Identification and Genotyping of Candida Species Involved in Oral Candidiasis among Diabetic Patients

Abstract

Objective: Oral candidiasis is more prevalent among diabetic patients than non-diabetics due to the factors that promote Candida oral carriage. This study aimed to isolate and identify Candida species involved in oral candidiasis of patients with diabetes mellitus in Sulaymaniyah city.  Methods: The study was performed from August 2021 to March 2022 on two diabetic patients, Type 1 and Type 2 (n=150) and non- diabetics (n=50), as a control group. In Iraq's Kurdistan region, oral swabs were taken from 200 participants at the Sulaymaniyah governorate's Diabetic and Endocrine Center and Shar hospital. Sabouraud dextrose agar (SDA) medium was used to culture the swabs. Candida isolates were identified using HiCromeTM Candida Differential agar, then confirmed using polymerase chain reaction based on the ITS region and CHS1 gene detection. Using the CA25S and CA-INT primers, all C. Albicans isolates were genotyped based on the transposable intron in 25S rDNA. ITS1 and ITS4 primers were used to sequence the 18S region of ribosomal DNA (rDNA). Descriptive statistics were used for summaries and to describe data.       Results: From the samples of 150 diabetes patients and 50 controls, 64 (42.6%) and 12 (24%) were positive for Candida spp. In the diabetic patients, 34 (53.1%) of the 64 isolated Candida spp. were identified as C. Albicans, while 6 (50%) of the healthy subjects had C. albicans. The genotypes A (450 bp), B (840 bp), C (450 and 840 bp) of C. Albicans and D (1040 bp) that belongs to C. dubliniensis were detected. Genotype A (54.69%) was the most frequent.   Conclusions: This study concluded that there was a difference in the proportion of Candida spp. colonization in the oral cavity of diabetic patients compared to the healthy group; also, we found that C. Albicans with Genotype A was the most prevalent species among all other species in both groups.