Comparison of resistance in isolates of Enterococcus faecalis and Enterococcus faecium

Objectives: Enterococci are Gram positive cocci causing hospital- and community-acquired infections even though they are found in normal flora and they have low-virulence. Their most common species detected as the causative agent are Enterococcus faecalis and Enterococcus faecium. This study aimed to evaluate the differences between the antibiotic susceptibilities of the isolates of these two species isolated from various clinical specimens. Materials and methods: In this study, 68 enterococci strains (40 E.faecalis and 28 E.faecium) isolated from the specimens sent to the clinical microbiology laboratory of Zonguldak Karaelmas Practice and Research Hospital in 2007-2008 were evaluated. Identification at species level and the susceptibilities were performed by using MicroScan WalkAway system (Dade Behring, USA). Results: No resistance to glycopeptides were detected among these isolates. High rates of resistance to ciprofloxacin, rifampicin and erytromycin were observed. Resistance rates to penicillin, ampicillin, ciprofloxacin, rifampicin, erytromycin and high-level gentamicin and streptomycin in E.faecium isolates were found statistically higher than the rates of E.faecalis group (p<0.05). Conclusions: As concordant with the literature, this study observed that E.faecium isolates were significantly more resistant. In enterococcal infections, performing the identification at the species level and determining the antibiotic susceptibility will be helpful in managing of the treatment.