TranslocatingMycobacterium ulcerans: an experimental model

Abstract

13 14 15 Abstract word count: 178 16 Text word count: 2419 17 18 Keywords: Mycobacterium, Mycobacterium ulcerans, animal model, infection, 19 translocation, Buruli ulcer. 1 20 ABSTRACT 21 Mycobacterium ulcerans is a non-tuberculous environmental mycobacterium 22 responsible for extensive cutaneous and subcutaneous ulcers in mammals, named 23 Buruli ulcer in patients. M. ulcerans has been seldom detected in the feces of 24 mammals but not in patients, nevertheless the detection and isolation of M. ulcerans 25 in animal feces does not feet with the current epidemiological schemes for the 26 disease. Here using an experimental model in which rats were fed with 10 9 colony-27 forming units of M. ulcerans, we detected M. ulcerans in feces of challenged rats for 28 two weeks and along their digestive tract for 10 days. M. ulcerans was further 29 detected in the lymphatic system including cervical and axillary lymph nodes and the 30 spleen, but not in any other tissue including the healthy and breached skin, 10 days 31 post-challenge. These observations indicate that in some herbivorous mammals, M. 32 ulcerans contamination by the digestive route may precede translocation and limited 33 infection of the lymphatic tissues without systemic infection. These herbivorous 34 mammals may be sources of M. ulcerans for exposed populations but are unlikely 35 reservoirs for the pathogen.