Figure 1.

Capsule production of hvKP SGH10. The capsule regulator mutant ∆rmpA, and the capsule‐null mutants ∆wza, ∆wzy and ∆wcaJ were created and the mutants were complemented by the expression of the corresponding gene in a pUCP28T(p28T) backbone. (a) The capsule gene cluster of SGH10 (b) Capsule production in stationary phase bacteria SGH10 and the above mutants was measured semi‐quantitatively by density‐dependent separation on a Percoll gradient. (c) Strain mucoidy was measured by low‐speed centrifugation of bacteria in LB. The optical density at 600 nm (O.D. 600) of the supernatant above pellet was measured, and mean ± SD are plotted (n = 3) and * denotes p < .05, while n.s. denotes not significant. (d) Capsule mutants and their complemented counterparts were grown in 75% human serum to determine if they were resistant to complement mediated killing. Mean ± SD are plotted (n = 3) and Dunnett's multiple comparison test was conducted for CFU values relative to SGH10 at 3 hr. * denotes p < .05, ** denotes p < .001, while n.s. denotes not significant [Colour figure can be viewed at wileyonlinelibrary.com]