title: Antimicrobial susceptibility and analysis of macrolide resistance genes in Streptococcus pneumoniae isolated in Hamadan.
abstract: OBJECTIVE
  Macrolide resistant Streptococcus pneumoniae pose an emerging problem globally. The aim of this study was to investigate the prevalence of ermB and mefA genes (macrolide resistant genes) by polymerase chain reaction (PCR) method and to detect drug resistance patterns of S. pneumoniae isolated from clinical samples to macrolides and other antibiotic agents by E-test method.
  
  
  METHODS
  Fifty five isolates of S. pneumoniae were obtained from clinical samples with microbial tests. The antibiotic susceptibility of isolates for erythromycin, azithromycin, clarithromycin, ceftazidime, ciprofloxacin and vancomycin were determined by E-test method. Genotypic antibiotic resistance pattern was determined by PCR with primer designed for ermB and mefA genes.
  
  
  RESULTS
  The number of S. pneumoniae isolates resistance to erythromycin, azithromycin, clarithromycin, ceftazidim, ciprofloxacin were 25.5%, 18.2%, 16.4%, 21.8% and 10.9%, respectively while no resistance to vancomycin was observed. The macrolide resistance genes of ermB and mefA were found in 10.9% and 18.2% of the isolates, respectively.
  
  
  CONCLUSIONS
  The result of the current study suggests the necessity of evaluation the changes in MIC (minimum inhibitory concentration) values as well as genetic mutations to estimate the prevalence of the resistance antimicrobial agents in S. pneumoniae.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Mohammad Najafi
authors.initials: MN
authors.lastname: Mosleh
authors.affiliation: Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Gharibi
authors.affiliation: Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Mohammad Yousef
authors.initials: MY
authors.lastname: Alikhani
authors.affiliation: Department of Molecular Medicine and Genetics, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Massoud
authors.initials: M
authors.lastname: Saidijam
authors.affiliation: Human and Animal Cell Bank, Iranian Biological Resource center (IBRC), ACECR, Tehran, Iran.
authors.forename: Faezeh
authors.initials: F
authors.lastname: Vakhshiteh
keywords: Antibiotic resistance; Autolysin gene; Macrolide; PCR; Streptococcus pneumoniae