Candida-Candida and Candida-Staphylococcus species interactions in in-vitro dual-species biofilms

Objective: In present study, interaction between different Candida species and also their interaction with Staphylococcus species were investigated in mono and dual-species biofilm model. Methods: Resistant and weak biofilms former Candida(C. albicans, C. glabrata, C. krusi) and Staphylococcus species (S. aureus, S. epidermidis, S. saprophyticus) alongwith ATCC isolates were used in mono and different dual-species combinations for estimation of biofilms by crystal violet (CV) biofilm biomass assay and XTT reduction assay. Aspartyl proteinase activity of Candida species was also measured in these developed biofilms. Results: CV assay showed increased in biofilm biomass after 48 h of incubation in developed mono and dual-species biofilms. XTT reduction assay showed overall decreasing trend in metabolic rate in biofilms after 48 h of incubation. All three Candida species with each other in dual-species in-vitro biofilms showed antagonistic behaviour. Biofilm biomass production was raised for C. albicans and C. glabrata dual-specie biofilm with allStaphylococcus species except with clinical isolate of S. aureus and in C. glabrata-S. epidermidis dual-specie biofilm. ATCC and clinical isolate of Candida showed markedly decrease aspartyle proteinase activity when co-cultured withStaphylococcuscompared to when it was cultured alone.