P-1693. Group A Streptococcus at Wadsworth Center; Surveillance for Antimicrobial Resistance

Background COVID-19 affected the epidemiology of many respiratory pathogens including GAS. Assessing genetic heterogeneity (emm type, antimicrobial resistance, virulence factors) can inform treatment recommendations and targets for potential GAS vaccines. We assessed GAS clinical antibiotic susceptibility and performed whole genome sequencing (WGS) among pediatric pharyngeal isolates from 2020–2022. Methods From 1/2020–3/2022 we collected throat swabs in pediatric clinics and EDs from children aged 3-18 years in Chicago, IL; Atlanta, GA; Portland, OR; and Phoenix, AZ: 1) with acute GAS pharyngitis and 2) among a convenience sample of asymptomatic children to assess for GAS colonization. Swabs were plated on blood agar. E-tests were used to assess clinical susceptibility to erythromycin (ERY) and ciprofloxacin (CIP). emm type and antimicrobial resistance genes (ERY, Clindamycin (CLI), and fluoroquinolones) were assessed by WGS. Results 1144 pharyngeal swabs were collected: 359/684 (52%) from children with GAS pharyngitis by rapid test and 20/460 (4.3%) from asymptomatic children yielded GAS on culture. Phenotypic resistance: 55/364 (15%) tested isolates were ERY resistant and 5/364 (1.4%) CIP resistant. The proportion of isolates with ERY resistance increased significantly from 2020 (6%) to 2021–2022 (25%) (χ2 = 23.70, p< .00001) (Figure 1). MICs were high among ERY resistant GAS (Table 1). Genotypic resistance: Of 304 sequenced GAS isolates 40/304 (13%) were ERY resistant, 35/304 (11.5%) were both ERY resistant and CLI (inducible or constitutive) resistant, and 4/304 (1.3%) fluoroquinolone resistant. ermB (62%) was the most common gene for ERY resistance and constitutive CLI resistance, followed by ermTR (23%) and ermT (11%) both conferring inducible CLI resistance. Among the 20 isolates from asymptomatic children no ERY, CLI, or CIP resistance occurred, and no resistance genes were identified. emm types 11, 9, 77, 58 and 94 were associated with ERY and CLI resistance. Conclusion ERY resistance increased from 2020–2022. The high rate of CLI resistance among ERY resistant GAS was associated with erm genes. These results are important to inform treatment recommendations for GAS pharyngitis and targets for vaccine development that can reduce antimicrobial-resistant GAS disease. Disclosures All Authors: No reported disclosures.

The detection of recombinant DNA in a vitamin B2 used as a feed additive was notified by the Belgian national authorities on 2 October 2018 via the Rapid Alert System for Food and Feed (RASFF). The European Commission requested scientific advice from EFSA on the risk posed to humans by the presence of genetically modified material in the feed additive, particularly with regard to antimicrobial resistance (AMR). EFSA assessed the analytical data from RASFF regarding the presence of AMR genes in both additive and feed. Samples of the additive and feed tested positive for the presence of DNA of a genetically modified Bacillus subtilis. The results were compatible with, but did not demonstrate the presence of, a full‐length chloramphenicol resistance gene. No information was made available on the presence of other AMR genes or viable cells of the B. subtilis. The statement provides a risk assessment pathway indicating the events needed to produce adverse human health effects from the presence of AMR genes in feed additives. Data on the likelihood of occurrence of all events are needed to produce an evidence‐based estimate of the risk. All the events are theoretically possible, but there are no scientific data available to estimate the probability of each taking place. Moreover, there is no evidence of the presence of full‐length AMR gene(s) in the vitamin B2 additive or feed; thus, it is not clear whether the first step towards AMR gene transfer is fulfilled. The sole presence of fragments of AMR genes in a feed additive is not a risk. If a full‐length AMR gene were present in a feed additive, it could lead to risks linked to its transmission to pathogens via the food chain and/or to the environmental spread of AMR bacteria/genes, potentially contributing to the environmental reservoir of AMR determinants.

Clindamycin is an alternative antibiotic in the treatment of Staphylococcus aureus (S.aureus) infections, both in infections by methicillin susceptible and resistant (MSSA and MRSA) strains. The major problem of use of clindamycin for staphylococcal infections is the presence of inducible clindamycin resistance that can lead to treatment failure in such infections. To determine inducible and constitutive clindamycin resistance among clinical isolates of S. aureus in a tertiary care centre of sub Himalayan region of India. A total of 350 isolates of S. aureus from various clinical samples were subjected to routine antibiotic sensitivity testing by Kirby Bauer disc diffusion method. Methicillin resistance was detected by cefoxitin (30μg) disc. All isolates were subjected to inducible clindamycin resistance was by Clinical Laboratory Standards Institute (CLSI) recommended D test. Among 350 S.aureus isolates, 82 (23.42%) were MRSA and 268 (76.57%) were MSSA. Erythromycin resistance was detected in 137 (39.14%) isolates. Erythromycin resistance in MRSA and MSSA was 71.6% and 29.36% respectively. Overall clindamycin resistance was seen in 108 (30.85%) isolates. Constitutive MSLB phenotype predominated (29.62% MRSA; 13.38% MSSA) followed by iMLSB (28.39% MRSA; 9.29% MSSA) and MS phenotypes (13.58% MRSA; 6.69%MSSA). Both inducible and constitutive clindamycin resistance was significantly higher (p=0.00001, 0.0008 respectively) in methicillin resistant strains than in methicillin susceptible strains. The present study gives a magnitude of clindamycin resistance among clinical isolates of S. aureus from this region of the country. Our study recommends routine testing of inducible clindamycin resistance at individual settings to guide optimum therapy and to avoid treatment failure.

To support the role of insects as sustainable feed and food ingredients, evaluating their potential microbiological risk and safety is crucial. In this study, we investigated the presence of antimicrobial resistance (AMR) genes in selected live opportunistic pathogenic bacteria isolated during the rearing process from clinically healthy farm-reared crickets. Molecular analysis was performed by wholegenome sequencing of a total of 14 of these bacterial strains, 7 from house crickets (Acheta domesticus) and 7 from banded crickets (Gryllodes sigillatus), belonging to Enterobacteriaceae, Staphylococcaceae, Enterococcaceae, and Bacillaceae families. The β-lactam AMR genes (blaOXY2-6, blaACT-16, and blaSHV variants) were the most predominant genes identified, mainly in Enterobacteriaceae strains and in association with fosfomycin (fosA) and oqxAB efflux pump complexes. In addition, blaZ and mecA genes were detected in Bacillus cereus and Mammaliicoccus sciuri strains isolated from both insect species. Genetic mobile elements including IncFIA, IncFIB, IncHI1A, IncHI1B, rep13, and Col3M-like plasmids were detected in Klebsiella pneumoniae, Enterobacter hormaechei, Staphylococcus arlettae, and B. cereus, respectively. The results indicate that, not only in the final product but also during the insect-rearing process, microbial safety control, regarding the presence of pathogenic bacteria and AMR genes, is essential for effectively decreasing the microbiological risk between cricket batches within their environment and in terms of the related feed and food chain.

To evaluate the rates of penicillin, clindamycin and erythromycin resistance and the serotype distribution among isolates of group B streptococcus (GBS) obtained from pregnant women at the University Hospital of Bern in Switzerland. We prospectively collected screening samples for GBS colonisation at the University Women's Hospital Bern, Switzerland, between March 2009 and August 2010. We included 364 GBS isolates collected from vaginal, cervical or vaginal-perianal swabs at any gestation time. The minimal inhibitory concentrations for penicillin, clindamycin and erythromycin were established using Etest with 24 hours of incubation, and inducible clindamycin resistance was tested with double disk diffusion tests. Serotyping was done with a rapid latex agglutination test or, if not conclusive, with polymerase chain-reaction (PCR) testing. We looked for significant associations between resistance patterns, age groups, serotype and ethnicity. All isolates were susceptible to penicillin. Resistance rates were 14.5% for erythromycin and 8.2% for clindamycin. Of 364 isolates, 5.8% were susceptible to clindamycin but not to erythromycin, although demonstrating inducible clindamycin resistance. Hence, the final reported clindamycin resistance rate was 14%. Serotype III was the most frequent serotype (29%), followed by V (25%) and Ia (19%). Serotype V was associated with erythromycin resistance (p = 0.0007). In comparison with all other ethnicities, patients from Asia showed a higher proportion of erythromycin and clindamycin resistance (p = 0.018). No significant association between resistance patterns and age groups was found. In pregnant women with GBS colonisation, penicillin is the antibiotic of choice for intrapartum prophylaxis to prevent neonatal early-onset GBS sepsis. In women with penicillin allergy and at high risk for anaphylactic reaction, clindamycin may be an alternative. The resistance rate for clindamycin at our institution was 14%; therefore, susceptibility must be tested before administration.

Background Antimicrobial resistance (AMR) is a growing global public health threat. In 2019, resistant bacterial infections and respiratory tract infections were a leading cause of death in children worldwide. While the gut is a known reservoir of AMR genes, there is little data on the AMR burden in the respiratory tract. We used metagenomic RNA next-generation sequencing (mNGS) to describe bacterial AMR genes detected in the upper respiratory tract of children and compare with adults. Methods We leveraged two established cohort studies of children and adults diagnosed with acute respiratory illnesses in the inpatient and outpatient setting in California and Colorado. Nasopharyngeal (NP) swabs were collected between March to September 2020. Specimens underwent RNA extraction and paired-end Illumina sequencing. AMR genes were detected using the ARG-ANNOT database and the CZID pipeline. Children ≤18 years of age and adults≥ 40 years of age were eligible for inclusion in the analysis. We described and compared AMR genes and AMR gene classes detected in children and adults. P-values were calculated using the Wilcoxon rank-sum test. A multiple logistic regression model was fitted to evaluate the association of age cohort (children vs adults) with presence of AMR genes, while accounting for possible confounding from sex and encounter setting. 95% confidence intervals (CI) were calculated using the Wald CI. Results NP swab mNGS data from 236 patients (82 children, 154 adults) were analyzed. Children were a median age of 4 years (range: 0-17 years), and adults were a median age of 62 years (range: 40-89 years). Both cohorts were 50% male. AMR genes were detected in 44 (54%) children and 109 (71%) adults. Genes conferring resistance to beta-lactams (n=112, 47%), macrolides (n=89, 38%), and tetracyclines (n=72, 31%) were the most frequently detected. Among children, children ages 0 to 2 years had a higher number of AMR genes than children of other age groups, particularly when compared with children ages 3 to 10 years (p-value: 0.031) (Figure 1A). When comparing children with adults, children had fewer AMR genes (p-value: 0.014) as well as fewer AMR gene classes (p-value: 0.031) (Figure 1B). In the multiple logistic regression model, children still had lower odds of any AMR genes detected compared with adults (odds ratio: 0.39, 95% CI: 0.21-0.71). Figure 1. Box plots of (A) the number of antimicrobial resistance (AMR) genes detected in children stratified by age, and (B) the number of AMR genes and AMR gene classes detected in children (n=82) and adults (n=154). The size of the individual data points within the box plots correlates with the number of patients at each data point. Conclusion Children had fewer AMR genes and gene classes than adults in their upper respiratory tract microbiome. Despite this, over half of the children had detectable resistance genes, and children 2 years and younger had more AMR genes than other children. Almost half of the children had resistance genes to beta-lactams, the most frequently prescribed antibiotics to children. These findings suggest that presence of AMR organisms in the airway is common even in children, and that continued efforts to reduce AMR burden in this population are essential.

ABSTRACTWe describe results from a multicenter study evaluating the Accelerate Pheno system, a first of its kind diagnostic system that rapidly identifies common bloodstream pathogens from positive blood cultures within 90 min and determines bacterial phenotypic antimicrobial susceptibility testing (AST) results within ∼7 h. A combination of fresh clinical and seeded blood cultures were tested, and results from the Accelerate Pheno system were compared to Vitek 2 results for identification (ID) and broth microdilution or disk diffusion for AST. The Accelerate Pheno system accurately identified 14 common bacterial pathogens and two Candida spp. with sensitivities ranging from 94.6 to 100%. Of fresh positive blood cultures, 89% received a monomicrobial call with a positive predictive value of 97.3%. Six common Gram-positive cocci were evaluated for ID. Five were tested against eight antibiotics, two resistance phenotypes (methicillin-resistant Staphylococcus aureus and Staphylococcus spp. [MRSA/MRS]), and inducible clindamycin resistance (MLSb). From the 4,142 AST results, the overall essential agreement (EA) and categorical agreement (CA) were 97.6% and 97.9%, respectively. Overall very major error (VME), major error (ME), and minor error (mE) rates were 1.0%, 0.7%, and 1.3%, respectively. Eight species of Gram-negative rods were evaluated against 15 antibiotics. From the 6,331 AST results, overall EA and CA were 95.4% and 94.3%, respectively. Overall VME, ME, and mE rates were 0.5%, 0.9%, and 4.8%, respectively. The Accelerate Pheno system has the unique ability to identify and provide phenotypic MIC and categorical AST results in a few hours directly from positive blood culture bottles and support accurate antimicrobial adjustment.

Clindamycin can serve as an alternative treatment for staphylococcal infections. Routine susceptibility tests may fail to determine inducible type clindamycin resistance and can be a source of failure in clinical therapeutics. Therefore, this study aimed to determine Staphylococcus aureus (S. aureus) prevalence, inducible clindamycin resistance pattern, and associated factors among patients attending the University of Gondar Comprehensive Specialized Hospital, Gondar, northwest Ethiopia. Methods. A cross-sectional study was conducted from January to April 2018. Clinical samples were inoculated on appropriate culture media. Standard bacteriological tests, including Gram stain, catalase, and coagulase tests, identified the presence of S. aureus. The antimicrobial susceptibility tests and the D-test were performed by using the Kirby–Bauer disk diffusion technique on the Mueller–Hinton agar. The D-test was performed using clindamycin (CLI) 2 ug and erythromycin (ERY) 15 ug disks located approximately 15 mm apart, and the cefoxitin susceptibility test was used to characterize methicillin-resistant S. aureus (MRSA). The association between S. aureus infection and different variables was assessed using bivariate and multivariate analysis. A P value <0.05 was considered statistically significant. Result. Of 388 study participants, the overall prevalence of S. aureus was 17% (66/388). Of these, the inducible type of clindamycin resistance was 25.8% (17/66) and 21.2% (14/66) were MRSA. All isolates were susceptible to chloramphenicol and resistant to tetracycline. A family size of 4–6 (AOR = 2.627, 95% CI (1.030–6.702)) and >7 (AOR = 3.892, 95% CI (1.169–12.959)), inpatient study participants (AOR = 3.198, 95% CI (1.197–8.070)), illness in the previous 4 weeks (AOR = 2.116, 95% CI (1.080–4.145)), and a history of chronic disease (AOR = 0.265, 95% CI (0.094–0.750)) were likely to have S. aureus infection. Conclusion. This study shows a considerable high magnitude of MRSA and inducible clindamycin resistance S. aureus isolates. To rule out clindamycin susceptibility testing, the D-test should be routinely performed.

BackgroundSurveillance of commensal Escherichia coli, a possible reservoir of antimicrobial resistance (AMR) genes, is important as they pose a risk to human and animal health. Most surveillance activities rely on phenotypic characterisation, but whole genome sequencing (WGS) presents an alternative.AimIn this retrospective study, we tested 515 E. coli isolated from pigs to evaluate the use of WGS to predict resistance phenotype.MethodsMinimum inhibitory concentration (MIC) was determined for nine antimicrobials of clinical and veterinary importance. Deviation from wild-type, fully-susceptible MIC was assessed using European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological cut-off (ECOFF) values. Presence of AMR genes and mutations were determined using APHA SeqFinder. Statistical two-by-two table analysis and Cohen’s kappa (k) test were applied to assess genotype and phenotype concordance.ResultsOverall, correlation of WGS with susceptibility to the nine antimicrobials was 98.9% for test specificity, and 97.5% for the positive predictive value of a test. The overall kappa score (k = 0.914) indicated AMR gene presence was highly predictive of reduced susceptibility and showed excellent correlation with MIC. However, there was variation for each antimicrobial; five showed excellent correlation; four very good and one moderate. Suggested ECOFF adjustments increased concordance between genotypic data and kappa values for four antimicrobials.ConclusionWGS is a powerful tool for accurately predicting AMR that can be used for national surveillance purposes. Additionally, it can detect resistance genes from a wider panel of antimicrobials whose phenotypes are currently not monitored but may be of importance in the future.

Simple SummaryWorldwide, antimicrobial resistance (AMR) is of major concern for human and animal health since infections with multidrug-resistant bacteria are often more challenging and costly. In the family Staphyloccocaceae, the species Staphylococcusaureus in particular was reported to cause severe infections. Although most of the other Staphylococcaceae members were not shown to cause severe illnesses, the transmission of AMR genes to harmful species might take place. Therefore, the monitoring of AMR potential in different environments is of high relevance. Mammaliicocci on dairy farms might represent such an AMR gene reservoir. Thus, in this study, the AMR potential of mammaliicocci isolates from German dairy farms was investigated. Whole-genome sequencing (WGS) of the isolates was conducted to evaluate the phylogenetic relationship of the isolates and analyze AMR genes. In addition, antimicrobial susceptibility testing was performed to compare the AMR genotype with the phenotype. It turned out that mammaliicocci may harbor large numbers of different AMR genes and exhibit phenotypic resistance to various antibiotics. Since some AMR genes are likely located on mobile genetic elements, such as plasmids, AMR gene transmission between members of the Staphylococcaceae family might occur.Mammaliicocci might play a major role in antimicrobial resistance (AMR) gene transmission between organisms of the family Staphylococcaceae, such as the potentially pathogenic species Staphylococcus aureus. The interest of this study was to analyze AMR profiles of mammaliicocci from German dairy farms to evaluate the AMR transmission potential. In total, 65 mammaliicocci isolates from 17 dairy farms with a history of MRSA detection were analyzed for AMR genotypes and phenotypes using whole genome sequencing and antimicrobial susceptibility testing against 19 antibiotics. The various genotypic and phenotypic AMR profiles of mammaliicocci from German dairy farms indicated the simultaneous occurrence of several different strains on the farms. The isolates exhibited a non-wildtype phenotype to penicillin (58/64), cefoxitin (25/64), chloramphenicol (26/64), ciprofloxacin (25/64), clindamycin (49/64), erythromycin (17/64), fusidic acid (61/64), gentamicin (8/64), kanamycin (9/64), linezolid (1/64), mupirocin (4/64), rifampicin (1/64), sulfamethoxazol (1/64), streptomycin (20/64), quinupristin/dalfopristin (26/64), tetracycline (37/64), tiamulin (59/64), and trimethoprim (30/64). Corresponding AMR genes against several antimicrobial classes were detected. Linezolid resistance was associated with the cfr gene in the respective isolate. However, discrepancies between genotypic prediction and phenotypic resistance profiles, such as for fusidic acid and tiamulin, were also observed. In conclusion, mammaliicocci from dairy farms may carry a broad variety of antimicrobial resistance genes and exhibit non-wildtype phenotypes to several antimicrobial classes; therefore, they may represent an important source for horizontal gene transfer of AMR genes to pathogenic Staphylococcaceae.

Staphylococcus aureus and coagulase-negative staphylococci (CNS) are recognized as causing nosocomial and community-acquired infections in every region of the world. The resistance to antimicrobial agents among staphylococci is an increasing problem. Clindamycin (CL) is considered to be one of the alternative agents in these infections. This study demonstrates a simple, reliable method (double-disc diffusion test) for detecting inducible resistance to CL in erythromycin-resistance (ER-R) isolates of S. aureus and CNS. A total of 883 (52.3%) isolates of S. aureus and 804 (47.7%) isolates of CNS were selected from recent (2003-2005) clinical isolates recovered in the laboratory of the authors; duplicate isolates were not included. A total of 214 (12.6%) S. aureus and 308 (18.3%) CNS isolates were selected based on ER-R and CL sensitivity using standard National Committee for Clinical Laboratory Standards disc diffusion testing. A total of 1687 staphylococcal isolates were included, consisting of 27.5% meticillin-resistant S. aureus, 24.8% meticillin-sensitive S. aureus, 36.1% meticillin-resistant CNS and 11.6% meticillin-sensitive CNS isolates: 30.9% of staphylococcal isolates (214 S. aureus and 308 CNS) that were erythromycin resistant and CL sensitive were tested for inducible resistance using the D-test. A D-shaped zone around the CL was observed for 70.9% of staphylococcal isolates (81.8% of S. aureus isolates and 63.3% of CNS isolates) with an ER-R and a clindamycin-sensitive (CL-S) phenotype. The organism was positive for inducible clindamycin resistance (CL-R). There was a 21.9% level of inducible macrolide-lincosamide-streptogramin B resistance phenotype among all the staphylococcal isolates. When the S. aureus and CNS strains among all the staphylococcal isolates were compared statistically, inducible CL-R in CNS strains was determined to be 23% more positive (P=0.028, odds ratio 0.77, 95% confidence interval 0.61-0.98). When a statistical comparison was performed among ER-R but CL-S staphylococcal isolates inducible CL-R in S. aureus strains was determined to be 2.6 times more positive (P=0.000, odds ratio 2.6, 95% confidence interval 1.68-4.04). A simple, reliable method of detecting inducible resistance to CL in ER-R isolates of S. aureus and CNS is described. Clinical microbiology laboratories should use the double-disc diffusion test as standard practice with all ER-R staphylococci. CL should not be used in patients with infections caused by inducibly resistant staphylococcal isolates. Therapeutic failures may thus be avoided.

Background: Streptococcus group B (GBS) or Streptococcus agalactiae is typically associated with neonatal disease and infection in pregnant women. Mortality of GBS sepsis in neonates is over 50% and is particularly high in preterm infants. GBS also causes invasive infection in pregnant and non-pregnant women including urinary tract infection (UTI). Penicillin-derived antibiotics remained as choice drugs for treatment of GBS infection; however, Erythromycin and Clindamycin are useful in cases of allergic to Penicillin. The aim of this study was to investigate the resistance to Erythromycin and Clindamycin, especially inducible Clindamycin resistance, in GBS isolated from urinary samples of women who attended medical offices in Tehran, Iran. M aterials and Methods: This study was conducted on 5000 urine samples from Jan. 2011 to Oct. 2012 that 104 GBS were isolated. The isolates were identified as GBS using laboratory criteria. Antimicrobial susceptibility test was done by Erythromycin disk 15µg and Clindamycin disk 2µg for observation inducible resistant D-zone test by double-disk diffusion method with Erythromycin and adjacent Clindamycin. R es ults: Among the 5000 urine samples 104 (2.08%) were Beta hemolytic GBS. Of the 104 isolated GBS, 22 (21.2%) were resistance, 24 (23%) were intermediate, and 58 (55.8%) were susceptible to Erythromycin; however, 24 (23%) were resistance, 5 (4.8%) were intermediate, and 75 (72.2%) were susceptible to Clindamycin. Of the 22 Erythromycin-resistant isolates, 10 (9.5% in total GBS isolated) displayed the D zone; it means they have inducible Erythromycin resistant to Clindamycin. C onclusion: Various studies in other countries report lower rates of inducible Clindamycin resistance; it indicates the use of more macrolides in the treatment of UTI.

BackgroundThe BioFire® FilmArray® Blood Culture Identification 2 (BCID2) Panel is a diagnostic test that provides results for 26 bacterial, 7 fungal pathogens and 10 antimicrobial resistance (AMR) genes from positive blood culture (PBC) specimens in about an hour. The BCID2 Panel builds upon the existing BCID Panel with several additional assays that include Candida auris and an expanded AMR gene menu that provides methicillin-resistant Staphylococcus aureus (MRSA) results plus detection for mcr-1, carbapenem resistance, and ESBL. Here, we summarize studies conducted to establish clinical performance using an Investigational Use Only version of the BCID2 Panel.MethodsThree studies were performed. The first involves prospective collection and testing of an expected ~1,000 residual PBCs at 7 US and 2 EU sites, which began in October 2018 and will conclude in June 2019. BCID2 Panel performance is compared with reference methods of microbial culture as well as PCR/sequencing for AMR genes. In addition, BCID2 Panel MRSA results are compared with the FDA-cleared Xpert MRSA/SA BC system (Cepheid, Inc). Relevant bacterial isolates recovered from PBCs are also evaluated by various phenotypic antimicrobial susceptibility testing (AST) methods. The prospective evaluation is supplemented with a second study that involves testing of ~300 pre-selected, archived PBCs containing rare organisms. The third study includes over 500 seeded blood cultures containing very rare organisms with an evaluation of co-spiked samples.ResultsWith over 1,200 samples tested to date (out of an anticipated 1,800 total), the BCID2 Panel has demonstrated an overall sensitivity of >98% and specificity of >99% for identification of microorganisms compared with culture. Concordance between the BCID2 Panel and the Xpert MRSA/SA BC test is >99% for identification of MRSA. Evaluation of BCID2 Panel AMR gene detection relative to AST and PCR is ongoing.ConclusionThe FilmArray® BCID2 Panel appears to be a sensitive, specific, and robust test for rapid detection of microorganisms and MRSA in PBCs. With the use of this comprehensive test, improved antimicrobial stewardship is anticipated.DisclosuresAll authors: No reported disclosures

The increasing incidence of erythromycin and erythromycin-induced resistance to clindamycin among Staphylococcus aureus (S. aureus) is a serious problem. Patients infected with inducible resistance phenotypes may fail to respond to clindamycin. This study aimed to identify the prevalence of erythromycin and erythromycin-induced resistance and assess for potential inhibitors. A total of 99 isolates were purified from various clinical sources. Phenotypic detection of macrolide-lincosamide-streptogramin B (MLSB)-resistance phenotypes was performed by D-test. MLSB-resistance genes were identified using PCR. Different compounds were tested for their effects on erythromycin and inducible clindamycin resistance by broth microdilution and checkerboard microdilution methods. The obtained data were evaluated using docking analysis. Ninety-one isolates were S. aureus. The prevalence of constitutive MLSB, inducible MLSB, and macrolide-streptogramin (MS) phenotypes was 39.6%, 14.3%, and 2.2%, respectively. Genes including ermC, ermA, ermB, msrA, msrB, lnuA, and mphC were found in 82.6%, 5.8%, 7.7%, 3.8%, 3.8%, 13.5%, and 3.8% of isolates, respectively. Erythromycin resistance was significantly reduced by doxorubicin, neomycin, and omeprazole. Quinine, ketoprofen, and fosfomycin combated and reversed erythromycin/clindamycin-induced resistance. This study highlighted the significance of managing antibiotic resistance and overcoming clindamycin treatment failure. Doxorubicin, neomycin, omeprazole, quinine, ketoprofen, and fosfomycin could be potential inhibitors of erythromycin and inducible clindamycin resistance.

Backround: Serious infections due to methicillin resistant Staphylococcus aureus (MRSA) have become a major clinical challenge. Globally Macrolide-lincosamide streptogramin B family of antibiotics are commonly used to treat such infections as an alternative to vancomycin. The study was to conducted to find out the presence of inducible clindamycin resistance among Staphylococcus aureus and their association with methicillin resistance. Method: The study conducted over one year (Jan 2016 - Dec 2016) in microbiology department of Guru Gobind Singh Medical College, Faridkot. Two hundred fifteen S.aureus isolates were included in the study. Methicillin resistance was detected by cefoxitin (30μg) disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-Test). Results: Of the 215 clinical isolates of S. aureus , 140 (65.11%) were MRSA. Erythromycin and clindamycin resistance was seen in 79.06%(170/215) and 49.30% ( 106/215) respectively. Resistance to erythromycin and clindamycin were higher in MRSA than MSSA (erythromycin resistance:100%v s 22.5% and Clindamycin resistance:70.1% vs 10.6%). Both iMLSB and cMLSBphenotypes are predominant in MRSA. Conclusion: Detection of MRSA in our study shows the need to improve health care practices and to formulate new infection control policies to control MRSA infections. Inducible and constitutive resistance is comparatively higher in our study in MRSA .So It is necessary to perform D-test for detection of inducible clindamycin resistance among MRSA in routine antibiotic sensitivity testing so that therapeutic failures can be avoided.