Figure 3. Contribution of hp0197 to the resistance to phagocytotic killing and to CPS synthesis.

(A) Percent of bacteria killed after 90 min incubation with murine phagocytes. The experiment was repeated five times. Error bars indicate standard deviations. “*” represents P value <0.05 of WT versus Δcps group or WT versus Δhp0197 group respectively. (B) Morphology of the WT (left), the Δhp0197 (middle) and cΔhp0197 (right) strains. Transmission electron microscopy revealed that the WT strain was surrounded by a thick polysaccharide capsule (52.8±10.4 nm); the thickness of the Δhp0197 capsule was markedly reduced (1.1±0.3 nm), and cΔhp0197 could if not completely, partially restore this phenotype (21.1±6.6 nm).