Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8842488 | Brazilian Journal of Microbiology | 2018 | 6 Pages |
Abstract
Salmonella Gallinarum is a host-restrict pathogen that causes fowl typhoid, a severe systemic disease that is one of the major concerns to the poultry industry worldwide. When infecting the bird, SG makes use of evasion mechanisms to survive and to replicate within macrophages. In this context, phoPQ genes encode a two-component regulatory system (PhoPQ) that regulates virulence genes responsible for adaptation of Salmonella spp. to antimicrobial factors such as low pH, antimicrobial peptides and deprivation of bivalent cations. The role of the mentioned genes to SG remains to be investigated. In the present study a phoPQ-depleted SG strain (SG ÎphoPQ) was constructed and its virulence assessed in twenty-day-old laying hens susceptible to fowl typhoid. SG ÎphoPQ did cause neither clinical signs nor mortality in birds orally challenged, being non-pathogenic. Furthermore, this strain was not recovered from livers or spleens. On the other hand, chickens challenged subcutaneously with the mutant strain had discreet to moderate pathological changes and also low bacterial counts in liver and spleen tissues. These findings show that SG ÎphoPQ is attenuated to susceptible chickens and suggest that these genes are important during chicken infection by SG.
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Authors
Lucas Bocchini Rodrigues Alves, Oliveiro Caetano de Freitas Neto, Diego Felipe Alves Batista, Fernanda de Oliveira Barbosa, Marcela da Silva Rubio, Andrei Itajahy Secundo de Souza, Adriana Maria de Almeida, Paul Andrew Barrow, Angelo Berchieri Junior,