Proteobacteria is a major phylum of Gram-negative bacteria. They include a wide variety of pathogenic genera, such as Escherichia, Salmonella, Vibrio, Helicobacter, Yersinia, Legionellales, and many others. Others are free-living (nonparasitic) and include many of the bacteria responsible for nitrogen fixation.
Yersinia pestis is a gram-negative, non-motile, coccobacillus bacterium, without spores that is related to both Yersinia pseudotuberculosis and Yersinia enterocolitica. It is a facultative anaerobic organism that can infect humans via the Oriental rat flea. It causes the disease plague, which caused the First plague pandemic and the Black Death, the deadliest pandemic in recorded history. Plague takes three main forms: pneumonic, septicemic, and bubonic.
Yersinia is a genus of bacteria in the family Yersiniaceae. Yersinia species are Gram-negative, coccobacilli bacteria, a few micrometers long and fractions of a micrometer in diameter, and are facultative anaerobes. Some members of Yersinia are pathogenic in humans; in particular, Y. pestis is the causative agent of the plague. Rodents are the natural reservoirs of Yersinia; less frequently, other mammals serve as the host. Infection may occur either through blood or in an alimentary fashion, occasionally via consumption of food products contaminated with infected urine or feces.
Yersinia enterocolitica is a Gram-negative, bacillus-shaped bacterium, belonging to the family Yersiniaceae. It is motile at temperatures of 22–29°C (72–84°F), but becomes nonmotile at normal human body temperature. Y. enterocolitica infection causes the disease yersiniosis, which is an animal-borne disease occurring in humans, as well as in a wide array of animals such as cattle, deer, pigs, and birds. Many of these animals recover from the disease and become carriers; these are potential sources of contagion despite showing no signs of disease. The bacterium infects the host by sticking to its cells using trimeric autotransporter adhesins.
Yersinia pseudotuberculosis is a Gram-negative bacterium that causes Far East scarlet-like fever in humans, who occasionally get infected zoonotically, most often through the food-borne route. Animals are also infected by Y. pseudotuberculosis. The bacterium is urease positive.
The class Gammaproteobacteria belongs to the Proteobacteria phylum and contains about 250 genera, which makes it the most genera-rich taxon of the Prokaryotes. Several medically, ecologically, and scientifically important groups of bacteria belong to this class. It is composed by all Gram-negative microbes and is the most phylogenetically and physiologically diverse class of Proteobacteria.
Mycobacterium chelonae is a species of the phylum Actinobacteria, belonging to the genus Mycobacterium. Mycobacterium chelonae is a rapidly growing mycobacterium, that is found all throughout the environment including sewage and tap water. It can occasionally cause opportunistic infections of humans.
Mycobacterium elephantis, a bacterium of the family Mycobacteriaceae, was discovered and isolated from a deceased elephant near India and may be linked to respiratory dysfunction. Organisms in the genus Mycobacterium are known to be aerobic and non-motile. Organisms within Mycobacterium belong to either the rapid growing group or the slow growing group. M. elephantis is classified as a rapid grower and relates most closely to Mycobacterium confluentis and Mycobacterium phlei.
Swarming motility is a rapid and coordinated translocation of a bacterial population across solid or semi-solid surfaces, and is an example of bacterial multicellularity and swarm behaviour. Swarming motility was first reported by Jorgen Henrichsen and has been mostly studied in genus Serratia, Salmonella, Aeromonas, Bacillus, Yersinia, Pseudomonas, Proteus, Vibrio and Escherichia.
Bacterial taxonomy is the taxonomy, i.e. the rank-based classification, of bacteria.
Yersinia frederiksenii is a Gram-negative species of bacteria. It uses rhamnose and sucrose. Its type strain is strain 6175. In humans, it can cause gastrointestinal infections, while it has also been found in fish.
Yersinia kristensenii is a species of bacteria. It is Gram-negative and its type strain is 105. It is potentially infectious to mice. It secretes a bacteriocin that targets related species.
Yersinia intermedia is a Gram-negative species of bacteria which uses rhamnose, melibiose, and raffinose. Its type strain is strain 3953. It has been found in fish, and contains several biotypes. It is not considered of clinical relevance, being isolated from humans in a routine manner.
Limosilactobacillus mucosae is a rod shaped species of lactic acid bacteria first isolated from pig intestines. It has mucus-binding activity. The species is an obligate anaerobe, catalase-negative, doesn't form spores and is non-motile. Its type strain is S32T, and has been found to be most closely related to Limosilactobacillus reuteri.
Psychrobacter arcticus is a Gram-negative, nonmotile species of bacteria first isolated from Siberian permafrost. Its type strain is 273-4T.
Yersinia mollaretii is a Gram-negative species of bacteria. The species is named after Henri Mollaret, the former head of the National Yersinia Center at Institut Pasteur.
Yersinia bercovieri is a Gram-negative species of enteric bacteria.
Psychrobacter is a genus of Gram-negative, osmotolerant, oxidase-positive, psychrophilic or psychrotolerant, aerobic bacteria which belong to the family Moraxellaceae and the class Gammaproteobacteria. The shape is typically cocci or coccobacilli. Some of those bacteria were isolated from humans and can cause humans infections such as endocarditis and peritonitis. This genus of bacteria is able to grow at temperatures between −10 and 42 °C. Rudi Rossau found through DNA-rRNA hybridization analysis that Psychrobacter belongs to the Moraxellaceae. The first species was described by Juni and Heym. Psychrobacter occur in wide range of moist, cold saline habitats, but they also occur in warm and slightly saline habitats.
Streptomyces bacillaris is a bacterium species from the genus of Streptomyces which has been isolated from forest soil in Oregon in the United States.
Yersinia hibernica is a species of Yersinia that was originally isolated in a pig-production environment. The type strain is CFS1934. This species has previously been misidentified as Yersinia enterocolitica and Yersinia kristensenii but it may be distinguished biochemically by lack of sucrose utilization. In addition to pig related environments, Y. hibernica has also been isolated from the feces of Rattus norvegicus and Hydrochoerus hydrochaeris.
