title: Molecular characterization of methicillin-resistant Staphylococcus aureus in hospitals in Niigata, Japan: divergence and transmission.
abstract: The major methicillin-resistant Staphylococcus aureus(MRSA) distributed among hospitals in Japan is New York/Japan clone [multilocus sequence type 5 (ST5), agr type 2 and methicillin resistance locus type (SCC mec) II] which possesses both the toxic shock syndrome toxin 1 gene (tst) and staphylococcal enterotoxin C gene (sec). In this study, we collected 245 MRSA strains from four hospitals during 2001 to 2005 in Niigata, Japan, and analyzed tst and sec genes and SCC mec type among them. A total of 13 strains were further examined for their genotypes, virulence gene patterns and drug resistance. Among the 245 strains four tst sec genes patterns were observed; tst(+) sec(+) strains represented a majority of 86.5% and 9.4% were tst(-) sec(-). SCCmec typing revealed that 91.4% had type II, 4.1% type IV and 4.1% type I. Multilocus sequence typing (MLST) revealed that 10 of the 13 typed strains belonged to clonal complex 5 (7 had ST5 while 3 were single locus variants of ST5) with similar characteristics to the New York/Japan clone and possessed multi-drug resistance with high virulence gene content. The remaining 3 strains were ST8 (n=2) and ST91 (n=1). The ST91 strain had SCC mec IV and seemed to originate in the community, while ST8 strains exhibited SCC mec type I, which is distinct from community type IV. The data suggest that MRSA in hospitals in Niigata now mainly includes the New York/Japan clone (undergoing genomic divergence and clonal expansion) and other minor types (e.g. ST8) as well as the community type.
authors.affiliation: Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Hassan
authors.initials: H
authors.lastname: Zaraket
authors.forename: Taketo
authors.initials: T
authors.lastname: Otsuka
authors.forename: Kohei
authors.initials: K
authors.lastname: Saito
authors.forename: Soshi
authors.initials: S
authors.lastname: Dohmae
authors.forename: Tomomi
authors.initials: T
authors.lastname: Takano
authors.forename: Wataru
authors.initials: W
authors.lastname: Higuchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ozaki
authors.forename: Misao
authors.initials: M
authors.lastname: Takano
authors.forename: Ivan
authors.initials: I
authors.lastname: Reva
authors.forename: Tatiana
authors.initials: T
authors.lastname: Baranovich
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics; D000328:Adult; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics; D003428:Cross Infection / Q000235:genetics / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004768:Enterotoxins / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D007231:Infant, Newborn; D007564:Japan; D016106:Methicillin Resistance / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification; D018089:Superantigens / Q000737:chemistry / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal; C034959:enterotoxin C, staphylococcal