Pre_GI: SWBIT SVG BLASTN

Query: NC_017361:930280 Helicobacter pylori SouthAfrica7 chromosome, complete genome

Lineage: Helicobacter pylori; Helicobacter; Helicobacteraceae; Campylobacterales; Proteobacteria; Bacteria

General Information: 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.

Subject: NC_020064:1854589 Serratia marcescens FGI94, complete genome

Lineage: Serratia marcescens; Serratia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria

General Information: This organism was discovered in 1819 by Bizio who named the organism after the Italian physicist Serrati. It was considered a nonpathogenic organism until late in the 20th century, although pathogenicity was noted as early as 1913. Serratia marcescens is an opportunistic human pathogen that is increasingly associated with life-threatening hospital-acquired infections. It is an environmental organism that has a broad host range, and is capable of infecting vertebrates and invertebrates, as well as plants. In humans, Serratia marcescens can cause meningitis (inflammation of the membrane surrounding the brain and spinal cord), endocarditis (inflammation of heart muscle) and pyelonephritis (inflammation of the kidneys). Many strains are resistant to multiple antibiotics. Environmental isolates are noted by production of the red pigment prodigiosin.