Objective: To determine the trends of antimicrobial susceptibility of enterococci in Thailand from 2000 to 2005.
Material and method: All enterococcal isolates from sterile site obtained from 28 hospitals in Thailand from 2000 to 2005 were tested for their susceptibility to ampicillin, high-level gentamicin, and vancomycin by the disk diffusion (Kirby Bauer) method. The relevant data were collected and analyzed by WHONET software program supported by the World Health Organization.
Results: Enterococcus faecalis (47%) and E. faecium (23%) were the two most frequent enterococcal isolates. There was no trend of increasing resistance to ampicillin, high level gentamicin, and vancomycin among E. faecalis isolates during the study period. There was a trend of an increasing resistance to ampicillin and high-level gentamicin among E. faecium isolates. Among E. faecium, the rates of vancomycin resistance were very low, ranging from 0.5% to 1.9%, and there was no trend of increasing rates of resistance.
Conclusion: In the present study, there is a trend of decreasing susceptibility to ampicillin and high-level gentamicin in E. faecium. In contrast, there is no trend of increasing resistance to vancomycin. This would have effects on selection of empirical antimicrobial treatment on enterococcal infections especially a decision to use ampicillin or gentamicin.