Ready Experimental Translocation of Mycobacterium canettii Yields Pulmonary Tuberculosis

Abstract

Mycobacterium canettii, which has a smooth colony morphology, is the tuberculous organism retaining the most genetic traits from the putative last common ancestor of the rough-morphology Mycobacterium tuberculosis complex. To explore whether M. canettii can infect individuals by the oral route, mice were fed phosphate-buffered saline or 10 6 M. canettii mycobacteria and sacrificed over a 28-day experiment. While no M. canettii was detected in negative controls, M. canettiiinfected mice yielded granuloma-like lesions for 4/4 lungs at days 14 and 28 postinoculation (p.i.) and positive PCR detection of M. canettii for 5/8 mesenteric lymph nodes at days 1 and 3 p.i. and 5/6 pooled stools collected from day 1 to day 28 p.i. Smooth M. canettii colonies grew from 68% of lungs and 36% of spleens and cervical lymph nodes but fewer than 20% of axillary lymph nodes, livers, brown fat samples, kidneys, or blood samples throughout the 28-day experiment. Ready translocation in mice after digestive tract challenge demonstrates the potential of ingested M. canettii organisms to relocate to distant organs and lungs. The demonstration of this relocation supports the possibility that populations may be infected by environmental M. canettii.

Bovine Tuberculosis in Britain and Ireland – A Perfect Storm? the Confluence of Potential Ecological and Epidemiological Impediments to Controlling a Chronic Infectious Disease

“…Other prominent veterinary pathogens have been observed to be aerosolizable from an environmental source - Coxiella burnetii , which causes of Q Fever, has been observed to infect animals and humans exposed to contaminated wool ( 189 ) and Mycobacterium avium paratuberculosis , the causative agent in Johne’s Disease has been observed to be aerosolised in dust particles derived from bovine faecal material in animal housing ( 190 ). An intriguing recent study demonstrated that M. canettii , a pathogen predicted to be a common ancestor for the M. tuberculosis Complex, could produce pulmonary infection, indistinguishable from aerosol-mediated pulmonary infection, in mice fed spiked material ( 191 ).…”

Culturomics Discloses Anti-Tubercular Enterococci Exclusive of Pulmonary Tuberculosis: A Preliminary Report

“…Such a heterogeneous natural history of tuberculosis in neonates in the Lübeck series of cases may partly be explained by different gut microbiota maturation in the neonates [ 37 ]. Indeed, translocating M. canettii and M. tuberculosis has been shown to lead to both disseminating in the lymphatic and lung tissues after experimental gavage in mice [ 18 , 38 ]. It would be interesting to further document E. mundtii and E. casseliflavus interactions with M. tuberculosis in a mouse model, to observe interference with M. tuberculosis gut survival, translocation, and recirculation in the lungs.…”

Decrypting the environmental sources of Mycobacterium canettii by high-throughput biochemical profiling

“…canettii inoculation has demonstrated the potential of ingested M . canettii bacilli to relocate to lungs and other organs [8]. This experimental data supported that people could get infected with environmental M .…”