Genotypic relatedness of yeasts in thrush and denture stomatitis

• Published in: Oral microbiology and immunology Vol. 21; no. 5; pp. 301 - 308
• Main Authors: Song, X., Sun, J., Støre, G., Eribe, E. R. K., Hansen, B. F., Olsen, I.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-2006; Blackwell
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Candida; Candida - classification; Candida - genetics; Candidiasis, Oral - microbiology; Case-Control Studies; Child; Dentistry; denture stomatitis; Denture, Complete, Upper - microbiology; DNA, Fungal - analysis; Female; Fundamental and applied biological sciences. Psychology; Genotype; genotypic relatedness; Gingival Pocket - microbiology; Humans; Male; Microbiology; Middle Aged; Mouth Mucosa - microbiology; Mycological Typing Techniques; Palate, Hard - microbiology; Phylogeny; Random Amplified Polymorphic DNA Technique; Stomatitis, Denture - microbiology; thrush; yeasts; Candidiasis; Yeast; Mycosis; Microbiology; Stomatology; denture stomatitis; Thrush; yeasts; Infection; Stomatitis; Immunology; genotypic relatedness; Oral cavity disease
• ISSN: 0902-0055; 1399-302X
• DOI: 10.1111/j.1399-302X.2006.00294.x

Background/aim:  Candida is an opportunistic pathogen. Understanding its genetic characters might increase our understanding of the pathogenesis of candidosis. We examined the genetic relationships of yeasts from the most common forms of oral candidosis: thrush and denture stomatitis.
Methods:  Yeasts were sampled from palate, buccal mucosa, gingival sulci/periodontal pockets and/or denture fitting surface of 19 thrush patients and 22 denture stomatitis patients. Random amplified polymorphic DNA and the Dendron computer‐assisted program were used to determine the genotypic relatedness of the yeasts.
Results:  A dendrogram generated from 105 thrush isolates had similarity coefficients (SAB) ranging from 0.58 to 1 with four clusters derived at SAB 68%. Another dendrogram was generated from 91 isolates from denture stomatitis, with SAB ranging from 0.59 to 1. Three clusters were established at SAB 71%. In a composite dendrogram incorporating the thrush and denture stomatitis data and orally healthy data compiled from a previous study, five genotypic clusters were generated at SAB 68%. Cluster II, the most dominant, comprised isolates from thrush, denture stomatitis and healthy conditions, while clusters III and IV contained yeasts mainly from thrush.
Conclusions:  Palatal yeast carriage was significantly increased in thrush and denture stomatitis, also after radiation, chemotherapy and denture wearing. The buccal mucosa was favorable for yeast colonization regardless of oral condition. Yeasts in thrush were more diverse than in conditions of oral health. The common clone (II) of infecting yeasts and commensals suggested that commensals could induce thrush and denture stomatitis, whereas the unique clones in thrush (III, IV) might have been established through strain replacement or maintenance with minor genetic variation.