Up-regulation of twoCandida albicansgenes in the rat model of oral candidiasis detected by differential display

Candida albicansis an opportunistic fungal pathogen responsible for the largest percentage of fungal-mediated oral and oesophageal disease. In this regard, knowledge concerning patterns of gene expression during the establishment and/or maintenance of infection may be the key to the design of new strategies for treatment, as well as providing insight into pathogenesis. To address this issue, experiments were performed that utilized differential display to compare the spectrum ofC. albicansgenes expressed during oral infectionversusgrowth inin vitroculture. Experimentally, the rat model of oral candidiasis served as thein vivosource. After initiation of infection and subsequent harvesting ofC. albicansfrom the rat oral cavity, RNA was isolated, and used with a small number of primers in reverse-transcriptase polymerase chain reaction (RT-PCR) and differential display experiments. Fragments unique toin vivosamples were subcloned and sequenced. Southern blot analysis verified the origin of seven fragments as fromC. albicans. Additionally, specific RT-PCR confirmed that two of these fragments represented genes that were up-regulated duringC. albicans in vivogrowth in the rat model. Database searches indicated the fragments share homology with a member of theC. albicansagglutinin gene family and to a bacterial gene (gidB) possibly involved in cell division.