Antimicrobial Administration Research Articles

Prolonged oral antimicrobial administration prevents doxorubicin-induced loss of active intestinal stem cells

ABSTRACT Acute intestinal mucositis is a common off-target effect of chemotherapy, leading to co-morbidities such as vomiting, diarrhea, sepsis, and death. We previously demonstrated that the presence of enteric bacteria modulates the extent of jejunal epithelial damage induced by doxorubicin (DXR) in mice. Despite conventional thinking of the crypt as a sterile environment, recent evidence suggests that bacterial signaling influences aISC function. In this study, we labeled aISCs using transgenic Lgr5-driven fluorescence or with immunostaining for OLFM4. We examined the effect of DXR in both germ free (GF) mice and mice depleted of microbiota using an established antimicrobial treatment protocol (AMBx). We found differences in DXR-induced loss of aISCs between GF mice and mice treated with AMBx. aISCs were decreased after DXR in GF mice, whereas AMBx mice retained aISC expression after DXR. Neither group of mice exhibited an inflammatory response to DXR, suggesting the difference in aISC retention was not due to differences in local tissue inflammation. Therefore, we suspected that there was a protective microbial signal present in the AMBx mice that was not present in the GF mice. 16S rRNA sequencing of jejunal luminal contents demonstrated that AMBx altered the fecal and jejunal microbiota. In the jejunal contents, AMBx mice had increased abundance of Ureaplasma and Burkholderia. These results suggest pro-survival signaling from microbiota in AMBx-treated mice to the aISCs, and that this signaling maintains aISCs in the face of chemotherapeutic injury. Manipulation of the enteric microbiota presents a therapeutic target for reducing the severity of chemotherapy-associated mucositis.

Ocular surface flora and prophylactic antibiotics for cataract surgery in the age of antimicrobial resistance.

According to the World Health Organization alert about the antimicrobial resistance crisis released in 2015, clinicians should strongly reconsider the prolonged use of antimicrobials. In this review, we focus on the ocular surface flora with respect to the trend of fluoroquinolone resistance, and its upset and restoration after topical administration of antimicrobials and preservatives. Even 3weeks of topical administration of levofloxacin (LVFX) yields a selection of fluoroquinolone-resistant isolates bearing genetic changes in the ocular surface flora. One month of topical prophylactic administration of LVFX after cataract surgery induces the loss of diversity with LVFX-resistance of the ocular surface flora. Restoration of LVFX-sensitive flora occurs 6 to 9months after the final topical administration of LVFX. The ocular surface flora recovers earlier in patients given LVFX for 1week after the surgical procedure. These findings suggest that shorter periods of postoperative topical antibiotics are less frequently associated with persistent antimicrobial-resistant bacteria in the ocular flora. In addition, microbiologic analysis of ocular surfaces treated with a long period of eye drops containing benzalkonium chloride (BAC) showed a higher incidence of isolates resistant to methicillin and fluoroquinolones than did ocular surfaces treated with eye drops not containing BAC. To avoid the emergence of antimicrobial-resistant bacteria on the ocular surface, an urgent discussion must be held about the appropriate use of antibiotics and preservatives in the ophthalmology field.

Antimicrobial usage in cattle and poultry production in Dar es Salaam, Tanzania: pattern and quantity

BackgroundAntimicrobials are extensively used in cattle and poultry production in Tanzania. However, there is dearth of information on its quantitative use. A questionnaire-based cross-sectional study was conducted from August to September 2019 in randomly selected poultry and small-scale dairy farms, in three districts of Dar es Salaam City eastern, Tanzania, to assess the practice and quantify antimicrobial use. Descriptive and statistical analyses were performed at a confidence interval of 95%. The ratio of Used Daily Dose (UDD) and Defined Daily Dose (DDD) were used to determine whether the antimicrobial was overdosed or under dosed.ResultsA total of 51 poultry and 65 small-scale dairy farms were involved in the study. The route of antimicrobial administration was 98% orally via drinking water and 2% in feeds for poultry and for small-scale dairy farms, all through parenteral route. Seventeen types of antimicrobials comprising seven classes were recorded in poultry farms while nine belonging to six classes in the small dairy farms. Majority of the farms (poultry, 87.7% and small scale dairy, 84.3%) used antimicrobials for therapeutic purposes. About 41% of the poultry and one third (34%) of the dairy farmers’ were not compliant to the drug withdrawal periods. Beta-lactams, fluoroquinolones, sulphonamides, tetracyclines and macrolides were the commonly used antimicrobials on these farms. In the poultry farms both those with records and those which relied on recall, antimicrobials were overdosed whereas in the small dairy farms, sulfadimidine, oxytetracycline and neomycin were within the appropriate dosing range (0.8–1.2). The majority (58.6%) of farmers had adequate level of practices (favorable) regarding antimicrobial use in cattle and poultry production. This was associated with the age and level of education of the cattle and poultry farmers.ConclusionThe study revealed a widespread misuse of antimicrobials of different types and classes in both poultry and small-scale dairy farming in Dar es Salaam, Tanzania. This result gives insight into the antimicrobial use practices and its quantification. The information obtained can guide and promote prudent use of antimicrobials among the farmers by developing mitigate strategies that reduce antimicrobial resistance risk potentials.

Updates in Sepsis Management Show Thoughtful Approach

Updates in Sepsis Management Show Thoughtful Approach

An antibiotic concentration gradient microfluidic device integrating surface-enhanced Raman spectroscopy for multiplex antimicrobial susceptibility testing.

Antimicrobial susceptibility testing (AST) is a key measure in clinical microbiology laboratories to enable appropriate antimicrobial administration. During an AST, the determination of the minimum inhibitory concentration (MIC) is an important step in which the bacterial responses to an antibiotic at a series of concentrations obtained in separate bacterial growth chambers or sites are compared. However, the preparation of different antibiotic concentrations is time-consuming and labor-intensive. In this paper, we present a microfluidic device that generates a concentration gradient for antibiotics that is produced by diffusion in the laminar flow regime along a series of lateral microwells to encapsulate bacteria for antibiotic treatment. All the AST preparation steps (including bacterium loading, antibiotic concentration generation, buffer washing, and isolated bacterial growth with an antibiotic) can be performed in a single chip. The viable bacterial cells in each microwell after the antibiotic treatment are then quantified by their surface-enhanced Raman scattering (SERS) signals that are acquired after placing a uniform SERS-active substrate in contact with all the microwells. For proof-of-concept, we demonstrated the AST performance of this system on ampicillin (AMP)-susceptible and -resistant E. coli strains. Compared with the parameters for conventional AST methods, the AST procedure based on this chip requires only 20 μL of bacteria solution and 5 h of operation time. This result indicates that this integrated system can greatly shorten and simplify the tedious and labor-intensive procedures required for current standard AST methods.

Knowledge-Practice Gaps of Practicing Doctors on Antimicrobial Stewardship-A Single Center Experience

The overwhelming, irrational behaviour of using Antimicrobial (AM) has added to the amplification and spread of Antimicrobial Resistance (AMR) burden. Healthcare professionals can curtail the AMR by practicing Antimicrobial Stewardship (AMS). The single-centre hospital-based observational study aimed at accessing the knowledge, attitude and practice of practicing doctors towards AMS based on a free online open WHO course, a global action plan to combat AMR, laid down by WHO in a tertiary care hospital. The study was designed as a questionnaire-based cross-sectional one, conducted among practitioners (faculty, senior residents, junior residents) in different clinical departments. A validated self-administered questionnaire consisting of 29 questions was designed and shared among 200 participants through the mail and physically. Different subgroup analysis (surgeon vs physician, faculty vs senior resident vs junior resident, open WHO course participant vs open WHO course aware non-participant vs open WHO course unaware non-participants) was done for differences in responses to questions. Pearson Chi-square test was used for categorical data. Differences amongst groups were tested using the Chi‐squared test. P-value <0.05 was considered statistically significant. Response rate was 62.5% (n = 200). Knowledge on AMS was observed among doctors’ with >50% near correct responses in each question except for the question asking on IV route of AM administration. A significant knowledge gap was found when a comparison was made between faculty members, senior residents and junior residents (p<0.001) in the spectrum of activity of AM. Knowledge gap on ASP is observed among practicing doctors but significant differences were found among faculty, senior residents and junior residents, among open WHO course participants vs open WHO course unaware non-participants. The open WHO course may help in nullifying this gap.

Efficacy and Safety of Sitafloxacin in Treating Low-risk Febrile Neutropenia in Patients with Lung Cancer.

Introduction: Febrile episodes in patients with cancer and chemotherapy-induced neutropenia can be life-threatening and generally require prompt administration of broad-spectrum antimicrobials. However, little evidence exists for treating patients with solid tumors and febrile neutropenia (FN) with oral antimicrobials. Methods: In this prospective study, we aimed to determine the efficacy and safety of sitafloxacin (STFX) for treating FN in lung cancer patients. In this prospective study, low-risk FN patients with lung cancer received STFX. The primary endpoint was response rate, defined as 5 sequential days of absence of fever without adverse events. The study was registered as UMIN000010911. Results: As a result, STFX was administered to 26 patients, all of whom survived during its administration. Of the 26, 14 completed primary endpoint (53.85%). The low response rate was attributed to occurrence of fevers of unknown cause rather than failure of FN treatment. Only two patients received antibacterial agents other than STFX. If response rate omitted absence of fever and been defined only as recovery from FN without changing microbial agents or serious complications, the response rate would have been 91.67%. Adverse events occurred in eight patients, none of which were serious. Conclusions: In conclusion, STFX might be used to treat low-risk FN in patients with lung cancer; however, a more detailed study will be required in future.

Development of the Korean Standardized Antimicrobial Administration Ratio as a Tool for Benchmarking Antimicrobial Use in Each Hospital.

BackgroundThe Korea National Antimicrobial Use Analysis System (KONAS), a benchmarking system for antimicrobial use in hospitals, provides Korean Standardized Antimicrobial Administration Ratio (K-SAAR) for benchmarking. This article describes K-SAAR predictive models to enhance the understanding of K-SAAR, an important benchmarking strategy for antimicrobial usage in KONAS.MethodsWe obtained medical insurance claims data for all hospitalized patients aged ≥ 28 days in all secondary and tertiary care hospitals in South Korea (n = 347) from January 2019 to December 2019 from the Health Insurance Review & Assessment Service. Modeling was performed to derive a prediction value for antimicrobial use in each institution, which corresponded to the denominator value for calculating K-SAAR. The prediction values of antimicrobial use were modeled separately for each category, for all inpatients and adult patients (aged ≥ 15 years), using stepwise negative binomial regression.ResultsThe final models for each antimicrobial category were adjusted for different significant risk factors. In the K-SAAR models of all aged patients as well as adult patients, most antimicrobial categories included the number of hospital beds and the number of operations as significant factors, while some antimicrobial categories included mean age for inpatients, hospital type, and the number of patients transferred from other hospitals as significant factors.ConclusionWe developed a model to predict antimicrobial use rates in Korean hospitals, and the model was used as the denominator of the K-SAAR.

Emphysematous liver abscess with Edwardsiella tarda infection.

This report presents the case of a 51-year-old woman on an immunosuppressant drug and steroids, who presented with general fatigue and was admitted to the intensive care unit. Her serum procalcitonin, lactate, aspartate aminotransferase, and alanine aminotransferase levels and white blood cell counts were elevated. Computed tomography revealed gas formation in her liver, and her culture results revealed Edwardsiella tarda and Escherichia coli infections. She underwent percutaneous transhepatic abscess drainage in addition to antimicrobial administration. She was discharged after 40 days. Cases of emphysematous liver abscess with Edwardsiella tarda infections are rarely reported in the literature and may present in patients with poorly controlled type 2 diabetes. The fatality rate associated with the condition is markedly high.

Show me the data: A statewide comparative report of National Healthcare Safety Network (NHSN) Antimicrobial Use Option standardized antimicrobial administration ratios (SAARs).

The Antimicrobial Stewardship Collaborative of South Carolina created quarterly Comparative SAAR Analysis Reports based on standardized antimicrobial administration ratio (SAAR) data from the NHSN Antimicrobial Use (AU) Option. These reports provide SAAR histograms and site-specific feedback to participating facilities in South Carolina. They were created to improve antimicrobial use throughout the state, especially in rural regions.

Forefoot infection by Staphylococcus lugdunensis following a stonefish sting: A case report

Several orthopedic injuries caused by marine creatures envenomation have been reported in recent years all around the world, occurring mainly during water sports practice. We reported a case of an Italian tourist who developed an acute forefoot infection by Staphylococcus lugdunensis following a penetrating wound at the plantar region of the fourth toe, caused by a Stonefish, during a session of snorkeling in Indonesia. Diagnosis by microbiological methods, soft tissue and bone biopsy, surgical debridement and administration of antimicrobials led to a successful treatment of this potentially severe infection in this case. From this experience, we suggest to consider this bacterium in the differential diagnosis of bone infection following stonefish envenomation in tropical areas.

Increased clostridium difficile infection in the era of preoperative chemotherapy for pancreatic cancer

BackgroundIn recent trend of preoperative chemotherapy, postoperative clostridium difficile infection (CDI) might be increasing in pancreatic ductal adenocarcinoma (PDAC) patients. This study aimed to elucidate the inducement of postoperative CDI in the new era of preoperative chemotherapy. MethodsEligible patients were those who received pancreaticoduodenectomy for PDAC. Patients were classified into two groups according to the presence or absence of postoperative CDI, and the independently associated factors for postoperative CDI were investigated. Additionally, eligible patients were classified using the identified associated factors, and the duration of preoperative antimicrobial administration and incidence of CDI were compared between the groups. ResultsTwo hundred PDAC patients were eligible for this study, and postoperative CDI was detected in 15 (7.5%) patients. Multivariate analysis revealed that preoperative biliary tract infection (BTI) and chemotherapy (Chemo) were independently associated with postoperative CDI (OR, 4.05; 95% CI, 1.25–13.1; p = 0.0200 and OR, 3.64; 95% CI, 1.14–11.6; p = 0.0209, respectively). The patients were classified into four groups according to the presence or absence of preoperative BTI and Chemo (BTI-/Chemo-, BTI-/Chemo+, BTI+/Chemo- and BTI+/Chemo + group). The median durations of preoperative antimicrobial administration were 0, 2, 8 and 15 days in each group, respectively. Postoperative CDI was detected in 3.7%, 10.0%, 10.5% and 31.3% in each group, respectively, and patients in BTI+/Chemo + group suffered CDI more frequently compared to those in BTI-/Chemo-group (p = 0.00778). ConclusionsPreoperative BTI and chemotherapy might induce postoperative CDI for PDAC patients.

Sustained reductions in unnecessary antimicrobial administration and hospital Clostridioides difficile rates via stewardship in a nonacademic setting.

A large community hospital sought to reduce its burden of hospital-acquired Clostridioides difficile infection (CDI). We implemented an antimicrobial stewardship program (ASP), resulting in marked reductions in unnecessary antimicrobial use, CDI rates, antimicrobial acquisition costs, with preservation of gram-negative susceptibilities. ASP programs are effective in a community setting.

Usage of antimicrobials on seven farms of beef producers in Switzerland

It was the objective of this study to evaluate morbidity, mortality, use of veterinary drugs and production output on seven representative Swiss beef fatteners, who bought on a regular basis batches of calves from traders (mean age and weight: 31 day, 75 kg) and practised an all in-all out system. From March 2015 until May 2016, 51 batches with a total of 1307 calves were included. The use of drugs during the first eight weeks following delivery of calves from the trader, casualty rate and carcass performance of 837 bulls. The administration of antimicrobials was calculated per calf as the number of days with effective therapeutic concentrations (daily doses per animal; DD/A). The average weight of the calves at arrival on the fattening unit was 75 kg and the age 31 days. The group size was between 13 to 47 calves (median 22, Q1 = 21, Q2 = 30). In 36 batches (70,6 %), a veterinary entry examination was performed which demonstrated that at admission 20 % of the calves suffered from a relevant disease. The median for the number of DD/A was 16 for the first 56 days on the farm (Q1 = 11, Q3 = 21); 68 % of these DD/A were attributed to metaphylactic medications after delivery. Thereafter, pneumonia (54 %), diarrhea (33 %) and otitis (10 %) were the most frequent indications for subsequent therapeutic interventions. Over all batches, a median of 71 % (Q1 = 47, Q3 = 85) of all DD/A were due to critically important antimicrobials (CIM) and drugs containing several antibiotics including a CIM. The losses due to death or euthanasia averaged 3,7 % of all calves. The median for daily weight gain for the total fattening period (median 354 days; Q1 = 328, Q3 = 379) accounted for 1325 g (Q1 = 1216, Q3 = 1425). The profound variation between the farms in respect to the results of drug use and production output reveals evidence for the strong impact of farm-specific factors (such as pen space per calf, barn climate, vaccination protocol, supervision). Concurrently, the remarkable differences between the results of different batches on one farm depict that there are further important risk factors which are beyond the control of the farmer (in particular season of the year, transport). It is concluded that a systematic minimization of risk factors as part of a continuous veterinary consultation is useful two improve herd health and to reduce the input of drugs in the production of beef.

39. Impact of Antimicrobial Stewardship Interventions in a Community Hospital setting: An Interrupted Times Analysis

Abstract Background Community hospitals have fewer resources for antimicrobial stewardship programs (ASP) compared to larger tertiary hospitals. At our 312-bed community hospital, Long Island Jewish Forest Hills/Northwell, a combination of modified preauthorization, prospective audit feedback, and ASP education was implemented starting in August 2019 (Monday through Friday 9 am to 5 pm). Methods This retrospective study evaluated the impact of ASP interventions on the rate of targeted antimicrobial use over a 7 month pre- vs 7 month post- intervention period (Aug 2018 to Feb 2019 vs Aug 2019 to Feb 2020). Targeted antimicrobials included piperacillin-tazobactam, vancomycin, daptomycin, and carbapenems. The primary outcome was the monthly mean for overall targeted antimicrobial use measured by the rate of antimicrobial days per 1000 days present. Secondary outcomes were the individual rates of antimicrobial days per 1000 days present for each of the targeted antimicrobials, and the hospital’s overall standardized antimicrobial administration ratio (SAAR). Data were analyzed as a segmented regression of interrupted time series. Results Pre-intervention, there was an increasing trend (positive slope, p&amp;lt; 0.05) in the monthly mean, hospital SAAR, vancomycin and piperacillin-tazobactam use. Post-intervention, there was a significant change in slope for these same metrics, indicating a decrease in the mean use. Immediate impact of ASP interventions, measured by the difference in antibiotic use between the end of each intervention period, was visually evident in all cases except carbapenems (Fig. 1 through 4). The immediate impact on the overall monthly mean represented a significant reduction in the rate of antimicrobial days per 1000 days present, -12.72 (CI -21.02 to -4.42, P &amp;lt; 0.0066). The pre- vs post- ASP gap for all measures was negative and consistent with fewer days of antibiotic use immediately following intervention. Conclusion A targeted, multifaceted ASP intervention utilizing modified preauthorization, prospective audit feedback, and education significantly reduced antibiotic use in a community hospital. Disclosures All Authors: No reported disclosures

753. Impact of COVID-19 on Healthcare Facility-Onset Clostridiodes difficile Infection

BackgroundIt is estimated that the majority of hospitalized COVID-19 patients around the world received antibiotics despite the fact that bacterial co-infections are rare. This can lead to increased antimicrobial resistance and Clostridioides difficile infections (CDI). Gastrointestinal symptoms of COVID-19 may also contribute to increased testing. The objective of this study was to assess the impact of the COVID-19 pandemic on our healthcare facility-onset (HO) CDI rates.MethodsThis was a retrospective cross-sectional study comparing CDI rate per 1,000 patient days, C. diff order rate per 1,000 patient days, Standardized Antimicrobial Administration Ratio (SAAR), and Standardized Infection Ratio (SIR) in the pre-COVID-19 period from January 1, 2019 to December 31, 2019 to the COVID-19 period from April 1, 2020 to March 31, 2021 at a 877-bed tertiary care hospital in Detroit, Michigan. CDI and order rates were extracted from the electronic medical record (Epic™ Bugsy). SAAR and SIR data were extracted from National Healthcare Safety Network (NHSN).ResultsThe average CDI rate per 1,000 patient days was 4.29 pre-COVID-19 compared to 1.98 during COVID-19 with a 54% reduction, and the C. diff order rate per 1,000 patient days also decreased from 130.89 to 93.03, resulting in a 29% reduction (Figure 1). The SIR was 0.383 compared to 0.308 during COVID-19 (P-value 0.404). SAAR decreased from 1.095 to 0.945 (P-value < 0.001). However, our institution experienced three COVID-19 waves, with peaks in April 2020, November 2020 and March 2021, that correlated with high risk CDI antibiotic utilization in intensive care unit (ICU) (Figure 2). The average hand hygiene rate increased from 82% to 92%. Figure 1. Clostridioides difficile order and infection rates pre-and during COVID-19 pandemic. Figure 2. Standardized Antimicrobial Administration Ratio (SAAR) pre-and during COVID-19 pandemic.ConclusionDespite the COVID-19 pandemic, the HO-CDI and C. diff order rates and overall SAAR decreased; however, antibiotic utilization increased in the ICU during the COVID-19 waves. The overall decrease may be multifactorial and related to increased hand hygiene compliance, isolation and personal protective equipment use and overall decreased antibiotic use and C. diff orders.Disclosures Rachel Kenney, PharmD, Medtronic, Inc. (Other Financial or Material Support, spouse is an employee and shareholder)

114. Optimization of Inpatient Antibiotic Use via an Electronic Antimicrobial Stewardship Module and an Infectious Diseases Pharmacy Resident

BackgroundAntibiotic resistance is a public health crisis and antimicrobial stewardship (AMS) pharmacists serve a crucial role in preventing inappropriate use. At Montefiore Medical Center (1,500-bed hospital), a new electronic medical record AMS module was implemented with assistance from an infectious diseases (ID) pharmacy resident in October 2020. The module utilizes a dynamic scoring system to assist in prioritizing interventions, including bug-drug mismatches, insufficient coverage, or de-escalation. The AMS module is operationalized by ID pharmacists during the week and an ID pharmacy resident every other weekend. The objective of this study was to assess the impact of an ID pharmacy resident performing AMS module interventions on broad spectrum antibiotic use.MethodsAn observational study of AMS module interventions on antibiotic use (AU) in days of therapy per 1,000 days present and standardized antimicrobial administration ratio (SAAR) was performed. AU data for piperacillin-tazobactam (P/T) and SAAR prior to (October 2019– December 2019) and after (October 2020 – December 2020) the integration of an ID pharmacy resident and the AMS module was compared. Additional data collected included total number and type of interventions.ResultsA total of 539 interventions were made by AMS pharmacists and 36.5% of these were completed by the ID pharmacy resident. Across 6 different units, there was a statistically significant decrease in the SAAR for broad spectrum antibacterial agents (Figure 1), and a decrease of at least 10% in P/T use during the two different time periods (Table 1). An estimated P/T cost reduction of 26% of (&48,708 to &36,235.80) was observed. AMS pharmacists made 63 interventions in respective units. The top three intervention types were dose/frequency/duration recommendations, pharmacokinetic vancomycin dosing/monitoring, and de-escalation. The acceptance rate of interventions was 99% (534 accepted interventions/539 total interventions).Figure 1. SAAR Comparison of Broad-Spectrum Agents Table 1. AU Rate of Piperacillin-tazobactam ConclusionOverall, there was a statistically significant impact on SAARs and a >10% change in P/T AU rate with an estimated cost reduction >25% on select units after implementation of the AMS module with an ID pharmacy resident.Disclosures Kelsie Cowman, MPH, Merck (Research Grant or Support) Priya Nori, MD, Merck (Grant/Research Support) Priya Nori, MD, Nothing to disclose Yi Guo, PharmD, BCIDP, Merck (Research Grant or Support)

155. Antimicrobial Resistance Patters as a Predictor of Standardized Antimicrobial Administration Ratio: A National Correlation Study

BackgroundData on antimicrobial usage (AU) and antimicrobial resistance (AR) is submitted to the National Healthcare Safety Network (NHSN) from facilities monthly. Bacterial proportion resistant (%R) from the AR option reports proportion of isolates resistant to specific antimicrobial categories. Standardized Antimicrobial Administration Ratio (SAAR), generated under the AU option, compares observed to predicted days of antimicrobial therapy. The purpose of this study was to evaluate the association between %R and SAAR for broad-spectrum antibacterial agents predominantly used for hospital-onset infections (BSHO) and antibacterial agents predominantly used for resistant gram-positive infections (gram-pos) in adult intensive care units (ICUs) and medical-surgical wards (M/S).MethodsThis retrospective observational review utilized data reported to NHSN to examine the association of BSHO and gram-pos SAARs with %R for various phenotypic categories by quarter from 2017 through the second quarter of 2020. Phenotypic categories included methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis and faecium (VRE), extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp. (ESBL), and multi-drug resistant Pseudomonas aeruginosa (MDR PSA). Pearson correlations were used to quantify the associations between SAARs and %R.ResultsA total of 182 institutions were included for analysis. Weak, positive correlations were observed between SAAR for BSHO in ICU and M/S for MDR PSA %R and also for ESBL %R (r = 0.14 to 0.22, all p < 0.0001). For the gram-pos SAAR in ICU and M/S, there were weak positive correlations between MRSA %R and VRE %R (r = 0.20 to 0.31, all p < 0.0001).ConclusionSAARs are multifactorial, yet these results highlight that more resistant organisms may possibly be contributing to higher use of antimicrobials for facilities. Future SAAR calculations could consider incorporating resistance trends from %R within the institution for increases in AU and adjusting SAARs accordingly. Comprehension of the relationship between %R and SAAR can aid facilities with stewardship programs and understanding how resistance contributes to antibiotic usage.Disclosures Julia Moody, MS, Medline (Other Financial or Material Support, Conducted studies in which participating hospitals received contributed antiseptic product)Molnlycke (Other Financial or Material Support, Conducted studies in which participating hospitals received contributed antiseptic product)

132. Standardized Antimicrobial Administration Ratios to Guide Antimicrobial Stewardship in the Neonatal Intensive Care Unit: a Single Center Experience

BackgroundAntimicrobial stewardship (AMS) is particularly challenging in the neonatal population. Both under- and overuse can negatively impact outcomes. There are limited reports of strategies to improve AMS in the neonatal population. Standardized Antimicrobial Administration Ratios (SAARs) are novel metrics of antimicrobial use, recently introduced for neonatal populations by the National Healthcare Safety Network (NHSN). We describe our experience using SAARs to guide AMS in the neonatal intensive care unit (NICU).MethodsThis was a retrospective study conducted from January 2020 to April 2021. A team consisting of AMS and NICU department staff identified and implemented AMS strategies. Based on a review of NICU SAAR data, a goal was set to reduce third generation cephalosporin use by encouraging aminoglycoside use when appropriate. The pre-implementation period was January 2020 to May 2020 and the post-implementation period was July 2020 to April 2021. Antibiotic use was measured as SAARs and compared between study periods. The primary outcome was the neonatal SAAR for third generation cephalosporins. Secondary outcomes included SAARs for aminoglycosides and all neonatal antibacterial agents. SAARs were compared using the NHSN Statistics Calculator.ResultsFor third generation cephalosporins, there were 385 observed antimicrobial days (OAD) and 115 expected antimicrobial days (EAD) in the pre-implementation period compared to 597 OAD and 228 EAD in the post implementation period. This resulted in a SAAR of 3.34 and 2.62, respectively; a reduction of 22% (p < 0.001). For aminoglycosides, there were 713 OAD and 584 EAD compared to 1617 OAD and 1155 EAD. This resulted in a SAAR of 1.22 and 1.4; an increase of 15% (p = 0.002). For all neonatal antibacterial agents, there were 2716 OAD and 1739 EAD compared to 5321 OAD and 3438 EAD. This resulted in a SAAR of 1.56 and 1.55; indicating no change in use (p = 0.70). See Table 1 for results.Table 1. Antibiotic Use ConclusionWhile this initiative resulted in decreased use of third generation cephalosporins, this was not associated with a decrease in antibiotic use overall. Use of SAARs in the NICU may be helpful in both identifying opportunities to improve antibiotic use and monitoring antibiotic use over time.Disclosures Steven Smoke, PharmD, Karius (Advisor or Review Panel member) Shionogi (Scientific Research Study Investigator, Advisor or Review Panel member)

Immunofluorescence Targeting PBP2a Protein: A New Potential Methicillin Resistance Screening Test.

The indiscriminate use of first-line drugs contributed to the spread of resistant bacteria, a major concern for both human and veterinary medicine. Methicillin resistance is acquired through the mecA gene, which encodes for the PBP2a protein and lends the resistance to β-lactams. Verifying the correspondence between gene harboring and protein expression and accelerating methicillin resistance diagnosis is critical to improve the management of antimicrobial administration and to reduce the spread of drug resistances. We tested the applicability of immunofluorescence targeting PBP2a protein to identify a new potential methicillin resistance screening test, ancillary to conventional culture methods. We collected 26 clinical Staphylococcus pseudintermedius (SP) isolates: 25 from canine pyoderma and 1 from dermatitis in a dog owner. SP is one of the most important etiological agents in canine pyoderma and can harbor the mecA gene. We performed PCR for mecA gene detection, broth microdilution (BMD) for phenotypic methicillin resistance, and immunofluorescence targeting PBP2a protein. Compared to the PCR as the gold standard, immunofluorescence showed an apparent prevalence of 34.6% vs. a true prevalence of 53.8%, with 100% specificity, 64.3% sensitivity, and 80.8% diagnostic accuracy. PBP2a expression showed isolate-dependent variability: in some isolates, most of the bacterial cells showed an intense and clearly membranous pattern, while in others only a few of them could be detected. Performing the assay in duplicate improved the diagnostic accuracy. Since the mecA gene is shared among the members of the Staphylococcus genus, the test can be applied to identify methicillin resistance independently from the staphylococcal species, both in human and animal samples. Being a rapid and easy method and providing the unique possibility to study the expression of PBP2a by directly visualizing the morphology, it could represent a new interesting tool for both research and diagnostics. To accelerate methicillin resistance diagnosis, it would be worth further testing of its performance on cytological samples.