Molecular Typing and Resistance Profiles of Vancomycin-Intermediate Staphylococcus aureus in Korea: Results from a National Surveillance Study, 2007-2013.
- Author:
Jung Wook KIM
1
;
Gi Su KANG
;
Jae Il YOO
;
Hwa Su KIM
;
Yeong Seon LEE
;
Jae Yon YU
;
Kwang Jun LEE
;
Chan PARK
;
Il Hwan KIM
Author Information
- Publication Type:Original Article
- Keywords: Sequence type; Vancomycin-intermediate Staphylococcus aureus
- MeSH: Agar; Anti-Infective Agents; Brain; Clone Cells; Daptomycin; Erythromycin; Genotype; Heart; Hospitals, General; Korea*; Linezolid; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Epidemiology; Molecular Typing*; Multilocus Sequence Typing; Prevalence; Staphylococcus aureus*; Staphylococcus*; Trimethoprim, Sulfamethoxazole Drug Combination; Vancomycin
- From:Annals of Clinical Microbiology 2016;19(4):88-96
- CountryRepublic of Korea
- Language:English
- Abstract: BACKGROUND: To investigate the national molecular epidemiology and resistance profiles of vancomycin-intermediate Staphylococcus aureus (VISA), we analyzed the characteristics of methicillin-resistant Staphylococcus aureus (MRSA) collected 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 12-week period in each year from 2007 to 2013. METHODS: VISA was defined by agar dilution, broth dilution and E-test methods with vancomycin minimum inhibitory concentrations of >2 μg/mL. All VISA isolates were characterized by multilocus sequence typing, staphylococcal cassette chromosome mec typing, spa typing, accessory gene regulator typing, Diversilab analysis, and antibiogram analysis. RESULTS: Of 109,345 MRSA isolates, 87,354 were screened and 426 isolates were identified as positive on brain heart infusion agar containing 4 μg/mL vancomycin (BHI-V4). Of 426 isolates, 76 isolates were identified as VISA. No VRSA isolates were detected among the isolates. Overall, a total of 6 genotypes were identified among VISA strains and the predominant clones were ST5-II-t2460, ST72-IV-t324, and ST239-III-t037 (44.7%, 15.8%, and 10.5%, respectively). Of note, ST72-IV-t324 clones are known to be a typical community-associated MRSA. ST239-III-t037 strains were more resistant to trimethoprim-sulfamethoxazole than any other type of strain. ST72-IV-t324 strains were susceptible to all of the antimicrobial agents tested except erythromycin and daptomycin. All of the VISA isolates were susceptible to linezolid and quinupristin-dalfopristin. CONCLUSION: Although VRSA is still rare, continuous monitoring of VRSA occurrence is needed, as well as VISA prevalence, epidemic clonal shift, and antimicrobial resistance.
