Antimicrobial susceptibility and analysis of macrolide resistance genes in Streptococcus pneumoniae isolated in Hamadan

Abstract

<em>Objective(s): </em>Macrolide resistant <em>Streptococcus pneumoniae</em> pose an emerging problem globally. The aim of this study was to investigate the prevalence of <em>ermB</em> and <em>mefA</em> genes (macrolide resistant genes) by polymerase chain reaction (PCR) method and to detect drug resistance patterns of <em>S. pneumoniae</em> isolated from clinical samples to macrolides and other antibiotic agents by E-test method. <br/><em>Materials and Methods: </em>Fifty five isolates of <em>S. pneumoniae</em> 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 <em>ermB</em> and <em>mefA </em>genes. <br/><em>Results: </em>The number of <em>S. pneumoniae</em> 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 <em>ermB</em> and <em>mefA</em> were found in 10.9% and 18.2% of the isolates, respectively. <br/><em>Conclusion: </em>The result of the current study suggests the necessity of evaluation the changes in MIC[FA1] [a2] (minimum inhibitory concentration) values as well as genetic mutations to estimate the prevalence of the resistance antimicrobial agents in <em>S. pneumoniae</em>.