The Mycobacterium tuberculosis complex (MTC or MTBC) is a genetically related group of Mycobacterium species that can cause tuberculosis in humans or other animals.
In addition, two branches exist which have phylogenetic similarities but are not completely described: the dassie and oryx bacilli. Oryx bacilli has been recently reclassified into a separate subspecies, orygis.[1]
Members of the MTC can be distinguished from all other bacteria by the presence of 63 conserved signature indels (CSIs) present in diverse proteins that are exclusively shared by these pathogens.[4] Due to their exclusivity for the MTC complex and presence in highly conserved regions of proteins, these CSIs provide novel means for functional and diagnostic studies (including potential targets for development of novel therapeutics).[4]
Since 2018, all members of this species complex are considered synonyms of M. tuberculosis as far as bacterial nomenclature is concerned. The IJSEM article reports that M. africanum, M. bovis, M. caprae, M. pinnipedii are 99.21–99.92% identical to M. tuberculosis on the whole-genome level, failing the criteria to be considered independent species. The same applies to "M. canetti", "M. mungi", and "M. orygis", species not validly published. The variation is even below the accepted level for subspecies. Authors of the article note that these names do refer to stable lineages with meaningful clinical distinctions, recommending that them become variants: M. bovis would become M. tuberculosis var. bovis, for example.[5]
Phylogeneticsedit
As MTBC diverged into different lineages, so did the expression of key and metabolic pathogenic genes, as a result of mutations introducing new TANNNT Pribnow boxes and mutations that impair the function of transcriptional repressors. This provides clear evidence that MTBC lineages probably reflect adaptation to different human populations. In fact, modifying gene expression could be a rapid mechanism for physiological adaptation to a new environment without the need to substantially change the genome.[6]
This can be seen reflected in the way that the different MTBC clades have their own transcriptomic signature. Even single-point mutations can completely change the transcriptional profile of a strain. An example is the N1177 strain, which carries a single mutation in the rpoB gene that confers resistance to rifampicin that modified transcription levels of multiple genes.[6]
The role of methylation is more elusive, the mutation inactivation pattern seems to confirm that methylases are not preserved throughout mtBC. Transcriptional adaptation can allow M. tuberculosis isolates to optimize their infectivity and transmission in subtly different environments provided by different human host populations.[6]
^ abvan Ingen J, Rahim Z, Mulder A, Boeree MJ, Simeone R, Brosch R, van Soolingen D (April 2012). "Characterization of Mycobacterium orygis as M. tuberculosis complex subspecies". Emerging Infectious Diseases. 18 (4): 653–5. doi:10.3201/eid1804.110888. PMC3309669. PMID 22469053.
^Patterson, S, Drewe, JA, Pfeiffer, DU, Clutton-Brock, TH (2017). "Social and environmental factors affect tuberculosis related mortality in wild meerkats". Journal of Animal Ecology. 86 (3): 442–450. Bibcode:2017JAnEc..86..442P. doi:10.1111/1365-2656.12649. PMC5413830. PMID 28186336.
^Vasconcellos SE, Huard RC, Niemann S, Kremer K, Santos AR, Suffys PN, Ho JL (March 2010). "Distinct genotypic profiles of the two major clades of Mycobacterium africanum". BMC Infectious Diseases. 10: 80. doi:10.1186/1471-2334-10-80. PMC2859774. PMID 20350321.
^ abGupta, Radhey S. (2018-10-02). "Impact of Genomics on Clarifying the Evolutionary Relationships amongst Mycobacteria: Identification of Molecular Signatures Specific for the Tuberculosis-Complex of Bacteria with Potential Applications for Novel Diagnostics and Therapeutics". High-Throughput. 7 (4): 31. doi:10.3390/ht7040031. ISSN 2571-5135. PMC6306742. PMID 30279355.
^Riojas, Marco A.; McGough, Katya J.; Rider-Riojas, Cristin J.; Rastogi, Nalin; Hazbón, Manzour Hernando (1 January 2018). "Phylogenomic analysis of the species of the Mycobacterium tuberculosis complex demonstrates that Mycobacterium africanum, Mycobacterium bovis, Mycobacterium caprae, Mycobacterium microti and Mycobacterium pinnipedii are later heterotypic synonyms of Mycobacterium tuberculosis". International Journal of Systematic and Evolutionary Microbiology. 68 (1): 324–332. doi:10.1099/ijsem.0.002507. PMID 29205127.
^ abcChiner-Oms Á, Berney M, Boinett C, González-Candelas F, Young DB, Gagneux S, et al. (September 2019). "Genome-wide mutational biases fuel transcriptional diversity in the Mycobacterium tuberculosis complex". Nature Communications. 10 (1): 3994. Bibcode:2019NatCo..10.3994C. doi:10.1038/s41467-019-11948-6. PMC6728331. PMID 31488832. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
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mycobacterium, tuberculosis, complex, mtbc, genetically, related, group, mycobacterium, species, that, cause, tuberculosis, humans, other, animals, includes, mycobacterium, tuberculosis, mycobacterium, africanum, mycobacterium, orygis, mycobacterium, bovis, ba. The Mycobacterium tuberculosis complex MTC or MTBC is a genetically related group of Mycobacterium species that can cause tuberculosis in humans or other animals It includes Mycobacterium tuberculosis Mycobacterium africanum Mycobacterium orygis 1 Mycobacterium bovis and the Bacillus Calmette Guerin strain Mycobacterium microti Mycobacterium canettii Mycobacterium caprae Mycobacterium pinnipedii Mycobacterium suricattae 2 Mycobacterium mungi 3 In addition two branches exist which have phylogenetic similarities but are not completely described the dassie and oryx bacilli Oryx bacilli has been recently reclassified into a separate subspecies orygis 1 Members of the MTC can be distinguished from all other bacteria by the presence of 63 conserved signature indels CSIs present in diverse proteins that are exclusively shared by these pathogens 4 Due to their exclusivity for the MTC complex and presence in highly conserved regions of proteins these CSIs provide novel means for functional and diagnostic studies including potential targets for development of novel therapeutics 4 Since 2018 all members of this species complex are considered synonyms of M tuberculosis as far as bacterial nomenclature is concerned The IJSEM article reports that M africanum M bovis M caprae M pinnipedii are 99 21 99 92 identical to M tuberculosis on the whole genome level failing the criteria to be considered independent species The same applies to M canetti M mungi and M orygis species not validly published The variation is even below the accepted level for subspecies Authors of the article note that these names do refer to stable lineages with meaningful clinical distinctions recommending that them become variants M bovis would become M tuberculosis var bovis for example 5 Phylogenetics editAs MTBC diverged into different lineages so did the expression of key and metabolic pathogenic genes as a result of mutations introducing new TANNNT Pribnow boxes and mutations that impair the function of transcriptional repressors This provides clear evidence that MTBC lineages probably reflect adaptation to different human populations In fact modifying gene expression could be a rapid mechanism for physiological adaptation to a new environment without the need to substantially change the genome 6 This can be seen reflected in the way that the different MTBC clades have their own transcriptomic signature Even single point mutations can completely change the transcriptional profile of a strain An example is the N1177 strain which carries a single mutation in the rpoB gene that confers resistance to rifampicin that modified transcription levels of multiple genes 6 The role of methylation is more elusive the mutation inactivation pattern seems to confirm that methylases are not preserved throughout mtBC Transcriptional adaptation can allow M tuberculosis isolates to optimize their infectivity and transmission in subtly different environments provided by different human host populations 6 See also editNontuberculous mycobacteriaReferences edit a b van Ingen J Rahim Z Mulder A Boeree MJ Simeone R Brosch R van Soolingen D April 2012 Characterization of Mycobacterium orygis as M tuberculosis complex subspecies Emerging Infectious Diseases 18 4 653 5 doi 10 3201 eid1804 110888 PMC 3309669 PMID 22469053 Patterson S Drewe JA Pfeiffer DU Clutton Brock TH 2017 Social and environmental factors affect tuberculosis related mortality in wild meerkats Journal of Animal Ecology 86 3 442 450 Bibcode 2017JAnEc 86 442P doi 10 1111 1365 2656 12649 PMC 5413830 PMID 28186336 Vasconcellos SE Huard RC Niemann S Kremer K Santos AR Suffys PN Ho JL March 2010 Distinct genotypic profiles of the two major clades of Mycobacterium africanum BMC Infectious Diseases 10 80 doi 10 1186 1471 2334 10 80 PMC 2859774 PMID 20350321 a b Gupta Radhey S 2018 10 02 Impact of Genomics on Clarifying the Evolutionary Relationships amongst Mycobacteria Identification of Molecular Signatures Specific for the Tuberculosis Complex of Bacteria with Potential Applications for Novel Diagnostics and Therapeutics High Throughput 7 4 31 doi 10 3390 ht7040031 ISSN 2571 5135 PMC 6306742 PMID 30279355 Riojas Marco A McGough Katya J Rider Riojas Cristin J Rastogi Nalin Hazbon Manzour Hernando 1 January 2018 Phylogenomic analysis of the species of the Mycobacterium tuberculosis complex demonstrates that Mycobacterium africanum Mycobacterium bovis Mycobacterium caprae Mycobacterium microti and Mycobacterium pinnipedii are later heterotypic synonyms of Mycobacterium tuberculosis International Journal of Systematic and Evolutionary Microbiology 68 1 324 332 doi 10 1099 ijsem 0 002507 PMID 29205127 a b c Chiner Oms A Berney M Boinett C Gonzalez Candelas F Young DB Gagneux S et al September 2019 Genome wide mutational biases fuel transcriptional diversity in the Mycobacterium tuberculosis complex Nature Communications 10 1 3994 Bibcode 2019NatCo 10 3994C doi 10 1038 s41467 019 11948 6 PMC 6728331 PMID 31488832 nbsp Material was copied from this source which is available under a Creative Commons Attribution 4 0 International License nbsp This Mycobacterium article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Mycobacterium tuberculosis complex amp oldid 1186789607, wikipedia, wiki, book, books, library,
