بررسی و تجسس باکتریولوژیک و سرولوژیک استرپتوکوک گروه GBS) B) در مادران حامله، نوزادان و شیر خواران مبتلا به عفونت ناشی از آن

Group B streptococcus (GBS) is the most important pathogen identified in bacterial cultures in neonatal sepsis, sepecially with early-onset in developed countries (approximately 1-5/1000 deliveries). Neonatal colonization with group B streptococcus results primarily from vertical transmission during the birth process. GBS carrier rate in pregnant women varies from 4.6 to 41 percent in different geographic populations. Contamination of neonates during passage through the birth canal is high (more than 50%). Of the 191 pregnant women screened in this study, 28 (14.7%) were found to be colonized with GBS, by the culture method. Direct CIE and SCA tests on SBM (Selective Broth Medium) containing mixed flora showed that only 11.5% and 18.3% had positive reaction. A total of 530 patients were studied. GBS was isolated from the blood of 4 infants (5.5%, 4 vs 73 positive cultures). Of 181 cultures of CSF only one case was positive for GBS (8.3%) and had meningitis. In another part of experiment, two false positive reactions were found using serum specimen for detection of GBS antigen by CIE. Sensitivity of CIE and SCA both were 75%, specificity, 99.3% and 98.7%. Conclusion: Although specimen collection and microbiologic methods are important factors in identification of women colonized with GBS, there is significant variation in the proportion of women colonization with GBS. This study suggests that GBS is a much less important cause of neonatal sepsis, but further studies are needed to explore these important issues.