The most common type of candidiasis involves mucosal sites such as the oral cavity, the gastrointestinal tract and the vagina. Among many of virulence factors, the production of secretory aspartyl proteinase (Sap) by Candida albicans (C. albicans) has gained much attention, and factors leading to Sap induction are thus under intense study. The aim of this study was to examine whether some microorganisms such as Lactobacillus, Gardnerella vaginalis (G. vaginalis), human immunodeficiency virus type-1 (HIV-1) and human herpes simplex virus type-2 (HSV-2) had any Sap inducing effect on C. albicans. Here we showed that among the microorganisms tested in vitro only HIV-1 induced Sap production from C. albicans. © Springer 2005.