Molecular identification of Candida species isolated from gastro-oesophageal candidiasis in Tehran, Iran

Aim: The aim of this investigation is identification of Candida strains isolated from patients with gastro-oesophageal candidiasis in Tehran, Iran. Background: Gastro-oesophageal candidiasis is a rare infection and appears mainly in debilitated or immunocompromised patients. Colonization by Candida spp. may occur in this region and the organism can remain for several months or years in the absence of inflammation. The main infection symptom is the presence of white plaques in gastro-oesophageal surface. C. albicans remains the most prevalent Candida spp. identified in gastrointestinal candidiasis. Regarding differences in susceptibilities to antifungal drugs among Candida spp., identification of isolates to the species level is significant to quick and appropriate therapy. Patients and methods: A total of 398 patients underwent gastrointestinal endoscopy during February 2012 to October 2014 were included in the present study. Histological sections from all endoscopic gastric and oesophageal biopsies were prepared, stained with Periodic acid–Schiff (PAS), and examined for the presence of fungal elements. Part of the biopsy sample was sub-cultured on sabouraud glucose agar. The genomic DNA of each strain was extracted using FTA® Elute MicroCards. Molecular identification of Candida isolates was performed by PCR-RFLP technique with the restriction enzyme HpaII. Results: Twenty-one out of 398 cases (5.2%) were found to have gastro-oesophageal candidiasis. Candida albicans was the main strain isolated from clinical samples (90.5%), followed by C. glabrata (4.7%), and C. parapsilosis (4.7%). Conclusion: Due to varying antifungal susceptibility of Candida spp. careful species designation for clinical isolates of Candida was recommended by a rapid and meticulous method like PCR-RFLP.