ProventriculusPlagueYersinia pestisSiphonapteraPlague VaccineStomach, AvianFlea InfestationsDigestive SystemCrop, AvianMadagascarYersinia pseudotuberculosisGizzardVirulencePore Forming Cytotoxic ProteinsPoultry DiseasesCtenocephalidesVirulence FactorsChick EmbryoDrosophila ProteinsChickensEctoparasitic InfestationsBacterial ProteinsXenopsyllaBacterial Outer Membrane ProteinsDrosophilaGene Expression Regulation, DevelopmentalAntigens, BacterialLymph NodesRickettsia felis