Objective: In recent years, enterococci which are the leading causes of nosocomial infections, have become increasingly resistant to a wide range of antimicrobial agents. The aim of this study was to determine the antimicrobial resistance rates of Enterococcus faecalis and Enterococcus faecium strains isolated from blood cultures of patients hospitalized in Meram Medical Faculty Hospital, Selçuk University, Konya, Turkey.

Materials and Methods: Antibiotic resistance of Enterococcus strains isolated from blood cultures between 2007 and 2010 were assessed retrospectively. The isolates were identified by conventional methods and Phoenix 100 BD automated system (Becton Dickinson Diagnostic Systems, Sparks). Antibiotic susceptibility tests were performed by the Kirby-Bauer disk-diffusion method according to the standards of Clinical and Laboratory Standards Institute (CLSI). Minimum inhibitory concentrations (MIC) were determined by Etest method for all isolates showing decreased susceptibility to vancomycin by the disk diffusion method.

Results: Of the 306 Enterococcus strains evaluated, 164 were identified as E. faecalis and 142 as E. faecium. Resistance rates of E. faecium and E. faecalis strain isolates against ampicillin, ciprofloxacin, vancomycin, teicoplanin, and linezolid were 93.7, 85.2, 16.2, 16.2, 2.1%, and 6.1%, 61%, 3%, 1.8%, 2.4%, respectively. High-level resistance to gentamicin and streptomycin were determined in 66.2%, 66.9% of E. faecium strains and in 42.7%, 52.4% of E. faecalis strains, respectively. MIC values of vancomycin were determined as >256 μg/ml by E-test.

Conclusion: In infections caused by enterococci, isolation of the infectious agent, accurate identification, determination of their antimicrobial susceptibilities, and clinicians' knowledge about antimicrobial patterns effective on the bacterial spectrum in their region are quiet important.