Resistance of Candida albicans to Fluconazole During Treatment of Oropharyngeal Candidiasis in a Patient with AIDS: Documentation by In Vitro Susceptibility Testing and DNA Subtype Analysis

Abstract

We describe a patient with recurrent episodes of oropharyngeal candidiasis who required progressively higher doses of fluconazole to control and infection. The patient was treated for 14 infections over a 2-year period with doses of fluconazole that ranged from 100 to 800 mg per day. Clinical response, two methods of in vitro susceptibility testing, and molecular epidemiologic techniques were evaluated for 12 of the 14 episodes. Ultimately, the patient became unresponsive clinically to a dose of 800 mg of fluconazole per day. In vitro susceptibility testing of isolates obtained during these successive episodes of infection revealed the development of resistance to fluconazole, and molecular epidemiologic techniques confirmed the persistence of the same Candida albicans strain throughout all 12 episodes.

Candida albicansSecreted Aspartyl Proteinases in Virulence and Pathogenesis

“…There is mounting evidence that Candida species colonizing the oral cavities of HIV-infected individuals are subject to selective pressures that may lead to the emergence of strains with altered genotypic and phenotypic characteristics and enhanced expression of known and putative virulence determinants. Studies have shown that the genotype of the infecting Candida cells in HIV infection is stable, and, as a result, HIV-infected patients tend to be colonized by a single endogenous strain of Candida that persists throughout recurrent bouts of oral candidiasis, even after antifungal therapy (34,130,143,169,175,204,245,248). However, these and other studies also suggest that in the majority of AIDS patients the original commensal strains are replaced and that this replacement of genotypes occurs only once, early in the course of HIV infection, producing a genetically conserved population (140,204).…”

Progress in Antifungal Susceptibility Testing of Candida spp. by Use of Clinical and Laboratory Standards Institute Broth Microdilution Methods, 2010 to 2012

“…The relationship between the fluconazole MIC and the various resistance mechanisms (MDR and CDR efflux pumps, overexpression/mutation of ERG11 [encodes the target enzyme]) has been derived by studying serial isolates of C. albicans from AIDS patients with recurrent orophryngeal candidiasis (OPC) (11,40,79,(95)(96)(97), as well as from patients with IC (43,44,47,49), and in genetically manipulated strains (41).…”

Comparative Analysis of Disc Diffusion and E-test with Broth Micro-dilution for Susceptibility Testing of Clinical Candida Isolates Against Amphotericin B, Fluconazole, Voriconazole and Caspofungin

“…, Gopa Banerjee 4 , MaStan SinGh 5 period of study: The study was carried out over a 12-month period, from August 2011 to July 2012.…”