VNTR typing of Mycobacterium leprae in South Indian leprosy patients.
OBJECTIVE
To study the suitability, stability and diversity of short tandem repeat (STR) genomic markers to elicit strain variation in the Mycobacterium leprae isolates within leprosy patients from Andhra Pradesh and Tamil Nadu states in South India.


METHODS
Slit skin smear (SSS) samples were collected from lesions and various body sites of newly diagnosed leprosy patients. The SSSs from each patient were pooled, except in the case of five patients. Total DNA was extracted from SSS samples. M. leprae STRs were amplified from the DNA either by multiplex PCR (MP) or single PCR methods. The number of repeats for each STR locus (the STR allele) was obtained either by fragment length analysis (FLA) or by DNA sequencing of the PCR amplicons.


CONCLUSIONS
Multiplex PCR minimised the use of DNA and reagents, and together with FLA, was time and cost effective for STR strain typing. After examination of the isolates of South Indian origin at 13 STR loci, it was determined that the alleles for (AC)8b, (GGT)5, 6-3a (rpoT), 21-3, 27-5, and 23-3 were conserved in two study populations. In a family from Andhra Pradesh, the M. leprae STR patterns in two patients were identical in 16 of 18 loci which indicate a common source of infection. Fourteen of 15 STR loci showed no intra-patient variation in the five patients tested in Tamil Nadu. Altogether, these studies indicate the suitability of STR strain typing for assessing short-range transmission chains.
Shinde
Vidyagouri
V
Blue Peter Research Centre, LEPRA Society, Cherlapally, Hyderabad 501301, India.
Newton
Hema
H
Sakamuri
Rama Murthy
RM
Reddy
Venkateshwar
V
Jain
Suman
S
Joseph
Abraham
A
Gillis
Tom
T
Nath
Indira
I
Norman
Gift
G
Vissa
Varalakshmi
V
D000293:Adolescent; D000328:Adult; D000368:Aged; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007194:India / Q000453:epidemiology; D007918:Leprosy / Q000453:epidemiology / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D009166:Mycobacterium leprae / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D055815:Young Adult
D004269:DNA, Bacterial