Clinical characteristics of the smooth tubercle bacilli ‘Mycobacterium canettii’ infection suggest the existence of an environmental reservoir

Koeck, Jean-Louis; Fabre, M.; Simon, Fabrice; Daffé, Mamadou; Garnotel, Éric; Matan, A.B.; Gérôme, P.; Bernatas, J. J.; Buisson, Y.; Pourcel, Christine

doi:10.1111/j.1469-0691.2010.03347.x

Cited by 82 publications

(96 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…M. canettii strains are remarkable, rare mycobacteria, which are almost exclusively isolated from patients in the region of the Horn of Africa (35, 36). Their mode of transmission seems to be different to M. tuberculosis because no human-to-human transmission of M. canettii strains was yet reported (18,35,37). M. canettii strains might have a yet-unknown, possibly aquatic, environmental reservoir where different strains can get in frequent direct contact, thereby enhancing the possibilities of HGT (10,17,38,39).…”

Section: Discussionmentioning

confidence: 99%

Key experimental evidence of chromosomal DNA transfer among selected tuberculosis-causing mycobacteria

Boritsch

Khanna

Pawlik

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

101

View full text Add to dashboard Cite

Horizontal gene transfer (HGT) is a major driving force of bacterial diversification and evolution. For tuberculosis-causing mycobacteria, the impact of HGT in the emergence and distribution of dominant lineages remains a matter of debate. Here, by using fluorescenceassisted mating assays and whole genome sequencing, we present unique experimental evidence of chromosomal DNA transfer between tubercle bacilli of the early-branching Mycobacterium canettii clade. We found that the obtained recombinants had received multiple donor-derived DNA fragments in the size range of 100 bp to 118 kbp, fragments large enough to contain whole operons. Although the transfer frequency between M. canettii strains was low and no transfer could be observed among classical Mycobacterium tuberculosis complex (MTBC) strains, our study provides the proof of concept for genetic exchange in tubercle bacilli. This outstanding, now experimentally validated phenomenon presumably played a key role in the early evolution of the MTBC toward pathogenicity. Moreover, our findings also provide important information for the risk evaluation of potential transfer of drug resistance and fitness mutations among clinically relevant mycobacterial strains.recombination | DNA transfer | tuberculosis | Mycobacterium canettii | evolution

show abstract

Section: Discussionmentioning

confidence: 99%

Key experimental evidence of chromosomal DNA transfer among selected tuberculosis-causing mycobacteria

Boritsch

Khanna

Pawlik

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

101

View full text Add to dashboard Cite

show abstract

“…Every MTC species has a limited range of natural hosts, but there is no specific barrier and any MTC species can potentially infect any susceptible host species (Djelouadji et al, 2011). Humans are infected worldwide by sympatric M. tuberculosis sensu stricto families (Gagneux et al, 2006), whereas patients who are exposed in Africa may also be infected by Mycobacterium africanum (de Jong et al, 2010) and Mycobacterium canettii (Koeck et al, 2011;Van Soolingen et al, 1997). Zoonotic tuberculosis can be due to Mycobacterium caprae, Mycobacterium microti (Panteix et al, 2010) or the bovine tuberculosis agent Mycobacterium bovis (Thoen & LoBue, 2007).…”

Section: Introductionmentioning

confidence: 99%

Long-term survival of tuberculosis complex mycobacteria in soil

et al. 2014

View full text Add to dashboard Cite

While there is evidence for the persistence of Mycobacterium bovis in soil, there are no reports for the other Mycobacterium tuberculosis complex (MTC) mycobacteria. Here, soil was inoculated with 10 8 c.f.u. g "1 M. tuberculosis, M. bovis and M. canettii and subcultured monthly for 12 months. The pathogenicity of mycobacterial colonies, identified by using matrix-assisted laser desorption/ionization time of flight mass spectrometry, was assessed in a mouse model. Moreover, mice were fed with food that contained 16.7 % M. tuberculosis-contaminated soil. The three tested MTC species survived in soil for 12 months with a final inoculum of 2¾10 3 c.f.u. g "1 for M. tuberculosis, 150 c.f.u. g "1 for M. bovis and 2¾10 4 c.f.u. g "1 for M. canettii. In an experiment that included negative controls, all (5/5) mice inoculated with such M. tuberculosis and M. canettii developed 0.03-0.3 granulomas mm "2 in their lungs and spleen and grew mycobacteria; five mice that were inoculated with M. bovis from soil did not develop granulomas but grew mycobacteria. Furthermore, 0.2-0.4 granulomas mm "2 were observed in the lungs and spleen of 3/5 mice fed with M. tuberculosis-contaminated soil in the presence of two negative control mice. M. tuberculosis grew in the stomach, intestine, spleen and lung in 5/5 challenged mice, whereas the negative controls remained M. tuberculosis-free (P50.008, Fisher exact test). This study provides clear evidence that MTC mycobacteria survive in soil, and that M. tuberculosis remains virulent while in the soil, outside its hosts, for extended periods of time.

show abstract

“…A detailed study has shown that the unusual smooth morphology "M. canettii" strains appear to form a pivotal role in the evolution of tuberculosis [84]. Although extant strains of "M. canettii" still cause human tuberculosis, they differ significantly in infectivity and appear to be relatively ancestral [85,86]. Genomic studies indicate that the very diverse "M. canettii" isolates appear to coalesce into a form of bottleneck after which all the modern human and animal biotypes evolved in a relatively linear manner [83,84,87,88].…”

Section: Evolutionary and Pathogenicity Aspects Of Cell Envelope Compmentioning

confidence: 99%

“…However, some most significant new lipid structural principles are introduced in "M. canettii" (Figure 11). Two major classes of acyl trehalose glycolipids, the DATs and PATs (Figure 5), are encountered [86]. The relatively polar DATs are good antigens, which probably contribute to the cell surface properties of tubercle bacilli [38].…”

Section: Evolutionary and Pathogenicity Aspects Of Cell Envelope Compmentioning

confidence: 99%

Pathophysiological Implications of Cell Envelope Structure in Mycobacterium tuberculosis and Related Taxa

Minnikin¹,

Lee²,

Wu³

et al. 2015

Tuberculosis - Expanding Knowledge

View full text Add to dashboard Cite

Clinical characteristics of the smooth tubercle bacilli ‘Mycobacterium canettii’ infection suggest the existence of an environmental reservoir

Cited by 82 publications

References 16 publications

Key experimental evidence of chromosomal DNA transfer among selected tuberculosis-causing mycobacteria

Key experimental evidence of chromosomal DNA transfer among selected tuberculosis-causing mycobacteria

Long-term survival of tuberculosis complex mycobacteria in soil

Pathophysiological Implications of Cell Envelope Structure in Mycobacterium tuberculosis and Related Taxa

Contact Info

Product

Resources

About