Abstract

Enterococci are one of the leading causes of nosocomial infections worldwide. Enterococcus faecalis and Enterococcus faecium are the most commonly isolated. The aim of this study was to determine prevalence of these species isolated from blood samples of hospitalized patients and their susceptibility to antibiotics particularly to vancomycin and high concentrations of aminoglycosides. A total of 89 enterococcal strains isolated from blood samples between January 1^st 2011 and August 31^st 2013 were tested. The species identification and susceptibility to antimicrobial drugs were performed using automated VITEK 2 system. The most common species was E. faecalis (55.05%), followed by E. faecium (41.57%). The enterococcal isolates were multidrug resistant with E. faecium resistance to vancomycin of 54.05%, while resistance in E. faecalis was not found. All vancomycin resistant enterococci had VanA phenotype of resistance. Thirty three (89.18%) isolates of E. faecium were high-level gentamycin resistant and 32 (91.4%) were resistant to high concentration of streptomycin, whereas frequency of resistant E. faecalis was 61.2 and 63.04%, respectively. This study shows that resistance in enterococcal species is a serious clinical problem in our hospital and suggests the need for regular susceptibility test and species level identification of enterococcal isolates.

Key words: Enterococci, blood culture, antimicrobial resistance.

Abbreviation

E. faecalis, Enterococcus faecalis; E. faecium, Enterococcus faecium; ATCC, American Type Culture Collection; PBP, penicillin binding protein; HLAR, high-level aminoglycoside resistance; VRE, vancomycin resistant enterococci; SPSS, statistical package for the social sciences; ICU, intensive care unit.