Nationwide surveillance study of vancomycin intermediate Staphylococcus aureus strains in Korean hospitals from 2001 to 2006.

We investigated the prevalence and the molecular characteristics of vancomycin-intermediate Staphylococcus aureus (VISA) among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from clinical samples at tertiary or general hospitals participating in a nationwide surveillance program for VISA and vancomycin-resistant Staphylococcus aureus (VRSA) in Korea during an 8-week period in each year from 2001 to 2006. Of 41,639 MRSAs isolated, 37,856 were screened and 169 grew on brain heart infusion agar supplemented with 4 microg/ml vancomycin. A vancomycin MIC of 4 microg/ml was confirmed for 33 VISA isolates of the 169 isolates. Eighteen of the 33 isolates were classified as hetero-VISA (hVISA) by the population analysis profile (PAP) method. All VISA isolates were susceptible to linezolid, tigecycline, and quinupristin-dalfopristin. Most VISA isolates (MIC 4 microg/ml) showed a PFGE C pattern with sec, seg, and sei enterotoxin genes, including ST5-SCCmec type II, or a PFGE A pattern with sea, including ST239-SCCmec type III.

Five-year report of national surveillance of antimicrobial resistance in Pseudomonas aeruginosa isolated from non-tertiary care hospitals in Korea (2002-2006).

A nationwide surveillance of the antimicrobial resistance of Pseudomonas aeruginosa isolates from non-tertiary care hospitals was conducted in Korea from 2002 to 2006. Resistance to almost all antimicrobial agents decreased significantly from 2003 (P < 0.01). Resistance rates to the major antipseudomonal agents, ceftazidime, imipenem, meropenem, and aztreonam, were 18.8%, 20.5%, 18.7%, and 19.7%, respectively, in 2003. However, they had all decreased to below 10% in 2006. The proportion of multidrug-resistant isolates that were resistant to at least 3 of 5 major antipseudomonal agent decreased from 33.5% in 2003 to 23.1% in 2006 (P < 0.05). In this study, we found a decreasing trend in resistance rates and low resistance rates in P. aeruginosa from non-tertiary care hospitals compared with those from general hospitals, including tertiary care hospitals, in Korea. Our data provide valuable information for the selection of reliable empiric therapies for P. aeruginosa infections in non-tertiary care hospital patients, including outpatients.

Antimicrobial resistance patterns (1999-2002) and characterization of ciprofloxacin-resistant Neisseria gonorrhoeae in Korea.

BACKGROUND: Antimicrobial susceptibilities of Neisseria gonorrhoeae were monitored during 4 years. In Korea, ciprofloxacin-resistant N. gonorrhoeae has dramatically increased after recommendation as a therapeutic drug. GOAL: The goal of this study was to determine the resistance patterns and characterize Korean ciprofloxacin-resistant N. gonorrhoeae. STUDY DESIGN: Antimicrobial susceptibilities were performed. PFGE profile and DNA sequencing of gyrA and parC genes were used to characterize the ciprofloxacin-resistant isolates in Korea. RESULTS: Tetracycline, ofloxacin, ciprofloxacin-resistant isolates were increased and among them, the proportion of isolates resistant to ciprofloxacin increased remarkably from 1% in 1999 to 48.8% in 2002. Fifteen different types by PFGE profile were identified. Major alteration type was M12 (67%), which have amino acid substitution in gyrA (S-91-->F, D-95-->G) and parC (S-87-->A). CONCLUSION: We could conclude that resistance for ciprofloxacin was remarkably increased during 4 years. Ciprofloxacin-resistant N. gonorrhoeae was supposed by the spread of several strains that had a small number of origins.