Mohammad Najafi Mosleh - Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
Marzieh Gharibi - Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
Mohammad Yousef Alikhani - Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
Massoud Saidijam - Department of Molecular Medicine and Genetics, Hamadan University of Medical Sciences, Hamadan, Iran
Faezeh Vakhshiteh - Human and Animal Cell Bank, Iranian Biological Resource center (IBRC), ACECR, Tehran, Iran

Objective(s): 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. Materials and 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 ۲۵.۵%, ۱۸.۲%, ۱۶.۴%, ۲۱.۸% and ۱۰.۹%, respectively while no resistance to vancomycin was observed. The macrolide resistance genes of ermB and mefA were found in ۱۰.۹% and ۱۸.۲% of the isolates, respectively. Conclusion: The result of the current study suggests the necessity of evaluation the changes in MIC[FA۱] [a۲]  (minimum inhibitory concentration) values as well as genetic mutations to estimate the prevalence of the resistance antimicrobial agents in S. pneumoniae.

Antibiotic resistance, Autolysin gene, Macrolide, PCR, Streptococcus pneumoniae