Differential expression of Candida albicans secreted aspartyl proteinase and phospholipase B genes in humans correlates with active oral and vaginal infections

The in vivo expression of Candida albicans secreted aspartyl proteinase (SAP1-SAP8) and phospholipase B (PLB1 and PLB2) genes was analyzed in 137 human subjects with oral and vaginal candidiasis or carriage. Total RNA was isolated from whole unstimulated saliva or vaginal swabs, and the expression of SAP1-8 and PLB1-2 was evaluated by reverse-transcriptase polymerase chain reaction using specific primer sets. A spectrum of SAP gene expression profiles was obtained from different C. albicans strains during symptomatic disease and asymptomatic carriage. SAP2 and SAP5 were the most common genes expressed during both infection and carriage. SAP1, SAP3, SAP4, SAP7, SAP8, and PLB1 expression was correlated with oral disease, whereas SAP1, SAP3, and SAP6-SAP8 expression was correlated with vaginal disease. Furthermore, SAP1, SAP3, and SAP8 were preferentially expressed in vaginal, rather than oral, infections. This study demonstrates the differential expression of the hydrolytic enzyme genes in humans and correlates the expression of specific Candida species virulence genes with active disease and anatomical location.