Specific binding of serum antibodies to the capsule of Spn10A. (A) ELISA detection of IgG subtypes of anti-CPS10A IgG in mouse serum. n = 3. (B) ELISA detection of IgG and IgM to different pneumococcal CPSs in mouse serum. n = 3. (C) ELISA detection of IgG and IgM to CPS10A in serum of male and female C57BL/6 mice. n = 5. (D) ELISA detection of serum IgG and IgM to CPS10A in SPF and GF mice. n = 3. (E) ELISA detection of serum IgG and IgM to CPS10A in C57BL/6, BALB/c or CD1 mice. n = 3. (F and G) Representative confocal images showing the deposition of IgG (F) or IgM (G) on TH860^10A or TH860^10A∆wcrG with percentages of deposition in the right. Scale bar, 10 μm. n = 5. Data were all representative results. Ordinary two-way ANOVA with Sidak’s multiple comparisons test (C and D) and unpaired t test (F and G) were performed. ****, P < 0.0001; ns, not significant.