Distribution of enterococcal species and detection of vancomycin resistance genes by multiplex PCR in Tehran sewage

BACKGROUND: Enterococci are important because of their role as the leading cause of nosocomial infections which have a significant role in the dissemination and persistence of antimicrobial resistance genes. METHODS: In this study, we determined the distribution of enterococcal species in the sewage treatment plants in Iran. Furthermore, we improved a rapid and specific PCR method using primers (sodA and ddl genes) for identification of enterococci spp. RESULTS AND CONCLUSION: A total number of 712 enterococci spp. were isolated and the results showed that 56%, 24%, 12%, 4%, 2%, 1% and 1% isolates were E. faecium, E. hirae, E. faecalis, E. gallinarum, E. casseliflavus, E. mundtii and other enterococcal spp., respectively. The use of species-specific PCR was in agreement with the biochemical tests. Furthermore, multiplex PCR was developed to study the presence of vancomycin resistant genes in E. faecium or E. faecalis. The multiplex PCR appeared to be a useful, rapid and specific method for detecting and discriminating genotypes for vancomycin-resistant Enterococcus.