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Acta Crystallographica. Section D,... Nov 2023Cell-surface proteins known as adhesins enable bacteria to colonize particular environments, and in Gram-positive bacteria often contain autocatalytically formed...
Cell-surface proteins known as adhesins enable bacteria to colonize particular environments, and in Gram-positive bacteria often contain autocatalytically formed covalent intramolecular cross-links. While investigating the prevalence of such cross-links, a remarkable example was discovered in Mobiluncus mulieris, a pathogen associated with bacterial vaginosis. This organism encodes a putative adhesin of 7651 residues. Crystallography and mass spectrometry of two selected domains, and AlphaFold structure prediction of the remainder of the protein, were used to show that this adhesin belongs to the family of thioester, isopeptide and ester-bond-containing proteins (TIE proteins). It has an N-terminal domain homologous to thioester adhesion domains, followed by 51 immunoglobulin (Ig)-like domains containing ester- or isopeptide-bond cross-links. The energetic cost to the M. mulieris bacterium in retaining such a large adhesin as a single gene or protein construct suggests a critical role in pathogenicity and/or persistence.
Topics: Female; Humans; Mobiluncus; Adhesins, Bacterial; Esters
PubMed: 37860959
DOI: 10.1107/S2059798323007507 -
NPJ Biofilms and Microbiomes Mar 2024Colonization of the vaginal space with bacteria such as Gardnerella vaginalis and Mobiluncus mulieris is associated with increased risk for STIs, bacterial vaginosis,...
Colonization of the vaginal space with bacteria such as Gardnerella vaginalis and Mobiluncus mulieris is associated with increased risk for STIs, bacterial vaginosis, and preterm birth, while Lactobacillus crispatus is associated with optimal reproductive health. Although host-microbe interactions are hypothesized to contribute to reproductive health and disease, the bacterial mediators that are critical to this response remain unclear. Bacterial extracellular vesicles (bEVs) are proposed to participate in host-microbe communication by providing protection of bacterial cargo, delivery to intracellular targets, and ultimately induction of immune responses from the host. We evaluated the proteome of bEVs produced in vitro from G. vaginalis, M. mulieris, and L. crispatus, identifying specific proteins of immunologic interest. We found that bEVs from each bacterial species internalize within cervical and vaginal epithelial cells, and that epithelial and immune cells express a multi-cytokine response when exposed to bEVs from G. vaginalis and M. mulieris but not L. crispatus. Further, we demonstrate that the inflammatory response induced by G. vaginalis and M. mulieris bEVs is TLR2-specific. Our results provide evidence that vaginal bacteria communicate with host cells through secreted bEVs, revealing a mechanism by which bacteria lead to adverse reproductive outcomes associated with inflammation. Elucidating host-microbe interactions in the cervicovaginal space will provide further insight into the mechanisms contributing to microbiome-mediated adverse outcomes and may reveal new therapeutic targets.
Topics: Infant, Newborn; Humans; Female; Gardnerella vaginalis; Mobiluncus; Proteomics; Premature Birth; Extracellular Vesicles
PubMed: 38514622
DOI: 10.1038/s41522-024-00502-y -
Biofilm Dec 2023Bacterial vaginosis (BV) affects approximately 26% of women of childbearing age globally, presenting with 3-5 times increased risk of miscarriage and two-fold risk of...
Bacterial vaginosis (BV) affects approximately 26% of women of childbearing age globally, presenting with 3-5 times increased risk of miscarriage and two-fold risk of pre-term birth Antibiotics (metronidazole and clindamycin) are typically employed to treat BV; however the success rate is low due to the formation of recalcitrant polymicrobial biofilms. As a novel therapeutic, promising results have been obtained using endolysins, although to date their efficacy has only been demonstrated against simple biofilm models. In this study, a four-species biofilm was developed consisting of and . Biofilms were grown in NYC III broth and treated using antibiotics and an anti- endolysin (CCB7.1) for 24 h. Biofilm composition, viability and structure were assessed using colony counts, live/dead qPCR and scanning electron microscopy. All species colonised biofilms to varying degrees, with being the most abundant. Biofilm composition remained largely unchanged when challenged with escalated concentrations of conventional antibiotics. A targeted endolysin candidate (CCB7.1) showed efficacy against several species planktonically, and significantly reduced viable within polymicrobial biofilms at 1 to 4X pMIC (p < 0.05 vs. vehicle control). Collectively, this study highlights the resilience of biofilm-embedded pathogens against the currently used antibiotics and provides a polymicrobial model that allows for more effective pre-clinical screening of BV therapies. The -specific endolysin CCB7.1 demonstrated significant activity against within polymicrobial biofilms, altering the overall community dynamic and composition.
PubMed: 36655001
DOI: 10.1016/j.bioflm.2022.100101 -
Current Microbiology Feb 2024The strains Marseille-Q7072 (= CSUR Q7072 = CECT 30604) and Marseille-Q7826 (= CSUR Q7826 = CECT 30727) were isolated from vaginal samples. As MALDI-TOF mass...
The strains Marseille-Q7072 (= CSUR Q7072 = CECT 30604) and Marseille-Q7826 (= CSUR Q7826 = CECT 30727) were isolated from vaginal samples. As MALDI-TOF mass spectrometry failed to identify them, their genomes were directly sequenced to determine their taxogenomic identities. Both strains are anaerobic without any oxidase and catalase activity. C is the most abundant fatty acid for both strains. Strain Marseille-Q7072 is non-spore-forming, non-motile, Gram-stain-positive, and coccus-shaped, while strain Marseille-Q7826 is non-spore-forming, motile, Gram-stain-variable, and curved rod-shaped. The genomic comparison of the Marseille-Q7072 and Marseille-Q7826 strains showed that all digital DNA-DNA hybridisation (dDDH) and mean orthologous nucleotide identity (OrthoANI) values were below published species thresholds (70% and 95-96%, respectively) with other closely related species with standing in nomenclature. Thus, we conclude that both strains are new bacterial species. Strain Marseille-Q7072 is a new member of the Bacillota phylum, for which the name Peptoniphilus genitalis sp. nov. is proposed, while the Marseille-Q7826 strain is a new member of the Actinomycetota phylum, for which the name Mobiluncus massiliensis sp. nov. is proposed.
Topics: Female; Humans; Mobiluncus; Bacteria; Clostridiales; Microbiota; DNA
PubMed: 38372813
DOI: 10.1007/s00284-023-03584-7