Influence of the major nitrite transporter NirC on the virulence of a Swollen Head Syndrome Avian Pathogenic E. coli (APEC) strain

Autor(es)

de Paiva, Jacqueline Boldrin ^[1] ; Leite, Janaina Luisa ^[1] ; Mendes da Silva, Livia Pilatti ^[1] ; Galvao Rojas, Thais Cabrera ^[1] ; de Pace, Fernanda ^[2] ; Conceicao, Rogerio Arcuri ^[1] ; Sperandio, Vanessa ^[3] ; da Silveira, Wanderley Dias ^[1]

Afiliação do(s) autor(es)

^[1] State Univ Campinas UNICAMP, Inst Biol, Dept Genet Evolut & Bioagents, Campinas, SP - Brazil

^[2] State Univ Campinas UNICAMP, Fac Med Sci, Dept Clin Med, Campinas, SP - Brazil

^[3] Univ Texas SW Med Ctr Dallas, Dallas, TX 75390 - USA

• Tipo de documento: Artigo Científico
• Fonte: Veterinary Microbiology; v. 175, n. 1, p. 123-131, JAN 30 2015.
• Citações Web of Science: 9

Resumo

Avian Pathogenic Escherichia coli (APEC) strains are extra-intestinal E. coli that infect poultry and cause diseases. Nitrite is a central branch-point in bacterial nitrogen metabolism and is used as a cytotoxin by macrophages. Unlike nitric oxide (NO), nitrite cannot diffuse across bacterial membrane cells. The NirC protein acts as a specific channel to facilitate the transport of nitrite into Salmonella and E. coli cells for nitrogen metabolism and cytoplasmic detoxification. NirC is also required for the pathogenicity of Salmonella by downregulating the production of NO by the host macrophages. Based on an in vitro microarray that revealed the overexpression of the nirC gene in APEC strain SCI-07, we constructed a nirC-deficient SCI-07 strain (Delta nirC) and evaluated its virulence potential using in vivo and in vitro assays. The final cumulative mortalities caused by mutant and wild-type (WT) were similar; while the Delta nirC caused a gradual increase in the mortality rate during the seven days recorded, the WT caused mortality up to 24 h post-infection (hpi). Counts of the Delta nirC cells in the spleen, lung and liver were higher than those of the WT after 48 hpi but similar at 24 hpi. Although similar number of Delta nirC and WT cells was observed in macrophages at 3 hpi, there was higher number of Delta nirC cells at 16 hpi. The cell adhesion ability of the Delta nirC strain was about half the WT level in the presence and absence of alpha-D-mannopyranoside. These results indicate that the nirC gene influences the pathogenicity of SCI-07 strain. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 10/51421-8 - Expressão proteica diferencial em linhagens de Escherichia coli septicêmicas para aves (APEC): da proteômica, à genômica, à função
• Beneficiário: Wanderley Dias da Silveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/09655-7 - Análise in vivo da expressão gênica de uma linhagem de Escherichia coli patogênica para aves (APEC) e mutação no sistema quorum sensing AI-2
• Beneficiário: Wanderley Dias da Silveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/50596-9 - Mutagenese sitio-dirigida em uma linhagem de escherichia coli (apec) causadora de sindrome de cabeca inchada em aves:analise in vitro e in vivo.
• Beneficiário: Jacqueline Boldrin de Paiva
• Modalidade de apoio: Bolsas no Brasil - Doutorado