Oral candidosis – Clinical challenges of a biofilm disease

This review summarizes the impact of biofilms in oral candidosis with special emphasis on medically compromised patients. The concept of oral candidosis as a mixed candidal-bacterial biofilm infection has changed our understanding of its epidemiology and diagnosis as well as approach to its treatment. Candida albicans is the most common causative agent of oral candidosis although Candida species other than C. albicans are often seen in medically compromised patients with a history of multiple courses of azole antifungals. Although C. albicans is usually susceptible to all commonly used antifungals when tested in vitro, their biofilm form are highly resistant to most antifungals. Therefore, treatment consists of mechanical destruction of the biofilm in combination with topical drugs. Azole antifungals should be avoided for patients suffering from recurrent oral yeast infections due to a risk of selection and enrichment of resistant strains within the biofilm. Oral candidosis can also be a symptom of an undiagnosed or poorly controlled systemic disease such as HIV infection or diabetes. If the response to appropriate treatment is poor, other causes of oral mucositis should be excluded. Oral candidosis arises from the patient's mixed candidal-bacterial biofilm, i.e., dental plaque, whereby good self-care is important for successful therapy.