Total Antibiotic Research Articles

Comprehensive overview of antibiotic distribution, risk and priority: A study of large-scale drinking water sources from the lower Yangtze River

Antibiotics have attracted widespread attention around the world because they are ubiquitous in the environment and can lead to antibiotic-resistant microbes developing and pose ecotoxicological risks. In this study, we determined the spatiotemporal distributions of 39 antibiotics in 19 drinking water sources in Jiangsu area of the lower Yangtze River and attempted to identify the sources of the antibiotics and to prioritize the antibiotics. The total antibiotic concentrations in spring and fall were 234.56–6515.99 and 151.12–2562.59 ng/L, respectively. In spring, the total antibiotic concentration gradually increased from upstream to downstream. In fall, the antibiotic concentration did not markedly vary upstream to downstream (total concentrations 151.12–432.17 ng/L) excluding site S9 and S10. Analysis using a positive matrix factorization (PMF) model indicated that the antibiotics had four main sources. Pharmaceutical wastewater was the main source, contributing 34.1% and 41.2% of total antibiotics in spring and fall, respectively, and domestic wastewater was the second most important source, contributing 24.4% and 43% of total antibiotics in spring and fall, respectively. Pharmaceutical wastewater was the main source from midstream to downstream, but the other sources made different contributions in different areas because of the various ranges of human activities. An ecological risk assessment was performed. Stronger risks were posed by antibiotics in spring than fall, and fluoroquinolone antibiotics posed the strongest risks. Optimized risk quotients indicated that norfloxacin was a high-risk contaminant. An assessment of the risk of resistance development indicated that norfloxacin, ciprofloxacin, and enrofloxacin posed moderate to high risks of resistance development and should be prioritized for risk management. The results of this study are important reference data for identifying key sources of antibiotics and developing strategies to manage antibiotic contamination in similar areas.

The effect of a One Health message intervention on willingness to pay for antibiotic-free animal foods: A randomized controlled trial among Chinese college students

Routine use of antibiotics in livestock for prophylactic purposes is a main driver of antimicrobial resistance, posing a significant threat to the health of humans, animals, and the environment. Ways to motivate farmers to voluntarily reduce antibiotics use need to be explored. Promoting antibiotic-free animal foods is one of the promising strategies. A three-arm double-blind randomized controlled trial was conducted online to explore the impact of a One Health message intervention on Chinese college students' willingness to pay for antibiotic-free animal foods. A total of 389 individuals participated in this study and were randomly assigned to one of the One Health message group, the food nutrition and safety message group, and the no message group. Each participant read a message from the corresponding group and answered a self-report questionnaire. Participants' willingness to pay (WTP) and willingness to buy (WTB) for antibiotic-free pork, eggs, and milk were measured before and after viewing the One Health message, and the results were compared to the other two groups using the Kruskal-Wallis rank sum test and the Bonferroni correction. In the One Health message group, 30.2% (39/129) reported improved WTP for all three foods, compared to 6.2% (8/130) and 13.6% (17/125) in the food nutrition and safety message group and the no message group, respectively. The One Health message intervention had a significant effect on increasing participants' WTP (p < 0.001) and WTB (p < 0.05) for antibiotic-free pork, eggs, and milk. The One Health message intervention is effective in raising participants' WTP for antibiotic-free animal foods. It is hopeful to motivate farmers and producers to voluntarily reduce prophylactic antibiotic use through market demand and consumer choice, leading to a potential decrease in total antibiotics use in livestock. Additionally, integrated approaches based on One Health principles need to be found in the future.

Urinary antibiotics concentrations, their related affecting factors and infant growth in the first 6 months of life: A prospective cohort study

Antibiotic exposure even in low-dose could have potential adverse health effects, especially during early life. There is a lack of data on antibiotic burdens in early infancy. We aim to assess antibiotic exposure in infants from birth to 6 months of age, their related affecting factors and the association between antibiotic exposure and infancy growth. Urine samples were collected at ages of 3 days, 42 days, 3 months and 6 months from 197 term-born Chinese infants. A total of 33 representative antibiotics were measured by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Urinary antibiotics were detectable in 69.4%, 63.2%, 75.0% and 84.3% of infants at ages of 3 days, 42 days, 3 and 6 months, respectively. The dominant antibiotic categories detected were: Preferred as Veterinary Antibiotics (PVAs), Human Antibiotics (HAs), and Veterinary Antibiotics (VAs). The detectable rates were 30.6%, 45.8%, 58.9%, and 81.4% for PVAs, 34.1%, 20.8%, 28.6%, and 45.1% for HAs, and 36.5%, 12.5%, 6.3%, and 5.9% for VAs, at age 3 days, 42 days, 3 and 6 months, respectively. Urinary concentrations of HAs and preferred as human antibiotics (PHAs) in newborns at age 3 days were not associated with maternal intrapartum antibiotic prophylaxis. Similarly, no associations were observed between urinary antibiotics concentration and antibiotics use in infants at age 42 days or 6 months. The numbers and concentrations of urine detectable antibiotics were similar between infants with exclusive breastfeeding and infants fed with formula or mixed-feeding at all ages of 42 days, 3 and 6 months. At age of 42 days, infants in the low tertile of total antibiotics concentration or with one antibiotic detected had higher weight-for-length Z score and greater head circumference, compared to infants with no antibiotics detected. No associations were found between urinary antibiotics and any of the infant anthropometric measures at age 6 months. In conclusion, urinary antibiotics were detectable in most infants during the first 6 months of life, and PVAs, HAs and VAs were the most commonly detected antibiotics. This suggested the possibility of a foods-originated antibiotics exposure in children. No strong nor consistent associations were found between urinary antibiotic concentration and infant growth at the first six months of life. Still, attention is needed on the adverse health effect of early life exposure to antibiotics in future studies.

Antibiotic resistome associated with inhalable bioaerosols from wastewater to atmosphere: Mobility, bacterial hosts, source contributions and resistome risk

Antibiotic resistome can be carried by the bioaerosols and propagate from wastewater treatment plants (WWTPs) to the atmosphere, but questions remain regarding their mobility, bacterial hosts, source, and resistome risk. Here, fine particulate matter (PM2.5) was collected within and around a large WWTP and analyzed by the metagenomic assembly and binning. PM2.5 was discovered with increasing enrichment of total antibiotic resistance genes (ARGs), potentially mobile ARGs, and antibiotic-resistant bacteria (ARB) along the WWTP-downwind-upwind gradient. Some ARGs were found to be flanked by certain mobile genetic elements and generally mediated by plasmids in WWTP-PM2.5. Totally, 198 metagenome assembled genomes assigning to seven phyla were identified as the ARB, and a contig-based analysis indicated that 32 pathogens were revealed harboring at least two ARGs. Despite disparate aerosolization potentials of ARGs or ARB at different WWTP units, high resistome risks were found, along with the dominant contribution of wastewater for airborne ARGs (44.79–62.82%) and ARB (35.03–40.10%). Among the detected WWTP matrices, the sludge dewatering room was characterized by the highest resistome risk associated with PM2.5. This study underscores the dispersion of ARGs and ARB from WWTPs to the atmosphere and provides a reference for managing risks of antibiotic resistance.

Impact of coronavirus disease 2019 (COVID-19) on antimicrobial resistance among major pathogens causing healthcare-associated infection

Coronavirus disease 2019 (COVID-19) has caused great impact on healthcare systems, including antibiotic usage and multi-drug resistant (MDR) bacterial infections at hospitals. We aim to investigate the trends of antimicrobial resistance among the major pathogens causing healthcare-associated infection (HAI) at intensive care units (ICU). The demographic characteristics of hospitalization, usage of antimicrobial agents, counted by half-an-year DID (defined daily dose per 1000 patient-days), and HAI density of five major MDR bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Klebsiella pneumoniae (CRKP), and carbapenem-resistant Pseudomonas aeruginosa (CRPA), of ICU patients at a medical center in Taiwan during January 2017 to December 2021 were collected and analyzed. The total antibiotic usage, counted by DID, had a significant increasing trend, before COVID-19 occurrence in 2017-2019, but no further increase during the pandemic period in 2020-2021. However, comparing the two time periods, antibiotics consumption was significantly increased during pandemic period. There was no significant change of HAI density in MRSA, VRE, CRAB, CRKP, and CRPA, comparing the pandemic to the pre-pandemic period. Although, CRKP and CRPA infection rates were increasing during the pre-pandemic period, there was no further increase of CRKP and CRPA HAI rates during the pandemic period. During COVID-19 pandemic, there was no significant increase in HAI density of five major MDR bacteria at ICU in Taiwan, despite increased antibiotic usage. Strict infection prevention measures for COVID-19 precautions and sustained antimicrobial stewardship probably bring these effects.

Decline in Antimicrobial Consumption and Stagnation in Reducing Disease Burden due to Antimicrobial Resistance in Japan.

Antimicrobial resistance (AMR) is a major global health threat. While antimicrobial consumption (AMC) in Japan substantially decreased after implementation of the AMR National Action Plan, the disease burden due to AMR seems to be unchanged. The main objective of this study is to examine the relationship between AMC and the disease burden due to AMR in Japan. We estimated the annual population-standardized AMC from 2015 to 2021 using defined daily doses (DDDs) per 1000 inhabitants per day (DIDs) and the disease burden due to bloodstream infections caused by nine major antimicrobial-resistant bacteria (AMR-BSIs) from 2015 to 2021 using disability-adjusted life years (DALYs). We then examined the correlation between AMC and DALYs using Spearman's rank correlation coefficient and cross-correlation function. Spearman's [Formula: see text] > 0.7 was considered to indicate a strong correlation. The sales amounts of third-generation cephalosporins, fluoroquinolones, and macrolides were 3.82 DIDs, 2.71 DIDs, and 4.59 DIDs, respectively, in 2015, but 2.11, 1.48, and 2.72 in 2021. This corresponded to reductions of 44.8%, 45.4%, and 40.7% during the study period. DALYs due to AMR-BSIs were 164.7 per 100,000 population in 2015 but 195.2 per 100,000 in 2021. Spearman's rank correlation coefficients between AMC and DALYs were-0.37 (total antibiotics),-0.50 (oral antibiotics),-0.43 (third-generation cephalosporins),-0.5 (fluoroquin,olones) and-0.5 (macrolides). No obvious cross-correlations were found. Our results reveal that changes in AMC are not associated with DALYs caused by AMR-BSIs. AMR countermeasures besides efforts to reduce inappropriate AMC might be necessary to mitigate the disease burden due to AMR.

P24 Auditing antibiotic course lengths for the management of community-acquired pneumonia and hospital-acquired pneumonia against current NICE guidance

Abstract Background Protracted antibiotic course lengths for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) contribute to increased risk of antibiotic resistance.1 Optimizing antibiotic course length in line with the current national guidance improves patient safety and overall cost savings.1 NICE guidelines state that antibiotic treatment should be stopped at day 5 if patients were afebrile for &amp;lt;48 hours with one or no sign of clinical instability, defined as systolic blood pressure &amp;lt; 90 mmHg, heart rate &amp;gt; 100/minute, respiratory rate &amp;gt; 24/minute, arterial oxygen saturation &amp;lt; 90% or oxygen partial pressure &amp;gt; 60 mmHg in room air.2 Objectives To assess the current prescribing practice for antibiotic course lengths of CAP and HAP across medical specialties at RCHT. Methods A list of patients discharged from medical specialities (respiratory, cardiology, nephrology, gastroenterology, endocrinology and geriatrics) between 1 August and 1 September 2022 with the coded indication of CAP or HAP was requested from the RCHT Informatics Team. Inclusion criteria were any hospitalized patient aged ≥18 years, with a CAP/HAP diagnosis with pulmonary infiltrate on chest X-ray plus at least one symptom including cough, fever, dyspnoea and chest pain. Patients were excluded if having chronic immunosuppression; HIV positive; living in a nursing/care home, onsite subacute care unit or intensive therapy unit (ITU) or palliative care unit within last 14 days; having taken antibiotics 30 days before admission; requiring a longer duration of therapy because of an uncommon cause; requiring a chest tube or having had a condition complicated by extrapulmonary infection.1 For each patient, the patient’s vital signs at day 5 of antibiotic course and the total antibiotic course lengths were recorded. Results A total of 27 patients were assessed for eligibility; of these, 22 patients (81%) met the inclusion criteria, and 5 patients were excluded. Among those excluded, two recently stepped down from ITU, two lived in a nursing/care home and one had taken antibiotics 30 days before admission. Of the 22 patients, 10 patients (45%) received 5 or 6 days of antibiotics for CAP/HAP. The remaining 12 patients (55%) received courses between 7 to 10 days despite meeting the criteria for stopping antibiotics at 5 days. The mean and median of antibiotic course length including all specialities were 6.5 and 6.3 days, respectively. Conclusions This audit demonstrates that almost half of patients with CAP /HAP are being managed with antibiotic courses of fewer than 7 days. Further prescriber and pharmacy team education sessions on appropriate course lengths are needed. There is consideration for an alert notification on EPMA which reminds prescribers to check patient’s vital signs on day 5 when prescribed an antibiotic for the treatment of CAP and HAP. Recommendation would be to reaudit with a longer data collection timeframe and larger sample size.

O02 Patterns of GP and nurse-independent prescriber prescriptions for antibiotics dispensed in the community in England: a retrospective analysis

Abstract Background The substitution of nurses for doctors is a strategy used in primary care to improve access to, and efficiency and quality of, care. Many of these nurses prescribe medicines including antibiotics. Objectives To identify nurse-independent prescriber (NIP) and GP numbers in England, the proportions and types of NIPs and GP antibiotic prescriptions dispensed in the community, and the impact of COVID-19 on the volume, rate and types of antibiotic prescriptions dispensed. Methods A descriptive population-based retrospective cohort study using data obtained from the National Health Service Business Service Authority (under a Freedom of Information request) on GP and nurse-independent prescriber prescriptions for antibiotics dispensed in the community in England between January 2014 and October 2021. Results Between 2014 and 2021, the number of NIPs (headcount) in England almost doubled from 24 457 to 41 649. Of the 41 649 NIPs in 2021, the prescriptions of 34 997 (84%) were dispensed in the community, i.e. a rise of 146% over this 6-year period. By contrast, GP numbers (headcount) rose by 10% to 44 681. Of the 25.373 million antibiotic prescriptions dispensed between 2014 and 2021, NIPs were responsible for 8.6%. The rate of dispensed antibiotic prescriptions decreased (NIPs by 50% and GPs by 21%) between 2014 and 2020 (where data across the full year were available). This decreasing trend continued following the onset of the pandemic across both groups. In line with guidance for the treatment of minor infections, narrow-spectrum antibiotics (penicillins, macrolides and tetracyclines) were the most frequently dispensed across both NIPs and GPs. Trends in prescription of antibiotics during the pandemic were reflected in the use of individual classes of antibiotics prescribed for RTIs. Conclusions Given the rising numbers of nurse prescribers and their increasing contributory influence on total antibiotic prescribing, it is important that this group is included in antimicrobial stewardship efforts. NIPs prescribe fewer antibiotics than GPs but work under different conditions (e.g. longer consultations and less complex patients), and so, interventions should also be tailored to this group and the population and context in which they are delivered.

P20 Addition of a pharmacy technician to the ward team improves antimicrobial stewardship and patient care and safety

Abstract Background Antimicrobial stewardship (AS) is essential in reducing the risk of antimicrobial resistance (AMR).1,2 Prospective feedback of AS issues and adopting a multidisciplinary approach are beneficial to patient care and safety.3 Within the multidisciplinary team, antimicrobial pharmacy technician (AMPT) roles are evolving and offer an excellent opportunity to support everyday AS.4 Documenting antibiotic stop dates and allergy status on the prescribing chart and restricting broad spectrum antimicrobials to ‘protected’ status can improve AS by ensuring patients receive the correct antibiotic for the appropriate duration.5 In addition, management of common antibiotic drug interactions with cation products such as oral iron and enteral feeds is important in preventing treatment failure and AMR.6 Objectives This study set out to determine if introduction of an AMPT to the multidisciplinary team can improve AS, patient care and safety and reduce AMR risk. Methods A quality improvement approach was used to introduce an AMPT ward service to the Royal Alexandra Hospital (RAH) over a period of 6 months. The service was developed, standardized, piloted and agreed. The AMPT visited medical, surgical and older people service wards daily and screened prescribing charts for the following: (i) documented allergy status, (ii) documented antibiotic stop/review dates, (iii) completion of ‘protected’ antimicrobial order forms, and (iv) management of antibiotic cation interactions. AS issues identified were shared prospectively with the ward team and data displayed on run charts to measure improvement. Results Following introduction of the AMPT service documentation of allergy status and oral antibiotic stop dates improved from baseline in all wards. IV antibiotic stop/review documentation increased in all downstream medical and surgical wards with the greatest improvement achieved in the respiratory ward, increasing from a 0% baseline to a median of 37% after service introduction. Awareness and management of antibiotic cation interactions increased from a 41% baseline to a median of 86% and total antibiotic doses compromised by this interaction reduced from 66% at baseline to 21% post change. Completion of ‘protected’ antimicrobial forms improved from a baseline median of 53% to a median of 85% after service introduction. Conclusions Introduction of an AMPT service resulted in improved documentation of allergy status, oral and IV antibiotic stop/review dates, recognition and management of antibiotic cation interactions and compliance with the local ‘protected’ antimicrobial policy. These results demonstrate that introduction of an AMPT to the ward team can improve AS, patient care and safety and reduce the risk of AMR.

Antimicrobial Dispensing Practices during COVID-19 and the Implications for Pakistan.

Antibiotics are one of the most frequently dispensed classes of medicines. However, excessive misuse and abuse enhances antimicrobial resistance (AMR). Previous studies in Pakistan have documented extensive dispensing of 'Watch' and 'Reserve' antibiotics, which is a concern. In view of this, there is a need to assess current dispensing patterns following COVID-19 in Pakistan. A cross-sectional study was undertaken, collecting dispensing data from 39 pharmacies and 53 drug stores from November 2022 to February 2023. Outlets were principally in urban areas (60.9%), with pharmacists/pharmacy technicians present in 32.6% of outlets. In total, 11,092 prescriptions were analyzed; 67.1% of patients were supplied at least one antimicrobial, 74.3% antibiotics, 10.2% antifungals and 7.9% anthelmintics. A total of 33.2% of antimicrobials were supplied without a prescription. Common indications for dispensed antibiotics were respiratory (34.3%) and gastrointestinal (16.8%) infections, which can be self-limiting. In addition, 12% of antibiotics were dispensed for the prevention or treatment of COVID-19. The most frequent antibiotics dispensed were ceftriaxone (18.4%) and amoxicillin (15.4%). Overall, 59.2% antibiotics were 'Watch' antibiotics, followed by 'Access' (40.3%) and 'Reserve' (0.5%) antibiotics. Of the total antibiotics dispensed for treating COVID-19, 68.3% were 'Watch' and 31.7% 'Access'. Overall, there appeared to be an appreciable number of antibiotics dispensed during the recent pandemic, including for patients with COVID-19, alongside generally extensive dispensing of 'Watch' antibiotics. This needs to be urgently addressed with appropriate programs among pharmacists/pharmacy technicians to reduce AMR.

Antimicrobial Stewardship in COVID-19 Patients: Those Who Sow Will Reap Even through Hard Times.

Since the SARS-CoV-2 pandemic emerged, antimicrobial stewardship (AS) activities need to be diverted into COVID-19 management. In order to assess the impact of COVID-19 on AS activities, we analyzed changes in antibiotic consumption in moderate-to-severe COVID-19 patients admitted to four units in a tertiary-care hospital across three COVID-19 waves. The AS program was introduced at the hospital in 2018. During the first wave, COVID-19 forced the complete withdrawal of hospital AS activities. In the second wave, antibiotic guidance calibration for COVID-19 patients was implemented in all units, with enhanced stewardship activities in Units 1, 2, and 3 (intervention units). In a controlled before and after study, antimicrobial usage during the three waves of the COVID-19 pandemic was compared to the 12-month prepandemic unit (Unit 4 acted as the control). Antibiotic consumption data were analyzed as the overall consumption, stratified by the World Health Organization AWaRe classification, and expressed as defined-daily-dose (DDD) and days-of-therapy (DOT) per 1000 patient-day (PD). In the first wave, the overall normalized DOT in units 2-4 significantly exceeded the 2019 level (2019: 587 DOT/1000 PD ± 42.6; Unit 2: 836 ± 77.1; Unit 3: 684 ± 122.3; Unit 4: 872, ± 162.6; p < 0.05). After the introduction of AS activities, consumption decreased in the intervention units to a significantly lower level when compared to 2019 (Unit 1: 498 DOT/1000 PD ± 49; Unit 2: 232 ± 95.7; Unit 3: 382 ± 96.9; p < 0.05). Antimicrobial stewardship activities resulted in a decreased amount of total antibiotic consumption over time and positively affected the watch class and piperacillin-tazobactam use in the involved units. During a pandemic, the implementation of calibrated AS activities represents a sound investment in avoiding inappropriate antibiotic therapy.

Predictors of antimicrobial use in intensive care unit patients

Background: Identification of predictors of antibiotic use can inform targeted antimicrobial stewardship initiatives and can account for sources of bias in before-and-after interventional stewardship studies. To date, no study has identified clinical predictors of antimicrobial use within intensive care units (ICUs), where antimicrobial resistance is most prevalent and problematic. Methods: As part of an ongoing prospective, single-arm, pilot feasibility trial of an ICU diagnostic stewardship intervention, we performed a nested retrospective cohort study to explore associations between patient clinical variables and ICUs antimicrobial use and resistance rates (AURs). We included all patients hospitalized in 3 ICUs (surgical, medical, and cardiac) from 2017 to 2021 at Michigan Medicine, a large, tertiary-care, academic medical center. Data were extracted from the electronic medical record using a structured query. Admission-level data were captured, including patient demographics, medical comorbidities, International Classification of Disease, Tenth Revision (ICD-10) admission diagnoses, as well as calendar day-level data including vital signs, clinical and microbiologic laboratory data, measures of acute severity of illness, ventilator–supplemental oxygen metrics, and procedural interventions using current procedural terminology (CPT) codes. ICU AURs were defined as total antibiotic days of therapy per patient per 100 ICU days. Associations between clinical variables and ICU AURs were calculated as rate ratios (RRs). Multiple imputation using fully conditional specification was performed to create 25 imputation data sets. Negative binomial regression models were constructed for each data set using backward selection. Variables retained in &gt;50% of models were included in a final multivariate model. Results: In total, 15,177 ICU patient admissions were captured. Age, sex assigned at birth, and race did not independently associate with ICU AURs. Comorbidities, medical interventions, admission diagnoses, and laboratory data that independently associated with ICU-AURs are shown in Table 1. The clinical variables most strongly associated with increased ICU-AURs were pneumonia (RR, 1.55; 95% CI, 1.451.64), bacteremia (RR, 1.35; 95% CI, 1.25– 1.46), intraabdominal infection (RR, 1.35; 95% CI, 1.18–1.55), SOFA score (RR, 1.27; 95% CI, 1.14–1.42), abnormal WBC (RR, 1.26; 95% CI, 1.20–1.32), and immunocompromised status (RR, 1.20; 95% CI, 1.10–1.31). Clinical variables most strongly associated with decreased ICU-AURs were cardiac ICU (RR, 0.56; 95% CI, 0.52–0.60), COVID-19 (RR, 0.62; 95% CI, 0.56–0.70), and receipt of an invasive nonsurgical procedure (RR, 0.90; 95% CI, 0.82–0.98). Conclusions: In this single-center retrospective cohort study, several clinical variables were independently associated with ICU-AURs. These results may be used to identify patient subgroups for potentially high-yield ICU-based stewardship interventions and to account for sources of bias in before-and-after studies of ICU-based stewardship interventions.Disclosures: None

Antimicrobial Stewardship in a Psychiatric Hospital: Opportunities for Improvement

Background: Western State Hospital (WSH) is an 800-bed, state-owned psychiatric hospital in Washington State which services individuals in 20 counties. WSH provides services and inpatient treatment to patients referred via behavioral health providers and/or the civil court system. Because many patients are admitted with serious, long-term illness, WSH also provides primary care and addresses infectious syndromes encountered in admitted patients. In January 2016, WSH officially began their antimicrobial stewardship program (ASP). In 2017 WSH joined the UW Center for Stewardship in Medicine (UW-CSiM) to grow and optimize their ASP. Methods: The lead pharmacist at WSH participated in weekly hour-long education and tele-mentoring sessions through the UW-CSiM program. Educational materials were adapted from UW-CSiM didactics and delivered to providers during regular meetings and grand rounds. Daily pharmacist led prospective audit with feedback was conducted. Antibiotic use data were collected and measured by days of therapy (DOT) per 1000-patient days from pharmacy dispensing records from 2015 to 2022. Results: From 1/1/15 to 12/31/22, there was a consistent trend of decreasing antibiotic consumption annually. In particular, antibiotic use decreased by over 65% ranging from 35-43 DOT per 1000 patient-days in 2015 to 9-11 DOT per 1000 patient-days in 2022 (Figure 1). This translates to approximately 1000 antibiotic days of therapy in 2015 and 200 days of antibiotic therapy in 2022. As of 2022, the two most common antibiotics used were cephalexin and sulfamethoxazole/trimethoprim Conclusion: Although treating infections is not a principal focus of a psychiatric hospital, patients receiving care in inpatient psychiatric facilities do experience common infections and receive antibiotics during their stay. At WSH, initiation of an antimicrobial stewardship program was associated with sustained decrease in total antibiotic DOT over 7 years. These data highlight the impact of tele-education and tele-mentoring in infectious diseases and antimicrobial stewardship as a path to build a successful antimicrobial stewardship even without formal infectious diseases training. Our single center experience at a large psychiatric hospital demonstrates the use of antimicrobials in these facilities and the opportunity for a large impact of an antimicrobial stewardship program in inpatient psychiatric facilities.Disclosures: None.

Reducing the rate of guideline-discordant therapy for inpatients with community-acquired pneumonia

Background: Despite guidelines recommending shorter durations of therapy and empiric coverage of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) only for patients with certain risk factors, optimizing therapy for community-acquired pneumonia (CAP) remains a challenge for antimicrobial stewardship (AMS) teams. We investigated the impact of a multimodal AMS initiative on the rate of guideline-discordant empiric antibiotic selection and total duration of therapy for CAP. Methods: A quality improvement initiative was implemented at 9 community hospitals in 2022 to optimize CAP therapy. Education was provided to pharmacists and providers. Alerts were implemented within the electronic medical record to prompt the AMS team to review fluoroquinolones, antipseudomonal β-lactams, and anti-MRSA agents ordered for CAP. Clinical pharmacists reviewed antibiotic orders for CAP at hospital discharge and encouraged providers to prescribe a total antibiotic duration of 5–7 days. For the preintervention period (July– September 2021) and the postintervention period (July to September 2022), a random sample of 320 patients with an antibiotic order for CAP were evaluated retrospectively via chart review. Patients treated for an indication other than CAP were excluded. The primary outcome was the proportion of patients with a total duration of therapy &gt;7 days. Secondary outcomes included average duration of therapy, rate of guideline-discordant empiric therapy, and type of guideline discordance. Results: In total, 317 patients were included. The proportion of patients with a total duration of therapy &gt;7 days decreased from 29% to 14% (P &lt; .01). Average duration of therapy and guideline-discordant empiric therapy also decreased significantly (Table 1). Conclusions: This multifaceted AMS initiative was associated with decreased guideline-discordant empiric therapy and decreased total duration of therapy for CAP.Disclosures: None

Effects of antibiotics on the endophyte and phyllosphere bacterial communities of lotus from above and below surface water in a typical shallow lake

Antibiotics are ubiquitous pollutants that are widely found in aquatic ecosystems, where the bacterial community of aquatic plants is influenced by antibiotics. However, differences between endophyte and phyllosphere bacteria of Lotus from above and below surface water remains unclear. Lotus samples from above and below the surface water were collected to investigate the differences in endophyte and phyllosphere bacteria and dominant environmental factors in regions with low (L-) and high (H-) total antibiotic levels. There were significant differences in Shannon diversity between endophyte and phyllosphere bacteria except between the below-surface water phyllosphere bacteria and below-surface water endophytes in both L-antibiotic and H-antibiotic regions, with higher values for phyllosphere bacteria. The dominant phylum in all phyllosphere samples was Proteobacteria (76.1%–92.5%), while Cyanobacteria (47.8%–81.1%) was dominant in all endophyte samples. The dominant source of above-surface water endophytes was below-surface water endophytes (83.68–91.25%), below-surface water phyllosphere bacteria (48.43–55.91%) for above-surface water phyllosphere bacteria, and above-surface water endophytes (53.83–61.80%) for below-surface water endophytes, while the dominant contributor to the below-surface water phyllosphere bacteria was also below-surface water endophytes (52.96–61.00%) in two regions, indicating that antibiotic stress changed the sink‒source relationship between endophytes and phyllosphere bacteria. The physical-chemical properties of surface water and sediments could be responsible for the variations in the above- and below-surface water endophytes and phyllosphere bacteria in both regions. It is suggested that antibiotics may have a substantial effect on endophyte and phyllosphere bacterial community.

수의사 처방제 전·후 가축에 대한 항생제 판매량

A veterinarian prescription system (VPS) was implemented in 2013 to reduce the use of antibiotics in food-producing animals in South Korea. To understand effects of VPS on sales of antibiotics for food-producing animals, this study compared average sales of antibiotics for seven years before (2006-2012) and after (2014-2020) implementing VPS using population correction unit (PCU). As a result, average sales (242 mg/PCU) after implementing VPS decreased by 36% compared to those (380 mg/PCU) before implementing it. In addition, average sales of HP-CIAs after implementing VPS decreased by 14% from 51.4 mg/PCU to 44.2 mg/PCU compared to those before implementing it. Although average sales of total antibiotics and HP-CIAs for food-producing animals decreased after implementing VPS compared to those before implementing it, they were still higher than those in Europe. Therefore, it is necessary to strengthen VPS continuously to reduce the use of antibiotics for food-producing animals in the future.

The impact of the COVID-19 pandemic on antibiotic consumption and prevalence of pathogens in primary and secondary healthcare settings in Northern Ireland.

To evaluate the impact of the COVID-19 pandemic on the patterns of antimicrobial use and the incidence of pathogens in primary and secondary healthcare settings in Northern Ireland. Data were collected on antibiotic use and Gram-positive and Gram-negative pathogens from primary and secondary healthcare settings in Northern Ireland for the period before (January 2015-March 2020) and during (April 2020-December 2021) the pandemic. Time series intervention analysis methods were utilized. In the hospital setting, the mean total hospital antibiotic consumption during the pandemic was 1864.5 defined daily doses (DDDs) per 1000 occupied-bed days (OBD), showing no significant change from pre-pandemic (P = .7365). During the pandemic, the use of second-generation cephalosporins, third-generation cephalosporins, co-amoxiclav and levofloxacin increased, there was a decrease in the percentage use of the hospital Access group (P = .0083) and an increase in the percentage use of Watch group (P = .0040), and the number of hospital Klebsiella oxytoca and methicillin-susceptible Staphylococcus aureus cases increased. In primary care, the mean total antibiotic consumption during the COVID-19 pandemic was 20.53 DDDs per 1000 inhabitants per day (DID), compared to 25.56 DID before the COVID-19 pandemic (P = .0071). During the pandemic, there was a decrease in the use of several antibiotic classes, an increase in the percentage use of the Reserve group (P = .0032) and an increase in the number of community-onset Pseudomonas aeruginosa cases. This study provides details of both changes in antibiotic consumption and the prevalence of infections in hospitals and primary care before and during the COVID-19 pandemic that emphasize the importance of antimicrobial stewardship in pandemic situations.

Combined effects of microplastics and chlortetracycline on the intestinal barrier, gut microbiota, and antibiotic resistome of Muscovy ducks (Cairina moschata)

Antibiotics and microplastics (MPs) have become critical concerns worldwide because of their increasing amount and ecological risks to ecosystems. However, how MPs exposure affects the bioaccumulation and risks of antibiotics in waterfowls remains poorly understood. In this study, Muscovy ducks were exposed to single and combined contamination with polystyrene MPs and chlortetracycline (CTC) for 56 days, and the effects of MPs on CTC bioaccumulation and their risks in duck intestines were investigated. MPs exposure reduced the bioaccumulation of CTC in the intestine and liver of ducks and increased their fecal CTC excretion. MPs exposure caused severe oxidative stress, inflammatory response, and intestinal barrier damages. Microbiome analysis showed that MPs exposure induced microbiota dysbiosis by increasing the abundance of Streptococcus and Helicobacter, the increase of which may exacerbate intestinal damages. Co-exposure to MPs and CTC alleviated the intestinal damage by regulating the gut microbiome. Metagenomic sequencing revealed that the combined exposure to MPs and CTC increased the abundance of Prevotella, Faecalibacterium, and Megamonas and incidence of total antibiotic resistance genes (ARGs), especially tetracycline ARGs subtypes in the gut microbiota. The results obtained herein provide new insights into the potential risks of polystyrene MPs and antibiotics in waterfowls living in aquatic environments.

Occurrence and risk levels of antibiotic pollution in the coastal waters of eastern China.

In order to preliminarily explore the distribution of antibiotic pollution in the coastal waters of eastern China, the concentrations of 13 antibiotics in 5 representative coastal rivers in Jiangsu and 21 sampling sites in the coastal waters of Jiangsu were analyzed. The total antibiotic concentrations in the 5 rivers ranged from 33.14 to 417.78 ng L-1, and the total antibiotic concentrations in the 21 sampling sites ranged from 0.90 to 86.33 ng L-1. Macrolides exhibited the highest total concentration and the maximum detection frequency in both coastal rivers and the coastal waters. The concentrations of antibiotics in a sampling site decreased as the distance of the sampling site from the coastline increased, indicating that river inputs are important sources of antibiotic pollution in the coastal waters of Jiangsu. The detection frequencies of roxithromycin, lincomycin, azithromycin, and sulfamethoxazole in the rivers and sampling sites were above 70%. Correlation analysis showed that the concentrations of antibiotics were positively correlated with the levels of chemical oxygen demand, total phosphorus, and total nitrogen. Risk assessments revealed that roxithromycin and ofloxacin posed medium ecological and resistance risks, respectively, to the most sensitive aquatic organisms in the coastal waters of Jiangsu. The results of this study highlight the significance of monitoring and controlling the concentrations of antibiotic contaminants in the coastal waters of Jiangsu.

Epidemiology and clinical features ofStreptococcus pyogenesbloodstream infectionsin childrenin Madrid, Spain.

Studies have shown increased invasive Group A Streptococcus (GAS) disease, including bloodstream infections (GAS-BSI). However, the epidemiological data of GAS-BSI are limited in children. We aimed to describe GAS-BSI in children in Madrid, over 13years (2005-2017). Multicenter retrospective cohort study from 16 hospitals from Madrid, Spain. Epidemiology, symptomatology, laboratory, treatment, and outcome of GAS-BSI in children ≤ 16years were analyzed. 109 cases of GAS-BSI were included, with incidence rate of 4.3 episodes/100,000 children attended at the emergency department/year. We compared incidence between two periods (P1:2005-June 2011 vs P2:July 2011-2017) and observed a non-significant increase along the study period (annual percentage change: + 6.0% [95%CI:-2.7, + 15.4]; p = 0.163).Median age was 24.1months (IQR:14.0-53.7), peaking during the first four years of life (89/109 cases;81.6%). Primary BSI (46.8%), skin and soft tissue (21.1%), and osteoarticular infections (18.3%) were the most common syndromes. We compared children with primary BSI with those with a known source and observed that the former had shorter hospital stay (7vs.13days; p = 0.003) and received intravenous antibiotics less frequently (72.5%vs.94.8%; p = 0.001) and for shorter duration of total antibiotic therapy (10vs.21days; p = 0.001). 22% of cases required PICU admission. Factors associated with severity were respiratory distress, pneumonia, thrombocytopenia, and surgery, but in multivariate analysis, only respiratory distress remained significant (adjusted OR:9.23 [95%CI:2.16-29.41]). Two children (1.8%) died. Conclusion: We observed an increasing, although non-significant, trend of GAS-BSI incidence within the study. Younger children were more frequently involved, and primary BSI was the most common and less severe syndrome. PICU admission was frequent, being respiratory distress the main risk factor. What is known: • In recent decades, several reports have shown a worldwide increase in the incidence of invasive Group A streptococcal disease (GAS), including bloodstream infection (BSI). Recently, there have been a few reports showing an increase in severity as well. • There needs to be more information on the epidemiology in children since most studies predominantly include adults. What is new: • This study, carried out in children with GAS-BSI in Madrid, shows that GAS-BSI affects mostly younger children, with a broad spectrum of manifestations, needing PICU admission frequently. Respiratory distress was the leading risk factor for severity, whereas primary BSI seemed to be less severe. • We observed an increasing, although non-significant, trend of GAS-BSI incidence in recent years (2005-2017).