Incidence rate of Candida species in the oral cavity of middle-aged and elderly subjects

Zaremba ML, Daniluk T, Rożkiewicz D, Cylwik-Rokicka D, Kierklo A, Tokajuk G, Dąbrowska E, Pawińska M, Klimiuk A, Stokowska W, Abdelrazek S


Purpose: The aim of this study was to determine the incidence rate of oral Candida species in middle-aged and elderly subjects.
Material and methods: The study carried out in 103 adults aged 35-92 years, in which 32 (31.1%) used complet or partial acrylic dentures. Mycological tests were performed by using culture (Sabouraud agar) and API 20C AUX (bioMérieux) for identification of the species level. Material for analysis included swabs taken from the palate mucosa and mucosal part of denture surfaces in denture wearers, as well as, from tooth surface and/or dentine carious lesions. The dental caries status of each patients was evaluated using DMF index (WHO 1986 criteria).
Results: Yeasts of Candida genus were isolated in 65/103 (63.1%) adults. The incidence rate of Candida spp. was higher in adults without dentures (46/71; 64.8%) compared to denture wearers (19/32; 59.4%); however, the differences were not statistically significant (p=0.59 >p=0.05). Candida albicans were the most frequently isolated species, and with a comparable rate (p=0.06), both in adults with and without dentures (17/32; 53.1% and 38/71; 53.5%, respectively). In 3 individuals without dentures, two other species were found apart from C. albicans, namely C. glabrata (2x) and C. krusei (1x). In a total of 11/49 (22.5%) strains belonging to 5 non- C. albicans species were detected in adults without dentures, while in denture wearers only 2/19 (10.5%) other species were found (C. krusei and C. oralis) (p=0.26 >p=0.05). Strains of C. glabrata species were isolated only from the elderly. No significant differences were noted in the incidence of Candida spp. between middle-aged subjects (35-44 years) (35/52; 67.3%) and the elderly (>55 years) (30/51; 58.8%) (p>0.05), both in denture wearers and non-denture wearing subjects. However, the frequency of oral Candida spp. strains was increased in advanced age subgroup 71-92 years (74.2%) compared with 56-70 years (35.0%) of elderly subjects (p<0.05), only in denture wearers (30.0% vs 5.0%) (p<0.05). The sex and DMF index distribution of both subject groups had no significant influence on the numbers of Candida spp. detected.
Conclusions: Yeasts of the genus Candida were isolated at a comparable rate (p>0.05) from the oral cavity of adults with and without dentures, as well as in middle-aged (35--44 years) and elderly subjects (56-92 years). However, a significant difference was observed only between elderly subgroups aged 56-70 (35%) and advanced age subgroup 71-92 years (74%).

Key words: adult subjects, denture wearers, oral Candida albicans, non-C. albicans species, DMF index.