title: Clonal distribution and possible microevolution of methicillin-resistant Staphylococcus aureus strains in a teaching hospital in Malaysia.
abstract: OBJECTIVE
  To genotypically characterize methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from medical and surgical wards in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) in 2009.
  
  
  METHODS
  MRSA strains were collected and molecularly typed by pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  PFGE typing on 180 MRSA isolated in UKMMC identified 5 pulsotypes (A-E) and 6 singletons, where pulsotypes B and C were suspected to be divergent clones originating from a single ancestor. This study also showed that most MRSA strains were isolated from swab (119 isolates), followed by blood (22 isolates), tracheal aspirate (11 isolates) and sputum (10 isolates). On the other hand, urine and bone isolates were less, which were 4 and 1 isolates, respectively. The distribution of different pulsotypes of MRSA among wards suggested that MRSA was communicated in surgical and medical wards in UKMMC, with pulsotype B MRSA as the dominant strain. Besides, it was found that most deceased patients were infected by pulsotype B MRSA, however, no particular pulsotype could be associated with patient age, underlying disease, or ward of admittance.
  
  
  CONCLUSIONS
  Five pulsotypes of MRSA and 6 singletons were identified, with pulsotype B MRSA as the endemic strains circulating in these wards, which is useful in establishment of preventive measures against MRSA transmission.
authors.affiliation: Department of Biomedical Science, Faculty of Allied Health Sciences, Malaysia.
authors.forename: Xin Ee
authors.initials: XE
authors.lastname: Tan
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Neoh
authors.forename: Salasawati
authors.initials: S
authors.lastname: Hussin
authors.forename: Noraziah Mohamad
authors.initials: NM
authors.lastname: Zin
mesh_terms: D016521:Electrophoresis, Gel, Pulsed-Field; D019143:Evolution, Molecular; D006761:Hospitals; D008296:Malaysia / Q000453:epidemiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology
keywords: Hospital infection; MRSA; Microevolution; PFGE typing