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.
The Plague of Justinian or Justinianic Plague was the first major outbreak of the first plague pandemic, the first Old World pandemic of plague, the contagious disease caused by the bacterium Yersinia pestis. The disease afflicted the entire Mediterranean Basin, Europe, and the Near East, severely affecting the Sasanian Empire and the Byzantine Empire and especially its capital, Constantinople. The plague is named for the Byzantine emperor in Constantinople, Justinian I who, according to his court historian Procopius, contracted the disease and recovered in 542, at the height of the epidemic which killed about a fifth of the population in the imperial capital. The contagion arrived in Roman Egypt in 541, spread around the Mediterranean Sea until 544, and persisted in Northern Europe and the Arabian Peninsula, until 549.
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.
Georges Girard was a French bacteriologist born in Isigny-sur-Mer, Calvados.
Yersiniabactin (Ybt) is a siderophore found in the pathogenic bacteria Yersinia pestis, Yersinia pseudotuberculosis, and Yersinia enterocolitica, as well as several strains of enterobacteria including enteropathogenic Escherichia coli and Salmonella enterica. Siderophores, compounds of low molecular mass with high affinities for ferric iron, are important virulence factors in pathogenic bacteria. Iron—an essential element for life used for such cellular processes as respiration and DNA replication—is extensively chelated by host proteins like lactoferrin and ferritin; thus, the pathogen produces molecules with an even higher affinity for Fe3+ than these proteins in order to acquire sufficient iron for growth. As a part of such an iron-uptake system, yersiniabactin plays an important role in pathogenicity of Y. pestis, Y. pseudotuberculosis, and Y. entercolitica.
Yersinia virus L413C is a virus of the family Myoviridae, genus Peduovirus.
Far East scarlet-like fever is an infectious disease caused by the gram negative bacillus Yersinia pseudotuberculosis. In Japan it is called Izumi fever.
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.
Yersinia aldovae is a species of bacteria that was originally described as Group X2 Yersinia enterocolitica. Its type strain is CNY 6005. Y. aldovae has been isolated from aquatic environments and soil, but it has not been associated with animal or human illnesses.
Pasteurella lymphangitidis is a bacterium; it causes bovine lymphangitis. Its reclassification to Yersinia has been proposed, given it poses a 99% sequence similarity to both Yersinia pseudotuberculosis and Yersinia pestis.
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 entomophaga is a species of bacteria that was originally isolated from the diseased larvae of the New Zealand grass grub, Costelytra zealandica. The type strain is MH96. It is currently being studied for biological pest control of insect pests like the porina moth, Wiseana cervinata.
Yersinia wautersii is a species of Gram-negative bacteria that was originally called the Korean Group of the Yersinia pseudotuberculosis complex. The type strain is 12-219N1.
Yersinia nurmii is a Gram-negative species of Yersinia that was originally isolated in packaged broiler meat cuts. The type strain is APN3a-c.
Yersinia pekkanenii is a Gram-negative species of Yersinia that has been isolated from water, soil, and lettuce samples. The type strain is ÅYV7.1KOH2.
Corynebacterium pseudotuberculosis is a Gram-positive bacterium known globally to infect ruminants, horses, and rarely people. This bacterium is a facultative anaerobic organism that is catalase positive and capable of beta-hemolysis. In small ruminants, C. pseudotuberculosis causes a disease called caseous lymphadenitis characterized by pyogranulomatous abscess formation. In general, this bacterium causes lesions of the skin, lymph nodes, and internal organs. A disease known as ulcerative lymphagenitis can also result from infection with C. pseudotuberculosis in the distal limbs of horses. This bacterium uses the virulence factors phospholipase D and mycolic acid to damage eukaryotic cell walls and resist phagocytic lysosomal degradation, respectively. Infection with this bacterium is often confirmed by bacterial culture of the purulent exudate. Once the diagnosis has been made, treatment of the infection can begin, but this is difficult due to the nature of the organism and the lesions it forms. Specifically, C. pseudotuberculosis is intrinsically resistant to streptomycin, with varying resistance to penicillin and neomycin depending on the strain. It has been shown to be susceptible to ampicillin, gentamicin, tetracycline, lincomycin, and chloramphenicol. Vaccines have also been produced to develop acquired immunity to this infection.
