title: Molecular analysis and antimicrobial susceptibility of methicillin resistant Staphylococcus aureus in one of the hospitals of Tehran University of Medical Sciences: high prevalence of sequence type 239 (ST239) clone.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA), particularly the multidrug-resistant clones, is an increasing worldwide problem. The average incidence rate of MRSA in Tehran was found to be over 40%. A total of 140 MRSA isolates obtained from patients attending a teaching hospital in Tehran, from May 2009 to December 2009, were included in this study. The antimicrobial susceptibility profile of MRSA isolates was determined by the agar disk diffusion method. Molecular analysis of MRSA strains was accomplished by Pulsed-Field Gel Electrophoresis (PFGE) and Multi-locus sequence typing (MLST). Detection of mecA gene was used to confirm resistance to methicillin among the MRSA isolates. All the MRSA isolates were susceptible to chloramphenicol, teicoplanin, tigecycline and vancomycin. All MRSAisolates were resistant to oxacillin, whilst 139 strains showed resistance against ciprofloxacin, erythromycin, gentamicin, tetracycline and trimethoprim-sulfamethoxazole. PFGE analysis of all the 140 MRSA isolates produced five distinct pulsotypes designated as pulsotypes A-E. Most of the isolates (n=132) were clustered into pulsotype A. The most prevalent sequence type (ST) was ST 239 (pulsotype A) found in 82% (37/45) of the tested isolates. The second most prevalent type was ST 1238 (pulsotypes B, C and D) found in 15% (7/45) of the isolates. The remaining type, ST 8 (pulsotype E) was found in a single isolate. The results of this study indicated that the MRSA clone ST 239 was a major clone in the selected university hospital of Tehran and that it was widely spread among the different wards as well as all the age groups of patients.
authors: Tehran University of Medical Sciences, Department of Microbiology, School of Medicine, Tehran, Iran.
authors: Shadi
authors: S
authors: Shahsavan
authors: Leila
authors: L
authors: Jabalameli
authors: Parviz
authors: P
authors: Maleknejad
authors: Marzieh
authors: M
authors: Aligholi
authors: Hossein
authors: H
authors: Imaneini
authors: Fereshteh
authors: F
authors: Jabalameli
authors: Shahnaz
authors: S
authors: Halimi
authors: Morovat
authors: M
authors: Taherikalani
authors: Babak
authors: B
authors: Khoramian
authors: Mohammad Amin
authors: MA
authors: Eslampour
authors: Mohammad Mehdi
authors: MM
authors: Feizabadi
authors: Mohammad
authors: M
authors: Emaneini
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000379:methods; D003428:Cross Infection / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005260:Female; D006784:Hospitals, Teaching / Q000458:organization & administration; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology / Q000379:methods; D046915:Penicillin-Binding Proteins; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus