Detection of species diversity in oral candida colonization and anti-fungal susceptibility among non-oral habit adult diabetic patients

BACKGROUND AND OBJECTIVES: Patients with diabetes mellitus are prone to secondary infections. In this study we aim to determine the prevalence of one such secondary infection (oral Candida colonization) and evaluate the influence of local and systemic factors on the oral candidal colonization in patients with diabetes mellitus. MATERIALS AND METHODS: Forty non-insulin-dependent diabetic patients and 40 healthy individuals were included in this study. Samples were collected by using the oral rinse method. The candidal species were isolated and identified through phenotypic methods. An in vitro antifungal susceptibility profile was evaluated. Glycemic control, as determined by the glycosylated hemoglobin concentrations (HbA(1c)) of the study subjects, was correlated with the candidal colonization. RESULTS: Patients with diabetes showed a significantly higher prevalence of candidal colonization. The rate of carriage and density (P = 0.001) was higher. Candida albicans was the most predominantly isolated species, however, C. dubliniensis, C. tropicalis, and C. parapsilosis were also observed. Variable resistance toward the antifungal drugs (amphotericin B and fluconazole) was observed in the Candida isolated from diabetics, but not from healthy patients. Interestingly, a positive correlation was observed between glycemic control and candidal colonization. CONCLUSION: Diabetic patients had a higher candidal carriage rate, with a variety of candidal strains, which significantly varied in their resistance to routinely used anti-fungal agents. Interestingly the higher oral candidal colonization in diabetic patients is related to local and systemic factors, independent of their oral habits.