Virulence potential of five major pathogeniCity islands (SPI-1 to SPI-5) of Salmonella enterica serovar Enteritidis for chickens

Background  

Salmonella is a highly successful parasite of reptiles, birds and mammals. Its ability to infect and colonise such a broad range of hosts coincided with the introduction of new genetic determinants, among them 5 major pathogeniCity islands (SPI1-5), into the Salmonella genome. However, only limited information is available on how each of these pathogeniCity islands influences the ability of Salmonella to infect chickens. In this study, we therefore constructed Salmonella Enteritidis mutants with each SPI deleted separately, with single individual SPIs (i.e. with the remaining four deleted) and a mutant with all 5 SPIs deleted, and assessed their virulence in one-day-old chickens, together with the innate immune response of this host.