Query: NC_011149:2701916 Salmonella enterica subsp. enterica serovar Agona str. SL483,
Lineage: Salmonella enterica; Salmonella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: Salmonella enterica subsp. enterica serovar Agona causes gastroenteritis in humans and is also pathogenic to swine and other food animals. This serovar is able to contain the Salmonella genomic island 1 multidrug resistance gene cluster. This group of Enterobactericiae have pathogenic characteristics and are one of the most common causes of enteric infections (food poisoning) worldwide. They were named after the scientist Dr. Daniel Salmon who isolated the first organism, Salmonella choleraesuis, from the intestine of a pig. The presence of several pathogenicity islands (PAIs) that encode various virulence factors allows Salmonella spp. to colonize and infect host organisms. There are two important PAIs, Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2) that encode two different type III secretion systems for the delivery of effector molecules into the host cell that result in internalization of the bacteria which then leads to systemic spread.
Subject: NC_000921:1007519 Helicobacter pylori J99, complete genome
Lineage: Helicobacter pylori; Helicobacter; Helicobacteraceae; Campylobacterales; Proteobacteria; Bacteria
General Information: This strain was isolated in 1994 in the USA from a patient with duodenal ulcer. This genus consists of organisms that colonize the mucosal layer of the gastrointestinal tract or are found enterohepatically (in the liver). It was only recently discovered (1983) by two Australians (Warren and Marshall) that this organism was associated with peptic ulcers. It is one of the most common chronic infectious organisms, and is found in half the world's population. This organism attacks the gastric epithilial surface, resulting in chronic gastritis, and can cause more severe diseases including those that lead to gastric carcinomas and lymphomas, peptic ulcers, and severe diarrhea. It is an extracellular pathogen that persists in the gastric environment, which has a very low pH, by production of the urease enzyme, which converts urea to ammonia and carbon dioxide, a process which can counteract the acidic environment by production of a base. The toxins include cytolethal distending toxin, vacuolating cytotoxin (VacA) that induces host epithelial cell apopoptosis (cell death), and the cytotoxin associated antigen (CagA) which results in alteration to the host cell signalling pathways. The CagA protein is translocated into host cells by a type IV secretion system encoded by the cag pathogenicity island.