Investigation of the susceptibility of Candida species isolated from denture wearers to different antifungal antibiotics

Abstract

The aim of this study was to determine the the prevalence of in vitro resistance amongst Candida species isolated from the oral cavity of denture wearers. The in vitro susceptibility of 156 Candida isolates to amphotericin B, fluconazole, 5-fluorocytosine, caspofungin and terbinafine was determined. The Clinical Laboratory Standards Institute' (CLSI; formally National Committee for Clinical Laboratory Standards) broth microdilution method was used and MIC 50 and MIC 90 determined. Candida albicans, the most frequently isolated strains, are sensitive to amphotericin (61%) and fluconazole (44%), frequently used agents in the treatment of Candida-associated denture stomatitis. A 100% susceptibility to 5-fluorocytosine was observed among the 109 isolates of C. albicans. Among non C. albicans strains only 1 Candida kefyr strain was determined as susceptible dependent upon dose for 5-fluorocytosine. Among Candida glabrata, the second most common isolate, a 100% susceptibility to caspofungin and 5-fluorocytosine were observed. Since the isolates are sensitive to Caspofungin and 5-fluorocytosine, rarely used in the treatment of oral fungal infections, it is suggested that these antifungal agents be used as alternative medicine in the treatment of oral infections especially caused by strains resistant to amphotericin B and fluconazole.

<p>Relationship between oral hygiene and fungal growth in patients: users of an acrylic denture without signs of inflammatory process</p>

“…Candida yeast colonies were found in the oral cavity of 60–100% of the denture-wearing people examined here 1,2,3,4,5,12. In our study, 53% of denture users who did not show signs of inflammation had Candida infections.…”

“…Oral fungal infection is a common disease in wearers of dentures 1–5. The long-term use of removable acrylic dentures creates the ideal environment for the growth of yeasts, resulting in the development of denture-related stomatitis (DRS) 6,7…”

“…The etiology of denture stomatitis is multifactorial, with factors including trauma caused by ill-fitting dentures, increased age of the patient and of the dentures, lack of prosthesis hygiene, and a favorable environment for the proliferation for Candida albicans in particular 4,5,8,9…”

“…Candida albicans is commensal in the oral cavity of 45–65% of healthy individuals, but in denture wearers, the prevalence of Candida increases to 60–100%,1,2,3,4,5 which increases the risk of infection. In cases where no symptoms of inflammatory state are evident, it is interesting to ask whether a yeast growth susceptible to pharmaceutical treatment is in fact present.…”

Antifungal chemicals promising function in disease prevention, method of action and mechanism

“…In a recent study, the minimum inhibitory concentration (MIC) of terbinafine against 179 clinical isolates of Candida albicans was found to be 1.2 g/ml when the M27 technique from the National Council for Clinical Laboratory Standards was used (Epp, 2011;Rugeles, 2003). Moreover, early information from our group and Ryder and colleagues suggests that terbinafine is effective at least some azole-resistant C. albicans strains (Abaci and Haliki-Uztan, 2011). Terbinafine seems to be exceptionally active against Cryptococcus neoformans according to the identical assay framework.…”