Candida africana and Candida dubliniensis as causes of pediatric candiduria: A study using HWP1 gene size polymorphism

Abstract

Background: Candida species cause a wide spectrum of disease entities. Candida africana and Candida dubliniensis-members of Candida albicans complex-are currently gaining both clinical and epidemiologic significance.

Materials and methods: Totally, 150 pediatric isolates that had previously been identified as C. albicans species complex based on a positive germ tube test were included. The isolates were cultured on CHROMagar Candida medium to ensure their purity and the results of germ tube test. For definitive speciation, PCR amplification and size polymorphism of the hyphal wall protein 1 (HWP1) gene was used. The results of HWP1-PCR were confirmed by sequencing the amplified fragments for randomly selected isolates of C. africana and C. dubliniensis.

Results: All 150 isolates included in this study were reconfirmed as C. albicans complex on chromogenic media. Based on the HWP1 gene size polymorphism, 141 (94%) isolates were identified as C. albicans, 2 (1.33%) as C. africana, and 1 (0.67%) as C. dubliniensis. The remaining 6 (4%) C. albicans complex isolates were a mix of C. albicans and C. africana. All isolates of C. africana and C. dubliniensis have been recovered from cases of candiduria.

Conclusion: C. africana, either alone or mixed with C. albicans, could be a cause of candiduria among pediatric patients and should not be ignored.

Keywords: Candida africana; Candida albicans complex; Candida dubliniensis; Candiduria; pediatrics.

Figure 1.. Distribution of 150 Candida albicans complex isolates based on the specimen type (BAL: bronchoalveolar lavage; CVC: central venous catheter; CSF: cerebrospinal fluid).