Vancomycin resistant enterococcal (VRE) colonization among patients treated in intensive care units at the National Hospital of Sri Lanka, and determination of genotype/s responsible for resistance

Introduction: The aim of this study was to assess the epidemiology of VRE colonization among patients in the intensive care units (ICU) of the National Hospital of Sri Lanka (NHSL). Method: A cross sectional study was carried out on 218 patients admitted to 12 ICUs of the NHSL from January to March 2012. Rectal swabs were collected on day 0, 4, 8 and every 4th day thereafter till discharge. Enterococci were isolated on selective media and identified up to species level using standard bacteriological procedures. Standardized disc diffusion antibiotic susceptibility testing to ampicillin, teicoplanin and vancomycin was performed using the Clinical and Laboratory Standards Institute (CLSI) method. Minimum inhibitory concentrations to vancomycin were determined, using the E-test in strains showing intermediate or frank resistance to vancomycin by disc diffusion. Genotype determination (van A / van B) was carried out on isolates identified as VRE using the polymerase chain reaction. Patients positive for VRE colonization were followed up to discharge or death. Result: VRE prevalence in the study sample was 5%. Univariate analysis showed that the use of metronidazole (odds ratio [OR] :15.73;95% 95% confidence interval [CI] : 3.94-62.67,P<0.05) or teicoplanin (OR: 12.56; 95% CI:2.65 ­ 59.52, p< 0.05) and diabetes (OR: 05.13; 95% CI: 1.36 ­ 18.7, p< 0.05) or hemodialysis during ICU stay (OR: 7.38 ;95% CI : 1.69-32.16, P<0.05) were associated with an increased risk of VRE colonization. Conclusion: The 5% prevalence of VRE colonization detected signals the emergence of VRE in the intensive care setting in Sri Lanka.

Author Correction: Rapid susceptibility profiling of carbapenem-resistant Klebsiella pneumoniae.

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Rapid susceptibility profiling of carbapenem-resistant Klebsiella pneumoniae.

The expanding global distribution of multi-resistant Klebsiella pneumoniae demands faster antimicrobial susceptibility testing (AST) to guide antibiotic treatment. Current ASTs rely on time-consuming differentiation of resistance and susceptibility after initial isolation of bacteria from a clinical specimen. Here we describe a flow cytometry workflow to determine carbapenem susceptibility from bacterial cell characteristics in an international K. pneumoniae isolate collection (n = 48), with a range of carbapenemases. Our flow cytometry-assisted susceptibility test (FAST) method combines rapid qualitative susceptible/non-susceptible classification and quantitative MIC measurement in a single process completed shortly after receipt of a primary isolate (54 and 158 minutes respectively). The qualitative FAST results and FAST-derived MIC (MICFAST) correspond closely with broth microdilution MIC (MICBMD, Matthew's correlation coefficient 0.887), align with the international AST standard (ISO 200776-1; 2006) and could be used for rapid determination of antimicrobial susceptibility in a wider range of Gram negative and Gram positive bacteria.