TABLE 5

Cecal persistence and clearance of wild-type S. Senftenberg from JOL1587- and PBS-inoculated chickens postchallenge

Groupa1 dayb5 days7 days14 days28 days
No. of positive samples/total no. of samplescRecovery (log10 CFU/g) (mean ± SEM)dNo. of positive samples/total no. of samplesRecovery (log10 CFU/g) (mean ± SEM)No. of positive samples/total no. of samplesRecovery (log10 CFU/g) (mean ± SEM)No. of positive samples/total no. of samplesRecovery (log10 CFU/g) (mean ± SEM)No. of positive samples/total no. of samplesRecovery (log10 CFU/g) (mean ± SEM)
A5/53.50 ± 1.2e5/55.0 ± 1.4e5/56.4 ± 1.6f5/57.0 ± 2.0f5/56.5 ± 1.9f
B3/52.8 ± 1.32/53.1 ± 1.61/50.8 ± 1.10/50.0 ± 0.00/50.0 ± 0.0
C2/51.2 ± 0.82/52.1 ± 1.00/50.0 ± 0.00/50.0 ± 0.00/50.0 ± 0.0
  • a Group A, PBS-treated control group; group B, chickens orally inoculated with JOL1587 (Δlon ΔcpxR); group C, chickens intramuscularly inoculated with JOL1587 (Δlon ΔcpxR).

  • b Days postchallenge.

  • c Number of positive samples per total number of samples observed with the enrichment culture method.

  • d Challenge strain recovery was determined by direct and enrichment culturing of cecal homogenates from birds at 1, 5, 7, 14, and 28 days postchallenge.

  • e Significantly greater number of S. Senftenberg-positive chickens in the control group, compared to the intramuscularly inoculated group, postchallenge (P ≤ 0.05).

  • f Significantly greater number of S. Senftenberg-positive chickens in the control group, compared to the orally and intramuscularly inoculated groups, postchallenge (P ≤ 0.05).