Recurrent oropharyngeal candidiasis with Candida albicans and Candida dubliniensis in an HIV-infected patient:: mycology, genotyping and immunology characteristics

A new species of Candida, Candida dubliniensis has been recently identified by molecular techniques. This yeast has been found mainly in human immunodeficiency virus (HIV)-infected patients, and it has often been identified as C. albicans because the two species have some identical phenotypical characteristics in common: germ tube formation, chlamydospores production, and close carbohydrate assimilation profiles. It has been shown in vitro that C dubliniensis is particularly virulent, due to increased levels of extracellular secreted aspartylproteinase (Sap) production. We report the case of a 37-year-old HIV-infected woman (CDC stage B), who presented multiple oropharyngeal candidiasis (OPC) episodes, in spite of immune cellular status restoration by a highly active antiretroviral therapy and several fluconazole, treatments. This patient was included in a one-year longitudinal study of Immoral anti-Candida mucosal response in August, 1998. Specific immunoglobulins G, A and M against Sap6 antigen were detected in monthly salivary samples. Antibody levels were very high in this patient, in comparison with results from 16 other HIV-infected patients (5 with C. albicans OPC and 11 without OPC). Monthly mycological samples were all positive with high fungal loads. Molecular typing of sequential isolates by electrophoretic karyotype and random amplified polymorphic DNA (RAPD) analysis showed that this patient was infected by two distinct genotypes. ITS (internal transcribed spacer) sequence analysis identified one of the two genotypes as a C. dubliniensis strain. Our case report shows the importance of genotyping in demonstrating the role of C. dubliniensis in recurrent OPC during HIV infection. This study also shows a greatly stimulated Immoral anti-Sap mucosal response in this particular candidiasis.