Journal of Associated Medical Sciences (Sep 2018)
Distribution of Candida species in oral candidiasis patients: Association between sites of isolation, ability to form biofilm, and susceptibility to antifungal drugs
Abstract
Background: The oral cavity is a complex structure. Differences in oral mucosa surfaces are keratinized epithelium (KE) lined on the gingival, palate, and tongue surface, while non-keratinized epithelium (NKE) lined on the buccal surface and lips. In denture wearer, denture surface is also exposed in the oral cavity. Clinical manifestations of oral candidiasis vary depending on the type of infection. The ability to form biofilm which is the virulent factor of Candida spp. may affects by these mucosa and abiotic surfaces and leading to drug resistant strains. Objectives: To compare the distribution of Candida spp. by site of infection, its ability to form biofilm, and susceptibility to antifungal agents. Materials and methods: The samples were collected from lesions in the oral cavity by using the imprint culture technique, and yeast species were identified by conventional and PCR methods. Biofilm formation was measured by crystal violet (CV) assay. Susceptibility to amphotericin B and azoles was performed in according to CLSI guideline (M27 A3). Results: One hundred and fifty-two isolates were identified from 99 patients. A majority of isolates were 50% isolated from KE surface (gingiva, palate, and tongue), followed by 34.9% from NKE surface (buccal mucosa and lip), and 15.1% from surface of denture. Candida albicans was the most common species (80.9%) frequently isolated from the tongue and buccal surface, followed by C. tropicalis (7.2%) frequently isolated from the tongue and palate, and C. glabrata (5.3%) was frequently isolated from dentures. In consideration to site of infections, yeast isolated from denture surface showed a significant lower biofilm production compared to the NKE surface (p=0.029). The percentage of drug resistant strains in Candida spp. isolated from denture was 17.4%, NKE surface 14.6% and KE surface 8.1%. Conclusion: This data indicate that site of infection; KE and NKE surfaces in the oral cavity had not affected to biofilm formation of Candida spp., except in denture wearer. Drug resistant in clinical isolates involved in high biofilm former strains and the species C. glabrata.
