作者: Donald G. Guiney , Joshua Fierer
关键词: Structural gene 、 Salmonella 、 Microbiology 、 Secretion 、 Phenotype 、 Phosphothreonine lyase activity 、 Biology 、 Virulence 、 Gene 、 Typhoid fever 、 Virology
摘要: Salmonella strains cause three main types of diseases in people: gastroenteritis, enteric (typhoid) fever, and non-typhoid extra-intestinal disease with bacteremia. Genetic analysis indicates that each clinical syndrome requires distinct sets virulence genes, isolates differ their constellation traits. The spv locus is strongly associated bacteremia, but are not present typhoid strains. region contains genes required for the phenotype mice: positive transcriptional regulator spvR two structural spvB spvC. SpvB SpvC translocated into host cell by pathogenicity island-2 type-three secretion system. prevents actin polymerization ADP-ribosylation monomers, while has phosphothreonine lyase activity been shown to inhibit MAP kinase signaling. exact mechanisms which act concert enhance still unclear. exhibits a cytotoxic effect on cells delayed death apoptosis following intracellular infection. Strains isolated from systemic infections immune compromised patients, particularly HIV usually carry locus, suggesting CD4 T control due positive. This association seen indicating pathogenesis immunology have fundamental differences