scholarly journals Insights into the ancestry evolution of the Mycobacterium tuberculosis complex from analysis of Mycobacterium riyadhense

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Qingtian Guan ◽  
Musa Garbati ◽  
Sara Mfarrej ◽  
Talal AlMutairi ◽  
Thomas Laval ◽  
...  

Abstract Current evolutionary scenarios posit the emergence of Mycobacterium tuberculosis from an environmental saprophyte through a cumulative process of genome adaptation. Mycobacterium riyadhense, a related bacillus, is being increasingly isolated from human clinical cases with tuberculosis-like symptoms in various parts of the world. To elucidate the evolutionary relationship between M. riyadhense and other mycobacterial species, including members of the M. tuberculosis complex (MTBC), eight clinical isolates of M. riyadhense were sequenced and analyzed. We show, among other features, that M. riyadhense shares a large number of conserved orthologs with M. tuberculosis and shows the expansion of toxin/antitoxin pairs, PE/PPE family proteins compared with other non-tuberculous mycobacteria. We observed M. riyadhense lacks wecE gene which may result in the absence of lipooligosaccharides (LOS) IV. Comparative transcriptomic analysis of infected macrophages reveals genes encoding inducers of Type I IFN responses, such as cytosolic DNA sensors, were relatively less expressed by macrophages infected with M. riyadhense or M. kansasii, compared to BCG or M. tuberculosis. Overall, our work sheds new light on the evolution of M. riyadhense, its relationship to the MTBC, and its potential as a system for the study of mycobacterial virulence and pathogenesis.

2021 ◽  
Author(s):  
Jean Bosco Ntivuguruzwa ◽  
Anita Michel ◽  
Francis Babaman Kolo ◽  
Ivan Emil Mwikarago ◽  
Claude Semuto Ngabonziza ◽  
...  

Background: Bovine tuberculosis (bTB) is an endemic disease in Rwanda, but little is known about its prevalence and causative mycobacterial species. The disease causes tremendous losses in livestock and wildlife and remains a significant threat to public health. Materials and methods: A cross-sectional study employing a systematic random sampling of cattle (n=300) with the collection of retropharyngeal lymph nodes and tonsils (n=300) irrespective of granulomatous lesions was carried out in six abattoirs to investigate the prevalence and identify mycobacterial species using culture, acid-fast bacteria staining, polymerase chain reaction, and GeneXpert assay. Individual risk factors and the origin of samples were analysed for association with the prevalence. Findings: Of the 300 samples, six were collected with visible TB-like lesions. Our findings demonstrated the presence of Mycobacterium tuberculosis complex (MTBC) in 1.7% (5/300) of sampled slaughtered cattle. M. bovis was isolated from 1.3% (4/300) animals while one case was caused by a rifampicin-resistance (RR) M. tuberculosis. Non-tuberculous mycobacteria were identified in 12.0% (36/300) of the sampled cattle. There were no significant associations between the prevalence and abattoir category, age, sex, and breeds of slaughtered cattle. Conclusions: This study is the first in Rwanda to isolate both M. bovis and RR M. tuberculosis in slaughtered cattle indicating that bTB is prevalent in Rwanda with a low prevalence. The isolation of RR M. tuberculosis from cattle indicates possible zooanthroponotic transmission of M. tuberculosis and close human-cattle contact. To protect humans against occupational zoonotic diseases, it is essential to control bTB in cattle and raise the awareness among all occupational groups as well as reinforce biosafety at the farm level and in the abattoirs.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1294
Author(s):  
Cristina Blanco Blanco Vázquez ◽  
Thiago Doria Barral ◽  
Beatriz Romero ◽  
Manuel Queipo ◽  
Isabel Merediz ◽  
...  

The present work investigated the prevalence, spatial distribution, and temporal distribution of tuberculosis (TB) in free-ranging Eurasian badgers (Meles meles) and cattle in Asturias (Atlantic Spain) during a 13-year follow-up. The study objective was to assess the role of badgers as a TB reservoir for cattle and other sympatric wild species in the region. Between 2008 and 2020, 673 badgers (98 trapped and 575 killed in road traffic accidents) in Asturias were necropsied, and their tissue samples were cultured for the Mycobacterium tuberculosis complex (MTC) isolation. Serum samples were tested in an in-house indirect P22 ELISA to detect antibodies against the MTC. In parallel, data on MTC isolation and single intradermal tuberculin test results were extracted for cattle that were tested and culled as part of the Spanish National Program for the Eradication of Bovine TB. A total of 27/639 badgers (4.23%) were positive for MTC based on bacterial isolation, while 160/673 badgers (23.77%) were found to be positive with the P22 ELISA. The rate of seropositivity was higher among adult badgers than subadults. Badger TB status was spatially and temporally associated with cattle TB status. Our results cannot determine the direction of possible interspecies transmission, but they are consistent with the idea that the two hosts may exert infection pressure on each other. This study highlights the importance of the wildlife monitoring of infection and disease during epidemiological interventions in order to optimize outcomes.


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