Dataset Information

Degradation, foraging, and depletion of mucus sialoglycans by the vagina-adapted Actinobacterium Gardnerella vaginalis.

ABSTRACT: Bacterial vaginosis (BV) is a polymicrobial imbalance of the vaginal microbiota associated with reproductive infections, preterm birth, and other adverse health outcomes. Sialidase activity in vaginal fluids is diagnostic of BV and sialic acid-rich components of mucus have protective and immunological roles. However, whereas mucus degradation is believed to be important in the etiology and complications associated with BV, the role(s) of sialidases and the participation of individual bacterial species in the degradation of mucus barriers in BV have not been investigated. Here we demonstrate that the BV-associated bacterium Gardnerella vaginalis uses sialidase to break down and deplete sialic acid-containing mucus components in the vagina. Biochemical evidence using purified sialoglycan substrates supports a model in which 1) G. vaginalis extracellular sialidase hydrolyzes mucosal sialoglycans, 2) liberated sialic acid (N-acetylneuraminic acid) is transported into the bacterium, a process inhibited by excess N-glycolylneuraminic acid, and 3) sialic acid catabolism is initiated by an intracellular aldolase/lyase mechanism. G. vaginalis engaged in sialoglycan foraging in vitro, in the presence of human vaginal mucus, and in vivo, in a murine vaginal model, in each case leading to depletion of sialic acids. Comparison of sialic acid levels in human vaginal specimens also demonstrated significant depletion of mucus sialic acids in women with BV compared with women with a "normal" lactobacilli-dominated microbiota. Taken together, these studies show that G. vaginalis utilizes sialidase to support the degradation, foraging, and depletion of protective host mucus barriers, and that this process of mucus barrier degradation and depletion also occurs in the clinical setting of BV.

SUBMITTER: Lewis WG

PROVIDER: S-EPMC3636892 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Degradation, foraging, and depletion of mucus sialoglycans by the vagina-adapted Actinobacterium Gardnerella vaginalis.

Lewis Warren G WG Robinson Lloyd S LS Gilbert Nicole M NM Perry Justin C JC Lewis Amanda L AL

The Journal of biological chemistry 20130311 17

Bacterial vaginosis (BV) is a polymicrobial imbalance of the vaginal microbiota associated with reproductive infections, preterm birth, and other adverse health outcomes. Sialidase activity in vaginal fluids is diagnostic of BV and sialic acid-rich components of mucus have protective and immunological roles. However, whereas mucus degradation is believed to be important in the etiology and complications associated with BV, the role(s) of sialidases and the participation of individual bacterial s ...[more]

PMID: 23479734

Similar Datasets

Project description:BACKGROUND: Gardnerella vaginalis is identified as the predominant colonist of the vaginal tracts of women diagnosed with bacterial vaginosis (BV). G. vaginalis can be isolated from healthy women, and an asymptomatic BV state is also recognised. The association of G. vaginalis with different clinical phenotypes could be explained by different cytotoxicity of the strains, presumably based on disparate gene content. The contribution of horizontal gene transfer to shaping the genomes of G. vaginalis is acknowledged. The CRISPR loci of the recently discovered CRISPR/Cas microbial defence system provide a historical view of the exposure of prokaryotes to a variety of foreign genetic elements. RESULTS: The CRISPR/Cas loci were analysed using available sequence data from three G. vaginalis complete genomes and 18?G. vaginalis draft genomes in the NCBI database, as well as PCR amplicons of the genomic DNA of 17 clinical isolates. The cas genes in the CRISPR/Cas loci of G. vaginalis belong to the E. coli subtype. Approximately 20% of the spacers had matches in the GenBank database. Sequence analysis of the CRISPR arrays revealed that nearly half of the spacers matched G. vaginalis chromosomal sequences. The spacers that matched G. vaginalis chromosomal sequences were determined to not be self-targeting and were presumably neither constituents of mobile-element-associated genes nor derived from plasmids/viruses. The protospacers targeted by these spacers displayed conserved protospacer-adjacent motifs. CONCLUSIONS: The CRISPR/Cas system has been identified in about one half of the analysed G. vaginalis strains. Our analysis of CRISPR sequences did not reveal a potential link between their presence and the virulence of the G. vaginalis strains. Based on the origins of the spacers found in the G. vaginalis CRISPR arrays, we hypothesise that the transfer of genetic material among G. vaginalis strains could be regulated by the CRISPR/Cas mechanism. The present study is the first attempt to determine and analyse the CRISPR loci of bacteria isolated from the human vaginal tract.

Dataset Information

Degradation, foraging, and depletion of mucus sialoglycans by the vagina-adapted Actinobacterium Gardnerella vaginalis.

Publications

Degradation, foraging, and depletion of mucus sialoglycans by the vagina-adapted Actinobacterium Gardnerella vaginalis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets