Colonization Rate, Serotypes, and Distributions of Macrolide-Lincosamide-StreptograminB Resistant Types of Group B Streptococci in Pregnant Women

GBS in the different culture media was S-THB (96.3%), NGM-B (92.6%), NGM-H (88.9%), and NGM-T (85.2%). The distribution of GBS serotypes was as follows: III (29.6%), V and VI (22.2%), Ib and II (11.1%), and Ia (3.7%). 33.3% of GBS isolates were resistant to erythromycin and 44.4% to clindamycin. Among the nine erythromycin-resistant isolates, eight were serotype V and VI, which are erm(B) positive serotypes. Conclusion: The colonization of pregnant women by GBS, and the incidence of resistance of the GBS isolates to erythromycin and clindamycin were higher than those previously reported. Serotypes V and VI, GBS serotypes that carry the erm(B), are novel serotypes that have not previously been identified in pregnant Korean women. (Korean J Clin Microbiol 2009;12:174-179)