Genotyping analysis of Mycobacterium leprae isolated in water environment of leprosy endemic places in Lamongan, East Java.

Background: Finding of Mycobacterium leprae from water of leprosy endemic areas were reported. East Java Province is ranked number eight as the endemic area of leprosy in Indonesia and Lamongan district is the local area with the highest new cases reported. To study the transmission of Mycobacterium leprae infection in endemic areas, it is important to detect the distribution of Mycobacterium leprae in the environment and population, also to analyze the genetic variation pattern. Methods: A total of 91 samples were collected (24 leprosy patients skin samples, 49 nasal swab samples from patients and household contacts, and 18 water samples). Detection is conducted by amplification of Mycobacterium leprae DNA using LP3 and LP4 primers. Variation of TTC nucleotide repeats in the intergenic region of Mycobacterium leprae genome was done to all positive results. Results: The finding of 4 strains of Mycobacterium leprae from 3 sources with TTC repeats from 11-28 copies. From skin smear samples, 2 strain of Mycobacterium leprae with TTC repeats between 13-18 copies. In nasal swabs, 1 strain was found with 28 TTC repeats. From water sources, 1 strain was found with 11 TTC repeats with frequency of repeats in all positive samples. Conclusion: Unmatched genetic variation between 3 sources indicated contradictive results of transmission pattern of non-human sources of infection. These results should be analyzed further based on different environmental factors to reveal the role of environment in the transmission of leprosy. Further genotyping analysis of Mycobacterium leprae in the environment using another genotyping marker is needed to prove the intimate relationship of host-agent-environment in the transmission of leprosy.