Background: Group B Streptococcus (GBS) or agalactia is an important cause of infection among the early newborns. The bacterium is transmitted from mother to child and most often leads to infant death. The goal of this study was to detect GBS among clinical samples of pregnant women in Kermanshah province, using Colony PCR and standard microbiological culture and then to compare the phenotypic and genotypic methods against each other.
 
Materials & methods: One hundred cases aged at 30- 38 weeks of life were selected during 4 months from April 2014 on at health centers of Kermanshah province. The samples were taken from the women’s vaginal secretions and tested by standard culture using basic culture medium Todd- Hewitt broth, blood agar and Colony- PCR targeting scpB gene.
 
Findings: The results showed phenotypic test among 100 samples, 5 (5%) as carriers of group B streptococci, compared to 7 patients (7%) by Colony PCR test.
 
Conclusion & discussion: According to our study, the rate of GBS incidence is high in women of Kermanshah. Furthermore,   the Colony PCR method that eliminates DNA extraction process can be a rapid, reliable and low cost method to detect the carrier.