Source of group B streptococci in the female genital tract.

Abstract

SUMMARY Swabs were taken from the posterior fornix, perineum, and anorectum of 135 patients on three occasions during their pregnancy. Multiple isolates of /3-haemolytic streptococci of group B were obtained from 24 women, in 21 of whom the strains were examined by a highly discriminative serotyping and phage typing method. In 18 of these patients their own isolates were indistinguishable but different from those of other women with multiple isolates. Women yielding group B streptococci from the posterior fornix usually carried an indistinguishable strain in the anorectum.Haemolytic streptococci of Lancefield's group B are an important and possibly increasing cause of neonatal morbidity and death.1-3 Neonatal colonisation usually arises from the mother's genital tract.4 5 In this study we have used a highly discriminative serological and bacteriophage typing methods to examine the similarity or otherwise of strains of group B streptococci obtained from the vagina, perineum, and anorectum of pregnant women in an attempt to gather evidence for the source of this organism in the female genital tract. Patients and methodsThe 135 patients studied were randomly selected from the women attending the antenatal clinics of Northwick Park Hospital. Swabs were obtained from their posterior fornix, perineum, and anorectum at 16, 28, and 36 weeks of pregnancy. In some patients the skin of the anterior axillary fold and the mucosa of the urethra were also swabbed. The perineum and axilla were sampled by cottonwool swabs moistened in peptone water, the urethra by a narrow-gauge soft-wire swab, and the posterior fornix and anorectum by charcoal-impregnated swabs. Swabs were immediately broken off into 10 ml Todd Hewitt broth containing 8 ,ug/ml gentamicin and 15 ,pg/ml nalidixic acid and the broth incubated at 371C.7 8 Subcultures were made on to Columbia blood agar and incubated aerobically. Isolates resembling group B streptococci which were able to grow on 40% bile agar and failed to hydro-

Streptococci and the Genital Tract

“…The use of selective enrichment media appears to increase the isolation rate of GBSZo, Ross and Needham14, using non-selective solid media to isolate GBS from vaginal swabs of pregnant women reported isolation rates of 1.5% at 16 weeks gestation rising to 3.6% at 36 weeks gestation both of which are significantly lower than those found by Sanderson et al 21 who used selective enrichment media.…”

Influence of diabetes on group B Streptococcus colonization in the pregnant patient

“…An inherent limitation of the present study was that cultures were only taken at the vaginal introitus. The anorectum has previously been implicated as the site or source of group B Streptococcus thus causing vaginal contamination [26,[33][34][35]. Previous studies have documented the concordance of group B Streptococcus carriage in the rectum and vagina especially when the lower genital tract was cultured [27].…”

Site‐Specific Prevalence and Cell Densities of Selected Microbesin the Lower Reproductive Tract of Menstruating Tampon Users

“…Despite the common assumption of niche specialization, few studies have systematically attempted to correlate the presence or absence of particular organisms at a single site with colonization of another genital site, and only single species have been investigated [20][21][22][23] . The present study examined enterococci, GNEs, yeast and S. aureus at multiple sites.…”

“…Few studies have examined more than one site in the same individual and of these, several focused on a single organism [17][18][19][20][21][22][23] . Studies that have delineated microbial changes over the menstrual cycle 1,7,17,18,[24][25][26] or the influence of menstrual products on genital microflora 27 have typically focused on a single vaginal site, self-obtained swabs, or vaginal washes.…”