Antimicrobial Resistance of Clinically Important Bacteria Isolated from 12 Hospitals in Korea in 2004

Background: A rapid increase in antimicrobial-resistant bacteria has become a serious problem in many countries including Korea, but the rate and pattern of antimicrobial resistance may vary significantly depending on countries and even on hospitals. The aim of this study was to determine the nationwide prevalence of resistance among frequently isolated bacterial pathogens in Korea. Methods: Routine susceptibility data for medically important bacterial pathogens from 12 university hospital and general hospital laboratories in Korea were analysed by patient group. These pathogens had been isolated during the period from April to November in 2004. Results: The proportion of methicillin-resistant Staphylococcus aureus (MRSA) was 67%. Vancomycin-resistance rate of Enterococcus faecalis was 1% and that of E. faecium was 20%. The resistance rates of Streptococcus pneumoniae to penicillin and Haemophilus influenzae to ampicillin were 70% and 54%, respectively. The resistant rates of Escherichia coli and Klebsiella pneumoniae were 7-10% and 26-31% to the 3rd generation cephalosporin, respectively. The resistance rates to 3rd generation cephalosporin were 22-30% in Citrobacter freundii, 35-44% in Enterobacter cloacae and 15-22 % in Serratia marcescens. Imipenem resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii were 26% and 17%. Cotrimoxazole and levofloxacin resistance rates of Stenotrophomonas maltophilia were 46% and 44%, respectively. Conclusion: Antimicrobial resistance rates of clinically important pathogens in Korea were still high and were generally higher among the bacteria isolated from the intensive care unit patients. Strict infection control and continuous nationwide surveillance program will be required to manage the antimicrobial resistance problem.ope