Oral Candida in HIV Infection and AIDS: New Perspectives/New Approaches

Abstract

Oral candidosis has become an increasingly important problem in HIV-infected individuals. At present, the small body of published literature on the characterization of the Candida strains and species found in HIV+ patients is full of confusion and contradictions. Some of these difficulties are the result of the methodological shortcomings of a number of the techniques that have been used. Examples of the problems that may be encountered on primary isolation and subculture are described and the drawbacks associated with the systems used to date for phenotyping Candida are quoted. While molecular characterization techniques would appear to offer a reliable and objective alternative, they too have their strengths and weaknesses. An attempt is made to summarize the progress that has been made recently in the detection and identification of Candida albicans and also the non-albicans species from HIV-infected individuals. What emerges is that the commensal Candida species that inhabit the oral cavities of HIV+ patients are subjected to a number of significant pressures that probably promote the selection of organisms with unusual phenotypes and genotypes. These Candida are more difficult to characterize and behave differently compared to their counterparts in HIV- individuals. It is clear that uncovering the factors that are important for the selection of treatment regimens and will be predictive of outcome will not be easy. Candida organisms are neither as benign nor as simple as once thought.

Copper- and zinc-containing superoxide dismutase (Cu/ZnSOD) is required for the protection of Candida albicans against oxidative stresses and the expression of its full virulence

“…Candida albicans, the major fungal pathogen of humans, causes not only oral and vaginal thrush but also systemic or life-threatening infections in immunocompromised patients (Cutler, 1991 ;Coleman et al, 1993). A number of factors are known to be involved in the virulence of C. albicans, such as its adhesion to host tissues, its evasion of the host immune system, its secretion of protease and its reversible morphological conversion from yeast to hyphal growth (Cutler, 1991 ;Va!…”

Identification of promoter elements responsible for the regulation of MDR1 from Candida albicans, a major facilitator transporter involved in azole resistance

“…The yeast Candida albicans is an opportunistic pathogen that causes oral, vaginal or systemic infections in immunocompromised individuals and immunocompetent women (Coleman et al, 1993). The azole class of antifungals (for example fluconazole) is widely used to treat C. albicans infections.…”

Host factors affecting oral candidiasis

“…[43][44][45] C. albicans strains are the prevailing species causing oral candidiasis among patients with HIV infection [46][47][48] and are identical to the commensal organisms found in healthy individuals. 49 Oral candidiasis is one of the earliest indictors of the progression to AIDS.…”