Chen FJ, Hiramatsu K, Huang IW, et al.
Division of Infectious Diseases, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan, ROC.
SourceDiagn Microbiol Infect Dis 2009 Dec; 65(4)
Methicillin-resistant Staphylococcus aureus (MRSA) arises when methicillin-susceptible S. aureus (MSSA) acquires the staphylococcal cassette chromosome mec (SCCmec). Most pvl-positive MRSA in Taiwan belong to ST59 lineage and carry SCCmec V. The genetic profiles of 51 MSSA were compared with those of 80 MRSA from the same hospitals. Nine pvl-positive MSSA (oxacillin MIC < or = 2 microg/mL) shared >80% similarity in pulsed field gel electrophoresis pattern with 17 pvl-positive SCCmec V MRSA. Further investigation found that 5 of these 9 isolates were MRSA by cefoxitin and carried SCCmec V. All 26 pvl-positive isolates had very similar genetic profile (ST59, protein A clonal complex [spa-CC] c2:441/437, and agr group I). The success of the ST59:SCCmec V MRSA may be due in part to its heterogeneous and borderline resistance to methicillin, which may be missed by testing only oxacillin, with subsequent exposure to beta-lactams causing the emergence of more resistant subpopulations.
MeshAnti-Bacterial AgentsBacterial ProteinsBacterial ToxinsBacterial Typing TechniquesCefoxitinCluster AnalysisDNA FingerprintingDNA, BacterialElectrophoresis, Gel, Pulsed-FieldExotoxinsGenes, BacterialGenotypeHospitalsHumansLeukocidinsMethicillin-Resistant Staphylococcus aureusMicrobial Sensitivity TestsOxacillinStaphylococcal InfectionsStaphylococcus aureusTaiwan
Journal Article Research Support, Non-U.S. Gov't