title: Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Bloodstream Isolates in a Turkish University Hospital Between 2002 and 2012.
abstract: OBJECTIVE
  Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in the hospital environment. Monitoring of this pathogen by molecular characterization and phenotypic methods is important for the development of suitable infection control measures and proper therapy design. In this study, our aim was to investigate the molecular epidemiological characteristics of MRSA bloodstream isolates obtained from patients hospitalized at Ankara University Ibn-i Sina Hospital in a 10-year period (2002-2012) and monitor the possible changes. A total of 134 isolates were characterized according to their antimicrobial susceptibility profiles, biofilm formation capabilities, accessory gene regulator (agr) locus types, presence of genes encoding Panton-Valentine leukocidin (PVL), staphylococcal enterotoxins A-J (SEs A-J), toxic shock syndrome toxin, sasX, and genes associated with biofilm formation (icaD, icaA, IS256) by polymerase chain reaction. The staphylococcal cassette chromosome mec (SCCmec) types of isolates were also defined and their clonal relationships were investigated by pulsed-field gel electrophoresis (PFGE) analysis and multilocus sequence typing was performed for representative isolates obtained by PFGE.
  
  
  RESULTS
  The majority of the isolates were resistant to rifampin (100%), ciprofloxacin (97%), tetracycline (97.7%), and gentamicin (94.7%); 100% carried type-III SCCmec and 89.5% were agr type-1. All the isolates were negative for PVL, and sasX genes while all of them carried the icaD, icaA, and IS256 genes. The most common SE was enterotoxin A (97%). Four major PFGE patterns with the dominance of one pattern and seven unique patterns were obtained. All the representative PFGE isolates (n = 11) belonged to sequence type 239.
  
  
  CONCLUSIONS
  We have documented the characteristics of the dominant MRSA clone in our hospital, which was a PVL (-), sasX (-) ST239 clone carrying sea (+) with type-III SCCmec, and type-1 agr locus.
authors.affiliation: 1 Department of Medical Microbiology, Ankara University School of Medicine , Ankara, Turkey .
authors.forename: Alper
authors.initials: A
authors.lastname: Tekeli
authors.affiliation: 2 Department of Microbiology, Ankara Diskapi Yildirim Beyazit Training and Research Hospital , Ankara, Turkey .
authors.forename: Duygu Nilufer
authors.initials: DN
authors.lastname: Ocal
authors.affiliation: 1 Department of Medical Microbiology, Ankara University School of Medicine , Ankara, Turkey .
authors.forename: Busra Betul
authors.initials: BB
authors.lastname: Ozmen
authors.affiliation: 1 Department of Medical Microbiology, Ankara University School of Medicine , Ankara, Turkey .|3 Central Bacteriology Laboratory, İbn-i Sina Hospital , Ankara, Turkey .
authors.forename: Zeynep Ceren
authors.initials: ZC
authors.lastname: Karahan
authors.affiliation: 1 Department of Medical Microbiology, Ankara University School of Medicine , Ankara, Turkey .
authors.forename: Istar
authors.initials: I
authors.lastname: Dolapci
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D002876:Chromosomes, Bacterial; D002939:Ciprofloxacin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial; D056426:Genetic Loci; D005839:Gentamicins / Q000494:pharmacology; D006785:Hospitals, University; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D010802:Phylogeny; D012189:Retrospective Studies; D012293:Rifampin / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology*; D013752:Tetracycline / Q000494:pharmacology; D014421:Turkey
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D002939:Ciprofloxacin; D013752:Tetracycline; D012293:Rifampin
keywords: Methicillin resistant Staphylococcus aureus; SCCmec typing; antimicrobial susceptibility; bloodstream infection; molecular characterization; toxin