title: Molecular analysis of meticillin-resistant Staphylococcus aureus strains isolated from different types of infections from patients hospitalized in 12 regional, non-teaching hospitals in southern Poland.
abstract: BACKGROUND
  Accumulated data indicate that meticillin-resistant Staphylococcus aureus (MRSA) infections are associated with a worse prognosis than methicillin-susceptible S. aureus infections.
  
  
  OBJECTIVE
  To assess the epidemiological profile of S. aureus infections and the genetic diversity of clinical strains of MRSA in 12 hospitals in southern Poland.
  
  
  METHODS
  Samples from bloodstream infections, pneumonia, and skin and soft tissue infections from adult patients were examined. S. aureus isolates were tested for MRSA and macrolide-lincosamide-streptogramin B (MLSB) phenotypes. Staphylococcal cassette chromosome mec (SCCmec) typing and S. aureus protein A (spa) typing were performed. Analysis of the genetic similarity was performed by pulsed-field gel electrophoresis.
  
  
  RESULTS
  This study included 555 patients. An MRSA phenotype was detected in 15.1% of strains. The prevalence of MRSA infection was higher in patients aged >80 years. An MLSBphenotype was detected in 18.2% of strains. Analysis of SmaI profiles did not reveal a dominant clone. Spa typing showed 25 different spa types, and spa type t003 was the most common (49% of strains). Among MRSA strains, SCCmecII (49%) and SCCmecIV (27.4%) were predominant.
  
  
  CONCLUSIONS
  The characteristics of MRSA showed considerable heterogeneity. The results demonstrate the need for caution when drawing conclusions on direct epidemiological relationships between isolates based on a single typing method. As the cases of infection in this study were not associated with the hospital environment and horizontal transfer, a focus on screening at hospital admission, and appropriate infection control, may help to reduce the risk of MRSA infections.
authors.affiliation: Department of Microbiology, Jagiellonian University Medical College, Krakow, Poland. Electronic address: agnieszka.chmielarczyk@uj.edu.pl.
authors.forename: A
authors.initials: A
authors.lastname: Chmielarczyk
authors.affiliation: Department of Microbiology, Analytical and Microbiological Laboratory of Ruda Slaska, KORLAB NZOZ, Ruda Slaska, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Pomorska-Wesołowska
authors.affiliation: Faculty of Health and Medical Science, Andrzej Frycz Modrzewski Krakow University, Krakow, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Szczypta
authors.affiliation: Department of Microbiology, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: D
authors.initials: D
authors.lastname: Romaniszyn
authors.affiliation: Department of Microbiology, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Pobiega
authors.affiliation: Department of Microbiology, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Wójkowska-Mach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D014644:Genetic Variation; D006767:Hospitals, District; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D011044:Poland / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D055815:Young Adult
keywords: MRSA infections; Pulsed-field gel electrophoresis (PFGE); SCCmec; Spa typing