Hemagglutination, adherence, and surface properties of vaginal Lactobacillus species

To address the poorly understood mechanisms through which lactobacilli adhere to vaginal epithelial cells (VECs), 65 wild type lactobacilli isolated from the vaginal flora of young women and 3 American Type Culture Collection Lactobacillus strains were studied. Group I isolates (n = 56) hemagglutinated sheep, rabbit, and human red blood cells (RBCs) and adhered poorly to VECs. In contrast, all 4 group II strains hemagglutinated sheep and human but not rabbit RBCs, adhered in large numbers to VECs, and were identical in five phenotypic tests and DNA-DNA hybridization. Eight other strains (group III) hemagglutinated all RBC types studied, adhered avidly to VECs, and had identical protein and hybridization patterns but showed heterogeneous enzyme activities. Although most wild type lactobacilli from the vaginal flora of young women adhered poorly to VECs, selected isolates (groups II and III) adhered in large numbers, demonstrated specific and reproducible hemagglutination patterns, and may have specific mechanisms of attachment to VECs.