In vitro evaluation of virulence factors of Candida species isolated from oral cavity

Abstract

The yeast Candida is a normal flora of the skin and the mucous membrane and it then becomes pathogen in immunocompromised people. Various virulence factors are contributing to establishment of the infection in the host. Adherence of the pathogen to host tissues, yeast-hyphal transition and extracellular hydrolytic enzymes secretion are important virulence factors of Candida species. These hydrolytic enzymes play important roles in pathogenicity of Candida infection. The present study was conducted with an aim to determine in vitro phospholipase, proteinase, haemolysin, esterase activities and biofilm formation in oral Candida isolates. A total of 38 Candida species were isolated from oral cavity of patients with symptoms of oral candidiasis. The specimens were identified by standard mycological techniques up to species level and were investigated for production of hydrolytic enzymes and biofilm formation. Phospholipase activity was in 52.6% of isolates, 86.8% produced proteinase and haemolysin activity was seen in 63.1%, esterase activity was demonstrated in 50% of isolates, 78.9% of Candida isolates showed biofilm formation. Candida albicans showed more extracellular hydrolytic enzyme activity, whereas, Candida tropicalis showed more biofilm formation. Both the C. albicans and Non-albicans Candida (NAC) species are capable of producing extracellular hydrolytic enzymes and biofilm formation.   Key words: Candida species, virulence factors, extracellular hydrolytic enzymes, biofilm formation.