A Salmonella Enteritidis hilAssrAfliG deletion mutant is a safe live vaccine strain that confers protection against colonization by Salmonella Enteritidis in broilers

A colonisation-inhibition culture consisting of Salmonella Enteritidis and Typhimurium ΔhilAssrAfliG strains protects against infection by strains of both serotypes in broilers

“…It is therefore not improbable that the observed strong protective effect of the Salmonella Typhimurium hilAssrAfliG strain is due to its high colonising capacity. A Salmonella Enteritidis hilAssrAfliG deletion mutant has been shown to colonise spleen and caecum to a lesser extent and was cleared rapidly from poultry, but also offered relatively less protection against Salmonella Enteritidis infection [15]. These and earlier observations suggest thus that there will be a trade-off between persistence and protection, as a highly colonising and thus protective strain will probably not be eliminated by slaughter age [26].…”

“…Salmonella Typhimurium MB2136, a streptomycin resistant wild-type strain originally isolated from swine was used as a challenge strain. A nalidixic acid-resistant Salmonella Enteritidis hilAssrAfliG deletion mutant, which has been described earlier [15], was also used in this study. The original Salmonella Enteritidis 76Sa88 strain, from which the Salmonella Enteritidis hilAssrAfliG deletion mutant is derived, was originally isolated from a poultry farm [2,19].…”

“…This concept has been recognised for a long time, and a great deal of effort has been put in developing strains that are appropriate for use as CI strains [13,14]. Earlier research demonstrated that deletion of the hilA, ssrA and fliG genes in a Salmonella Enteritidis strain resulted in a CI strain that was safe and effective in protecting broilers against challenge with a Salmonella Enteritidis wild-type strain [15]. Because there is greater inhibition within a serovar than between serovars [16], the Salmonella Enteritidis hilAssrAfliG strain can be expected to mainly protect against Salmonella Enteritidis infection, and not or to a lesser extent against e.g., Salmonella Typhimurium infection.…”

Potential Impact of Food Safety Vaccines on Health Care Costs

“…Recently, a handful of studies have focused on live attenuated strains that are defective in the Salmonella T3SS (Matulova et al, 2012a(Matulova et al, , 2012bDe Cort et al, 2013). Salmonella Pathogenicity Island 1 and 2 (SPI-1 and SPI-2) encode for two T3SS that are used to inject virulence factors into host cells (Galan and Collmer, 1999;Galan 2001;Hensel, 2000;Hensel and Kuhle, 2004) and play an important role in Salmonella pathogenesis (Desin et al, 2009;Wisner et al, 2010).…”

“…Immunization of chickens with a SPI-1 lon mutant vaccine strain (Lon protease is a negative regulator of SPI-1) resulted in lower levels of Salmonella Enteritidis in the internal organs as well as the cecal contents (Matulova et al, 2013b). Likewise, a Salmonella Enteritidis DhilADssrADfliG triple mutant vaccine strain that contains deletions in the SPI-1, SPI-2, and flagellar genes was effective in reducing the number of chickens that were positive for Salmonella Enteritidis postvaccination (De Cort et al, 2013). Moreover, another group has demonstrated that DSPI-1 mutants (entire SPI-1 region deleted) induce cross-protective immunity in chickens (Matulova et al, 2013a).…”