Antimicrobial resistance surveillance of bacteria in 1999 in Korea with a special reference to resistance of enterococci to vancomycin and Gram-negative bacilli to third generation cephalosporin, imipenem, and fluoroquinolone

The trend of antimicrobial resistance of bacteria isolated from patients in 30 Korean hospitals in 1999 was analyzed with a particular attention to ce fotaximeor fluoroquinolone-resistant gram-negative bacilli, imipenem-resist ant Pseudomonas aeruginosa, and vancomycin-resistant enterococci. Adequacy of susceptibility testing, and any change in the frequencies of isolated sp ecies were also analyzed. The results showed that only 20% and 30% of hospi tals tested the piperacillin-tazobactam and cefoxitin susceptibility of Ent erobacteriaoeae, respectively, only 24% of hospitals the piperacillin-tazob actam susceptibility of P. aeruginosa, and 17% of hospitals the fusidic aci d susceptibility of staphylococci. Among the isolates 26.3% were glucose-no nfermenting gram-negative bacilli. and 34.7% of Enterococcus were Enterococ cus faecium, Slight decline of cefotaxime-resistance rate to 20% was noted in Klebsiella pneumoniae, while fluoroquinolone-resistantce rate was 68% in Acinetobacter baumannii. The ceftazidime- and imipenem-resistance rates we re 17% and 18%, respectively in P. aeruginosa, The vancomycin-resistance ra te of E. faecium rose significantly to 15.1%, but the rates varied signific antly depending on hospitals suggesting presence of different degree of sel ective pressure or nosocomial spread. In conclusion, the prevalence of imip enem-resistant P. aeruginosa and the increase of vancomycin-resistant E, fa ecium were the particularly worrisome phenomena observed in this study.