FIG. 6.
Effect of ppk1 deletion on chicken colonization. Chicks were randomly assigned to six groups of five. The first three groups were inoculated with 103, 104, and 105 CFU/chick of the wild-type strain, while the other three groups received 103, 104, and 105 CFU/chick of the Δppk1 mutant strain. At 8 days postinoculation, the chicks were euthanized and the numbers of CFU/gram of cecal contents, feces, and bursae were calculated. Each bar represents the mean ± SE of five chicks. *, P < 0.01; **, P < 0.05. WT, wild type.