Molecular Analyses Unravel Mycobactrium ulcerans Transmission Pathway from Animal Host and Environment to Human in Ogun State, Nigeria
Otuh Patricia I. and Adeyemo Olanike I.
Veterinary Public Health and Preventive Medicine, University of Ibadan, Nigeria
Buruli ulcer (BU) disease is a neglected tropical disease caused by Mycobacterium ulcerans pathogen; an environmental mycobacterium which has affinity to inhabit aquatic niches. Global distribution of BU spans across more than 33 countries however, in West African sub region, incidence is alarming with severe devastating burden especially in children of school age resident in rural communities. The exact mode of transmission remains evasive hampering prevention and control strategies. In this study, we explored the agent-host-environment molecular inter-relatedness in the transmission of Buruli ulcer disease in some communities in Ogun State, Nigeria, contingent to Benin Republic; a BU epicenter.
Mycobacterium ulcerans DNA were extracted from samples collected from suspected BU patients, water samples from rivers routinely accessed by the patients and aquatic fauna (fish and crabs) from the same rivers. M. ulcerans. Variable Number Tandem Repeats (VNTRs) were amplified from the extracted DNA using primers targeting loci 6 and 19 which are the genetic markers to assess M. ulcerans diversity. Locus 19 of the VNTR showed the presence of the same population of M. ulcerans in water, fish and human samples. Locus 6 of the M. ulcerans VNTRs further confirmed the initial finding showing presence of M. ulcerans population in fish, crab, water and human samples.
The above results are indicative of an animal (fish and crab) to human transmission of M. ulcerans or an environmental transmission of the pathogen to human through water. We therefore propose a possible transmission pathway of M. ulcerans to humans from its animal host or the environment.