Panel A shows representative FACS contour plots with outliers indicating IgA staining of SYBR Green nucleic acid-positive microbiota isolated from the feces of infected and sham-infected mice at 45 days post-infection (dpi). The right panel summarizes the results, showing the percentage of IgA-coated fecal bacteria over time. Panel B presents similar contour plots for IgG staining, with a summary of the percentage of IgG-coated fecal bacteria over time. Panel C includes bar graphs showing total IgA and IgG levels in the serum of infected and sham-infected mice at various dpi. Panel D features contour plots of fecal microbiota isolated from infected and sham-infected mice at 90 dpi, incubated with and without serum for detection of IgA and IgG binding, with a summary of the results. Panel E displays a bar graph showing the mean frequencies of IgA-coated bacteria in feces of infected mice collected at 90 dpi and 15 days after treatment with ceftriaxone or sham-treatment with PBS. Each symbol represents results from one mouse, and each time point represents one longitudinal analysis of samples from the same mice. The graphs illustrate trends in IgA and IgG binding to gut microbiota over time and under different conditions.
Loss of IgA binding to gut microbiota after Bb infection. (A and B) Left, representative FACS contour plots with outliers showing (A) IgA and (B) IgG staining of SYBR Green nucleic acid–positive microbiota isolated from the feces of Bb-infected and sham-infected mice at 45 dpi; right panel, summary of results. (C) Total (left) IgA and (right) IgG in the serum of Bb- and sham-infected mice at indicated dpi. (D) Upper panel represents FACS contour plots of fecal microbiota isolated from of Bb-infected and sham-infected mice at 90 dpi and incubated with and without serum for detection of IgA (left) and IgG (right) binding. Lower panel, summary of results. (E) Mean ± SEM frequencies of IgA-coated bacteria in feces of Bb-infected mice collected at 90 dpi and 15 days after the end of 30-day treatment with ceftriaxone or sham treatment with PBS. Each symbol represents results from one mouse (n = 4–5/group). (A–C) Each time point represents one longitudinal analysis of samples from the same mice. D and E represent one independent experiment. Mann–Whitney U test (A–C and E); paired Student’s t test (D); *P < 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, and ns, not significant (P > 0.05).