title: Genotype-specific prevalence of heterogeneous vancomycin-intermediate Staphylococcus aureus in Asian countries.
abstract: Although heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) has been increasingly reported, the true prevalence of hVISA is unclear, especially in Asia. In this study, the genotype-specific prevalence of hVISA among meticillin-resistant S. aureus (MRSA) clinical isolates collected from Asian countries was determined. Among MRSA collections from South Korea, Taiwan, Hong Kong, Thailand, the Philippines, Vietnam, India and Sri Lanka in the ANSORP surveillance study during 2004 and 2006, isolates with a vancomycin minimum inhibitory concentration of ≥0.25mg/L were randomly selected. After screening by macro Etest, hVISA was confirmed using the modified population analysis profile method. MRSA isolates were typed by spa tying and multilocus sequence typing (MLST). Among 462 MRSA isolates, 16 (3.5%) were confirmed as hVISA. The proportion of hVISA was highest in South Korea and Vietnam (both 7.0%), followed by Thailand (3.2%) and Taiwan (1.9%). spa type t601 belonging to clonal complex (CC) 5 showed the highest proportion of hVISA (33.3%), and hVISA accounted for 6.9% among isolates of t002 belonging to CC5. Among CC239 isolates, only those of t037 were hVISA (1.6%). Among isolates of community-associated MRSA genotypes, hVISA was found only in those of t437 (4.8%) belonging to CC59, and no hVISA was found among those of CC30 or CC72. The prevalence of hVISA in the Asian region differed by country and was dependent upon the genotype of MRSA strains. It suggests that differences in hVISA prevalence between countries can be affected by the genotype distribution of MRSA strains.
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Asia Pacific Foundation for Infectious Diseases (APFID), Seoul, South Korea. Electronic address: iddrchung@gmail.com.
authors.forename: Doo Ryeon
authors.initials: DR
authors.lastname: Chung
authors.affiliation: Asia Pacific Foundation for Infectious Diseases (APFID), Seoul, South Korea.
authors.forename: Chaeyoeng
authors.initials: C
authors.lastname: Lee
authors.affiliation: Asia Pacific Foundation for Infectious Diseases (APFID), Seoul, South Korea.
authors.forename: Yu Ri
authors.initials: YR
authors.lastname: Kang
authors.affiliation: Asia Pacific Foundation for Infectious Diseases (APFID), Seoul, South Korea.
authors.forename: Jin Yang
authors.initials: JY
authors.lastname: Baek
authors.affiliation: Asia Pacific Foundation for Infectious Diseases (APFID), Seoul, South Korea.
authors.forename: So Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Ha
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Cheol-In
authors.initials: CI
authors.lastname: Kang
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Kyong Ran
authors.initials: KR
authors.lastname: Peck
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Nam Yong
authors.initials: NY
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Asia Pacific Foundation for Infectious Diseases (APFID), Seoul, South Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Song
mesh_terms: D001208:Asia / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058889:Molecular Typing; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D020713:Vancomycin Resistance
keywords: Genotype; Heteroresistance; Microbial drug resistance