species identification and inv estigation of vancomycin and high-level aminoglycoside among clinical isolates of enterococcal strains

a study was performed to determine the species and antimicrobial susceptibility of 100 enterococcus strains from various clinical specimens as etiological agents at the clinical microbiology laboratory, istanbul university, medical faculty hospital. out of 100 enterococcal isolates, 86 were identified as e. faecalis, 11 as e. faecium, 1 as e. avium and 2 as e. raffinosus. by the disk diffusion tests 36 of 100 strains were found to be resistant to erythromycin, 32 to penicillin, 30 to ampicillin, 7 to ciprofloxacin, 6 to norfloxacin and 5 to nitrofurantoin. no resistance was observed to vancomycin or teicoplanin. twenty-six strains showed high-level resistance to streptomycin (2000 )..lg/ml) and 13 strains exhibited high-level resistance to gentamicin (500 )..lg/ml). ten of these strains had high-level resistance to both aminoglycosides. none of the strains produced beta -lactamase.