title: Methicillin-resistant Staphylococcus aureus DNA electrophoretic pattern: temporal changes in an endemic hospital environment.
abstract: OBJECTIVE
  To describe the analysis of geographical and temporal distribution of DNA profiles determined by pulsed-field gel electrophoresis (PFGE) of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from hospitalized patients in a tertiary care university hospital in Brazil.
  
  
  METHODS
  Ninetynine samples of MRSA obtained from 89 patients in the period 1999-2004 were studied. MRSA strains were isolated from central venous catheters (33 isolates) and bloodstream infections (66 strains). PFGE with 20 units of SmaI restriction endonuclease was used for genomic typing.
  
  
  RESULTS
  Analysis of DNA PFGE of 99 strains of MRSA revealed 26 profiles and their respective related profiles. The mean time interval for detecting MRSA infection was 26 days from hospital admission. Forty-nine patients (57.6%) had a recent hospitalization. The DNA PFGE MRSA profiles were distributed in three clonal groups-I, II, and III-according to the period of time when the MRSA strains were isolated. DNA PFGE MRSA profiles were spread homogeneously through all hospital wards.
  
  
  CONCLUSIONS
  Changes in the distribution of DNA PFGE MRSA profiles were largely temporal, with clonal groups being replaced over time, without predominance in any hospital ward or any specific area of the hospital.
authors.affiliation: Pós-Graduação em Clínica Médica, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Sao Paulo, Brazil.
authors.forename: Gleice Cristina
authors.initials: GC
authors.lastname: Leite
authors.forename: Maria Clara
authors.initials: MC
authors.lastname: Padoveze
authors.forename: Maria Luiza
authors.initials: ML
authors.lastname: Moretti
mesh_terms: D000328:Adult; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology; D001938:Brazil / Q000453:epidemiology; D055499:Catheter-Related Infections / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006757:Hospital Units / Q000706:statistics & numerical data; D006785:Hospitals, University; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D008875:Middle Aged; D010802:Phylogeny; D011183:Postoperative Complications / Q000453:epidemiology / Q000382:microbiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial