Prevalence of Vancomycin and Teicoplanin Resistant Enterococcus faecalis and Enterococcus faecium Isolated from Fecal Samples of Healthy Individuals and Hospital Environmental Samples

Abstract

Background and purpose: Glycopeptide resistance genes can be transmitted to clinical strains from gram-positive environmental bacteria and the normal flora. The aim of this study was to evaluate the prevalence of vancomycin and teicoplanin-resistant Enterococcus faecalis and Enterococcus faecium isolates in hospital environment and fecal samples of healthy individuals. Materials and methods: Human stool and hospital environment samples were collected and inoculated on selective M-enterococcus agar medium. Then, E. faecalis and E. faecium were identified using phenotypic and molecular methods. Antibiotic susceptibility pattern of the isolates against teicoplanin and vancomycin was determined by micro-broth dilution method. Data were analyzed in SPSS applying Chi-square test. Results: From 145 isolates, E. faecalis and E. faecium were detected in 84 (54.93%) and 61 (42.07%) isolates, respectively. One (1.19%) E. faecalis isolate and 4 (6.56%) E. faecium isolates were resistant to vancomycin, while 4 (6.56%) E. faecium isolates were found to be resistant to teicoplanin. The minimum inhibitory concentrations of 50 (MIC50) and 90 (MIC90) for vancomycin and teicoplanin in E. faecalis and E. faecium were 4 and 16 μg/ml, respectively. Conclusion: The MIC results of vancomycin and teicoplanin showed that most of enterococci isolates studied were sensitive to these two antibiotics. Therefore, their use should be closely monitored to prevent resistance.

Keywords

• enterococcus faecalis
• enterococcus faecium
• vancomycin
• teicoplanin
• healthy individuals
• hospital environment