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. 2014 Aug 18;9(8):e105011. doi: 10.1371/journal.pone.0105011

Figure 4. Antibody-mediated opsonization of B. pertussis.

Figure 4

The binding of serum (A) and nasal lavage (B) IgG antibodies to Bvg+ or Bvg− grown B. pertussis B1917 was determined using flow cytometry. Bars represent the geometric mean ±95% confidence interval (CI) of 6 individual mice. *p<0.05, ***p<0.0005 relative to PBS group; Kruskal-Wallis test followed by a Dunns post-hoc test (α = 5%). To determine the distribution of IgG subtypes, whole-cell ELISA was performed with the post-immunization serum samples to detect pertussis-specific IgG1 (C), IgG2a (D), and IgG2b (E). Each symbol represents one mouse and the geometric mean is represented by a line. Dashed lines indicate the lower limit of detection (23, 4, and 27 ng/ml for IgG1, IgG2a, and IgG2b, respectively). For IgG1, a 1-tailed Wilcoxon Signed Rank Test was performed because IgG1 levels of the PBS mice were below the detection limit. IgG2a and IgG2b levels were statistically compared to the PBS mice using a 2-tailed Mann-Whitney U-test. *p<0.05, **p<0.005.