Infecção de aves (Gallus gallus domesticus) com Salmonella enterica subesp. enterica sorovar Enteritidis contendo deleções nos genes cobS, cbiA, pduC, pduD e pduE: avaliação da colonização intestinal, invasão sistêmica e resposta imune

• Ano de defesa: 2015
• Autor(a) principal: Denadai, Janine [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Ave; Salmonella enteritidis; Genes; Resposta imune; Infecção; Immune response
• Link de acesso: http://hdl.handle.net/11449/127833; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/20-08-2015/000845411.pdf

Salmonella Enteritidis (SE) is responsible for majority of the cases of foodborne diseases in humans and usually is associated with the consumption of poultry origin products. In birds, SE colonizes the intestine and can survive using 1,2 propanodiol (1,2-Pd) as substrate. The metabolisation of the 1,2-Pd is possible by the action of propanodiol dehydratase enzyme, encoded by genes pdu operon. Cyanocobalamin, which is encoded by genes cobS and cbiA, is the cofactor required by propanodiol dehydratase. In this study, we used one SE wild type strain and two mutants, one with mutations in pduC, pduD and pduE genes (SE ΔpduCDE) and another with mutations of pduC, pduD, pduE, cobS and cbiA genes (ΔcobSΔcbiAΔpduCDE) in attempt to evaluate the importance of 1,2-Pd for intestinal colonization and invasion of organs during infection of birds. In the first experiment, bacterial counts for all strains were obtained from spleen, liver and cecal content of white and brown varieties of commercial egg-layers. In the second assay, faecal shedding of the strains was assessed by cloacal swabs. Additionaly, immunological responses were characterised by the assessment of T CD4+ and T CD8+ cell populations in liver and cecal tonsils from SPF (Specific Pathogen Free) chicks challenged with the three strains. Complementary transcripts of genes encoding the cytokines IL-6, CCL4, CXCLi2 and IL-22 in cecal tonsils, and IL-6 and IL-18 in liver were obtained for relative quantification by qRT-PCR. It was observed that SE mutant strains were able to colonise the intestine and invade spleen and liver in the same way as the wild type strain. Brown variety of birds was more susceptible to systemic infection than white birds. Furthermore, the immune response profiles triggered by the SE wild type and the two mutants in SPF chicks were very similar. Therefore, data for the present study suggest that pduC, pduD, pduE, cobS e cbiA genes would not be essencial to ...