Deletion of sodCI and spvBC in Salmonella enterica serovar Enteritidis reduced its virulence to the natural virulence of serovars Agona, Hadar and Infantis for mice but not for chickens early after infection.

Salmonella enterica serovars Typhimurium, Enteritidis, Dublin, Choleraesuis or Gallinarum can colonise liver and spleen in particular hosts while infections with serovars Infantis, Agona, Hadar, etc. are usually limited to gastrointestinal tract. Reasons for this behavior are unknown, although it has been shown that sodCI and spv genes exhibit a strict distribution between more and less virulent serovars and they influence Salmonella virulence. However to what extent the presence or absence of these genes is associated with the increased virulence of serovars which possess them has never been addressed experimentally. In this study we therefore first confirmed the exclusive association of spvB and sodCI genes with the former group of serovars. In the next step we removed these two genes from S. Enteritidis genome and compared the virulence of such a mutant with the virulence of S. Infantis, S. Agona and S. Hadar for chickens and highly sensitive Balb/C mice. Single strain infection showed that the deletion of these two genes from S. Enteritidis resulted in the reduction of its virulence for mice but not for chickens. Mixed infection further confirmed these observations and indicated that in mice but not in chickens the virulence of sodCI and spv mutant was reduced to the natural virulence of serovars Infantis, Agona and Hadar. Although sodCI and spv genes do not influence S. Enteritidis virulence for chickens directly, they may be of an indirect effect through the increased persistence of S. Enteritidis in mice and increased probability of the reintroduction of S. Enteritidis into poultry flocks.

Karasova D ，Havlickova H ，Sisak F ，Rychlik I ... -  《-》

Differences in the carriage and the ability to utilize the serotype associated virulence plasmid in strains of Salmonella enterica serotype Typhimurium investigated by use of a self-transferable virulence plasmid, pOG669.

Olsen JE ，Brown DJ ，Thomsen LE ，Platt DJ ，Chadfield MS ... -  《MICROBIAL PATHOGENESIS》

Differences in abilities to colonize reproductive organs and to contaminate eggs in intravaginally inoculated hens and in vitro adherences to vaginal explants between Salmonella enteritidis and other Salmonella serovars.

Okamura M ，Miyamoto T ，Kamijima Y ，Tani H ，Sasai K ，Baba E ... -  《AVIAN DISEASES》

Specific adhesion and invasion of Salmonella Enteritidis in the vagina of laying hens.

Mizumoto N ，Sasai K ，Tani H ，Baba E ... -  《VETERINARY MICROBIOLOGY》

A live Salmonella enterica serovar Enteritidis vaccine allows serological differentiation between vaccinated and infected animals.

Adriaensen C ，De Greve H ，Tian JQ ，De Craeye S ，Gubbels E ，Eeckhaut V ，Van Immerseel F ，Ducatelle R ，Kumar M ，Hernalsteens JP ... -  《-》