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Updated: May 28, 2026
DNA Fingerprinting of Mycobacterium leprae Strains Using Variable Number Tandem Repeat (VNTR) - Fragment Length Analysis (FLA)
Published on: July 15, 2011
Comparison between microsatellites and Ml MntH gene as targets to identify Mycobacterium leprae by PCR in leprosy
Andrezza Furquim da Cruz1, Renata Bazan Furini, Ana Maria Ferreira Roselino
1Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.
Background:
The Polymerase Chain Reaction (PCR) technique has been frequently used in the molecular diagnosis of leprosy.
Objectives:
To compare the results of PCR with four pairs of Mycobacterium leprae specific primers as well as to compare these results to multibacillary (MB) and paucibacillary (PB) leprosy according to the WHO operational classification.
Method:
28 DNA samples, collected from the frozen skin biopsies and biopsy imprints on filter paper of 23 patients (14 MB and PB 9), were examined for PCR using primers which amplify 131, 151 and 168bp of specific microsatellite regions and a 336 fragment of the Ml MntH (ML2098) gene.
Results:
M.leprae bacillus could be detected in 22 (78.6%) of the 28 samples. 9 (45%) of the 20 biopsy samples and 6 (75%) of the 8 imprints were positive to TTC. 7 (35.5%) skin biopsy specimens and 5 (62.5%) imprints were positive to AGT, and 11 (55%) biopsies and 4 (50%) were positive to AGT. 11 (55%) skin biopsies and 4 (50%) imprints were positive to AT. 8(38%) skin biopsies and 5 (62.5%) imprints were positive to the Ml MntH gene. In the MB group, the microsatellites detected the bacillus in 78.5% of the samples, and the Ml MntH gene in 57.1% of the samples, independent of the clinical material. In the PB group 55.5% of samples were positive to the microsatellite primers, while 22.2% were positive to the Ml MntH gene.
Conclusions:
These results show that both the specific regions of microsatellites, as well as the Ml MntH gene fragment can be useful tools for detecting the M. leprae DNA by PCR in frozen skin biopsy samples and filter paper biopsy imprints.
