Journal: mSphere

Article Title: Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes

doi: 10.1128/msphere.00450-24

Figure Lengend Snippet: cpn60 alignment to determine species designation of Gardnerella strains of interest. Neighbor-joining phylogenetic tree of full-length cpn60 nucleotide sequences (1629 bp) of 91 Gardnerella spp. available genomes from GenBank. Clade distribution as described by . AKK101 most closely groups with clade C and strain 3336 with clade B. Strain 2492 is closest to clade D but may be outside of the original four clade designation. Regardless, each strain of interest is a distinct Gardnerella species. Arrows mark strains characterized in this study.

Article Snippet: Further analysis of the number of homopolymeric tracts in publicly available Gardnerella genomes ( n = 91) on NCBI (National Center for Biotechnology Information) showed median tract counts of 20 and 38 for G/C and A/T tracts, respectively.

Techniques:

Journal: mSphere

Article Title: Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes

doi: 10.1128/msphere.00450-24

Figure Lengend Snippet: Gardnerella spp . exhibit variation in colony size and opacity. ( A ) (Left) Strains from three different Gardnerella species assembled into large (Lg) and small (Sm) colonies on BHIFF agar medium. (Right) Opaque (Op) and translucent (Tr) colonies were observed on sBHI plates. Black arrows indicate Op, and white arrows indicate Tr. ( B ) Colonies from strain AKK101 show a spectrum of opacity intensities. Images were taken with a Leica S8 APO stereo microscope.

Article Snippet: Further analysis of the number of homopolymeric tracts in publicly available Gardnerella genomes ( n = 91) on NCBI (National Center for Biotechnology Information) showed median tract counts of 20 and 38 for G/C and A/T tracts, respectively.

Techniques: Microscopy

Journal: mSphere

Article Title: Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes

doi: 10.1128/msphere.00450-24

Figure Lengend Snippet: Supernatants from small variants elicit greater hemolysis. Bacteria were grown in BHI YDS medium, and the culture supernatant was collected after 24 h. ( A ) Concentrated supernatant from triplicate wells was assayed for VLY production by percent hemolysis of human erythrocytes. ( B ) Strain growth was measured by the change in OD 600 between inoculation and supernatant harvesting. Data from A and B are presented as an average of three independent experiments. Error bars represent standard deviation. * P < 0.05,** P < 0.01, *** P < 0.001. ( C ) Western blots of VLY in Gardnerella spp. supernatants. Reported VLY molecular weight is 57 kDa for the full-length protein (with signal sequence). It is unclear why multiple bands are present for some strains.

Article Snippet: Further analysis of the number of homopolymeric tracts in publicly available Gardnerella genomes ( n = 91) on NCBI (National Center for Biotechnology Information) showed median tract counts of 20 and 38 for G/C and A/T tracts, respectively.

Techniques: Bacteria, Standard Deviation, Western Blot, Molecular Weight, Sequencing

Journal: mSphere

Article Title: Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes

doi: 10.1128/msphere.00450-24

Figure Lengend Snippet: Colony variants differ in their antagonism of urogenital bacteria. Gardnerella colony variants from strain AKK101 were streaked onto BHI YDS medium + 10% FBS (fetal; bovine serum) and grown for 24 h before adding a spot of diluted bacterial culture from N. gonorrhoeae , L. crispatus , or L. gasseri . After 24 h of co-culture, plates were assessed for a zone of clearing (red brackets) within the spot suggestive of growth inhibition. The results from a representative experiment are shown, but three independent experiments were performed.

Article Snippet: Further analysis of the number of homopolymeric tracts in publicly available Gardnerella genomes ( n = 91) on NCBI (National Center for Biotechnology Information) showed median tract counts of 20 and 38 for G/C and A/T tracts, respectively.

Techniques: Bacteria, Co-Culture Assay, Inhibition

Journal: mSphere

Article Title: Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes

doi: 10.1128/msphere.00450-24

Figure Lengend Snippet: Homopolymer tract distribution in Gardnerella genomes. ( A ) Characteristics of homopolymer tracts in strains of interest. ( B ) Median tract number grouped by Gardnerella cpn60 clade. The line within each box represents the median; the “X” represents the mean. Bars extending from boxes represent maximum and minimum values. Data points outside of bars are outliers. ** P < 0.01, *** P < 0.001.

Article Snippet: Further analysis of the number of homopolymeric tracts in publicly available Gardnerella genomes ( n = 91) on NCBI (National Center for Biotechnology Information) showed median tract counts of 20 and 38 for G/C and A/T tracts, respectively.

Techniques:

Journal: mSphere

Article Title: Phase variable colony variants are conserved across Gardnerella spp. and exhibit different virulence-associated phenotypes

doi: 10.1128/msphere.00450-24

Figure Lengend Snippet: Gardnerella colony variant infection cycle hypothesis. ( A ) The BV biofilm encasing both Lg and Sm Gardnerella variants and other BV-associated bacteria enters the vaginal canal. ( B ) Upon biofilm dispersal, the Sm variant withstands the host innate immune defenses. ( C ) Increased expression of GA-module-containing proteins enhances autoaggregation and subsequent Sm adhesion to the host epithelium. ( D ) Secretion of vaginolysin toxin releases glycogen stored in epithelial cells, which Sm uses as a nutrient source through increased PulA and MalQ production. ( E ) An environmental cue triggers phenotype switching from the Sm to Lg variant. ( F ) The Lg variant produces sugars and amino acids that support the growth of Prevotella and other anaerobes. The presence of Lg is inhibitory toward Lactobacilli. ( G ) Lg initiates biofilm production and other BV-associated bacteria become incorporated. ( H ) Maturation of the BV biofilm gives rise to Sm variants. Biofilm aggregates, either themselves or attached to shed epithelial cells (clue cells), are transmitted to the next host.

Article Snippet: Further analysis of the number of homopolymeric tracts in publicly available Gardnerella genomes ( n = 91) on NCBI (National Center for Biotechnology Information) showed median tract counts of 20 and 38 for G/C and A/T tracts, respectively.

Techniques: Variant Assay, Infection, Bacteria, Expressing