Comparison of wild type and Δspi1 Δspi2 (deletion of SPI1 and the structural SPI2 genes) colonization of the chicken cecum (A) and spleen (B). Competitive indexes are from mixed oral infections in chickens with the wild type and the Δspi1 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