Group B streptococcus colonization of pregnant wom

Authors: Tarek A A Moussa Rasha Hamed Elsherif Youssef Abdelfattah Mohamed Mohamed E A Dawoud Asmaa Mohamed AboElAref

Publish Date: 2012/07/24

Volume: 22, Issue: 6, Pages: 1229-1234

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Abstract

This study aimed to compare the sensitivity of different culture methods from three different anatomic sites and to evaluate the sensitivity of polymerase chain reaction PCR assay targeting the 16 S ribosomal RNA gene in detection of group B streptococcus GBS colonization in pregnant women From 100 pregnant women at 35–37 weeks of gestation three cotton swabs were used to obtain vaginal rectal and rectovaginal RV specimens and plated onto Columbia agar with colistin and nalidixic CNA group B streptococcus differential agar GBSDA and chromID Strepto B agar CA with and without Lim broth enrichment PCR assay was done on the RV swabs The overall GBS colonization rate was 29  by culture and 31  by PCR GBS positivity for RV sampling 100  was significantly higher than detection on the basis of vaginal sampling 50  but not significantly higher than for rectal sampling 82  Direct plating of the rectovaginal swab on CNA GBSDA and CA resulted in detection of 74 58 and 100  of the carriers respectively whereas subculturing of Lim broth yielded 65 59 and 83  positivity respectively Using GBS culture as the “gold standard” the sensitivity of PCR was 100  and specificity was 97  We found that the inoculation of RV secretions directly onto CA is the most rapid easy and sensitive method than that of Lim broth enrichment Also we found that group B streptococci can be detected rapidly and reliably by a PCR assay of rectovaginal secretions from pregnant women

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