Query: NC_006086:1329915 Streptococcus pyogenes MGAS10394, complete genome
Lineage: Streptococcus pyogenes; Streptococcus; Streptococcaceae; Lactobacillales; Firmicutes; Bacteria
General Information: This strain is a serotype M6 isolate cultured from a child with pharyngitis in private elementary school in Pennsilvania, USA. Causes tonsilitis. Streptococci are Gram-positive, nonmotile, nonsporeforming, catalase-negative cocci that occur in pairs or chains. Members of this genus vary widely in pathogenic potential. Most streptococci are facultative anaerobes, and some are obligate anaerobes. Serologic grouping is based on antigenic differences in cell wall carbohydrates, in cell wall pili-associated protein, and in the polysaccharide capsule in group B streptococci. This organism is a member of the normal human nasopharyngeal flora. Streptococcus pyogenes is a group A streptococcus and is the leading cause of uncomplicated bacterial pharyngitis and tonsillitis. This organism is commonly referred to by the lay press as "flesh eating bacteria".
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.