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Publication

Mutation at codon 442 in the rpoB gene of Mycobacterium leprae does not confer resistance to rifampicin.

Abstract

BACKGROUND: Rifampicin is the major drug in the treatment of leprosy. The rifampicin resistance of Mycobacterium leprae results from a mutation in the rpoB gene, encoding the β subunit of RNA polymerase. As M. leprae is a non-cultivable organism observation of its growth using mouse food-pad (MFP) is the only Gold Standard assay used for confirmation of "in-vivo" drug resistance.

OBJECTIVE: Any mutation at molecular level has to be verified by MFP assay for final confirmation of drug resistance in leprosy.

MATERIAL AND METHODS: In the present study, M. leprae strains showing a mutation only at codon 442 Gln-His and along with mutation either at codon 424 Val-Gly or at 438 Gln-Val within the Rifampicin Resistance Determining Region (RRDR) confirmed by DNA sequencing and by high resolution melting (HRM) analysis were subjected for its growth in MFP.

RESULT AND CONCLUSION: The M. leprae strain having the new mutation at codon 442 Gln-His was found to be sensitive to all the three drugs and strains having additional mutations at 424 Val-Gly and 438 Gln-Val were conferring resistance with Multi drug therapy (MDT) in MFP. These results indicate that MFP is the gold standard method for confirming the mutations detected by molecular techniques.

More information

Type
Journal Article
Author
Lavania M
Hena A
Reja H
Nigam A
Biswas NK
Singh I
Turankar RP
Gupta U
Kumar S
Rewaria L
Patra PK R
Sengupta U
Bhattacharya B
Year of Publication
2016
Journal
Leprosy review
Volume
87
Issue
1
Number of Pages
93-100
Language
eng
ISSN Number
0305-7518
Alternate Journal
Lepr Rev
Publication Language
eng