Fig 5.

Mutation of cj1136 results in a reduced ability to colonize chicks. The C. jejuni wild-type (WT) 01/51 and its cj1136 mutant derivative (1136−) were tested in an in vivo model of chick colonization. A low dose and a high dose of each strain were administered to 10 birds in each group. The number of bacteria that had colonized the birds was determined in cecal contents at 5 days after infection. The C. jejuni 01/51 wild-type strain colonized to ∼10⁸ CFU g⁻¹ irrespective of dose; however, both low and high doses of the mutant in cj1136 showed significantly lower levels of chick colonization compared to cognate doses of the wild-type strain, confirming that cj1136 plays a role in chick colonization by C. jejuni. A nonparametric Mann-Whitney (two-tailed) test was used to assess statistical significance of colonization levels of the mutant compared with the wild type at each dose (P < 0.001).