The Phenotypic variation of Candida albicans and susceptibility to fluconazole and voriconazole

Document Type: Original Articles

Author

Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran

Abstract

Candida albicans is the most frequent opportunistic fungal agent in human being. One of its virulence factors is phenotypic switching. In this study, we investigated the susceptibility of different phenotypes of C. albicans, obtained from clinical specimens, to fluconazole (FLZ) and voriconazole (VRZ) with microdilution reference method. In this study, 281 C. albicans of six different phenotypes including 66.19% smooth, 11.38% stipple, 8.89% fuzzy, 6.40% star, 4.27% irregular and 2.84% ring form were collected. Among these specimens, 75.80% and 88.61% of the phenotypes were susceptible (s), 13.52% and 5.96% were susceptible, but dose dependent and finally 10.67% and 1.77% were resistant (r) to FLZ and VRZ, respectively. Most of (s) samples were smooth form and most (r) forms were stipple. The mean minimum inhibitory concentration of FLZ was higher than VRZ. In general, two antifungal medicines were effective on different phenotypes of C. albicans. Samples of (s) group had a significant difference with (r) group (p<0.05). The raising prevalence of candidiasis and more probability of susceptibility pattern in C. albicans phenotypes are the reasons to use the susceptibility tests on the antifungal drugs in clinical laboratory.

Keywords

Main Subjects


Article Title [French]

Etude de sensibilité des différents phénotypes de Candida albicans isolés à partir de patients souffrant de Candidose vis-à-vis des médicaments antifongiques Fluconazole et Voriconazole

Abstract [French]

Candida albicans est la cause la plus fréquente d’ infections fongiques opportunistes et l'une de ses caractéristiques est son changement phénotype. Dans cette étude, la sensibilité aux médicaments antifongiques Fluconazole et Voriconazome a été déterminée chez 281 isolats de Candida albicans montrant 6 différents phénotypes infectieux de candidose. A cet effet, la méthode de dilution dans un liquide a été utilisée comme norme de référence. Les phénotypes avaient la forme plane (66.19%), tachetée (11.38%), duveteuse (8.89%), étoilée (6.40%), rugueuse (4.27%) et en anneau (2.84%). D'après les résultats, 75.80% et 88.61% des phénotypes étudiés étaient respectivement sensibles aux Fluconazole et Voriconazole, 13.6% et 5.96% montraient une sensibilité intermédiaire aux deux médicaments alors que 10.67% et 1.77% étaient résistants. La plus haute sensibilité aux deux médicaments était relative à la forme plane et la sensibilité la plus faible concernait la forme tachetée. Cette étude a démontré que le Voriconazole est capable d'inhiber la croissance de la plupart des phénotypes de C. albicans à des concentrations inférieures au Fluconzole . Dans l'ensemble, les deux médicaments montraient une bonne activité contre les différents phénotypes et la différence observée chez le groupe sensible au médicament était statistiquement significative comparée aux deux autres groupes (p<0.05). L’augmentation des dispositions à cette maladie, des sensibilités variables aux médicaments et la sensibilité déterminable dans les différents phénotypes de C. albicans ont révélé la nécessité d'utiliser en routine des méthodes de détermination et d’évaluation de la sensibilité aux médicaments dans les laboratoires cliniques afin d’ améliorer le traitement de cette infection.

Keywords [French]

  • Candida albicans
  • les changements dans le phénotype
  • Fluconazole
  • voriconazole
  • dilution dans liquide

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