Translocating Mycobacterium ulcerans: An experimental model.

Nassim Hammoudi,Michel Drancourt,Amar Bouam,Mustapha Fellag,Muriel Militello,Selvakumar Subbian

doi:10.1371/journal.pone.0230544

Nassim Hammoudi, Michel Drancourt + Show 4 more

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https://doi.org/10.1371/journal.pone.0230544

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Abstract

Mycobacterium ulcerans is a non-tuberculous environmental mycobacterium responsible for extensive cutaneous and subcutaneous ulcers in mammals, known as Buruli ulcer in humans. M. ulcerans has seldom been detected in the faeces of mammals and has not been detected in human faeces. Nevertheless, the detection and isolation of M. ulcerans in animal faeces does not fit with the current epidemiological schemes for the disease. Here, using an experimental model in which rats were fed with 109 colony-forming units of M. ulcerans, we detected M. ulcerans DNA in the faeces of challenged rats for two weeks and along their digestive tract for 10 days. M. ulcerans DNA was further detected in the lymphatic system including in the cervical and axillary lymph nodes and the spleen, but not in any other tissue including healthy and broken skin, 10 days post-challenge. These observations indicate that in some herbivorous mammals, M. ulcerans contamination by the digestive route may precede translocation and limited contamination of the lymphatic tissues without systemic infection. These herbivorous mammals may be sources of M. ulcerans for exposed populations but are unlikely to be reservoirs for the pathogen.

Highlights

Mycobacterium ulcerans is an environmental, slow growing, non-tuberculous mycobacterium responsible for a progressively extending cutaneous and subcutaneous ulcer known as Buruli ulcer [1]
Ten days after the challenge, the real-time PCR (RT-PCR) detection of M. ulcerans DNA remained negative on the internal organs and faeces collected in control group rats whereas it was positive in some of the M. ulcerans-challenged rats
At 60 days post-challenge, the RT-PCR detection of M. ulcerans DNA remained negative on the internal organs and in faeces collected in control and challenged groups

Summary

Introduction

Mycobacterium ulcerans is an environmental, slow growing, non-tuberculous mycobacterium responsible for a progressively extending cutaneous and subcutaneous ulcer known as Buruli ulcer [1]. Buruli ulcer is a World Health Organization-notifiable neglected infection which has been notified by 34 countries over the last ten years [2]. It is a tropical infection mainly affecting rural populations in South America, West Africa, Australia, South China and Japan [3]. A genetic trait was recently described among seven individuals in a family, two of whom suffered from Buruli ulcer and carried a specific deletion on chromosome 8 [4], in addition to a previously reported deletion in the NRAMP-1 gene [5], Buruli ulcer is not a contagious infection but rather results from contact with M. ulcerans-contaminated environments [2].

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