Differentiation of Candida albicans complex species isolated from invasive and non-invasive infections using HWP1 gene size polymorphism

The taxonomy of Candida is controversial and has undergone changes due to the investigation of the novel species. Candida africana and Candida dubliniensis are new members of C. albicans complex that are currently gaining both clinical and epidemiologic significance. This study reports the prevalence of C. africana among the strains isolated from patients, by using HWP1 gene size polymorphism. Materials and Methods: A total of 235 yeasts confirmed as C. albicans complex based on chromogenic media and ITS-sequencing isolated from various clinical forms of invasive and non-invasive candidiasis mainly candidemia, were re-identified based on HWP1 gene polymorphisms. The Hwp1-PCR amplicons were re-confirmed by sequencing and BLAST analysis. Results: Based on the HWP1 gene size polymorphism, 223 strains were identified as C. albicans (94.89%) from which 7 isolates produced two DNA fragments (850 and 941 bp). C. dubliniensis (n=4, 1.7%), C. africana (n=1, 0.42%) and mix of C. albicans and C. africana (n=7, 2.97%) were also identified. Conclusion: Although C. albicans remains the most common Candida species, C. dubliniensis and C. africana are rarely found among the patient isolates. Due to limited information on the molecular epidemiology of this novel yeast, more studies using molecular methods are recommended.