Three Year Epidemiological Review of Candida at Glasgow Dental Hospital

Methods: Specimens from the oral cavity were collected over a period of three years (January 2006 to Dec 2008), which were submitted to our accredited diagnostic oral microbiology laboratory at GDHS for identification and sensitivity testing. These included oral rinses (65%) and swabs of the palate, angles and tongue (35%).

Results: In total 686 sites infected with Candida species were processed, of which 83% were identified as C. albicans. The remaining species were composed of C. glabrata (11%), C. tropicalis (2%), C. dubliniensis (1.3%), Saccharomyces cerevisiae (1.3%) and others (1.4%). Mixed infections with either Staphylococcus species or coli forms were observed in 38.5% of specimens. None of the isolates were resistant to amphotericin B, nystatin or miconazole. Sensitivity testing with fluconazole revealed that 91.25% were sensitive, with a range of 0.38 – 256 mg/L (MIC_50/90 of 1.5/16). Sensitivity testing with itraconazole revealed that 85% were sensitive, with a range of 0.002 – 256 mg/L (MIC_50/90 of 0.032/4). All C. glabrata isolates were resistant to azoles.

Conclusions: C. albicans remains the predominant pathogen associated with oral candidosis, which does not appear to be associated with resistance to commonly used antifungal agents. C. glabrata is the second most common pathogen and is associated with intrinsic azole resistance. The use of a diagnostic microbiology laboratory to identify this increasingly common pathogen is essential for effective management of patients with oral candidosis.