Abstract
The purpose of this study was to compare the species of Lactobacillus present in the vagina of gynaecologically normal women with those isolated from women with certain gynaecological conditions. Fifty-nine strains, isolated from gynaecologically normal women, and seventeen reference strains were characterised by 71 morphological, biochemical and nutritional tests. Groups of isolates, produced by computer-aided principal components and cluster analyses of the data, correlated well with the species identification, made according to a few conventionally used tests. The species of Lactobacillus isolated most frequently were L. acidophilus (35.6 per cent.), L. jensenii (23.7 per cent.) and L. fermentum (15.3 per cent.). Antisera raised against representatives of these species showed that L. jensenii, a species previously reported from this habitat only twice and little studied, was serologically distinct from the other isolates. Lactobacilli were also isolated from women with four gynaecological conditions, namely infections with Candida albicans and Trichomonas vaginalis respectively, pregnancy and abnormalities of the uterine cervix. These isolates were speciated using a reduced list of characterisation tests. No significant differences were found between the species of Lactobacillus from these women and those from gynaecologically normal women. No relationship could be established between the forms of lactobacilli isolated and clinical characteristics or other microorganisms isolated from the vagina. Women from whom lactobacilli were not isolated had a significantly higher vaginal pH and greater incidence of potentially pathogenic organisms. Estimations of the abundance of vaginal isolates showed that some organisms were consistently present in greater numbers than others. Individual species of Lactobacillus also showed definite tendencies to be present in particular grades of abundancy.