FIG 1 .

(A) C. jejuni cecal colonization of conventional day-of-hatch chicks inoculated with 10⁵ CFU of either 81-176 Str^r or the ΔznuA mutant at 6, 12, 24, and 48 h postinoculation. Each dot represents the bacterial recovery in a single chick. (B) C. jejuni cecal colonization of germfree mice, germfree chicks, and conventional chicks. The animals were inoculated with the indicated doses of either 81-176 Str^r or the ΔznuA mutant, and the cecal contents were plated for C. jejuni recovery after 7 days. Chicks were inoculated on the day of hatching, and germfree mice were inoculated postweaning (1 month old). (C) Conventionalization of ΔznuA mutant-colonized germfree chicks. Day-of-hatch germfree chicks were inoculated with 10⁶ CFU of either wild-type C. jejuni 81-176 Str^r or the ΔznuA mutant. Cecal contents were plated on day 3 postinoculation. On day 3, birds colonized with wild-type C. jejuni or the ΔznuA mutant were conventionalized with the cecal contents of age-matched conventional chicks or were not conventionalized (black symbols). Recovery of either the wild type or the ΔznuA mutant from the cecal contents was monitored on days 7 and 13 postinoculation.