Mycobacterium kansasii
Classification
Domain: Bacteria; Phylum: Actinomycete; Class: Actinomycetia; Order: Mycobacteriales; Family: Mycobacteriaceae; Genus: Mycobacterium; Species: kansasii
Species
|
NCBI: Taxonomy |
Mycobacterium kansasii
Description and Significance
Describe the appearance, habitat, etc. of the organism, and why you think it is important.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Circular
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Ecology and Pathogenesis
M. kansasii has been cultured in many countries including Australia, Brazil, United States, Canada, and in parts of Europe. In the United States, M. kansasii is often found in midwestern and southwestern states including Texas. Like most other Non-Tuberculosis Mycobacterium (NTM) infections, infection occurs in humans through inhalation of the bacterium in aerosols. However, this bacterium can be found in drinking water, natural waters, pipes/plumbing, and in soils. Though most studies present human infection case studies, M. kansasii is an opportunistic pathogen and has the ability to infect other organisms. Statistically, infection is more likely to occur in urban areas rather than rural areas; possibly due to an abundance of dirt in the air from mining or farming practices.
Because of the similarities to Tuberculosis, the symptoms are often very similar. Patients often present with a cough and sputum production, fever, chills, night sweats, and weight loss. Mycobacterium kansasii causes most episodes of non-tuberculous systemic disease and can often present in patients with an underlying pulmonary disease or immune deficiency. Because of the presence of similar symptoms, it is likely that many cases of M. kansasii are misdiagnosed as Tuberculosis. Furthermore, M. kansasii can cause a false positive on a tuberculosis skin test. Diagnosis by culture and virulence factors are also inadequate due to the bacterium's slow growth, often taking greater than 7 days to culture, and due to the absence of virulence factors. Therefore, a diagnosis is often made through specific PCR tests and radiology. M. kansasii microbial clusters are often visible in infected patient scans of the lungs.
The standard initial treatment regimen for M. kansasii infections include a combination of three antibiotics: rifampicin, isoniazid, and ethambutol. These drugs are initially administered daily for 18 to 24 months. After completing the initial phase of treatment, patients may transition to a continuation phase, which typically involves the same combination of antibiotics but at reduced dosages. The continuation phase may last an additional 9 to 15 months, for a total treatment duration of 24 to 36 months. In cases of extensive pulmonary disease, cavitary lesions, or treatment failure, surgical resection may be considered as additional therapy to antibiotics.
References
Levendosky, Keith, et al. “Comprehensive Essentiality Analysis of the Mycobacterium Kansasii Genome by Saturation Transposon Mutagenesis and Deep Sequencing.” mBio, vol. 14, no. 4, pp. e00573-23. PubMed Central, https://doi.org/10.1128/mbio.00573-23. Accessed 18 Apr. 2024.
Luo, Tao, et al. “Population Genomics Provides Insights into the Evolution and Adaptation to Humans of the Waterborne Pathogen Mycobacterium Kansasii.” Nature Communications, vol. 12, no. 1, May 2021, p. 2491. www.nature.com, https://doi.org/10.1038/s41467-021-22760-6.
“Mycobacterium Kansasii.” Mycobacterium Kansasii - an Overview | ScienceDirect Topics,www.sciencedirect.com/topics/immunology-and microbiology/mycobacterium-kansasii. Accessed 18 Apr. 2024.
StatPearls. “Mycobacterium Kansasii Infection.” StatPearls, StatPearls Publishing, 8 Aug. 2023, www.statpearls.com/articlelibrary/viewarticle/25421/.
Author
Page authored by Cameron Phipps and Adrian Pena, student of Prof. Jay Lennon at Indiana University.
