Korean J Clin Microbiol.  2009 Dec;12(4):174-179.

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

• Uh Y
• Choi SJ
• Jang IH
• Lee KS
• Cho HM
• Kwon O
• Yoon KJ

Abstract

BACKGROUND
The prevalence of neonatal group B streptococcal infection depends mainly on the colonization rate of pregnant women by group B streptococci (GBS). Although the colonization rate of Korean women by GBS is considered lower than in other countries, recent data on the maternal colonization rate of GBS are sparse.
METHODS
From August 2008 to June 2009, swab specimens from the anorectus, vagina, and urethral orifice of a sample of 234 pregnant Korean women were placed in new Granada medium (NGM-H), tube medium (NGM-T), commercial NGM (NGM-B), and selective Todd-Hewitt broth (S-THB) for 18~24 hours in 5% CO2 at 35degrees C. Agar dilutional antimicrobial susceptibility tests, serotyping, and PCR were performed for GBS isolates.
RESULTS
The colonization rate of GBS in pregnant women was 11.5% (27/234). Of the specimen cultures, 9.8% of anorectal cultures were positive, 8.1% of urethral orifice cultures were positive, and 7.3% of vagina cultures were positive. The detection rate of 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.

Keyword

Group B streptococci; Erythromycin; Clindamycin; erm(B); Serotype

MeSH Terms

Agar
Clindamycin
Colon
Culture Media
Erythromycin
Female
Humans
Incidence
Polymerase Chain Reaction
Pregnant Women
Prevalence
Serotyping
Streptococcal Infections
Vagina
Agar
Clindamycin
Culture Media
Erythromycin

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