Biology:Mycobacterium kansasii
| Mycobacterium kansasii | |
|---|---|
| |
Scientific classification 
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| Domain: | Bacteria |
| Phylum: | Actinomycetota |
| Class: | Actinomycetia |
| Order: | Mycobacteriales |
| Family: | Mycobacteriaceae |
| Genus: | Mycobacterium |
| Species: | M. kansasii
|
| Binomial name | |
| Mycobacterium kansasii Hauduroy 1955,[1] ATCC 12478
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Mycobacterium kansasii is a bacterium in the Mycobacterium genus. It is an environmental bacteria that causes opportunistic infections in humans, and is one of the leading mycobacterial causes of human disease after tuberculosis and leprosy.[2]
Description
Gram-positive, nonmotile, moderately-long to long, and acid-fast rods.
Colony characteristics
M. kansasii forms smooth to rough colonies after 7 or more days of incubation and is considered a slow grower. Colonies grown in dark are nonpigmented, when grown in light or when young colonies are exposed briefly to light, colonies become brilliant yellow (photochromogenic) according to the Runyon classification of Non-Tuberculous Mycobacteria. Oxygen is essential for the development of the pigment. If grown in a lighted incubator, most strains form dark red crystals of β-carotene on the surface and inside of colony.
Growth characteristics
M. kansasii grows on Middlebrook 7H10 agar at 37 °C.[3] The species is classified as a slow grower and may take up to six weeks to grow. The species if resistant to pyrazinamide and susceptible to ethambutol.
Differential characteristics
It is closely related to the non-pathogenic, also slowly growing, nonpigmented, M. gastri. Both species share an identical 16S rDNA but differentiation is possible by differences in the ITS and hsp65 sequences.
M. kansasii complex
Several former subtypes of M. kansasii have been reclassified as closely related species, and along with M. gastri form the M. kansasii complex (MKC). The species in the MKC are
- Mycobacterium kansasii (former subtype I)
- Mycobacterium persicum (former subtype II)
- Mycobacterium pseudokansasii (former subtype III)
- Mycobacterium ostraviense (former subtype IV)
- Mycobacterium innocens (former subtype V)
- Mycobacterium attenuatum (former subtype VI)
- and Mycobacterium gastri[4][5][6]
Discovery
Mycobacterium kansasii was first described in 1952 after being identified as the cause of two cases of disease resembling human pulmonary tuberculosis at Kansas City General Hospital and the University of Kansas Medical Center.[7]
Pathogenesis
M. kansasii may cause chronic human pulmonary disease resembling tuberculosis.[8] Extrapulmonary infections, such as cervical lymphadenitis in children, cutaneous and soft tissues infections, and musculoskeletal system involvement are uncommon. Rarely it causes disseminated disease in patients with severely impaired cellular immunity (such as organ transplants or AIDS). Pre-existing lung disease such as silicosis is a risk factor.[9] Mycobacterium kansasii occasionally involves the skin in a sporotrichoid pattern.[10]: 341 It is unclear where people acquire the infection and person-to-person spread is not thought to occur. Tap water is believed to be the major reservoir associated with human disease.[11] Biosafety level 2 is indicated.
Type strain
References
- ↑ Derniers aspects du monde des mycobactéries. Paris: Masson et Cie. 1955. OCLC 876707134.
- ↑ "Mycobacterium kansasii". Microbiology Spectrum 5 (1). January 2017. doi:10.1128/microbiolspec.TNMI7-0011-2016. PMID 28185617.
- ↑ Johnston, James C.; Chiang, Leslie; Elwood, Kevin (2017-02-10). "Mycobacterium kansasii". Microbiology Spectrum 5 (1): 10.1128/microbiolspec.tnmi7–0011–2016. doi:10.1128/microbiolspec.tnmi7-0011-2016. PMID 28185617. PMC 11687434. https://journals.asm.org/doi/10.1128/microbiolspec.tnmi7-0011-2016.
- ↑ "Population genomics provides insights into the evolution and adaptation to humans of the waterborne pathogen Mycobacterium kansasii". Nature Communications 12 (1): 2491. May 2021. doi:10.1038/s41467-021-22760-6. PMID 33941780. Bibcode: 2021NatCo..12.2491L.
- ↑ "Phylogenomics reveal that Mycobacterium kansasii subtypes are species-level lineages. Description of Mycobacterium pseudokansasii sp. nov., Mycobacterium innocens sp. nov. and Mycobacterium attenuatum sp. nov". International Journal of Systematic and Evolutionary Microbiology 69 (6): 1696–1704. June 2019. doi:10.1099/ijsem.0.003378. PMID 30950782.
- ↑ "Genomic Insights Into the Mycobacterium kansasii Complex: An Update". Frontiers in Microbiology 10 (1): 2918. Jan 2020. doi:10.3389/fmicb.2019.02918. PMID 32010067.
- ↑ "Human infection with atypical acid-fast organisms; report of two cases with pathologic findings". American Journal of Clinical Pathology 23 (4): 363–374. April 1953. doi:10.1093/ajcp/23.4.363. PMID 13040295.
- ↑ Mycobacterium Kansasii at eMedicine
- ↑ "Silicosis and Mycobacterium Kansasii Infection". Diseases of the Chest 55 (6): 479–482. 1969-06-01. doi:10.1378/chest.55.6.479.
- ↑ Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. 2006. ISBN 978-0-7216-2921-6.
- ↑ "Mycobacteria in drinking water distribution systems: ecology and significance for human health". FEMS Microbiology Reviews 29 (5): 911–934. November 2005. doi:10.1016/j.femsre.2005.02.001. PMID 16219512.
External links
- "Mycobacterium kansasii". NCBI Taxonomy Browser. https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=1768.
- Type strain of Mycobacterium kansasii at BacDive – the Bacterial Diversity Metadatabase
Wikidata ☰ Q4044720 entry
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