title: Molecular typing of nosocomialStaphylococcus aureusstrains associated to biofilm based on the coagulase and protein A gene polymorphisms.
abstract: OBJECTIVE
  Staphylococcus aureusis an important bacterial pathogen responsible for a variety numbers of nosocomial and community acquired infections. Biofilm formation is regarded as an important factor in the establishment ofS. aureusinfection. The contribution of the genetic background ofS. aureusto biofilm formation is poorly understood. The aim of the present work was to genotypeS. aureusstrains associated to biofilm based on the coagulase and protein A genes and to evaluate the association between the genetic background and the biofilm forming ability of clinicalS. aureusisolates.
  
  
  METHODS
  A total number of 100S. aureuswere isolated from nosocomial infections and biofilm formation capability was investigated using phenotypic assay and molecular detection of biofilm associated genes. The strains were genotyped based on coagulase (coa) and protein A (spa) gene polymorphisms using restriction fragments length polymorphism-polymerase chain reaction (RFLP-PCR).
  
  
  RESULTS
  RFLP-PCR ofcoagene generated two types and three subtypes. Amplification of spa gene resulted in two banding patterns and their restriction digestion generated three subtypes. The combinedcoaandspaRFLP patterns generated nine genotypes (G1-G9). The genotypes G4and G1were the most prevalent (32.1% and 24.3%, respectively).
  
  
  CONCLUSIONS
  High clonal diversity ofS. aureusstrains able to produce biofilm was observed. Biofilm formation correlates with thespaandcoaclonal lineage in our population and testing for multiple gene polymorphisms could be employed for local epidemiologic purposes.
authors.affiliation: Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Salehzadeh
authors.affiliation: Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran.
authors.forename: Hojjatolah
authors.initials: H
authors.lastname: Zamani
authors.affiliation: Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran.
authors.forename: Maedeh Keshtkar
authors.initials: MK
authors.lastname: Langeroudi
authors.affiliation: Young Researchers and Elite Club, East Tehran Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Mirzaie
keywords: Adhesion molecules; Biofilm; Coagulase; RFLP; S. aureus; Spa typing