ABSTRACT
Objective To investigate the change of antimicrobial resistance among gram-positive cocci from 1999 to 2006 in Beijing Chaoyang Hospital. Methods Antimicrobial susceptibility test was car-ried out by MIC method, data were analyzed by WHONET 5.3 software. Results A total of 6192 clinical isolates were collected. The top four pathogens were Staphylococcus coagulase-negative, Staphylococcus au-reus, Enterococcus faecalis and Enterococcus faecium. The prevalence of methicillin-resistant S. aureas and coagulase-negative were identified in 88.4% and 86.9%, respectively. The resistance rates of S. aureus to penicillin G and ampicillin were more than 90.0% during 1999-2006. Neither strains of S. aureus nor strains of coagulase-negative Staphylococcus were found resistant to vancomycin. Vancomyein-resistant Enterococci (VRE) strains were firstly isolated in 2003, thirteen vancomycin-resistant E.faecalis isolates were identified as VanB genotype by PCR and sequencing. The VanA gene was confirmed by PCR and sequencing in seven-teen vancomycin-resistant E.faecium, vancomycin-resistance E.faecium rate increased sharply. The most ac-tive antibiotics against E. faecalis were vancomycin, ampicillin, penicillin with the susceptible rates of 98.7%, 95.7% and 85.6%, however, the susceptibility rate of E. faecalis to penicillin decreased from 94.3%-84.6%. The resistance rates of E.faecalis to clindamycin was 99.0%. The resistance rates of E. faecium to erythromycin and clindamycin were more than 95.0%. The resistance rates of E.faecium to ampi-cillin, penicillin, ciprofloxacin were more than 90.0%. The most active antibiotics against E. faecium was vancomycin. The susceptibility rate of E.faecium to tetracycline increased from 27.8% to 82.6%. Conclu-sion Vancomycin remains highly active against gram-positive cocci. A total of 30 Enterococci isolates were found resistant to vancomycin.