Jpn. J. Infect. Dis., 65 (1), 52-56, 2012
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Benjawan Phetsuksiri1*, Sopa Srisungngam1, Janisara Rudeeaneksin1, Supranee Bunchoo31, Atchariya Lukebua1, Ruch Wongtrungkapun2, Soontara Paitoon3, Rama Murthy Sakamuri4, Patrick J Brennan4, and Varalakshmi Vissa4
1National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi; 2Raj Pracha Samasai Institute, Department of Disease Control, Ministry of Public Health, Nonthaburi; and 3The Office of Disease Prevention and Control Regional Center 5, Nakhon Ratchasima, Thailand; and 4Colorado State University, Fort Collins, Colorado, USA
(Received June 17, 2011. Accepted November 21, 2011)
*Corresponding author: National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Tiwanond Rd., Nonthaburi, Thailand. 11000. Tel: +66-2-5801567, Fax: +66-2-9659700, E-mail This email address is being protected from spambots. You need JavaScript enabled to view it.
SUMMARY: Based on the discovery of three single nucleotide polymorphisms (SNPs) in Mycobacterium leprae, it has been previously reported that there are four major SNP types associated with different geographic regions around the world. Another typing system for global differentiation of M. leprae is the analysis of the variable number of short tandem repeats within the rpoT gene. To expand the analysis of geographic distribution of M. leprae, classified by SNP and rpoT gene polymorphisms, we studied 85 clinical isolates from Thai patients and compared the findings with those reported from Asian isolates. SNP genotyping by PCR amplification and sequencing revealed that all strains like those in Myanmar were SNP type 1 and 3, with the former being predominant, while in Japan, Korea, and Indonesia, the SNP type 3 was found to be more frequent. The pattern of M. leprae distribution in Thailand and Myanmar is quite similar, except that SNP type 2 was not found in Thailand. In addition, the 3-copy hexamer genotype in the rpoT gene is shared among the isolates from these two neighboring countries. On the basis of these two markers, we postulate that M. leprae in leprosy patients from Myanmar and Thailand has a common historical origin. Further differentiation among Thai isolates was possible by assessing copy numbers of the TTC sequence, a more polymorphic microsatellite locus.