Journal: The Journal of Infectious Diseases
Article Title: Group B Streptococcus Biofilm Regulatory Protein A Contributes to Bacterial Physiology and Innate Immune Resistance
Figure Lengend Snippet: Group B Streptococcus (GBS) biofilm regulatory protein A (BrpA) deficiency influences cell survival, biofilm formation, and epithelial cell adherence but not autolysis. ( A ) Autolysis (left) in cultures of wild-type (WT) and Δ brpA organisms suspended in phosphate-buffered saline was measured spectrophotometrically (at OD 600 ), using turbidity normalized to T = 0. Viability (right) of WT and Δ brpA strains grown in Todd-Hewitt broth (THB) over time, as determined by plating on THB agar. Data from independent replicates (n = 3) are shown, with symbols representing mean values and lines indicating standard errors of the mean (SEMs). Data were analyzed using 2-way repeated measures analysis of variance with the Sidak multiple comparisons test. B , Biofilm formation of WT, Δ brpA , and revertant strains quantified by crystal violet uptake (left). Independent replicates (n = 6) are shown, and lines represent mean values ± SEMs. Data were analyzed using 1-way ANOVA with the Holm-Sidak multiple comparisons test. Fluorescent images of in vitro biofilms (center and right) stained with Syto 13 (green), taken at 100× original magnification. Scale bar = 100 µm. Experiments were performed twice independently, with representative images shown. C, Adherence of WT (black symbols) and Δ brpA (open circles) strains to vaginal (VK2) and bladder (HTB-9) epithelial cells. Independent replicates (n = 7) are shown, and lines represent median values ± 95% confidence intervals. Data were analyzed using the 2-tailed Mann-Whitney U test. D , In a competition model, CD1 mice were inoculated intravaginally with 1 × 10 7 CFU of WT and Δ brpA organisms (2 × 10 7 CFU total/mouse), and bacterial burdens were quantified daily after infection. Symbols represent biological replicates (n = 18), and paired values (WT and Δ brpA CFU) from each mouse are connected with dashed lines. Data were analyzed using the 2-tailed Wilcoxon matched-pairs signed rank test with Spearman rank-order correlation. *** P
Article Snippet: GBS CNCTC 10/84 serotype V (catalog no. 49447; American Type Culture Collection [ATCC]) and isogenic strains were grown to stationary phase at 37°C in Todd-Hewitt broth (THB; Hardy Diagnostics) supplemented with 50 µg/mL erythromycin when needed.
Techniques: In Vitro, Staining, MANN-WHITNEY, Mouse Assay, Infection