title: Investigation of an outbreak caused by methicillin-resistant Staphylococcus aureus in a cardiovascular surgery unit by ribotyping, randomly amplifed polymorphic DNA and pulsed-field gel electrophoresis.
abstract: An outbreak caused by rapid spread of methicillin-resistant Staphylococcus aureus (MRSA) in an intensive care unit for cardiovascular surgery was investigated by phenotypic and genotypic methods. Fourteen isolates were collected during a 2-month period from clinical and environmental specimens in the unit recently re-opened after reconstruction. The isolates were tested for antibiotic susceptibility patterns and genotyped by automated ribotyping, randomly amplified polymorphic DNA-PCR (RAPD) analysis and pulsed-field gel electrophoresis (PFGE). Automated ribotyping applying EcoRI digestion proved to be of no value in separating the isolates. In contrast, PFGE grouped the isolates into four clusters different from the reference strain. These results fully correlated with the antibiograms. Twelve of the isolates were grouped into two clonally related clusters. RAPD analyses grouped the isolates into five clusters. Except for two isolates of one patient, which had different RAPD patterns, PFGE and RAPD analyses presented very similar results. The results verified the usefulness of PFGE in studies of MRSA epidemics. A combination of these two methods reduces the time to identification of an outbreak and increases the accuracy in detection of intraspecies differences.
authors.affiliation: Department of Medicine, Veterans General Hospital-Taipei, and National Yang-Ming University, Taiwan.
authors.forename: C P
authors.initials: CP
authors.lastname: Fung
authors.forename: M W
authors.initials: MW
authors.lastname: Ho
authors.forename: F D
authors.initials: FD
authors.lastname: Wang
authors.forename: K
authors.initials: K
authors.lastname: Tsai
authors.forename: C E
authors.initials: CE
authors.lastname: Liu
authors.forename: C Y
authors.initials: CY
authors.lastname: Liu
authors.forename: L K
authors.initials: LK
authors.lastname: Siu
mesh_terms: D001483:Base Sequence; D013504:Cardiovascular Surgical Procedures / Q000009:adverse effects; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007362:Intensive Care Units; D016106:Methicillin Resistance; D019105:Random Amplified Polymorphic DNA Technique; D021521:Ribotyping; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013503:Surgery Department, Hospital; D013624:Taiwan / Q000453:epidemiology
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial