Journal of Pure and Applied MicrobiologyVol. 11 No. 1

Capsular Genotypes Distribution and Antibiotic Resistance pattern of Group B Streptococcus (GBS) Isolated from Clinical Samples, Tehran, Iran

Masoumeh Navidinia1* and Marjan Rashidan2

1Medical Bacteriology (PhD), Assistant Professor, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran. 2Medical Microbiology (PhD), Assistant Professor, Shahroud University of Medical Sciences, Shahroud, IR Iran.

Received on 20 December 2016 and accepted on 17 February 2017



Group B Streptococcus (GBS) is an opportunistic harmless bacterium which the leading cause of neonatal infections. Our purpose was to determine capsular genotypes distribution and antibiotic resistance pattern of GBS isolated from clinical samples. Two hundred and twenty two GBS strains isolated from clinical samples from different hospitals in Tehran, Iran. After identification by specific cultures and biochemical tests, broth microdilution method was used to determine the minimal inhibitory concentration (MIC) of antibiotics based on standard protocol. The erythromycin-clindamycin double-disk test was used to determine the inducible resistance phenotypes. Capsular genotypes were identified by PCR method. The high rates of antibiotic resistance in GBS were related to gentamycin 89.18%, tetracycline 87.38%, kanamycin 62.16%, clindamycin (67.1%), erythromycin 57.2%, and chloramphenicol 32.8%. All strains were sensitive to vancomycin, penicillin, and ampicillin. Between eleven capsular antigens, serotypes such as III(50.9%) ,V(27.47%) ,Ib(17.76%) ,Ia(15.54%) , Ic (5.85%)were the highest. The genotypes distribution and the patterns of resistance phenotypes of GBS may vary in different areas. Thus, it is required to be considered in each region to work out strategies for prevention. The PCR method is recommended as a rapid and reliable technique for identification and molecular epidemiology study of GBS.

Keywords : Group B Streptococcus (GBS), Genotypic characterization, Antibiotic Resistance.