Contribution of flagella and invasion proteins to pathogenesis of Salmonella enterica serovar enteritidis in chicks

To explore the relative contribution that flagella and Salmonella invasion proteins make to the virulence of Salmonella enteritidis in poultry. 20-day -old chicks were challenged orally and by subcutaneous injection with wild- type strain SE-HCD, two non-flagellated mutants (fliC::Tn10 mutant and flhD ::Tn10 Mutant) and two Salmonella invasion protein insertion mutants (sipD and iacP). When injected subcutaneously, wild-type SE-HCD was the only stra in to cause substantial mortality and morbidity and to grow well in organs. The flhD mutant of SE-HCD was invasive when given orally, whereas wild-typ e SE-HCD and the fliC mutant were significantly attenuated, Salmonella inva sion protein mutants were not invasive by either route, These results sugge st that temporary suppression of Class I regulators of flagellin biosynthes is may aid oral infection in Poultry. (C) 2001 Federation of European Micro biological Societies. Published by Elsevier Science B.V. All rights reserve d.