Genomics of Newly Discovered Leprosy Pathogen: Mycobacterium lepromatosis and Its Geographic Isolation in Mexico Subhrajit Barua 1 , Tandra Ghosh 2 *, Nibir Biswas 3 *, Asesh Banerjee 1 * and Prabuddha Gupta 1 * 1 Amity Institute of Biotechnology, Amity University Kolkata, Rajarhat, Newtown, Kolkata, West Bengal, India 2 Dept of Physiology, AIIMS Kalyani, NH-34 Connector, Basantapur, Saguna, Kalyani, West Bengal, India 3 Calcutta school of tropical medicine 108 CR Avenue Kolkata 700073, India Overview Leprosy is a chronic dermatologic infection that has plagued human populations for thousands of years. Mycobacterium leprae, the etiological agent for leprosy, has puzzled scientists since its identification by Hansen in 1873 [1]. Leprosy is one of the leading causes of treatable neuropathy [2]. It has been affecting mankind since the earliest historically recorded identification and far beyond (2000 B.C, in ancient Indus civilization) [3]. Leprosy is also one of the earliest recognized diseases which have a proven association with the bacterial pathogen, M. leprae [3]. In 2008, a new bacterium, M. lepromatosis was discovered in Mexico which was also reported to cause leprosy [4]. M. lepromatosis was found to be associated with a typical severe form of lepromatous leprosy (LL), called Diffuse Lepromatous Leprosy (DLL) which is usually seen in the Americas [5-7]. DLL is characterized by an unusual form of immune reaction against the pathogen, called Lucio’s phenomenon, characterized by diffuse, non-nodular cutaneous infiltration with sharply demarcated skin lesions, which often gets infected to result in life threatening situations [8,9]. Epidemiology Genome sequence analysis of M. leprae and M. lepromatosis shows that both the organisms have diverged from a common ancestor about 13.9 million years ago, long before ancient humans stepped out of Africa. Still, most of the human infection of M. lepromatosis has been detected only in Western Mexico and the Caribbean islands, at the Multibacillary-LL (Lepromatous Leprosy) / Multibacillary-DLL (MB-LL/MB-DLL) end of the disease spectrum, co-existing with M. leprae infections [1]. In a few cases, M. lepromatosis is also found in other countries like Brazil, the USA, Indonesia, British Isis, Singapore & Myanmar, both in human and non-human hosts. [7,10-14]. Although India harbors the largest number of confirmed and newly diagnosed leprosy cases till date, there are no confirmed reports for M. lepromatosis infection in India so far [15]. This might be due to the fact that the majority of leprosy cases in India are tuberculoid (TT) in nature, whereas in Mexico the majority are (Lepromatous) LL [7]. Few hypotheses have been proposed to explain the paradox of asymmetric distribution but none of them have specifically addressed the incidence of negligible Lucio’s leprosy cases and no recorded M. lepromatosis infection till date from India, where more than 60% of the total leprosy cases of the world has been reported. Genomics M. leprae and M. lepromatosis, together named as the M. leprae complex, can cause leprosy individually or by co-infection [1,16]. M. leprae was the only known organism to cause leprosy until 2008, when two cases of leprosy in Mexico were identified to be caused Crimson Publishers Wings to the Research Mini Review *Corresponding author: Prabuddha Gupta, Asesh Banerjee, Amity University Kolkata, West Bengal, India, Tandra Ghosh, AIIMS Kalyani, West Bengal, India, Nibir Biswas, Calcutta school of tropical medicine 108 CR Avenue Kolkata 700073, India Submission: February 20, 2020 Published: May 12, 2020 Volume 3 - Issue 1 How to cite this article: Subhrajit Barua, Tandra Ghosh, Nibir Biswas, Asesh Banerjee, Prabuddha Gupta. Genomics of Newly Discovered Leprosy Pathogen: Mycobacterium Lepromatosis and Its Geographic Isolation in Mexico. Open Acc Biostat Bioinform. 3(1). OABB.000553. 2020. DOI: 10.31031/OABB.2020.03.000553 Copyright@ Prabuddha Gupta, This article is distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use and redistribution provided that the original author and source are credited. ISSN: 2578-0247 1 Open Access Biostatistics & Bioinformatics