Comparison of Δspi1 (deletion of SPI1) and Δspi2 (deletion of SPI2 structural genes) colonization of the chicken cecum (A) and spleen (B). Competitive indexes are from mixed oral infections in chickens with the Δspi1 and Δspi2 strains. Each point represents an organ from an individual bird at the indicated day following the infection. The table summarizes the number of animals sampled (n), the geometric mean of the competitive indexes (mean CI), and the P value from a two-tailed T-test.
Dieye et al. BMC Microbiology 2009 9:3 doi:10.1186/1471-2180-9-3