Microbiologie médicale et diagnostic

Characterization of the ?Candida albicans Complex?: First Report of Candida africana in Tunisia

Abstract

Hana S, Latifa M, Camilia C and Boutheina J

Background: New molecular studies tools have recently recognized Candida africana as a new atypical
strain of the ‘C. albicans complex’ which consists previously of C. albicans and C. dubliniensis only. As currently
available yeast identification tools fail to differentiate these species, their incidence is poorly understood in different
geographical regions such as Tunisia. In this study, we analyzed the genetic diversity of the ‘C. albicans complex’.
Materiel and methods: We selected 105 isolates of C. albicans and C. dubliniensis from oral and vaginal
samples. These yeasts were phenotypically identified by chlamydosporulation on Agar Tween and Sunflower
medium and biochemical tests using Vitek 2 Compact. To confirm this identification, the HWP1 gene was amplified
by PCR using a single primer pair (CR-f/CR-r) for all isolates and sequenced for 16 strains.
Results: Out of 105 oral and vaginal swabs, conventional identification tools revealed 67 C. albicans and 38
C. dubliniensis. Screening of PCR products by electrophoresis gel highlights the presence of 64 C. albicans, 43 C.
dubliniensis and one strain of C. africana. This is the first description of this species in Tunisia. Three cases of coinfection
by C. albicans and C. dubliniensis were detected after molecular analysis.
Conclusion: Candida albicans is the major selected yeast in human fungal pathologies. The study highlights
the need to discriminate between this species and its related subgroups which greatly facilitates early initiation of
pathogen-specific therapy.