Molecular epidemiology of leprosy based on VNTR typing in Thailand.
Recently about 500 new cases of leprosy have been reported each year in Thailand. In addition to a steady rate of new case detection, Thailand is in Southeast Asia where leprosy is endemic in neighbouring countries; therefore, strain differentiation could be useful in tracing origins and routes of infection, and general leprosy surveillance. To identify suitable markers for differentiation of M. leprae strains in different global geographic regions and to determine the applicability of a systematic genotyping method for tracing leprosy transmission, variable nucleotide tandem repeats (VNTRs) of 14 loci were evaluated using DNA extracts from a total of 97 skin biopsies and slit skin smear samples. The alleles per locus ranged from 2-26 providing adequate strain differentiation. Microsatellite loci (GAA)21, (AT)17 are highly polymorphic followed by (GTA)9, (AC)8a, (AC)8b, and (AC)9. The minisatellites 6-7, 21-3 and 27-5 exhibited a limited number of alleles. The repeat of 23-3 showed no polymorphism. Overall, the strain types can be divided into two distinct Thai groups, according to the alleles at the (GGT)5 and 21-3 loci. However, there are no obvious geographical patterns of distribution of VNTR strain types. Closely matched VNTR profiles found in household members of two multi-case families suggested infection through a common source.
Srisungnam
Sopa
S
Mycobacterial Laboratory, National Institute of Health, Ministry of Public Health, Thailand.
Rudeeaneksin
Janisara
J
Lukebua
Atchariya
A
Wattanapokayakit
Sukanya
S
Pasadorn
Supanee
S
Mahotarn
Krisada
K
Ajincholapan
Sakamuri
Rama Murthy
RM
Kimura
Miyako
M
Brennan
Patrick J
PJ
Phetsuksiri
Benjawan
B
Vissa
Varalakshmi
V
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D006801:Humans; D056006:Leprosy, Multibacillary / Q000453:epidemiology / Q000382:microbiology*; D056005:Leprosy, Paucibacillary / Q000453:epidemiology / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology / Q000379:methods; D009166:Mycobacterium leprae / Q000235:genetics*; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
D004269:DNA, Bacterial