| Mycobacterium aviumsubsp. paratuberculosis | |
|---|---|
Scientific classification | |
| Domain: | Bacteria |
| Kingdom: | Bacillati |
| Phylum: | Actinomycetota |
| Class: | Actinomycetes |
| Order: | Mycobacteriales |
| Family: | Mycobacteriaceae |
| Genus: | Mycobacterium |
| Subgenus: | |
| Species: | |
| Subspecies: | M. a.subsp. paratuberculosis |
| Trinomial name | |
| Mycobacterium aviumsubsp. paratuberculosis (Bergey et al. 1923) Thorel et al. 1990 | |
Mycobacterium avium subspeciesparatuberculosis (MAP) is an obligatepathogenic bacterium in thegenusMycobacterium.[1] It is often abbreviatedM. paratuberculosis orM. avium ssp.paratuberculosis. It is the causative agent ofJohne's disease, which affects ruminants such as cattle, and suspected causative agent in humanCrohn's disease andrheumatoid arthritis.[2] Thetype strain isATCC 19698 (equivalent to CIP 103963 or DSM 44133).[3]
MAP causesJohne's disease incattle and otherruminants. It has long been suspected as a causative agent inCrohn's disease in humans,[4][5] but studies have been unable to show definite correlation.[6] One study has argued that the presence of antibodies againstMycobacterium avium subspeciesparatuberculosis is associated with increased propensity of patients with Crohn's disease to receive biological therapy.[7]
Recent studies have shown that MAP present inmilk can survivepasteurization, which has raised human health concerns due to the widespread nature of MAP in modern dairy herds. MAP survival duringpasteurization is dependent on the D72C-value of the strains present and their concentration in milk.[8] It is heat resistant and is capable of sequestering itself inside white blood cells, which may contribute to its persistence in milk. It has also been reported to survivechlorination in municipal water supplies.
MAP is a slow growing organism and is difficult to culture. Bacterial cultures were regarded as Gold standards for detection of MAP. Detection is very limited in fresh tissues, food, and water. Recently, John Aitken and Otakaro Pathways have discovered a method to culture MAP from human blood. Testing is ongoing. Professor John Hermon-Taylor of King's College London is developing a new vector type anti MAP vaccine which he claims is both curative and preventative. Stage 1 human trials began in January 2017 and concluded successfully in September 2019. He is also developing a companion MAP blood test.[citation needed][non-primary source needed]
It is not susceptible to antituberculosis drugs (which can generally killMycobacterium tuberculosis). MAP is susceptible toantibiotics used to treat Mycobacterium avium disease, such asrifabutin andclarithromycin, however the capacity of these antibiotics to eradicate MAP infection in vivo has not been established.[citation needed][non-primary source needed]
MAP is recognized as a multi-host mycobacterial pathogen with a proven specific ability to initiate and maintain systemic infection andchronic inflammation of the intestine of a range of histopathological types in many animal species, including primates.[9]
MAP has been found in larger numbers within the intestines of Crohn's disease patients[10] and in significant amount ofirritable bowel syndrome patients[11] compared to those withulcerative colitis or otherwise healthy controls. One study concluded that MAP "may act as a causative agent, have a role in the context of secondary infection, which may exacerbate the disease, or represent non-pathogenic colonisation."[6] TheCrohns MAP Vaccine is an experimental vaccine based on this hypothesis.[12]
The genome of MAP strain K-10 was sequenced in 2005 and found to consist of a single circular chromosome of 4,829,781 base pairs, and to encode 4,350 predictedORFs, 45tRNAs, and onerRNAoperon.[13]
Mycobacterium avium subsp. paratuberculosis was detected in 15 of 20 (75%) patients with irritable bowel syndrome, 3 of 20 (15%) healthy controls, and 20 of 23 (87%) people with Crohn's disease
