Antibiotic Resistance and Biofilm Formation of Enterococcus faecalis in Patient and Environmental Samples

Enterococci are opportunistic pathogens and are a major factor in nosocomial infections. They may contain ebp operon, which upon expression makes them highly prone to biofilm formation on biotic and abiotic surfaces.

The aim of the current study was to detect the polymorphism of ebp genes in Enterococcus faecalis.

Samples were isolated from patients (n = 58) and hospital environments (n = 32) of two hospitals in Tehran, Iran. All enterococcal species were identified by species-specific polymerase chain reaction (PCR); the antibiotic resistance pattern against nine antibiotics was determined. The ebp A, ebp B, ebp C and srt C genes were detected by PCR and the biofilm formation by the isolates was evaluated using the microtiter plate method. The genetic diversity of ebp genes was analyzed by restriction fragment length polymorphism (RFLP).

The results indicated that, 86% of patient and 29% of environmental isolates carried ebp genes. The ability of the isolates to strongly attach was 62% and 71% for patient and environmental samples, respectively. The RFLP of the ebp showed no genetic variations amongst the isolates.

The results of the antibiotic resistance and other data suggest that there is a possible common clone of E. faecalis, which could rapidly disseminate in patients and the environment.