title: Molecular Characterization of Methicillin Resistant Staphylococcus aureus Strains Isolated from Intensive Care Units in Iran: ST22-SCCmec IV/t790 Emerges as the Major Clone.
abstract: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different patient populations is a major public health concern. This study determined the prevalence and distribution of circulating molecular types of MRSA in hospitalized patients in ICU of hospitals in Tehran.
  
  
  
  A total of 70 MRSA isolates were collected from patients in eight hospitals. Antimicrobial resistance patterns were determined using the disk diffusion method. The presence of toxin encoding genes and the vancomycin resistance gene were determined by PCR. The MRSA isolates were further analyzed using multi-locus sequence, spa, SCCmec, and agr typing.
  
  
  
  The MRSA prevalence was 93.3%. Antimicrobial susceptibility testing revealed a high resistance rate (97.1%) to ampicillin and penicillin. The rate of resistance to the majority of antibiotics tested was 30% to 71.4%. Two isolates belonging to the ST22-SCCmec IV/t790 clone (MIC ≥ 8 μg/ml) had intermediate resistance to vancomycin. The majority of MRSA isolates (24.3%) were associated with the ST22-SCCmec IV/t790 clone; the other MRSA clones were ST859-SCCmec IV/t969 (18.6%), ST239-SCCmec III/t037 (17.1%), and ST291-SCCmec IV/t030 (8.6%).
  
  
  
  The circulating MRSA strains in Iranian hospitals were genetically diverse with a relatively high prevalence of the ST22-SCCmec IV/t790 clone. These findings support the need for future surveillance studies on MRSA to better elucidate the distribution of existing MRSA clones and detect emergence of new MRSA clones.
authors.affiliation: Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Goudarzi
authors.affiliation: Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Goudarzi
authors.affiliation: Departamento de Microbiologia Medica, Instituto de Microbiologia Paulo de Goes, Centro de Ciencias da Saude, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Agnes Marie
authors.initials: AM
authors.lastname: Sá Figueiredo
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
authors.forename: Edet E
authors.initials: EE
authors.lastname: Udo
authors.affiliation: WHO Collaborating Center for Reference and Research on Rabies, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Fazeli
authors.affiliation: Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asadzadeh
authors.affiliation: Department of Medical Mycology, Pasteur institute of Iran, Tehran, Iran.
authors.forename: Sima Sadat
authors.initials: SS
authors.lastname: Seyedjavadi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D002999:Clone Cells; D005260:Female; D006801:Humans; D007223:Infant; D007362:Intensive Care Units; D007492:Iran / Q000453:epidemiology; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology
chemical_list: D000890:Anti-Infective Agents