Unusual case of resistance to amphotericin B in visceral leishmaniasis in a region in India where leishmaniasis is not endemic.

The case of a patient with visceral leishmaniasis showing inadequate response to amphotericin B from a region where leishmaniasis is not endemic is reported, with the Leishmania donovani isolate showing increased tolerance to amphotericin B in vivo. Four single nucleotide polymorphisms (SNPs) detected in the cysteine proteinase B gene resulted in changes to the deduced amino acid sequence: valine→alanine and arginine→leucine. Overexpression and underexpression of proteins were observed in the 65- to 80-kDa range and at 20 kDa, respectively.