Siriraj Medical Journal (Jun 2004)

Antifungal Susceptibility and Molecular Typing of Candida albicans isolated from AIDS and non-AIDS Thai Patients

  • Penphun Naenna,
  • Ariya Chindamporn,
  • Pintip Pongpech,
  • Chertsak Dhiraputra

Journal volume & issue
Vol. 56, no. 6

Abstract

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The antifungal susceptibility of Candida albicans isolated from 2 groups of Thai patiens; AIDS patients and non-AIDS patients was investigated. Two hundread and seventeen C. albicans were isolated from the specimens from 54 AIDS patients and 163 non AIDS patients. All isolate were included in the antifungal susceptibility test against amphotericin B, fluconazole, ketoconazole and nystatin. A hundred isolates were randomly selected from both groups for the electrophoretic karyotypes determination.    There was not much difference in the value of Mic, MIC50 and MIC90 of all antifungal agent for C. albicans isolates between AIDS and non-AIDS patients. The amphoter B MIC for 61.0% if AIDS isolates and 71.0% of non-AIDS isolates were >0.5 mg/l, while ketoconazole MIC for 94.4% of AIDS and 74.9% of non-AIDS isolates were >0.125 mg/l and fluconazole MIC of 100% of AIDS and non-AIDS isolates were 2.0 mg/l. For nystatin, the MIC for more than 90% of both isolates was <8 mg/l. The MIC50 and MIC90 of all antifungal agents for the two groups of isolates were almost at the same concentration except for fluconazole which showed a two-fold difference of MIC50.    The chromosomal DNA karyotypic of C. albicans indicated genetic diversity among all isolates. Twenty-three distinct pulsed-field gel electrophoresis karyotypes and molecular sizes ranging from 3.5 to 0.5 megabases were identified. Most isolates (61%) from both AIDS and non-AIDS isolates belong to type 1 and type 3. Among the AIDS isolates, 38.3% and 29.8% were type 1 and 3, respectivety, and non-AIDS isolates, 20.8% and 33.9% were type 1 and 3, respectively. C. albicans isolates were show to have 8 to 10 chromosomal DNA brands. Most of the isolates (78%) along with C. albicans FC18 control strain had 8 band patterns. The recovery of the common karyotypes in AIDS patients, as well as in non-AIDS patients, suggests that C. albicans infection may develop from a common source by the cross contamination between both groups of patients.

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