Integrated Management of Childhood Illness (IMCI) guidelines. This algorithm was developed previously and is described elsewhere . All heaWe defined inappropriate antibiotic prescriptions as those being prescribed during an outpatient consultation for a child’s health event that does not require antibiotic therapy, regardless of the duration of prescription, type of antibiotic, and dosage.We constructed a standardized classification algorithm in 2 steps to determine which health events require antibiotics or not . The firSome children received multiple diagnoses and/or multiple antibiotic prescriptions during a single consultation; hence, the number of consultations not requiring antibiotics and the number of antibiotics prescribed among consultations not requiring antibiotics are considered as distinct outcomes. For children receiving multiple diagnoses during their consultation, antibiotic therapy was defined as inappropriate provided that none of the diagnoses required antibiotic therapy. For children receiving prescriptions for multiple antibiotic classes or molecules during a single consultation, all prescriptions were defined as inappropriate provided that none of the corresponding clinical diagnoses required antibiotic therapy.First, we calculated basic descriptive statistics of characteristics of the study population in each country, including the total number of consultations, diagnoses, antibiotic prescriptions, and inappropriate antibiotic prescriptions. Comparisons between countries were made using the chi2 test or exact Fisher test (depending on the variable’s distribution) for qualitative variables and the Student test or nonparametric Mann–Whitney test (depending on the variable’s distribution) for quantitative variables. All tests were bilateral, and the significance threshold was set at 0.05.Second, we evaluated risk factors for inappropriate antibiotic prescribing. Specifically, we investigated whether antibiotic prescription during outpatient consultations among children not requiring antibiotic therapy was associated with exposures of primary interest, defined as characteristics of the health event . We considered site, child sex, child nutritional status, and sociodemographic, maternal, and pregnancy characteristics as potential confounders. We included all consultations among children whose health event was determined not to require antibiotic therapy by the classification algorithm described above.Nutritional status was defined using the z-score, adjusted according to the child’s age and weight using WHO reference tables, where children with a z-score < -2 were considered underweight . When inWe used a mixed logistic regression model to account for repeated measures  with a random intercept for each child. Effects of exposures of primary interest on inappropriate antibiotic prescription were assumed to be the same for all children and, accordingly, were modeled as fixed effects. Upon recommendation from a statistical reviewer, we conducted a full model including data from all 3 countries. First, we conducted the full model without any interaction terms . Then, wA secondary analysis was also carried out, in which separate mixed logistic regression models were developed for each country to identify risk factors for inappropriate prescribing that are directly reflective of the local contexts  Tables. The study was approved by the respective ethics committees of Madagascar (068-MSANP/CE), Senegal (SEN 14–20), Cambodia (108 NEHCR), and the Institutional Review Board of Institut Pasteur (IRB/2016/08/03), France. Written informed consent was given by parents of all participants.Among the 3,710 children enrolled at birth between 2012 and 2018, 2,719 (73%) children had at least 1 outpatient medical consultation during their follow-up and were included in this study, including 572 children in Cambodia, 1,816 children in Madagascar, and 331 in Senegal . Overallp < 0.001, p < 0.001). Most mothers gave birth in a healthcare facility in Cambodia (98.6%) and Senegal (96.1%), while 37.7% of mothers delivered at home in Madagascar (p < 0.001).The proportion of mothers who completed secondary school or attended university was 24.3% in Madagascar, compared to 13.6% in Cambodia and 9.1% in Senegal  consultations led to antibiotic prescriptions. These consultations represented 59.9% , 19.4% , and 61.9% (306/494) of all consultations in Cambodia, Madagascar, and Senegal, respectively .In both Cambodia and Madagascar, the most frequent diagnosis was rhinopharyngitis, representing 34.6%  and 29.5%  of consultations, respectively. Gastroenteritis was the next most common diagnosis, accounting for 17.6%  of consultations in Cambodia and 12.5%  in Madagascar. The third most common diagnosis was bronchiolitis in Cambodia, with 8.9%  of consultations, and lower respiratory infection in Madagascar, with 10.8%  of consultations. In Senegal, the 3 most common diagnoses were bronchiolitis with 15.6% of consultations (77/494), healthy child (consultations without specific diagnoses/symptoms) with 13.3% of consultations (66/494), and rhinopharyngitis with 10.9% of consultations (54/494).Across all consultations that led to antibiotic prescriptions, a total of 4,648 distinct antibiotics were prescribed, as some prescriptions included multiple antibiotics. The most prescribed antibiotic in Cambodia and Madagascar was amoxicillin, accounting for 35.7%  and 24.0%  of all antibiotics prescribed, respectively. Cefixime was the most prescribed antibiotic in Senegal, representing 34.4% (114/331) of all antibiotics prescribed .p < 0.001). Altogether, 76.5%  of all outpatient consultations resulting in antibiotic prescriptions did not require them, including 83.3%  in Cambodia, 71.5%  in Madagascar, and 73.9%  in Senegal (p < 0.001). If we consider distinct antibiotic prescriptions, altogether 67.1%  of all prescriptions were inappropriate, including 74.8%  in Cambodia, 60.8%  in Madagascar, and 71.6%  in Senegal (p < 0.001)  considered not to require antibiotic therapy. Of these, 25.3%  led to an antibiotic prescription. This proportion differed greatly among the 3 countries: 57.0%  in Cambodia, 15.6%  in Madagascar, and 57.2%  in Senegal (< 0.001) .Among the consultations determined not to require antibiotics, the diagnoses accounting for the greatest absolute share of inappropriate prescribing in Cambodia were rhinopharyngitis, with 480 of 814 (59.0%) associated consultations resulting in prescriptions and non-bloody gastroenteritis with 253 of 411 consultations (61.6%) . In MadaThe most frequently prescribed inappropriate antibiotic was amoxicillin in Cambodia and Madagascar, accounting for 42.1%  and 29.2%  of inappropriate prescriptions, respectively. In Senegal, cefixime was the antibiotic most frequently prescribed inappropriately, representing 31.2% of inappropriate prescriptions (74/237) .p < 0.001), 3.34 , and 4.51  in Madagascar, Senegal, and Cambodia, respectively. For children followed up beyond 1 year of age, aORs were 3.65  and 5.25  in Madagascar and Cambodia, respectively.We found that older age at consultation was associated with higher risk of receiving inappropriate antibiotic prescription in all 3 countries. Children aged >3 months had higher risk of inappropriate prescription compared to children aged <3 months, with adjusted odds ratios (aORs) for children aged 3 months to 1 year estimated at 1.91 . Children living in rural areas had a higher risk of inappropriate prescription compared to those living in urban areas, with aORs of 1.83  in Madagascar, 4.40  in Senegal, and 4.07  in Cambodia.Consultations during the rainy season were associated with higher risk of inappropriate antibiotic prescription . Finally, children with higher clinical severity score had a higher risk of inappropriate antibiotic prescription compared to children with a lower score, with aORs ranging from 2.00  to 3.10  for children with severity scores of = 1 or = 2, respectively, relative to severity score = 0.Having already received an antibiotic prescription in the 15 days prior to the consultation also increased the risk of inappropriate prescription  were also identified as statistically significant in the primary analysis considering a single model .In this multicentric community cohort study conducted among children under 2 years old in Madagascar, Cambodia, and Senegal, we observed that approximately 1 quarter of outpatient consultations not requiring antibiotic therapy nonetheless resulted in an antibiotic prescription. Overall, approximately 3 quarters of consultations resulting in antibiotic prescription did not require them, and approximately two thirds of all antibiotics prescribed to these young children were not necessary. These inappropriate antibiotics may contribute to the emergence of antibiotic resistance despite providing little to no benefit—or even harm—to the patients concerned.Our results suggest that inappropriate antibiotic prescribing is frequent but highly heterogeneous across countries. In particular, approximately 57% of consultations not requiring antibiotics resulted in antibiotic prescriptions in Cambodia and Senegal, but only 16% in Madagascar. Although relatively few previous studies have estimated the share of inappropriate antibiotic prescribing in LMICs, substantial heterogeneity across countries is nonetheless consistent with the literature. In a secondary data analysis study, Sulis and colleagues estimated the proportion of patient–provider interactions resulting in inappropriate antibiotic prescriptions in 3 LMICs . They found that approximately 50% of interactions in India and Kenya resulted in inappropriate prescriptions, compared to approximately 29% in China . HoweverFor children with gastroenteritis not requiring antibiotics, we found that the share of consultations resulting in antibiotic prescription was 24.6%, 51.2%, and 61.6% in Madagascar, Senegal, and Cambodia, respectively. In Senegal, our estimates can be compared to those of a study conducted in children under 5 with gastroenteritis in a primary healthcare in Dakar . In this study, in which all episodes were microbiologically documented, the authors found that 36% of children received antibiotics when no pathogens were detected in the stool . In a stFor respiratory illness (upper and lower combined) not requiring antibiotics, Rogawski and colleagues further estimated that between 20.2% and 62.2% of consultations, depending on the country, resulted in inappropriate prescription . By compIn Senegal, one striking finding is that consultations reported as “healthy” represented one of the most common diagnoses. Reviewing these diagnoses in detail, we found that all consultations reported as “healthy” took place at birth and occurred mainly in the rural site (87%). In addition, there was only 1 “healthy” consultation per child. This seems to be a pattern that is specific to Senegal, reflecting local consultation behavior or prescribing practices, and this result should therefore be interpreted in that specific context. Further studies should be conducted to better understand motivations of both mothers to consult for their newborn at delivery and physicians to prescribe antibiotics despite no clear indication.Our study also provides information on all-cause antibiotic exposure (regardless of diagnosis or symptoms), which has been more frequently described in the literature. A recent meta-analysis evaluated all-cause antibiotic prescribing across all age groups in primary care in LMICs, estimating that 44% to 60% of consultations resulted in antibiotic prescriptions across 48 studies . HoweverBy contrast, choice of antibiotic was more similar between Cambodia and Madagascar than Senegal. In particular, the most prescribed antibiotic was amoxicillin in Madagascar and Cambodia , but cefixime (34.4%) in Senegal. Padget and colleagues conducted face-to-face interviews with caregivers of 1,401 children living in the same urban and rural sites in Madagascar and the same urban site in Senegal as in our study and examined antibiotic consumption in the community [A study on the sale of antibiotics across low-, middle-, and high-income countries suggests that extensive intercountry variation in both the quantity and classes of antibiotics sold cannot be explained solely by differences in disease burden . Rather,Another recent spatial modeling study provided estimates of global antibiotic consumption based on data from Demographic Health Surveys and UNICEF’s Multiple Indicator Cluster Surveys . The autIn this study, we also identified leading determinants of inappropriate antibiotic prescribing. We found that children older than 3 months had a higher risk of receiving an inappropriate prescription than younger infants. This may be explained by a higher risk of severe bacterial infection during the postnatal period and the fact that several diagnoses that are more common in these youngest children require antibiotics –30. ThisClinical severity score was also associated with a higher risk of inappropriate prescription. During consultations in which patients express more frequent or severe symptoms, parents or guardians may be more likely to demand antibiotics. During such consultations, practitioners may also choose to prescribe antibiotics due to concern about the risk of bacterial superinfection. These factors may be particularly relevant for certain diagnoses with extensive symptom expression and known risk of superinfection, such as bronchiolitis, which received a large share of inappropriate prescriptions in this study.We found that consultations occurring in the rainy season were more likely to result in inappropriate prescriptions than those in the dry season. During rainy periods, respiratory and fecal-oral infections generally circulate more widely, which may have an impact on practitioners’ prescribing practices. If the overall number of consultations for infectious pathologies increases, the practitioner’s choice to prescribe an antibiotic during subsequent consultations may be influenced. Although increases in the total volume of antibiotic prescribing are well observed in winter months in HICs and have been documented in the rainy season in LMICs, seasonality in inappropriate antibiotic prescribing is less well documented, particularly in LMICs –34.We found that children living in rural areas were at increased risk of receiving inappropriate antibiotic prescriptions. This may be explained by a limited presence of qualified health professionals in rural areas, especially physicians. Indeed, several studies have shown that rural areas suffer from a form of medical staff desertification, where public sector physicians initially work in rural areas after graduating from medical school but later move to urban areas ,36. ThusStreptococcus and may help to prevent inappropriate antibiotic prescribing by suggesting when viral origin may be more likely [Our results suggest a need for interventions to prevent the inappropriate prescribing of antibiotics to children in LMICs. One possible intervention is to train prescribers with validated pediatric clinical management guidelines. For example, training practitioners with IMCI guidelines has been shown previously to decrease inappropriate antibiotic prescribing in Tanzania and Uganda . Also, le likely . For broe likely . C-reacte likely ,41.To our knowledge, our study is the first in LMICs to estimate the proportion of outpatient consultations resulting in inappropriate antibiotic prescriptions in young children. It is also the first to estimate the total share of antibiotic prescriptions that are inappropriate in these settings. Our prospective, longitudinal study design with rigorous documentation of patient symptoms and diagnoses facilitated the evaluation of antibiotic necessity for each consultation. This makes our findings a good reflection of local practices regarding both inappropriate and overall antibiotic prescribing, particularly as over-the-counter antibiotics have been shown to represent only a small portion of antibiotic consumption in children .Our study also has several limitations. Bacteriological investigations were performed only in prespecified cases, therefore, not all infectious diagnoses were microbiologically confirmed, and in particular, those presumed to be of viral origin . This maDepending on the availability of particular healthcare providers at the time of the health event, as well as potential parental preferences, children could consult healthcare providers from either the public or private sectors. This could potentially bias findings as private sector providers may receive economic incentives to prescribe certain types of antibiotics . FinallyIn conclusion, in a community-based cohort of young children spanning 3 LMICs, we observed that the majority of all outpatient antibiotic prescriptions were inappropriate. While the proportion of consultations resulting in inappropriate prescriptions was variable across countries, several common risk factors for inappropriate prescribing were nonetheless identified. These findings support the expansion of interventions to guide antibiotic prescribing that have already proven effective in certain LMIC settings, including training with validated clinical practice guidelines  and the use of rapid diagnostic tests. The decision-making process underlying antibiotic prescription is complex, particularly in the absence of robust microbiological information and given challenging socioeconomic contexts, requiring the implementation of locally adapted multimodal strategies –47. FutuS1 Checklist(DOCX)Click here for additional data file.S1 Table(DOCX)Click here for additional data file.S2 Table(DOCX)Click here for additional data file.S3 Table(DOCX)Click here for additional data file.S4 Table(DOCX)Click here for additional data file.S5 Table(DOCX)Click here for additional data file.S6 TableN = 4,648 antibiotic prescriptions across all countries.(DOCX)Click here for additional data file.


This cross-sectional descriptive study aims to explore the knowledge, attitudes, and practices among pharmacy, dentistry, medicine, and nursing interns in Saudi Arabia regarding antibiotic use and antibiotic resistance. Interns received a soft copy of a structured and validated self-administered questionnaire using an online survey platform. A total of 266 interns responded to the questionnaire. On average, the participants achieved good scores in the knowledge and practice domains, followed by the attitude domain. The average knowledge percentage was 76.1% (SD 17.1) compared to 84.6% (SD 20.5) for practices and 61.5% (SD 23.2) for attitudes. The results suggest that pharmacy interns had insignificantly better overall scores compared to non-pharmacy interns for knowledge, attitudes, and practices. This study shows that the scores for knowledge, attitudes, and practices of pharmacy, dentistry, medicine, and nursing interns regarding antibiotic use and resistance were high overall. However, interns’ belief in their responsibility in preventing antibiotic resistance is lacking. Antimicrobials are medications used to treat or prevent infectious diseases caused by microorganisms, including bacteria, viruses, fungi, and parasites . InapproAt least 2.8 million individuals in the United States become infected with antimicrobial-resistant fungi or bacteria each year, with more than 35,000 people dying as a result ,4. AccorThe scientific understanding of the issues linked to antibiotic use must be improved . The majEvery healthcare member has particular responsibilities toward antibiotic stewardship . DentistFuture health workers should be educated about antimicrobial use and resistance during their undergraduate studies, and it is important to assess their knowledge and attitudes during their internship year . They shMany global studies have found areas of mistrust and knowledge gaps in prescribing antibiotics, and students recognize the need for additional learning and training in antimicrobial stewardship and prescribing . AwareneEducating future practitioners on antibiotic use and antimicrobial stewardship is a global strategic goal. Promoting responsible antibiotic use is vital to limit the risk of antibiotic resistance ,23. HoweA cross-sectional descriptive study was conducted between January and April 2022 in Saudi Arabia. A self-administered questionnaire was used to assess the knowledge, attitudes, and practices of antibiotic use and antimicrobial resistance among pharmacy and non-pharmacy interns. The data were collected using the online survey tool Google Forms.http://www.raosoft.com/samplesize.html) (accessed on 1 January 2022) based on a margin of error of 5%, a confidence level of 90%, a population size consisting of the number of pharmacy and non-pharmacy interns in the kingdom, and a response distribution of 50%. The calculated sample size was 266. The total sample was proportionally allocated based on the number of healthcare graduate students in Saudi universities according to the Ministry of Health statistic report of approximately 15,000 [The sample size was estimated using the Raosoft Sample Size Calculator  who graduated from governmental or private Saudi universities.The exclusion criteria included interns who had completed their internship year.Pharmacy and non-pharmacy interns received a soft copy of the survey questionnaire using the online survey platform Google Forms. After reviewing the literature ,26,27 reThe questionnaire consisted of two sections. The first explored participants’ demographics, including gender, profession, college, and region. The second evaluated the interns’ knowledge, attitudes, and practices concerning antibiotic prescriptions and antimicrobial resistance. The second part had 3 domains; the knowledge domain was assessed using 15 items, the attitude domain was assessed using 8 items, and the third domain assessed practices on 5 items. All questions were close-ended, and participants’ responses were obtained for the knowledge and attitude domains on a 3-point response scale . The response to the practice domain was assessed through yes or no responses. The correct response to each question carried one mark. The overall score was graded as poor (≤50%), adequate (from 51 to <75%), or good ≥75% depending on the percentage of correct responses.The local Research Ethics Committee at the University of Tabuk officially approved this study . Informed consent was obtained from all participants.p values of the percentages of the correct responses for each item of the questionnaire between pharmacy and non-pharmacy interns. A p value of less than 0.05 was considered statistically significant. The sum scores of the correct responses per participant on each of the knowledge, attitude, and practice domains of antibiotic use were calculated. Then, the mean proportions and standard deviations of the three scores were calculated and tested for pharmacy and non-pharmacy interns using the Wilcoxon–Mann–Whitney test. The Spearman’s rank correlation was used to measure the direction of association between interns’ knowledge and their practices of antibiotic use.The internal consistency and reliability of the questionnaire were examined by calculating Cronbach’s alpha coefficient. The antibiotics questionnaire had a good internal consistency (Cronbach’s α = 0.81). The standard descriptive analysis was summarized to describe the demographic characteristics of the participants. A bivariate analysis using chi-square or Fisher exact test, when appropriate, was used to generate All analyses were carried out using STATA SE V.11 .A total of 266 respondents agreed to participate in this study, of whom 140 (52.6%) were male, and 244 (91.7%) attended governmental universities. The majority of participants were pharmacy interns , while 142 participants (53.4%) were interns at non-pharmacy schools, including schools in the medicine , dentistry , and nursing  domains. Many interns were from the middle region  and the south region . The characteristics of the study participants are illustrated in The average percentages of correct scores for pharmacy interns compared with non-pharmacy interns on the knowledge, attitude, and practice domains of the antibiotic use questionnaire are illustrated in . The disOn average, interns demonstrated good scores (≥75% correct response) on the knowledge and practice domains of the questionnaire and adequate scores (51–75% correct response) on attitude toward antibiotic use. The analysis showed that pharmacy interns demonstrated higher but insignificant differences in the percentage of correct scores on the knowledge, attitude, and practice domains of antibiotic use of the questionnaire. The percentage of correct responses for each item of the questionnaire is illustrated in p = 0.02) and the spread of nosocomial infection (p = 0.03). Pharmacy interns were more likely to be aware of the contribution of overconsumption of antibiotics to antibiotic resistance (p = 0.05). Two-thirds of interns  reported poor knowledge and confusion about whether antibiotic resistance can spread from animals to humans in question 15 without significant differences between professions.The pattern of average scores on each item of the knowledge domain showed that pharmacy interns achieved a higher percentage of correct responses than non-pharmacy medical interns. The scores of pharmacy interns were significantly higher for some questions inquiring about the association between the development of antibiotic resistance and appropriate antibiotic selection . Self-reported practices were appropriate, and there was no significant difference between pharmacy and non-pharmacy interns .p = 0.001).The weakly positive and significant correlation between the percentage of correct scores on the practices of participants regarding antibiotic use and their score on knowledge of the use of antibiotics is illustrated in Globally, educating future healthcare professionals about antimicrobial use and resistance is a strategic objective . With thThis cross-sectional study assessed the awareness, attitudes, and practices of pharmacy and non-pharmacy interns, including medicine, dentistry, and nursing interns, regarding antibiotic use and antibiotic resistance in Saudi Arabia. To the best of our knowledge, this is the first study in Saudi Arabia to assess interns’ knowledge of antibiotic use and antibiotic resistance. We chose interns as the participants in our study as they are future healthcare practitioners who will prescribe, dispense, monitor, and administer antibiotics. Assessing their awareness levels will help improve practices and minimize antibiotic misuse and resistance.Our results reveal overall good levels of knowledge (76.1%) and practice (84.6%) and adequately positive attitudes (61.5%) among interns in Saudi Arabia, which reflect a satisfactory level of material in undergraduate curricula about antibiotic use and mechanism and causes of antimicrobial resistance.In the current study, pharmacy interns had higher but insignificant scores in the knowledge domain than non-pharmacy interns. The scores of pharmacy interns were significantly higher for some questions inquiring about appropriate antibiotic selection, the spread of nosocomial infection, and the development of antibiotic resistance. A cross-sectional study was conducted to assess the infectious disease contents in pharmacy curricula at Saudi universities, including material on antibiotic use and antimicrobial stewardship . They foIn this study, although all interns scored and expressed a good level of knowledge about antibiotic use, poor to adequate responses were reported for three questions regarding sending clinical samples before starting antibiotics, the efficacy of new antibiotics, and the spread of nosocomial infection. Unfortunately, our study showed that two-thirds of interns had poor knowledge and confusion about whether antibiotic resistance can spread from animals to humans. Similar results were reported by a previous study conducted in India, including medical interns . This poIn the current study, despite the good knowledge of the participating interns, they had adequate scores for attitudes toward antibiotic use (61.5%). Moreover, some responses showed negative attitudes; half of the respondents believed that antibiotic resistance can be reduced by using broader-spectrum antibiotics and that they do not have a pivotal role in controlling the resistance, and 85% of the participants agreed that medical experts will solve the problem of antibiotic resistance before it becomes too serious. Adequate responses (51–75%) were scored for items related to the use of antibiotics and irrational practice. Similar attitudes were reported from studies conducted in India on medical students and interns  and mediRegarding self-reported practices in this study, all interns expressed good levels with an average score of more than 80%, and there was no significant difference between pharmacy and non-pharmacy interns. However, our study showed that there was a positive correlation between the knowledge of interns and their practices of antibiotic use. This reflects the pharmacy and medical interns’ readiness to implement their awareness and beliefs in practice. On the other hand, a cross-sectional study conducted in Spain to identify factors that affect antibiotic prescribing practices among medical interns demonstrated the judgment of the attending physician was the main factor affecting medical interns’ antibiotic prescribing practices in this study .Our study addressed the awareness and attitudes of pharmacy and non-pharmacy interns who shared many demographic characteristics, such as age, Saudi nationality, and socioeconomic status. The majority (92%) were enrolled in governmental universities and had limited experience in dealing with antibiotics, with the exception of their advanced training year. The demographic variable that was hypothesized to influence their awareness and attitudes toward antibiotic use was the undergraduate educational program (profession). Therefore, the study focused on this variable in the analysis. Moreover, the findings of the univariate analysis revealed no significant differences in the average scores of each domain, so a multivariate analysis was not necessary.This study has the strength of being the first study to assess interns’ knowledge, attitudes, and practices regarding antibiotic use and resistance in Saudi Arabia. These interns are in their initial steps of professional practice. However, the current study has some limitations that should be acknowledged, mainly related to the study design. A cross-sectional survey design limited our ability to identify factors affecting the awareness and beliefs of interns. The small sample size of participants from different universities is another limitation. Third, the self-report scale used for data collection may lead to recall bias. The participants might overestimate some socially desirable attitudes or practices regarding antibiotic use.The current study demonstrates that the knowledge, attitudes, and practices regarding antibiotic use and resistance among pharmacy and non-pharmacy interns in Saudi Arabia are adequate overall. In addition, knowledge was positively correlated with interns’ experience in practices related to antibiotic use. However, interns’ attitude toward their role and responsibility regarding the spread of antibiotic resistance is lacking. Further studies are needed to identify areas and effective means of development for pharmacy and non-pharmacy interns in Saudi Arabia.


At this large academic children’s hospital, providers were required to select a stop date at the time of antibiotic order entry beginning in May 2022. There currently is limited to no published data surrounding the implementation of this practice and its effect on antimicrobial stewardship. This study aims to determine if requiring stop dates on antibiotic orders impacted antibiotic utilization.This was a retrospective, pre- post-interventional study of antibiotic usage at a large academic children’s hospital. The pre-invention period was June – November 2020 and 2021. The post-intervention period was June – November 2022. Normalized days of therapy were based on the National Healthcare Safety Network (NHSN) definition. The following indications were selected: empiric for suspected infection, respiratory tract infection (RTI), intraabdominal/gastrointestinal infection, and skin and soft tissue infection. The secondary objective was to subdivide days of therapy, by drug according to the NHSN classifications. Statistical analysis with the Mann-Whitney U test was completed.The pre-invention group consisted of 3004 patients and the post-intervention group consisted of 1803 patients. There were no major differences between groups, Table 1. The implementation of stop dates decreased total days of therapy per 1000 days present (DOT) from 251 to 235 (p< 0.001) for the entire sample population as well as DOT for empiric indications , Table 2. For RTI, there was an increase from 42 DOT to 49 DOT (p=0.011). Further analysis revealed an increase in patients with RTI indications and a decrease in duration of therapy from 6 days to 4 days. There was an overall decrease in use of hospital-onset antibiotics  as well as vancomycin , Table 3.After implementation of stop dates, DOT was significantly lower overall and for empiric indication. Decreased usage in hospital onset antibiotics and vancomycin was also seen. The increase in DOT for RTI can be attributed to the increased prevalence in the post-intervention group. Requiring stop dates at the time of antibiotic order entry was associated with lower antibiotic utilization and is a useful tool for stewardship programs.Sophie E. Katz, MD MPH, Dolly Parton Pediatric Infectious Diseases Research Funds: Grant/Research Support|Optum: Advisor/Consultant|Pfizer: Grant/Research Support Ritu Banerjee, MD, Ph.D, bioMerieux: Grant/Research Support|bioMerieux: company is providing partial support for an ongoing trial unrelated to submitted abstract


Oxytenanthera abyssinica has a unique solid or semi-solid culm, which may endow it with superior mechanical performance. In this study, the variation in fiber morphology and micro-mechanical properties across the radial regions of bamboo culm was examined by optical microscopy, scanning electron microscopy, X-ray diffraction, and nanoindentation. Results showed that the mean values of vascular bundle frequency and fiber tissue proportion were 1.76 pcs/mmUnlike the culm hollow structure of most bamboo species,  Oxytenanthera abyssinica, an indigenous bamboo species in Ethiopia and having an exclusive characteristic of tropical Africa, belongs to the subfamily Bambusoideae and the family Poaceae. It accounts for 85% of the approximately one million hectares area of pure natural bamboo forest in Ethiopia [O. abyssinica can grow to a height of 13 m and a diameter of 10 cm, which is to be largely used for construction, fencing, furniture, and fuel [O. abyssinica has a solid or semi-solid culm, which is regarded as a highly distinctive trait and might possess superior mechanical performance. The distinctive macroscopic properties of bamboo are largely linked to the graded distribution of fibers in its ground tissues, where fibers act as the reinforcing phase and play a crucial role in the load-bearing capacity of a material [Within the plant kingdom, bamboo exhibits a distinctive architecture that bears resemblance to a unidirectional, fiber-reinforced composite . Bamboo  and day . These u and day . OxytenaEthiopia ,7. O. abmaterial .w/w%) of bamboo- and kenaf fibers has been shown to enhance both the dimensional stability and dynamic mechanical properties of hybrid composites, making them suitable for high-demand applications in the building materials industry [O. abyssinica, which possesses exceptional characteristics, has received much less attention to the morphology and micromechanics of its fibers. In this study, various methods were used to examine the microstructure of bamboo culms, including the tissue proportion, dimensions, crystallinity, and mean microfibril angle of fibers, and the frequency of vascular bundles, which are the main structural units of bamboo. The micromechanical properties of fibers, which are the main load-bearing components of vascular bundles, were also measured by using a Triboidenter device. By delving deeper into fiber morphology and composition, a deeper understanding of the underlying mechanisms behind the exceptional mechanical properties of bamboo can be achieved. This knowledge laid the foundation for the development of advanced biomimetic materials with extraordinary mechanical performance.The use of natural plant fibers has undeniably played a significant role in driving economic prosperity and sustainability in modern society. Among them, bamboo fibers hold a prominent position and have been used in a wide range of industrial applications such as textiles, paper, and construction, etc. ,11. Bambindustry ; Moreoveindustry ,16. The industry . Crystalindustry . As emphindustry ,20. By cindustry . The appindustry ,23. The Oxytenanthera abyssinica were collected in Ethiopia with 11.5% water content, which was randomly selected. The internode  at 1-m was then chosen as the sample. The radial sections were divided into three parts for further analysis, namely the inner, middle, and outer regions  were cut from three different regions, respectively, and then immersed in water and microwaved for 15 min . The cross-section of samples was polished by a sliding microtome . Prior to imaging, the samples were coated with gold using a sputter coater  for 90 s. The polished samples were then imaged by SEM  at an acceleration voltage of 3 kV.Clear visible cross-sections of vascular bundles and parenchymal cells were obtained using a Buehler IsoMet4000 precision cutting saw . The cross-sectional areas of the bamboo were scanned using an Epson perfection V850 pro-high-resolution scanner  at a resolution of 9600 pixels per inch (PPI) in 16-bit grayscale mode. The frequency of vascular bundles was obtained by analyzing the cross-sectional images with ImageJ software  . The vasMatchstick-sized samples were immersed in the mixture consisting of 30% hydrogen peroxide and glacial acetic acid at a 50:50 weight ratio. Analytical grade glacial acetic acid and 30% HThe bamboo chips were pulverized to pass through a 60-mesh sieve. The bamboo powders were suspended in distilled water and vigorously stirred. After standing for 5 min, the difference in density caused the fibers to precipitate while parenchyma cells (PCs) floated, so fibers and PCs were separated from each other. The fibers were collected from the bottom of the beaker and were dried for XRD measurement . X-ray diffraction patterns of the fiber samples were measured with continuous scanning over a 2 formula : (1)CrI=Fiber bundles were stripped from the bamboo strips by hand and then were arranged closely together to form opaque sheets with a dimension of 1 mm in thickness, 10 mm in width, and 15 mm in length. The tangential section of the fibers was scanned by a point-focused X-ray  beam with Cu Kr minute . The mear minute , which iThe samples were cut into a conical shape with the fiber of interest located at the tip of the cone. The tip of the cone was polished using a diamond blade. A Triboindenter  was used as the test apparatus. A Triboindenter as the test apparatus has more cost-efficiency and less time-consuming data analysis compared to alternative single molecule techniques . The fibanalysis . The indH) is calculated using the peak load (P) and the projected area at peak load (E) and Poisson ratio (v) of the sample is also required for calculations, with the values previously determined to be 0.22 and reported by Yu et al. [The indentation hardness  is close to that of Phyllostachys edulis (2.00 mm) and Bambusa emeiensis (2.20 mm) [Dendrocalamus giganteus Munro (2.72 mm) [O. abyssinica belong to the category of long-fiber raw materials, which can be considered a high-quality pulp material for producing superior paper products. Similarly, composite materials made of long bamboo fibers have high tensile and bending strength, suitable for construction, transportation, and other fields [In bamboo, the dimension of fibers influenced Young’s modulus, tensile strength, flexural properties, and crush resistance of bamboo. These properties were important for evaluating the performance of bamboo as a structural material . Moreoveectively , where t2.20 mm) , but sho2.72 mm) . Based or fields .O. abyssinica fibers have a relatively uniform diameter along the radial direction, and considering the difference in length, the fibers in the inner region appear to be shorter and thicker than those in other regions. The fiber diameter in this study was close to that of Gigantochloa levis, or Gigantochloa scortechinii [The diameters of the fibers were  largest . After otechinii .Phyllostachys edulis ranges between 1.23 and 2.71 mm, which satisfies the demands of most paper types [O. abyssinica are between 1.71 and 2.30 mm in length and have a smaller size distribution range, which makes them more suitable as a raw material for paper production [The length-diameter ratios of the fibers from the inner to outer regions were  regions . After oer types . In contoduction .O. abyssinica demonstrated a higher degree of crystallinity compared to Phyllostachys edulis and Dendrocalamus farinosus. As cellulose crystallinity is known to reflect the physical properties of bamboo fibers to a certain extent [O. abyssinica may possess superior mechanical properties.The mechanical properties of fibers are influenced by factors such as their crystallinity and MFA . The CrIectively . While tn extent , suggestO. abyssinica demonstrate mean MFA of The inner, middle, and outer regions in sections . The oneNanoindentation is currently one of the most-used methods to characterize the mechanical properties of various materials at submicro- and nanoscale levels. The trend of mechanical properties of the fiber cell wall from the inner to the outer is clearly illustrated in O. abyssinica was 21.34 GPa and 545.88 MPa, respectively. The cell walls of O. abyssinica exhibit superior mechanical properties that are comparable to the widely used fibers of Phyllostachys edulis (21.7 GPa and 610.00 MPa) but demonstrate superior strength when compared to Dendrocalamus farinosus (18.56 GPa and 410.72 MPa) [O. abyssinica may have a higher resistance to deformation and fracture than Dendrocalamus farinosus. However, the distinctive non-hollow structure of O. abyssinica implies that its fibers may be a more robust and reliable choice for use in various applications in which high tensile strength and structural integrity are demanded. The cellulose crystallinity exhibits a positive correlation with the indentation modulus and hardness, indicating that highly crystalline fiber has higher mechanical strength and better resistance to deformation. In contrast, a negative correlation exists between the MFA of fiber and the indentation modulus and hardness, suggesting that a lower MFA led to higher mechanical strength and better resistance to deformation. Therefore, these mechanical properties of fibers are closely associated with fiber structural characteristics, which can potentially guide the optimization of the processing and synthesis of fiber materials with desired mechanical properties.The mean IMOE and hardness of fibers in .72 MPa) ,54. ThisO. abyssinica not only have a high tissue proportion but also have quite superior micromechanical properties, which make the macroscopic mechanical properties of O. abyssinica possibly better than some common bamboo.The micromechanical properties obtained by nanoindentation are usually much higher than the macroscopic mechanical properties, because the macroscopic mechanical properties are the result of the coupling of vascular bundles with higher mechanical properties and parenchyma tissues with lower mechanical properties, while the target of nanoindentation is the fiber cell wall with better mechanical properties . This inO. abyssinica, the vascular bundle frequency and the fiber tissue proportion increased radially from inner to outer. The vascular bundle frequency and the fiber tissue proportion of the inner were much lower than those of the middle and outer. The inner fibers were found to be the shortest, while there was no significant difference in length between the middle and outer fibers. The diameter of fibers did not vary significantly across radial regions, but the length-diameter ratio increased from the inner to outer sections.In O. abyssinica. The indentation modulus of elasticity exhibited a significant increase from the inner to middle region, However, little change was observed from the middle to outer region. Although there were minor fluctuations in hardness along the radial direction, they did not result in any significant differences. The cell wall strength of the bamboo fiber remained stable from the inner to outer regions. The results indicate that there is a positive correlation between the cellulose crystallinity and the indentation modulus of elasticity and hardness, while there is a negative correlation between the MFA and the IMOE and hardness.There is no significant difference in cellulose crystallinity and the MFA among the inner, middle, and outer fibers from O. abyssinica reveals some fascinating features, but there are still many unanswered questions about this material. One of the key areas that require further investigation is the mechanical properties of O. abyssinica. How do Young’s modulus, tensile strength, flexural properties, and crush resistance of O. abyssinica fibers compared with other bamboo or plant fibers? How do these properties affect the potential applications of O. abyssinica as a biomaterial? Another important aspect that needs to be studied is the wettability properties and compatibility of O. abyssinica surfaces with different adhesives. Interfacial adhesion mechanisms are among the most influential yet seldom discussed factors that affect the physical, mechanical, and thermal properties of plant-fiber-reinforced polymer composites. In particular, the chemical nature of the fibers and the matrix can greatly affect the interfacial adhesion between them. Bamboo fibers are highly lignified, similar to kenaf and jute fibers. Lignin is a hydrophobic polymer, which means that it does not interact well with polar matrices such as polybutylene succinate (PBS). On the other hand, lignified plant fibers can display strong interfacial forces with non-polar matrices such as polypropylene (PP) [The microstructure of ene (PP) . These f


This study aims to evaluate the feasibility of 68Ga radiolabeling. Immunohistochemical staining was used to evaluate the expression and location of Col-IV and elastin in aortas treated with 3-aminopropionitrile fumarate (BAPN) at different time points . The imaging performance of 68Ga-DOTA-WVP was investigated using Micro-PET/CT in a BAPN-induced TAAD mouse model. The relationship between 68Ga-DOTA-WVP uptake in aortic lesions and the serum levels of TAAD-related biomarkers including D-dimer, C-reactive protein (CRP), and serum soluble suppression of tumorigenicity−2 (sST2) was also analyzed.WVP peptide was modified with bifunctional chelator DOTA for 68Ga-DOTA-WVP was readily prepared with high radiochemical purity and stability in vitro. 68Ga-DOTA-WVP Micro-PET/CT could detect Col-IV exposure of unstable aneurysms and early dissection in BAPN-induced TAAD mice, but little 68Ga-DOTA-WVP uptake was shown in the control group at each imaging time point. The differences of Col-IV expression and distribution of 68Ga-DOTA-WVP both in TAAD and control groups further verified the imaging efficiency of 68Ga-DOTA-WVP PET/CT. Additionally, a higher sST2 level was found in the imaging positive (n = 14) than the negative (n = 8) group .68Ga-DOTA-WVP could trace the exposure and abnormal deposition of Col-IV in enlarged and early injured aortas, showing a potential for biological diagnosis, whole-body screening, and progression monitoring of TAAD. Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening vascular disease, especially when unstable aneurysms with inflammatory conditions progress to aortic dissection, which starts from a tear in the intimal layer of the aorta and bleeding within the media , 2. DissMolecular imaging, such as hybrid positron emission tomography (PET)/computed tomography (CT), as an adjunctive tool to conventional structural imaging technology, can be used to non-invasively assess anatomic, hemodynamic, and molecular biological features of the aorta, providing a more accurate selection of patients who can benefit from preventative surgical intervention and different options of surgery . The comIt has been demonstrated that progressive endothelial injury occurs before intimal tearing, including endothelial cell (EC) loss, increased permeability, and subsequent exposure of the subendothelial basement membrane , 13. Typ68Ga (68Ga-DOTA-WVP) as a novel PET probe for TAAD imaging. This study aims to evaluate the feasibility of 68Ga-DOTA-WVP as a Col-IV-targeted probe for PET/CT of unstable thoracic aneurysms and early TAAD biological diagnosis. To the best of our knowledge, this is the first example regarding the development of a WVP-based PET probe for TAAD imaging.Herein, the Col-IV-targeted WVP peptide was radiolabeled with WVP peptide was manufactured using the solid-phase peptide synthesis method by ChinaPeptides Co., Ltd. . During the synthesis process, the C-terminus of WVP was modified with DOTA to obtain DOTA-WVP. Sodium acetate (NaOAc), hydrogen chloride (HCl), 3-aminopropionitrile fumarate salt (BAPN), Sirius red, and picric acid were supplied by Sigma-Aldrich . Rabbit anti-mouse Col-IV and elastin were purchased from Abcam, Inc. . Other chemicals and solvents were supplied by Sinopharm Chemical Reagent Co., Ltd. .68Ga was eluted from a 68Ge/68Ga generator  with 4 ml of 0.5 M HCl solution and collected in a 10 ml sterile vial. One milliliter of eluted 68GaCl3 was mixed with 65 μl of DOTA-WVP (1 mg/mL) dissolved in 1 M NaOAc. Then the reaction mixture was incubated at 95°C for 15 min. After being cooled to room temperature, the formed 68Ga-DOTA-WVP was analyzed using the Agilent 1260 high-performance liquid chromatography (HPLC) system  equipped with a UV-Vis detector (λ = 220 nm) and radioactive flow detector . The SunFire C18 column  was used at a flow rate of 1 ml/min using the following gradient method: 0.1% trifluoroacetic acid in water and acetonitrile (CH3CN) . The final product was diluted with 0.9% saline and filtered through a 0.22 μm Millipore filter. To assess in vitro stability, 500 μl of 68Ga-DOTA-WVP (4 mCi) was mixed with 500 μl of phosphate-buffered saline  at room temperature. The radiochemical purities (RCPs) were tested using HPLC at different time intervals .68Ga-DOTA-WVP for early detection of unstable aortic aneurysm and diagnose early dissection (n = 62) and control (n = 10) performed PET/CT imaging and immunohistochemistry staining in different pathogenesis to compare 68Ga-DOTA-WVP uptake in aorta and expression of Col-IV on aortic lesions.All animal experiments complied with the Guidelines for the Care and Use of Research Animals established by the ethical committee of Shanghai General Hospital. C57BL/6J male mice were purchased from the Shanghai Laboratory Animal Center of the Chinese Academy of Sciences . Three-week-old male mice (weight: 8–12 g) were fed a normal diet (control) or 0.1% Wt/Vol BAPN in drinking water for 6 weeks to establish the TAAD disease model. The lower dose of BAPN used in this study to extend the survival of the mice to monitor the whole process of TAAD formation and evaluated the efficiency of ssection , 18. Ani68Ga-DOTA-WVP solution  was administered as an intravenous bolus to mice with TAAD and the control mice. PET images were acquired at 0.5, 1, and 2 h after injection using a Micro-PET/CT scanner . All PET studies were reconstructed as a series of three-dimensional (3D) PET images using a two-dimensional-ordered subsets expectation maximization algorithm , resulting in a voxel size of 0.86 × 0.86 × 0.79 mm. Whole-body CT was used for attenuation correction, and PET studies were corrected for random coincidences, dead time, scatter, and decay.The in vivo biodistribution of the novel peptide probe. The VROIs in the control group were created in the same manner.PMOD software 3.8  was used to perform image analysis. The CT and PET images were co-registered using the “Fuse it” toolkit. Abnormal findings that visually matched the characteristics of TAAD were outlined in transverse slices and automatically adapted to 3D volume. Volumetric regions of interest (VROIs) were placed on the anatomical CT images to identify the thoracic aorta and drawn around the high uptake area within the aortic wall lesions. Additional VROIs were drawn in other important organs, including the liver, muscle, heart, brain, bone, lung, and intestine, to measure the 68Ga-DOTA-WVP uptake was analyzed in the VROI with respect to the maximum standardized uptake value (SUVmax). To determine the probe uptake in the early and late phases (static) in the defined TAAD regions, data were compared and analyzed at three time points  in the TAAD group to explore the in vivo dynamic information of the novel peptide probe.The After imaging, the aortas of mice were excised, embedded in an optimal cutting temperature compound, sectioned, and stained for immunohistochemistry using rabbit anti-mouse Col-IV and elastin antibodies and the secondary antibody was goat antirabbit IgG. Elastin on sections of the aorta in the control mice and mice with TAAD was incubated for 5 min in Lugol's iodine solution, washed twice with PBS, and then incubated with sodium thiosulfate for 5 min. Next, sections were washed for 5 min with running tap water, followed by 70% ethanol, incubated with aldehyde-fuchsin for 10 min, washed with 70% ethanol until they no longer bleached, and stained with Acid Orange G for 10 s.Collagen was stained directly with Sirius red and saturated aqueous picric acid (1.3% in water). Nuclei were stained with Weigert's hematoxylin for 8 min, washed with running tap water for 10 min, stained with picric-Sirius red for 1 h, and then washed in two changes of acidified water. This achieved near-equilibrium staining that did not increase with longer staining times as shorter times were not sufficient, even when the colors appeared adequate. The slides were then dehydrated in three changes of 100% ethanol, cleared in xylene, and mounted in a resinous medium. The results were observed using a digital slide scanner (3DHISTECH. Ltd).TAAD ≥ 1.6 SUVliver) and negative (SUVTAAD < 1.6 SUVliver) imaging groups based on the data from 68Ga-DOTA-WVP PET/CT imaging. Blood samples were collected in anticoagulant tubes and centrifuged for 10 min. The supernatant was used to measure the levels of serum D-dimer, C-reactive protein (CRP), and serum soluble suppression of tumorigenicity-2 (sST2) using enzyme-linked immunosorbent assay.All collected blood samples were divided into positive . P-values < 0.05 were considered statistically significant.Data were expressed as mean ± standard deviation. The differences between the two groups were analyzed using unpaired Student's t-tests, and comparisons between more than two groups were conducted using one-way analysis of variance, followed by Bonferroni's 68Ga via the bifunctional chelator DOTA in 15 min. As shown in 68Ga-DOTA-WVP had a single radioactive peak with a retention time of 10.16 min, which was consistent with that of the corresponding DOTA-WVP (10.13 min). The RCP of 68Ga-DOTA-WVP was calculated to be more than 99% without further purification. No obvious changes in the labeling peptide were found in PBS at room temperature within 3 h, suggesting good stability of 68Ga-DOTA-WVP in vitro.The WVP peptide was effectively radiolabeled with n = 12, weight: 8–10 g) were fed 0.1% Wt/Vol BAPN in drinking water for 4 weeks and observed EC loss occurred as early as the first week of BAPN administration by Evans blue staining, and the area of EC loss increased with progressive TAAD development, as reported in a previous study (Three-week-old C57BL/6J mice (us study . Elastinus study . Col-IV us study . These rn = 12) were intravenously injected with 100 μl of the 68Ga-DOTA-WVP solution [(68Ga) = 2 mCi/ml] and PET/CT imaging was performed at 0.5, 1, and 2 h after injection. Significantly increased uptake was observed in the thoracic aortic region, followed by the heart , the mice (he heart . The tho68Ga-DOTA-WVP in detecting unstable TAAD lesions using PET/CT (TTAD group: n = 20 and control group n = 10). The aortic diameters of thoracic aneurysm become progressively enlarged with prolonged BAPN administration shown by representative photographs thoracic aorta. Whole-body static images were compared at 0.5 h after injection of 68Ga-DOTA-WVP in mice with TAAD and control mice group in different pathologic stage . Moreover, the 68Ga-DOTA-WVP uptake in the heart was also significantly increased in the TAAD group compared to that in the control group at 0.5 h after injection .We evaluated the efficacy of ic stage . The tho results . The retP < 0.001)   . In cont< 0.001) . The upt imaging . The mic imaging .68Ga-DOTA-WVP PET/CT imaging when assessing the severity of vascular damage after BANP administration. The body weight of this mouse increased slowly and was lighter than other mice in group 2 from 2 to 4 weeks post BAPN administration. When imaged at 4 weeks, the mouse had the lowest body weight among all surviving TAAD mice and was subsequently euthanized by overexposure to isoflurane and found blood clot in chest cavity after dissected. Whole-body images showed a significantly intense concentration of probe was detected in the thoracic and abdominal aorta, heart, and lung. This possibly demonstrated whole body vasculature damage from BAPN administration  and negative imaging groups (n = 8). The sST2 level was significantly higher in the positive imaging group than in the negative group ; however, the levels of CRP and D-dimer did not differ significantly between the groups  by targeting Col-IV, which was exposed to a small tear site of the intimal aorta. During TAAD development, Col-IV exposure gradually increased with BAPN administration and processive TAAD, owing to the compensatory repair of the degenerated aorta, which was consistent with the gradual increase in 68Ga-DOTA-WVP uptake and intensive signal on thoracic aortic wall lesions in vivo PET/CT imaging. Importantly, the in vivo biodistribution results showed high 68Ga-DOTA-WVP uptake in the heart, but lower uptake in the liver, brain, lung, bone, muscle, and intestine, which was beneficial to acquire good imaging quality and have robust potential applications in clinical screening of high risk TAAD patients.In the present study, the novel probe 68Ga-DOTA-WVP PET/CT imaging could provide whole-body molecular information on Col-IV exposure and expression as an ideal biological characteristic target of unstable TAAD lesions. We showed firstly that 68Ga-DOTA-WVP administration resulted in a clear and significantly high uptake in aortic lesions in whole body imaging, which was confirmed by the high SUVmax after 2 and 4 weeks following BAPN administration, whereas no obvious uptake was observed in the control group at the same time points. Patients with TAAD reportedly exhibit significantly increased expression of collagen, which may be a new target molecule in the molecular imaging of TAAD (68Ga-DOTA-WVP trace Col-IV expression in high-risk aneurysms and the early stages of dissection (The accuracy of diagnosing unstable aneurysms and early TAAD has varied in each trial, and the appropriate imaging technique to apply in each at-risk population remains unclear. Molecular imaging techniques, such as PET/CT, have shown promise in detecting vessel wall instability at an early stage , 20. Our of TAAD . This fissection .68Ga-DOTA-WVP (68Ga-DOTA-WVP observed in heart and kidney in TAAD mice was caused of systematic aortic pathologies induced from BAPN administration in this TAAD model. But in the other hand, we should also pay an attention to the relationship of TAAD and heart as well as renal disease based on common pathogenesis. Renal injury was indicated by prolonged excretion time in mice with TAAD compared to that of the normal mice in the control group. However, previous studies demonstrated that type IV collagen that accumulates in the glomerular mesangium and renal interstitium contributes to the progression of chronic renal disease via the TGF-β signal path (68Ga-DOTA-WVP may play an important role in systematic assessing function changes of heart, renal and atherosclerosis in patients with TAAD. Reportedly, immune responses against collagen type IV contributed to vascular injury, affecting the development of atherosclerosis (68Ga-DOTA-WVP PET/CT imaging targeted Col-IV detection in various other diseases accompanied by Col-IV deposition and exposure should be studied in future research.Col-IV can not only be exposed and posited on the intima beneath the TAAD, but also in the pathological tissues of renal fibrosis, atherosclerosis, and hepatic fibrosis, which is consistent with our results that the heart and kidneys also showed high uptake of DOTA-WVP . On one nal path . Therefonal path . Therefoclerosis . Steffenclerosis . The proclerosis . Col-IV 68Ga-DOTA-WVP PET/CT positive imaging group compared to the negative imaging group, which reflected the damage caused by sST2 in the heart and thoracic aortic wall. However, no relationship was observed between probe uptake and sST2 levels. CRP and D-dimer are systemic laboratory diagnostic biomarkers have been investigated and linked to the risk for aortic aneurysms or its outcomes but not sensitive and specific enough in clinical application. Reportedly, CRP is an independent risk factor in detection of vascular inflammation was associated with abdominal aortic aneurysm progression but few studies in TAAD (68Ga-DOTA-WVP was designed to target imaging exposure of Col-Ⅳ to detect aorta damage earlier and specifically in unstable TAAD in this study. Therefore, no significant association between 68Ga-DOTA-WVP accumulation and the serum levels of these non-specific biomarkers in PET/CT positive and negative imaging groups of TAAD mice (Reportedly, the sST2 level was significantly elevated in patients with severe aortic valve stenosis who presented with pulmonary hypertension and associated with earlier death and high mortality . Another in TAAD . InflammAAD mice . The neg68Ga-DOTA-WVP and Col-IV expression, which will be studied further. Secondly, this pilot study lacks sufficient sample size for serial visualization of TAD progression using PET/CT to quantitatively analyze the relationship between probe uptake in vivo and Col-IV exposure at different time points as well as lack of confocal microscope photography scanning due to the COVID-19 pandemic. In our timeframe of experimentation, most aorta samples did not develop dissection. However, we observed that many animals with significant accumulation of 68Ga-DOTA-WVP in the aorta died from TAAD rupture. In our future study, we will continue analyzing the relationship between probe uptake and formation of dissection as well as the specificity of the probe for TAAD detection. Another limitation is that, although we showed that 68Ga-DOTA-WVP could be used to detect early TAD in a mouse model, this agent needs to be investigated further in large animals and eventually confirmed in humans. Furthermore, we should also visualize the aorta using CT-enhanced scans to co-locate TAAD lesions from structural information of size and functional imaging of Col-IV exposure via hybrid PET/CT imaging, which will be conducted in our following study.The main limitation of this pilot study is the lack of reliable binding and inhibition experiments to quantify the quantitative-efficacy relationship between the uptake of 68Ga-DOTA-WVP through a simple method with a high RCP and stability and demonstrated its ability to detect the biological characteristics of unstable aneurysms and early TAAD. Biological diagnosis of dissection plays an important role in clinical management. Thus, the current study proposes a promising method for dissection screening in high-risk patient populations, monitoring disease progression and assessing therapeutic response. Therefore, clinicians may benefit from PET-based whole-body risk assessments in guiding patient management and surgical decisions.In summary, we prepared


Dear Editor,Antibiotic prophylaxis is critical in cardiac surgery to prevent surgical site infections (SSIs) and improve patient outcomes. However, the overuse of antibiotics can lead to antibiotic resistance, making it challenging to treat infections in the future. This editorial aims to provide an overview of the current state of antibiotic prophylaxis in cardiac surgery, including the types of antibiotics used and issues associated with their use.1. The most common forms of SSI in cardiac surgery patients include graft harvesting sites and sternal wound infections. To prevent SSI, several measures are employed preoperatively, intraoperatively, and postoperatively in cardiac surgery including antibiotic prophylaxis1. Cephalosporins, vancomycin, and aminoglycosides are examples of antibiotics currently used for SSI prophylaxis in cardiac surgery. However, the effectiveness of these antibiotics varies, and some bacteria are becoming resistant to them. A recent study by de Tymowski et al. investigated the impact of antibiotic prophylaxis on SSIs in cardiac surgery. The study concluded that antibiotic prophylaxis is associated with a lower incidence of SSIs and reduced postoperative complications. However, the study also highlighted the need for proper antibiotic stewardship and the risk of antibiotic resistance2.SSIs are one of the most prevalent infections in healthcare settings, intricately linked to poor prognosis. It generally affects about 10–20% of patients who undergo surgery, with incidence rates that fluctuate between 3.5 and 26.8% exclusively for those who undergo cardiac surgeriesStaphylococcus aureus. These bacteria can cause severe infections that are difficult to treat, leading to prolonged hospital stays, higher healthcare costs, and increased mortality rates. According to Zukowska and Zukowski1, the emergence of antibiotic-resistant bacteria has decreased the effectiveness of antibiotics used in cardiac surgery. Therefore, the judicious use of antibiotics is essential to prevent the development of antibiotic-resistant strains. The impact of other factors that can influence the effectiveness of prophylactic antibiotics on SSI rates, such as dosing, duration, and adherence to guidelines, have been well established in the literature. A systematic review by Amato et al.3 evaluated perioperative antibiotic prophylaxis in vascular surgery and found that adherence to guidelines and duration of prophylaxis may impact the incidence of groin SSI. Moreover, a study by Hamouda et al. compared different perioperative antibiotic prophylaxis duration strategies in adult patients undergoing cardiac surgery. The study concluded that a shorter duration of antibiotic prophylaxis was associated with similar outcomes compared to a longer duration4. Therefore, practitioners should consider administering shorter antibiotic prophylaxis in cardiac surgery while ensuring appropriate antibiotic stewardship measures are taken. Another study on perioperative antibiotic prophylaxis recommendations in various surgical specialities found that adherence to guidelines is critical in preventing postoperative SSI5.Antibiotic resistance is currently a growing concern in cardiac surgery and SSI management. The increasing use of antibiotics has led to the emergence of antibiotic-resistant bacteria, such as methicillin-resistant Given the increasing concern over antibiotic resistance, there is a need for continued research on the optimal use of antibiotics in cardiac surgery. This includes investigating alternative antibiotic regimens, such as the use of narrow-spectrum antibiotics or combination therapy, as well as the use of non-antibiotic strategies, such as probiotics, to prevent SSIs. In addition, efforts to improve antibiotic stewardship and reduce unnecessary antibiotic use in cardiac surgery should be a priority.Not applicable.Not applicable.The authors received no external funding for this project.T.A.-R.: conceptualization of ideas; T.A.-R.: data curation; M.O.O., O.E., and S.G.: writing of initial draft; T.A.-R. and W.A.A.: review and editing.The authors declare no conflicts of interest.Not applicable.Toufik Abdul-Rahman.The authors declare that no new data were generated.The paper was not invited.The authors would like to acknowledge Toufik’s World Medical Association and ICORMed Collaborative for organizing this project.