Functions exerted by the virulence-associated type-three secretion systems during Salmonella enterica serovar Enteritidis invasion into and survival within chicken oviduct epithelial cells and macrophages.
Avian Pathol
; 38(2): 97-106, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19322708
ABSTRACT
Salmonella enterica serovar Enteritidis (SE) infection of chickens is a major contributing factor to non-typhoidal salmonellosis. The roles of the type-three secretion systems (T3SS-1 and T3SS-2) in the pathogenesis of SE infection of chickens are poorly understood. In this study, the functions of T3SS-1 and T3SS-2 during SE infection of primary chicken oviduct epithelial cells (COEC) and macrophages were characterized. The T3SS-1 and T3SS-2 mutants (sipB and ssaV), impaired in translocation and secretion, respectively, were significantly less invasive than their wild-type parent strain. The genes encoding effector proteins of T3SS-1 (SipA, SopB, and SopE2) and T3SS-2 (PipB) contributed equally to the entry of SE into COEC. The sipA mutant had reduced survival and the pipB mutant had enhanced replication in COEC. Mutations in the T3SS-2 genes ssaV and pipB reduced the survival of SE in chicken peripheral blood leukocyte-derived macrophages (PBLM), but not in the established chicken macrophage cell line HD11. A mutation in the ssaV gene also abolished SE-induced PBLM death between 1 h post-inoculation and 4 h post-inoculation. This study has shown that both T3SS-1 and T3SS-2 are required by SE to invade COEC; that SipA and PipB are necessary for the survival of SE in COEC and chicken PBLM, respectively; and that T3SS-2 triggers PBLM death during the early stages of SE infection, and this process does not depend on PipB.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oviductos
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Salmonelose Animal
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Salmonella enterica
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Células Epiteliais
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
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Female
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Humans
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article