A reassessment of the microbial flora of the female genital tract, with special reference to the occurrence of Bacteroides species.

Two hundred and twelve randomly selected vaginal or uterine cervical specimens were investigated for the presence of anaerobic and aerobic bacteria and yeasts. Anaerobes of possible clinical significance, including Bacteroidaceae, Peptococcaceae and clostridia were isolated from 34% of the specimens and were identified to specific or generic level. Among the Bacteroidaceae isolated, B. bivius was the most common, followed by other propionate-negative species. Members of the Bacteroides fragilis group were seldom isolated. Of the aerobic or facultatively anaerobic isolates, enterococci and Escherichia coli were most often found. The results show that clinically significant anaerobes, especially Bacteroides species, are not regular members of the vaginal flora and that the species distribution of anaerobes occurring in the genital tract is significantly different from that of the intestinal tract.