Figure 1

Distribution of S . Enteritidis 147 wild-type strain and SPI mutants in the spleen of orally infected chickens. S. Enteritidis counts in the liver correlated with counts in the spleen except for the fact that ΔSPI2 mutant colonised liver significantly less efficiently than the wild type S. Enteritidis also on day 12 (not shown). Y axis, average log CFU/g of spleen ± SD. a, b - ANOVA different at p < 0.05 in comparison to the group infected with the wild-type S. Enteritidis (a) or ΔSPI1-5 mutant (b). Abbreviations: wt - wild-type S. Enteritidis 147; ΔSPI1-5: mutant from which all major 5 SPI have been removed, ΔSPI1, ΔSPI2, ΔSPI3, ΔSPI4, ΔSPI5: mutants from which the respective SPI has been removed, SPI1o, SPI2o, SPI3o, SPI4o, SPI5o: "SPIonly" mutants, mutants with only the respective SPI retained.