Cumulative Antibiograms Research Articles

P067 Cumulative hospital antibiogram of AIIMS Bhopal for Candida species

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectives Primary Objectives: To perform the phenotypic identification of the Candida isolates.To perform genotypic identification for confirmation of the Candida species.To prepare antifungal susceptibility profiles of each Candida isolate. Secondary Objectives: To determine the clinical spectrum.To stratify patients based on clinical risk such as per parameters as prior hospitalization and risk for invasive fungal infections.MethodsCross-sectional hospital-based study of 1-year duration 2020-2021. All samples sent to the microbiology laboratory with clinical suspicion of Candida infection and fulfilling the inclusion criteria were considered as sample size for the study period. The study population was the clinically relevant Candida isolates for which antifungal susceptibility testing was done and fulfilling the inclusion criteria. Study duration was for 1-year and was held at AIIMS, Bhopal. The data collected was entered in MS EXCEL and latest WHONET software and analyzed by WHONET software to generate antibiogram for Candida. Results are summarized in percentages and frequencies.ResultsTotal 110 Candida isolates were included in the study for antifungal susceptibility testing and WHONET entry after fulfilling the inclusion criteria.The commonest isolate across all samples processed and included was C. tropicalis 40% followed by C. glabrata 15.5%. A total of 43.6% Candida species were isolated from urine samples followed by 29% from blood samples and 10% from sputum samples. In all 54.5% of yeast isolates were from ICU followed by 40% from ward patients and at least 5.45% from OPD.The commonest isolate across all locations was C. tropicalis 40% followed by C. glabrata 15.5%, C. albicans 14.5% and C. parapsilosis 11.8%. The predominant isolates were under the age category 19-60 years, 69% followed by 26.4% >60 years of age. The percentage susceptibility of C. tropicalis isolates showed >90% susceptibility to tested antifungals. The percentage susceptibility of C. glabrata isolates showed susceptibility to echinocandin but reduced susceptibility to fluconazole. For Candida albicans overall no azole or echinocandin resistance was noted. For Candida parapsilosis overall no azole or echinocandin resistance was noted. C. krusei showed 100% susceptibility to anidulafungin, caspofungin, micafungin, and voriconazole by BMD. C. guilliermondii percentage susceptibility available for caspofungin 33.3%.A total of 80% of the isolates were from patients with community-acquired infections and 19% Candida species were from health care-associated infections. Among the community-acquired infections C. tropicalis was the commonest 37.5% followed by C. albicans 17%, C. glabrata 16%, and C. parapsilosis 12.5%. Among the HAI commonest isolate was C. tropicalis 47.6% followed by 14.3% each of C. auris, and C. glabrata. C. auris all isolates showed elevated MIC fluconazole(≥64 μg/ml), voriconazole (≥1 μg/ml), and caspofungin (≥1 μg/ml).ConclusionThe study conducted just over a year period in the department of microbiology of AIIMS Bhopal has been instrumental in generating cumulative antifungal antibiogram for Candida species.

Antimicrobial susceptibility testing of Staphylococcus aureus isolates from patients at a tertiary hospital in Tehran, Iran, 2018–2019

BackgroundStaphylococcus aureus, a human skin and mucous membranes colonizer, could opportunistically cause a variety of infectious diseases. Frequently, it is resistant to methicillin (MRSA), and often, co-resistant to many clinically available antibiotics. MRSA is a major burden for healthcare systems and communities all over the world, especially in developing countries. We addressed the issue that more than a decade had passed since the last report about cumulative antibiogram for S. aureus from our center, whereas The Clinical and Laboratory Standards Institute (CLSI) recommends to analyze and report it on an annual basis in order to guide clinicians to select the best initial empiric antimicrobial therapy.MethodsIn a cross-sectional retrospective design, data of culture-proven S. aureus from clinical specimens of hospitalized patients at Imam Khomeini Hospital Complex, Tehran, Iran, were collected from September 2018 to September 2019. Antimicrobial susceptibility testing (AST) had been performed using either Kirby–Bauer disk diffusion or VITEK 2 automated system which is based on minimum inhibitory concentration (MIC). The Chi-squared test was used considering the critical p-value to be ≤ .05.ResultsAmong 576 unique isolates, the overall prevalence of MRSA was 37.5%. Patients admitted to the infectious diseases ward and ICUs have a greater chance to have such an isolate. Methicillin resistance was predictive of resistance to most antibiotics: erythromycin (90.9%), clindamycin (85.4% including inducible resistance), gentamicin, cipro-/levo-/moxi-floxacin, trimethoprim–sulfamethoxazole (58.3%), tetracycline, and rifampin. Resistance rate of zero was observed for daptomycin, linezolid, tigecycline, and (roughly) vancomycin. The prevalence of multiple-drug resistant (MDR) isolates was 48.5%.ConclusionsAlthough in this study, the prevalence of MRSA was lower than the previous ones from the same hospital, it is still far from the desired rates. Besides, resistance to clindamycin and trimethoprim–sulfamethoxazole were remarkable. So far, vancomycin is the best choice for empiric treatment of MRSA, with linezolid as the second choice. It is advised to avoid prescribing the newer antibacterial agents as long as the older ones are effective to prevent the emergence of MDR species.

Antimicrobial Stewardship Programs: A Review of Strategies to Avoid Polymyxins and Carbapenems Misuse in Low Middle-Income Countries

Antibiotics misuse and overuse are concerning issues worldwide, especially in low middle-income countries. These practices contribute to the increasing rates of antimicrobial resistance. One efficient strategy to avoid them is antimicrobial stewardship programs. In this review, we focus on the possible approaches to spare the prescription of polymyxins and carbapenems for the treatment of Acinetobacter baumannii, carbapenem-resistant Enterobacterales, and Pseudomonas aeruginosas infections. Additionally, we highlight how to implement cumulative antibiograms and biomarkers to a sooner de-escalation of antibiotics.

Trends of antimicrobial resistance in patients with complicated urinary tract infection: Suggested empirical therapy and lessons learned from a retrospective observational study in Oman.

Complicated urinary tract infection (cUTI) is defined as an infection associated with structural, functional, or metabolic abnormalities of the genitourinary tract. These infections are caused frequently by multidrug-resistant Gram-negative bacilli. The rapid emergence of extended-spectrum beta-lactamase (ESBL), AmpC, and carbapenemase (CR) producers has made the treatment of such infections increasingly more challenging. The aims of the present study were threefold: to assess the clinical profile, trends in etiology, and antimicrobial susceptibility profile in cUTI over the past 10 years at a tertiary care center in Oman as an interrupted time series on the one hand and to develop guidelines for empirical management of such cases on the other. We conducted a retrospective analysis of cUTI in patients presenting at Sultan Qaboos University Hospital over 3 years (2008, 2013, and 2018) covering a span of 10 years. Data were obtained from the patient's electronic records in the hospital information system. Analysis was done using the Statistical Package for Social Sciences program (SPSS), version 23. Among the 650 cases of cUTI, 284 (44%) were males and 366 (56%) were females, with dysuria being the most common symptom (34%). The biggest risk factor for developing cUTI was diabetes (35%). The predominant pathogen was Escherichia coli (53%), followed by Klebsiella spp. (16%), Enterococcus faecalis (7%), Pseudomonas aeruginosa (7%), Candida spp. (2%), and Enterobacter cloacae (2%). Over the years, E. coli emerged as the predominant ESBL and AmpC producer, Acinetobacter baumannii as the multidrug-resistant bug, and Klebsiella pneumoniae as the major carbapenem-resistant Enterobacterales (CRE) producer. Nitrofurantoin emerged as the most effective drug for cystitis. Aminoglycosides, piperacillin-tazobactam, and carbapenems demonstrated the highest activity with an overall resistance of less than 10%. Higher resistance (30%) was observed against cephalosporins, fluoroquinolones, and trimethoprim/sulfamethoxazole. Analysis of the 10-year trend threw up some unexpected results. As expected, resistance increased from 2008 to 2013. Surprisingly, however, antimicrobial resistance in 2018 was lower against majority of the antimicrobials compared to 2013. There is a paucity of data for developing evidence-based guidelines management of cUTI. Targeted antibiograms and not cumulative antibiograms are essential for promoting appropriate prescribing and optimizing patient care. The welcome decline in resistance may be attributed cascade reporting, introduction of more ID physicians. Another possibility is increased utilization of fluoroquinolones which spared the other groups of antimicrobials. Judicious heterogeneous mixing of antimicrobials should be spearheaded in both cystitis and pyelonephritis so that there is no undue pressure on one drug. We strongly recommend carbapenem-sparing protocols in treatment of cUTI when anticipating augmented resistance due to AmpC production. Synergistic combinations such as piperacillin-tazobactam plus aminoglycosides/fluoroquinolones may be prescribed. In sepsis, however, carbapenems are the drugs of choice.

Enhancing the empiric antibiotic selection by introducing an antibiogram toolkit in a tertiary care hospital in Southern India - A prospective study.

Antibiograms gives an overview of the cumulative susceptibility of formal antibiotics to bacterial isolates, which reflects the portion of each bacterium susceptible to a given antibiotic formulation by using antimicrobial susceptibility testing. The objective of this study is to gather and analyse data from drug utilization evaluation (DUE) studies and antimicrobial susceptibility tests in order to create an antibiogram toolkit that will help clinicians to select appropriate antimicrobial agents for initial empirical antibiotic therapy at point of care settings and avoid irrational use of antibiotics. A prospective interventional study was conducted at tertiary care hospital, biological samples of infectious patients were collected from various wards as per Clinical & Laboratory Standards Institute CLSI M39-A4guidelines. Antimicrobial susceptibility results were analysed using WHONET software. Antibiotic stewardship committee was formed and involved in monitoring the usage of antibiotics, measuring outcomes, collecting feedback and finding the scope for improving the application of antibiogram toolkit in the hospital. Antibiotic usage tracking method was followed to know the level of adherence to the prescribing guidelines by the health care professionals. A total of 157samples were obtained from various wards of the hospital. In that, Escherichia coli, Staphylococcus aureus and Klebsiella Pneumoniae were isolated in significant numbers. Antibacterial susceptibility results were collected, an initial antibiogram was developed for 18 antibacterial agents with respect to 3gram-positive (+) and 1gram-negative (-) organisms. 90% of prescribers mentioned that the antibiogram was useful, and 76% of them adhered to the guidelines. 26% were not adhered due to the patient-related factors. In our study, we have used qualitative and quantitative evaluation of drug utilization (DUE) reports to understand the existing prescribing pattern of antibiotics and setting target organisms and antibacterials to develop the hospital antibiogram. Combining DUE studies and antibiogram development was helpful in implementing effective antibiotic policies for the hospital. Further, this study pattern will be continued on a yearly basis and focused on developing cumulative antibiograms to understand the changes in resistance pattern of antimicrobials and utilization of antibiotics in the hospital.

Antibiotics’ susceptibility patterns of bacterial isolates causing lower respiratory tract infections in ICU patients at referral hospitals in Namibia

ABSTRACT Background Lower respiratory tract infections (LRTIs) are a particular public health concern especially among sub-Saharan African countries. This is especially the case in Namibia, where LRTIs are currently the third leading cause of death, 300 deaths in children under 5 years of age. To reduce the burden of LRTIs on health systems and ensure appropriate patient management, it is critical to know the most prevalent pathogens leading to LRTIs and their susceptibility patterns in the local setting. Consequently, the objective of this study was to formulate cumulative antibiograms for Intensive Care Units (ICUs) of referral hospitals in Namibia to guide future antibiotic use. Methods A retrospective analytical cross-sectional study was conducted over 2 years. The cumulative antibiograms were constructed in accordance with current guidelines. Results A total of 976 first isolate cultures were obtained from ICUs of the different referral hospitals. K. pneumoniae (8.8%, 8.1%) was a predominant pathogen in Windhoek Central hospital ICU in 2017 and 2018. In Oshakati intermediate hospital ICU, Enterobacter sp. (22.2%) and P. aeruginosa (37.5%) were the common pathogens in 2017 and 2018, respectively. A. baumannii isolates were >90% susceptibility to colistin, carbapenems, and tigecycline in 2017. In 2017, K. pneumoniae isolates were more susceptible to carbapenems (94% and 93.8% among isolates), amikacin (89.3%), and tigecycline (88.7%). In 2018, K. pneumoniae isolates were 100% susceptible amikacin, colistin, and carbapenems. S. maltophilia isolates were more than 80% susceptible to all the tested antibiotics. S. aureus isolates were 100% susceptible to linezolid, rifampicin, teicoplanin, and vancomycin in 2017 and in 2018. Its susceptibility to these antibiotics did not change. Conclusion The susceptibility patterns of the common isolated gram-negative pathogens were highly variable. Meropenem in combination with gentamicin is now the recommended antibiotic combination for empiric therapy for patients with LRTIs in Windhoek Central Hospital ICU.

Cumulative Antimicrobial Susceptibility Data of Pseudomonas Aeruginosa Isolates from Cystic Fibrosis Patients: 4-Year Experience

Abstract Objective Pseudomonas aeruginosa is the most important cause of lung infection among cystic fibrosis (CF) patients, and to reduce the severity of the infection, facility-specific cumulative antibiograms could help clinicians in empirical treatment. Methods Respiratory samples of CF patients between January 2015 and December 2018 were scanned through Laboratory Operating System retrospectively. Demographical data of patients, culture results, and antibiotic susceptibilities are recorded using Microsoft Excel 2010. Cumulative antibiogram data were obtained according to the CLSI M39A4 document. Results The number of registered patients increased in 4 years from 154 to 253. The mean age of patients varied from 9 to 11.7 (range, 2–42). The ratio of patients with a positive culture for P. aeruginosa increased from 32 to 40%, and the mean patients' age decreased from 16.6 to 11.1 (p <0.05). A total number of 4,146 respiratory samples were analyzed. Sputum samples consisted of 42.5% (n: 1,767) of the samples with a 58.4% isolation rate of P. aeruginosa (n: 1,034). A notable increase of resistance was seen almost all antimicrobials tested by years. The ratio of multidrug-resistant (MDR) P. aeruginosa was 4.1, 10.2, 4.5, and 8.6% in 2015, 2016, 2017, and 2018. Conclusion Antimicrobial resistance is a challenging problem in CF patients, and surveillance should be done regularly.

Influence of hospital size on antimicrobial resistance and advantages of restricting antimicrobial use based on cumulative antibiograms in dogs with Staphylococcus pseudintermedius infections in Japan.

BackgroundAntimicrobial resistance in Staphylococcus pseudintermedius (SP) and the prevalence of meticillin‐resistant SP (MRSP) is increasing in dogs worldwide.ObjectivesTo evaluate the influence of hospital size on antimicrobial resistance of SP and whether restricted use of antimicrobials based on antibiograms could reduce the identification of antimicrobial resistance in SP from infected dogs.Methods and materialsIn Study 1, a total of 2,294 SP isolates from dogs with pyoderma (n = 1,858, 52 hospitals) or otitis externa (OE; n = 436, 44 hospitals) taken between 2017 and 2019 were analysed. Clinics were categorised into small, medium and large based on numbers of practicing veterinary surgeons. In Study 2, a cumulative antibiogram was constructed for 12 antimicrobials from one large veterinary clinic from 2017 to 2018. Referring to this antibiogram, the clinic introduced strict antimicrobial selection criteria to treat dogs with pyoderma and OE, starting in 2018.ResultsMRSP was identified in 981 dogs (42.8%). In large clinics, the isolation rate of MRSP was 51.1% (404 of 791), which was significantly higher (P < 0.01) than in small clinics with less than two veterinary practitioners (34.0%, 154 of 453). In the antibiogram study, the susceptibility rates of oxacillin (MPIPC, 61.5%), cefpodoxime (CPDX, 55.8%) and minocycline (MINO, 55.8%) were significantly higher in 2019 (n = 52) than in 2017 to 2018 (n = 54; MPIPC, 37.0%; CPDX, 33.3%; MINO, 20.4%; P < 0.05).Conclusions and clinical relevanceHospital size could affect the isolation rate of MRSP in dogs. Restricted use of antimicrobials for over a year based on cumulative antibiograms could reduce the resistance rate of multiple antimicrobials in SP isolated from dogs with pyoderma and OE.

Patient risk factor stratification is essential for the hospital antibiogram

Empiric antimicrobial therapy in hospitalized patients is guided by an institution’s cumulative antibiogram, which may not be adequate in giving information on decision-making for optimal treatment in different patient populations. Adding patient risk factors can make it more useful for clinicians in guiding empiric therapy and for antimicrobial stewardship. Cumulative data were obtained for blood culture and urine isolates from the laboratory information system of a tertiary care hospital for 6 months (January to June 2019). Further stratification of organism types and resistance rates on the basis of patient risk factors (Patient Types 1, 2, and 3) was performed and analyzed. Salmonella spp. was seen in community-acquired ward patients (Types 1 and 2). Streptococcus pneumoniae was seen in Type 1 patients, and Acinetobacter spp. was seen in Type 3 patients. Extended-spectrum beta-lactamase-producing gram-negative infection rates were higher in community patients than in hospital patients. Carbapenem-resistant Enterobacteriaceae rates were high in Type 3 hospitalized patients. Cumulative blood methicillin-resistant Staphylococcus aureus rates were 43% but stratification showed it only in Type 2 and Type 3 ICU patients with 0% in ward patients. Stratified antibiograms based on patient risk factors are valuable for antimicrobial stewardship and help to optimize empiric therapy and increase the understanding of antimicrobial resistance trends.

Sputum susceptibilities in a nationwide veteran cohort

Respiratory infections are one of the most common causes of morbidity and mortality. This study examined antimicrobial susceptibility of common respiratory isolates from veterans. Sputum culture data from the Veteran Health Administration were obtained retrospectively between January 2009 and 2019. Cumulative antibiograms were constructed for bacterial isolate susceptibility. Sputum and bronchial cultures from approximately 10,345 veterans were included each year. Haemophilus influenzae has maintained high levels of susceptibility to third generation cephalosporins from 2009 (99.7%) to 2018 (97.2%). Third generation cephalosporin susceptibilities amongst Klebsiella pneumoniae have trended upward from 2009 to 2018 as well (79.1% vs 86.4%). In Pseudomonas aeruginosa isolates, there has been an increase in susceptibility rates to cefepime from 2009 to 2018 (79.6%, to 86.6%), gentamicin (81.5% to 89.1%), and piperacillin/tazobactam (86.5% to 90%). Fluoroquinolone susceptibilities amongst Escherichia coli have remained low but stable between 2009 and 2018. Third generation cephalosporin susceptibilities for S. pneumoniae improved slightly from 92.2% to 95% between 2009 and 2018 while susceptibility to azithromycin trended down slightly from 56.8% in 2009 to 51.7% in 2018 for S. pneumoniae. The antibiogram of sputum isolates from the VA Healthcare System were examined to determine changes in patterns of resistance over a decade of use. This large-scale study investigated nationwide sputum culture susceptibility trends. Avoidance of macrolides for empiric treatment of community acquired pneumonia and avoidance of fluoroquinolones for empiric treatment of hospital acquired or ventilator associated pneumonia may be warranted based on susceptibility trends.

Trend of Antimicrobial Resistance among Bacterial Pathogens using Cumulative Antibiogram in a Tertiary Care Centre in Ahmedabad, Gujarat, India

Introduction: A rising incidence of Multidrug Resistance Organisms (MDRO) have become a major challenge to human health infections due to MDRO results in higher mortality rates, longer durations of hospital stays, and higher healthcare costs. MDRO contribute to over 50% of Healthcare Associated Infections (HAIs). Aim: To monitor the trends of Antimicrobial Resistance (AMR) among bacterial pathogens over a period of three years by using Cumulative Antibiogram (CA). Materials and Methods: A retrospective study was done to measure the trends of AMR among gram positive and gram negative organisms over a period of three years. CA capturing the susceptibility data was prepared for Enterobacteriacae, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter spp. and Enterococcus spp. once in every three year (2017, 2018 and 2019) in the month of January. Results: A total of 1032 isolates, of 10 medically important bacteria were analysed. Total of 21.49%, 30.38% and 54.55% isolates were Extended Spectrum β Lactamase (ESBL) producer in 2017, 2018 and 2019, respectively. There was a rising carbapenem resistance in 2019 (15.5% in E.coli, 26% in Klebsiella pneumonaie an 21% in P. aeruginosa). Among isolates of S. aureus identified in 2019, 56% were Methicillin Resistant Staphylococcus aureus (MRSA). Conclusion: CA helps in monitoring resistance trends among clinical isolates which helps in preparation of antibiotic policy. There is rising incidence of ESBL and carbapenem resistance among gram negative bacilli.

182. increasing Odds of Resistance for Subsequent Urinary e. Coli Isolates

BackgroundAnnual cumulative antibiograms are routinely used by clinicians to guide selection of empirical antibiotic therapies. CLSI guidelines recommend that these antibiograms to analyze data yearly, include only final, verified results, include bacterial species with > 30 isolates and to include only the first isolate for each species/patient instance per analysis period. Handling multiple isolates from individual patients in cumulative antibiograms is a controversial topic within the antimicrobial stewardship community. Current practice favors removing subsequent isolates, thereby discarding data reflecting impact of selective antibiotic pressure on resistance patterns in recurring urinary tract infection (UTI).In this study we analyzed a five-year data set of deidentified outpatient antibiotic results from a commercial laboratory to determine whether there were significant differences in resistance patterns between first and subsequent isolates from the same patient.MethodsThe 5-year antibiotic susceptibility data was restricted to urinary Escherichia coli (EC) isolates. Patient occurrence(s) of urinary EC were categorized by frequency: 1st occurrence, 2nd occurrence, 3rd occurrence, and 4th or greater occurrence. A logistic regression analysis using a binary outcome for resistance and independent variable of patient isolate occurrence was run for amoxicillin-clavulanate, ampicillin, ceftriaxone, ciprofloxacin, gentamicin, levofloxacin, nitrofurantoin, and trimethoprim-sulfa.ResultsFrom a logistic regression analysis, we estimate that for each occurrence in the data, an isolate’s odds of resistance were higher for every increase in a patient’s number of occurrences in the data for all antibiotics reported with p values < 0.0001.Table 1: Odds ratios (OR) of resistance for each subsequent urinary EC isolate occurrence over 5 years ConclusionOur findings suggest that individuals with higher numbers of urinary EC occurrences have more resistant EC than the first EC occurrence, with effects that vary by antibiotic class. Although traditional antibiograms include only the first occurrence of urinary EC from a single patient, this approach may underestimate levels of reservoir resistance in a community. Such an underestimation likely impacts efficacy of empiric therapeutic choice, healthcare outcomes, and cost.Disclosures All Authors: No reported disclosures

Cumulative antibiogram and multidrug-resistant organisms in a regional equine referral hospital.

Prudent use of antimicrobials is paramount to slow the development of resistance and for successful treatment. The use of cumulative antibiograms will allow evidence-based antimicrobial selection with consideration of local resistance patterns. We generated a "first-isolate-per-patient" cumulative antibiogram for a regional equine referral hospital. Bacterial organisms cultured from horses between 2011 and 2018, sample origin, antimicrobial susceptibilities, and multidrug-resistant (MDR) status were tabulated. Of 1,176 samples, 50% were culture positive. Overall, 93 of 374 (25%) were MDR. Of the MDR isolates, 11 (12%) were susceptible to high-importance antimicrobials only (as defined by the Australian Strategic and Technical Advisory Group on antimicrobial resistance). β-hemolytic streptococci were uniformly susceptible to penicillin (76 of 76); 17 of 20 (85%) non-β-hemolytic Streptococcus spp. were susceptible to penicillin. Despite veterinary-specific challenges in constructing an antibiogram, our study provides an exemplar of the clinical utility of regional-, farm-, or hospital-specific cumulative antibiograms for evidence-based empirical antimicrobial selection by veterinarians prior to susceptibility result availability.

Importance of Susceptibility Rate of 'the First' Isolate: Evidence of Real-World Data.

Background and objectives: For proper antimicrobial therapy, cumulative antibiograms should be representative of geographic region and be accurate. Clinical and Laboratory Standards Institute (CLSI) guidelines recommend that only the first isolates (FI) of a species per patient are used when reporting cumulative antibiograms. However, >50% of hospitals in the United States report antibiograms of all isolates. We compared antibiograms from the FI with those from total isolates (TI). Materials and Methods: Antimicrobial data of all isolates identified in the Microbiology unit of Ilsan Paik Hospital in 2019 were retrospectively acquired from the hospital information system. The susceptibility rates to antimicrobials of Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecium, and Enterococcus faecalis were analyzed by FI and TI, respectively. Isolate counts and susceptibility rates of each species for the reported antimicrobials were compared. Results: The numbers of isolates by FI/TI were as follows: 1824/2692 E. coli, 480/1611 A. baumannii, and 662/1306 K. pneumoniae, and 407/953 P. aeruginosa for gram-negative bacteria and 649/1364 S. aureus, 211/313 E. faecium, and 323/394 E. faecalis for gram-positive bacteria. All antimicrobial agents showed higher susceptibility rates when calculated as FI than as TI in gram-negative bacteria except colistin: 3.7% for E. coli, 14.5% for A. baumannii, 8.3% for K. pneumoniae, and 7.9% for P. aeruginosa. In S. aureus, 8/11 antimicrobial agents revealed higher susceptibility rates for FI than for TI. E. faecalis and E. faecium showed lower susceptibility rates for 7/10 antimicrobial agents for FI than for TI. The oxacillin susceptibility rates of S. aureus were 36.6%/30.2% with FI/TI and vancomycin susceptibility rates for E. faecium were 54.1% and 49.5%, respectively. Conclusions: When comparing cumulative antibiograms by FI with TI using real-world data, there is a large gap for critical species requiring hospital infection control. Although FI calculation is difficult, antibiograms must be calculated as FI for proper preemptive antimicrobial therapy because FI provides proper antimicrobial susceptibility data.

Utilization of cumulative antibiograms for public health surveillance: Trends in Escherichia coli and Klebsiella pneumoniae susceptibility, Massachusetts, 2008-2018.

Antimicrobial resistance is an urgent public health threat. Identifying trends in antimicrobial susceptibility can inform public health policy at the state and local levels. To determine the ability of statewide antibiogram aggregation for public health surveillance to identify changes in antimicrobial resistance trends. Facility-level trend analysis. Crude and adjusted trend analyses of the susceptibility of Escherichia coli and Klebsiella pneumoniae to particular antibiotics, as reported by aggregated antibiograms, were examined from 2008 through 2018. Multivariable regression analyses via generalized linear mixed models were used to examine associations between hospital characteristics and trends of E. coli and K. pneumoniae susceptibility to ciprofloxacin and ceftriaxone. E. coli and K. pneumoniae showed inverse trends in drug susceptibility over time. K. pneumoniae susceptibility to fluoroquinolones increased by 5% between 2008 and 2018 (P < .05). In contrast, E. coli susceptibility declined during the same period to ceftriaxone (6%), gentamicin (4%), and fluoroquinolones (4%) (P < .05). When compared to Boston hospitals, E. coli isolates from hospitals in other regions had a >4% higher proportion of susceptibility to ciprofloxacin and a >3% higher proportion of susceptibility to ceftriaxone (P < .05). Isolates of K. pneumoniae had higher susceptibility to ciprofloxacin (>3%) and ceftriaxone (>1.5%) in all regions when compared to Boston hospitals (P < .05). Cumulative antibiograms can be used to monitor antimicrobial resistance, to discern regional and facility differences, and to detect changes in trends. Furthermore, because the number of years that hospitals contributed reports to the state-level aggregate had no significant influence on susceptibility trends, other states should not be discouraged by incomplete hospital compliance.

A Feasible Laboratory-Strengthening Intervention Yielding a Sustainable Clinical Bacteriology Sector to Support Antimicrobial Stewardship in a Large Referral Hospital in Ethiopia.

Background: Access to clinical bacteriology in low resource settings (LRS) is a key bottleneck preventing individual patient management of treatable severe infections, detection of antimicrobial resistance (AMR), and implementation of effective stewardship interventions. We sought to demonstrate the feasibility of a practical bundle of interventions aimed at implementing sustainable clinical bacteriology services at Tikur Anbessa Specialized Hospital in Addis Ababa, Ethiopia, and report on cost and intensity of supervision.Methods: Starting in Dec 2015, an intervention based on the CLSI QMS01-A guideline was established, consisting of (i) an initial needs assessment, (ii) development of key standard operating procedures, (iii) adaptation of processes for LRS, (iv) training and supervision of laboratory staff via consultant visits and existing online resources, and (v) implementation of a practical quality systems approach. A guiding principle of the bundle was sustainability of all interventions post implementation.Outcomes and challenges: An initial investment of ~US$ 26,200 for laboratory reagents, and a total of 50 visit-days per year from three Canadian and Norwegian microbiologists were committed. Twelve SOPs, including antimicrobial susceptibility testing, were adapted, and an automated blood culture platform was donated (bioMerieux). In the first 18 months of implementation of the intervention, the average volume of specimens analyzed in the lab went from 15/day to 75/day. The number of blood cultures tested increased from an average of 2/day to over 45/day. Antimicrobial susceptibility testing was introduced and cumulative antibiograms were generated for the institution. Quality control was implemented for all procedures and quality assurance tools implemented included external quality assurance and proficiency testing of six technologists with longitudinal follow-up. The laboratory is on the path toward SLIPTA accreditation by the African Society for Laboratory Medicine. Reagent costs, staff training and retention, and engagement of clinical personnel with the lab proved to be manageable challenges. Key external challenges include in-country supply-chain management issues, lack of competition among distributors, and foreign-currency exchange distortions.Conclusions: Using a relatively low-intensity intervention based on existing training tools and accreditation schemes, we demonstrate that establishment of reasonable-quality clinical bacteriology is not only within reach but also a critical step toward assessing the burden of AMR in settings like this one and implementing effective stewardship strategies.

Antibiotic Consumption and Microbiological Epidemiology in Surgery Departments: Results from a Single Study Center.

The spectrum and antibiotic sensitivity of isolated strains vary between departments, hospitals, countries; the discrepancies are related to the use and dosage of these antibiotics. The purpose of our research was to compare the type of pathogens and the susceptibility of the isolated strains, as well as the use of antibiotics in the surgical departments of the Emergency Clinical County Hospital, Oradea, Romania; for one year, all the patients admitted to the mentioned sections were monitored. Antibiotic sensitivity of isolated strains was expressed using cumulative antibiogram. The total consumption of antibiotics was 479.18 DDD/1000 patient-days in the surgical sections. The most commonly used drugs were cephalosporins third and first generation, and clindamycin. Infections of wounds, urinary tract and fluids were most commonly diagnosed, and the most isolated was Escherichia coli, followed by Staphylococcus aureus and Enterococcus faecalis. The most commonly prescribed antimicrobial was ceftriaxone, but its sensitivity was low. This study revealed that the intake of antimicrobials in the surgical sections is increased and the comparison of antimicrobial prescriptions, sensitivity rates, and the spectrum of isolated pathogens showed differences between antimicrobials.

Antimicrobial resistance of gram-negative bacteria: A six-year longitudinal study in a hospital in Saudi Arabia

IntroductionIncreasing prevalence of antimicrobial resistance is a major concern especially in light of lack of new antimicrobial agents. Here, we present antibiotic resistance pattern of gram-negative bacteria (GNB) over six years (2013–2018) in a hospital in Saudi Arabia. Materials and MethodsThe study included a report of the cumulative antibiogram of GNB. Interpretation of the antibacterial susceptibility tests was based on the Clinical and Laboratory Standards Institute guidelines and VITEK® 2 system. ResultsThere was a total of 32,890 GNB isolates and the most common were: Escherichia coli (69.8%), Klebsiella pneumoniae (17.2%) and Pseudomonas aeruginosa (12.8%). Antimicrobial susceptibility of P. aeruginosa and E. coli did not change overtime, however, susceptibility to ceftazidime decreased from 92% to 85% in P. aeuroginosa. Yearly antimicrobial susceptibility did not change significantly overtime for K. pneumoniae. ESBL isolates among K. peumoniae and E. coli was about 26% and 20%, respectively (p=0.0068). For ESBL E. coli, the least effective antibiotics were ciprofloxacin (26%) and trimethoprim-sulfamethoxazole (34%). For ESBL K. pneumoniae, gentamicin, ciprofloxacin, trimethoprim-sulfamethoxazole, and nitrofurantoin had poor activity. For K. pneumoniae, both ciprofloxacin (90%) and trimethoprim-sulfamethoxazole (86%) had better coverage than for E. coli. K. pneumoniae showed less susceptibility to nitrofurantoin than E. coli (20% vs. 92%). ConclusionAntibiotic resistance among P. aeruginosa and E. coli did not change overtime (2013–2018) and the rate of ESBL-producing E. coli and K. pneumoniae was high. Thus, continued surveillance is needed.

Diagnostic Microbiology from the Beginning to the Future: Regional Antibiograms as Public Health Tools to Slow Down Antibiotic Resistance.

Infectious diseases is the only area of medicine where we can isolate the cause and study it in the laboratory under conditions similar to human body. Once isolated, we are able to determine the most optimal drug to treat it. Unfortunately, it is also the only specialty where after making truly wondrous strides we find ourselves at the crossroads of a public health crisis in the form of ongoing antibiotic resistance. Among the factors responsible for the current status, is the suboptimal utilization of the diagnostic microbiology laboratory. In this review authors provide a short historical perspective of diagnostic microbiology. The focus of discussion is the generation and utilization of cumulative antibiograms at the institutional and regional levels and discuss the pitfalls in large national databases with respect to the day-to-day patient care. This public health tool to slow down antibiotic resistance happens to be low-tech and inexpensive.

542. Los Angeles County Acute Care Regional Antibiogram Suggests Changing Landscape of MDRO Threats Between 2015 and 2017

BackgroundNational surveillance for multidrug-resistant organisms (MDRO) are limited by narrow geographic sampling, few hospitals, and failure to account for local epidemiology. A Los Angeles County (LAC) regional antibiogram was created to inform public health interventions and provide a baseline for susceptibility patterns countywide. We present data to compare the 2015 and 2017 LAC regional antibiogram.MethodsWe conducted a cross-sectional survey of cumulative facility-level antibiograms from all hospitals in LAC; 83 hospitals (AH) and 9 Long-term Acute Care (LTAC). For 2015, submission was voluntary, 2017 data were collected by public health order. Non-respondents were contacted by phone and in person. Isolates from sterile sources were pooled. Countywide susceptibility was calculated by weighting each facility’s isolate count by its reported susceptibility rate with minimum–maximim observed (2015) and Interquartile range (IQR) for 2017. Change from 2015 mean susceptibility is reported.ResultsSeventy-five (75) facilities submitted antibiograms for 2015 and 86 facilities for 2017. Among non-respondents in 2017, two facilities could not provide an adequate antibiogram and 4 were specialty hospitals with too few cultures to create an antibiogram. Regional summmary tables are presented in Tables 1–4. Klebsiella pneumoniae (n = 50 hospitals/19,382 isolates) % S to meropenem was 97% (IQR 94–100%), no change from 2015. Pseudomonas aeruginosa (PA) (n = 52 hospitals/17,770 isolates)% S to meropenem was 84% (IQR 74–93%), no change from 2015. Susceptibility to Acinetobacter baumannii (AB) was reported by 48 hospitals, including 1,4361 isolates,% S to meropenem was 39% (IQR 25–75%), 14% lower than 2015. Streptococcus agalactiae (n = 13 hospitals/647 isolates)% S to clindamycin was 43% (IQR 13–59%), a 22% increase from 2015.ConclusionLAC regional antibiograms identified stable patterns of antimicrobial resistance for most pathogens, but concerning results with AB and PA. Analysis of highly drug-resistant pathogens such as AB and PA would be improved with patient-level data to generate a combination antibiogram. We favor presenting IQR %S as done for 2017. Ongoing analysis will include multivariable analysis of observed changed S controlling for hospital characteristics. Disclosures All authors: No reported disclosures.