title: Vaginal lactobacilli: self- and co-aggregating ability.
abstract: Lactic acid bacteria are the dominant bacteria of the vaginal tract in healthy women. Lactobacillus species form a barrier population that protects from pathogen colonisation by mechanisms that include adhesion to epithelial surfaces, self-aggregation and co-aggregation. In this study, factors involved in the self-aggregating ability of vaginal lactobacilli and in the co-aggregation of these microorganisms with Candida spp. are studied. Both self-aggregation and co-aggregation are monitored quantitatively by the decrease in the absorbance of suspensions of the microorganisms and qualitatively by light microscopy. The self-aggregating ability of four vaginal lactobacilli was shown to be caused by a peptide or protein sensitive to trypsin. However, in self-aggregating Lactobacillus acidophilus CRL 1294 the factor was resistant to trypsin and sensitive to pepsin. Among self-aggregating lactobacilli, L. acidophilus CRL 1294 and L. salivarius CRL 1328 were able to co-aggregate with Candida spp. The co-aggregating factor for both strains proved to be peptide of the surface and a peptide on the bacterial surface, while the receptor on the yeast was a carbohydrate. Co-aggregation of both lactobacilli and Candida spp. was inhibited by the addition of mannose but was not affected by other carbohydrates. Self and co-aggregation factors were not able to induce aggregation in non-aggregating lactobacilli.
authors.affiliation: CERELA (Centro de Referencia para Lactobacilos)-CONICET, Chacabuco 145, 4000 Tucumán, Argentina.
authors.forename: Virginia S
authors.initials: VS
authors.lastname: Ocaña
authors.forename: María Elena
authors.initials: ME
authors.lastname: Nader-Macías
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology*; D002175:Candida / Q000502:physiology; D005260:Female; D006801:Humans; D007778:Lactobacillus / Q000502:physiology*; D008358:Mannose / Q000494:pharmacology; D010434:Pepsin A / Q000494:pharmacology; D014357:Trypsin / Q000494:pharmacology; D014621:Vagina / Q000382:microbiology*
chemical_list: D014357:Trypsin; D010434:Pepsin A; D008358:Mannose