Saliva flow and oral Candida colonization in Sjögren’s syndrome patients

Abstract

Objectives: The aim of this study was to assess the relationship between oral Candida colonization and salivary flow in patients with Sjögren’s syndrome (SS). Methods: 85 SS patients (83 females and 2 males; 38 primary (pSS) and 47 secondary cases (sSS)) were recruited from the Rheumatology Clinics, Queen Mary Hospital and Queen Elizabeth Hospital, Hong Kong. Flow rates of unstimulated (UWS) and stimulated (SWS) whole saliva were measured. Oral rinse and dental plaque samples were collected and streaked onto Sabouraud’s dextrose agar (SDA) and CHROMagar plates. All plates were incubated at 37°C in air for 2 days. Candida colony-forming unit (CFU) was recorded. Species identification was based on colony morphology, Gram-staining reaction and biochemical analysis using API ID 32C system.

Results: More than 60% of SS patients had oral Candida. Prevalence of oral Candidain oral rinse and dental plaque samples of SS patients was 63.5% and 68.2% respectively. Candida albicans was the most frequently isolated Candida species, contributing to 52.9% and 57.6% of total Candida in the oral rinse and dental plaque samples respectively. There were mixed colonization of oral Candidain 12.9 % (oral rinse samples) and 11.8 % (dental plaque samples) of patients. The UWS and SWS flow rates were 0.23 ml/min (SD=0.24) and 0.47 ml/min (SD=0.51) respectively. A negative correlation existed between the UWS flow and Candida counts in oral rinse (r=-0.70, p<0.001) and dental plaque samples(r=-0.71, p<0.001). Likewise, SWS flow was inversely correlated with Candida counts in oral rinse (r=-0.66, p<0.001) and dental plaque samples(r=-0.65, p<0.001).

Conclusions: SS patients had reduced salivary output and were prevalent to oral Candida colonization. There were inverse relationships between salivary flow rates and Candida counts.

(Funded by Hong Kong Research Grants Council, GRF Grant #769408M)