Abstract
We randomly screened 363 yeast isolates during 2008 for their ability to form white colonies on CHROM agar Candida medium. Two of these isolates (0.5%) were identified as Candida nivariensis based on detailed phenotypic characterization and DNA sequencing. One was recovered from the sputum of an HIV-positive patient with a pneumonic lesion and the second from the blood of a diabetic with oropharyngeal lesions. Direct DNA sequencing of the D1/D2 region of 28S rRNA gene and/or the internal transcribed spacer (ITS) regions of rDNA confirmed that both of the isolates were C. nivariensis. The carbohydrate assimilation profiles with the ID 32 C and VITEK 2 yeast identification systems revealed only glucose assimilation. In vitro antifungal susceptibility profiles by broth microdilution and Etest methods revealed susceptibility of both isolates to fluconazole, itraconazole, voriconazole, amphotericin B and 5-flucytosine, with low MICs for posaconazole and caspofungin. These results document the occurrence of Candida nivariensis for the first time in India and focus on its potential as an opportunistic human pathogen.
Acknowledgements
The work was carried out with financial assistance from the Indian Council of Medical Research, New Delhi, and Kuwait University Research Grant MI01/08. H.S.R acknowledges the award of an Honorary Scientist position to the Indian National Science Academy, New Delhi.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
This paper was first published online on Early Online on 01 February 2010.