Oral Candida Carriage and Fungi Species Prevalence

Abstract

This study aims to identify the prevalence of oral fungal species in routine dental patients via the laboratory culturing of the isolates and identification by the Erba expert identification program plus the evaluation of the antifungal susceptibility pattern of the isolated fungi by agar diffusion method with Neo-Sensitabs. Subjects and Methods: A total 310 dental patients examined at Al salmani central dental clinic in Benghazi throughout 9 months in the year 2021 in full observation of the measures imposed to combat COVID-19 pandemic. The patients were adults aged 18 years or above, with different dental complaints (dental caries, gingivitis, periodontal disease, dental prosthesis problems), few of them had associating medical illness such as (diabetes, hypertension, asthma, paranasal sinusitis, hyperthyroidism, hypothyroidism or anemia) which might have modified their oral fungal carriage. The later can also be modified by personal habits such as smoking or alcoholism. All relevant information was recorded prior taking an oral smear and immediately transferring it to the laboratory for cultivation on a Sabouraud’s Dextrose Agar (SDA) by standard mycological methods. The isolates were first tested by gram stain then by germ tube test. The colony color and culture characteristics were recorded. CANDIDAtest 21 was used along with antifungal susceptibility test by Agar Diffusion method with Neo-Sensitabs method. The susceptibility to seven antifungal agents (fluconazole, amphotericin B, Nystatin, fluocytosine, Clotrimazole, Itraconazole, and voriconazole) was tested. Results: In 310 cases, the prevalence of oral carriage of yeasts was 32% (100 patients; 54 females and 46 males). No correlation was found between clinical variables and candida carriage except for minor increased tendency of fungal carriage in the patients using dental prostheses. Twelve strains of candidal and non-candidal species could be isolated. Candida albicans was the most predominant species and found in 68% of the isolates, while Candida dubliniensis was the second isolated species in 15 cases, Trichosporon spp in 5 cases, Candida catenulata in 2 cases, Candida krusei in 2 cases, Candida glabrata in 2 cases, and (1 case each) for Candida magnolia, Candida pelliculosa, Cryptococcus humicola complex, Cryptococcus Laurentii, Geotrichum capitatum, and Rhodotorula rubra. Almost all isolates expressed high resistance to (amphotericin, fluocytosine, and Clotrimazole) 98%, 97% and 83% respectively, while the resistance was intermediate to (fluconazole and Nystatin), 67% and 60% respectively and high sensitivity was recorded to (voriconazole and Itraconazole) 91% and 71% respectively. Interestingly, fluconazole has performed well in this study, as the isolates were either sensitive (67%) or intermediately sensitive (33%) to it, and no single resistant was isolated. Conclusions: Candida albicans is the most predominately isolated species followed by Candida dubliniensis, while different figures were recorded for the other less commonly encountered species. Resistance to antifungal agents is high to some agents particularly amphotericin, fluocytosine, and Clotrimazole and less profound to other agents such as voriconazole and Itraconazole and no fluconazole resistant strains could be found.