02298nas a2200241   4500000000100000008004100001653002500042653001500067653001200082653001000094100001400104700001400118700001200132700001100144700001500155700001200170700001200182700001500194245014100209050001900350520167300369022001402042       2014                            d10aRifampicin-resistant10aResistance10aleprosy10aIndia1 aVedithi S1 aLavania M1 aKumar M1 aKaur P1 aTurankar R1 aSingh I1 aNigam A1 aSengupta U00aA report of rifampin-resistant leprosy from northern and eastern India: identification and in silico analysis of molecular interactions.  aCHAITANYA 20143 a<p>Presence of point mutations within the drug resistance determining regions of Mycobacterium leprae (M. leprae) genome confers molecular basis of drug resistance to dapsone, rifampin and ofloxacin in leprosy. This study is focused on the identification of mutations within the rpoB gene region of M. leprae that are specific for rifampin interaction, and further in silico analysis was carried out to determine the variations in the interactions. DNA and RNA were isolated from slit skin scrapings of 60 relapsed leprosy patients. PCR targeting rpoB gene region and amplicon sequencing was performed to determine point mutations. mRNA expression levels of rpoB and high-resolution melt analysis of mutants were performed using Rotor Gene Q Realtime PCR. Molecular docking was performed using LigandFit Software. Ten cases having point mutations within the rpoB gene region were identified and were clinically confirmed to be resistant to rifampin. A new mutation at codon position Gln442His has been identified. There is a 9.44-fold upregulation in the mRNA expression of rpoB gene in mutant/resistant samples when compared with the wild/sensitive samples. In silico docking analysis of rifampin with wild-type and Gln442His mutant RpoB proteins revealed a variation in the hydrogen-bonding pattern leading to a difference in the total interaction energy and conformational change at position Asp441. These preliminary downstream functional observations revealed that the presence of point mutations within the rifampin resistance determining regions of rpoB gene plays a vital role in conferring genetic and molecular basis of resistance to rifampin in leprosy.</p>  a1432-1831