Antibiotic resistance of enterococci isolated from blood cultures during 2003–2006

Abstract number: 1733_381

Arslan U., Feyzioglu B., Uysal E.B., Tuncer E.I., Findik D.

Objectives: Enterecocci have become a significant problem due to their aetiologic role in bacterial infections. An alarming problem is the increasing rate of enterococci resistant to vancomycin (VRE) and therefore the source and spreading of these strains are very important epidemiological problems. The aim of the study was to evaluate antibiotic resistance and monitoring of VRE isolated from blood cultures during July 2003 – October 2006 in our hospital.

Methods: A total of 138 strains of enterococci were isolated from blood cultures. The identification of the isolated bacteria was performed by conventional methods and bioMérieux API 20 STREP test (Marcy I'Etoile, France). The susceptibility testing was carried out by disc-diffusion method and Etest. Determination of glycopeptide resistance genotypes (van A, van B, van C1, van C2/3) of VRE was performed by GenoType Enterococcus assay (Hain Lifescience GmbH, Nehren, Germany).

Results: Of the 138 enterococci strains isolated 72 strains were E. faecium, 59 E. faecalis, five E. gallinarum, two E. casseliflavus. 123 (89.1%) enterococ strains were isolated from inpatients. 53 (38.4%) of them were isolated from intensive care units, 40 (29%) from medical units, 28 (20.3%) from paediatric units, 17 (12.3%) from surgery units. A total of 108 strains were resistant to ampicillin (78.3%), 58 to high level gentamycin (42.0%) and 9 to vancomycin and teicoplanin (6.5%). All of VRE strains was identified as E. faecium. All of the VRE strains were susceptible only to linezolide. VRE showing high resistance to vancomycin and teicoplanin suggest the presence of Van A phenotype. In all of the VRE strains with glycopeptide resistance genotypes we detected Van A genotype.

Conclusion: This study indicates that in our hospital Enterecoccus spp. shows high resistance to high level aminoglycosides and to aminopenicillins and VRE strains carry Van A gene.