Evaluation of the antifungal activity of Lactobacillus reuteri against Candida species

Abstract

BackgroundCandidiasis is a variety of diseases, including cutaneous, mucosal, and disseminated organ infections caused by members of the genus Candida. The incidence of candidiasis is increasing in immunocompromised patients. Probiotics are microorganisms that have health benefits when used properly. The present study aimed to assess the inhibitory activity of Lactobacillus reuteri against five different Candida species isolated from the oral cavity of Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) patients. MethodsThe inhibitory effect of L. reuteri versus oral Candida species was studied with broth microdilution (BMD), agar overlay interference, and co-aggregation assays. ResultsBoth cells and cell free supernatant (CFS) of L. reuteri had antifungal effects versus the five oral Candida species. In this study, Minimum inhibitory concentration (MIC) and Minimum fungicidal concentration (MFC) amounts for CFS of L. reuteri ranged from 6.25 to 25 μl/ml and 50 to 200 μl/ml, respectively. C. tropicalis and C. krusei were shown to be the most susceptible to CFS of L. reuteri. At 1010 and 108 colony forming unit (CFU/ml) of L. reuteri, no colonies of Candida species grew, and growth of all studied Candida species were completely inhibited. L. reuteri showed the most significant co-aggregation percentage for C. tropicalis (96%) followed by C. parapsilosis (95%). The ranking of the co-aggregation of L. reuteri with the five Candida species was C. tropicalis > C. parapsilosis > C. glabrata > C. krusei > C. albicans. ConclusionToday, the increasing resistance of antifungal drugs to infectious agents of Candida species has caused concern around the world. Hence, the role of probiotic, especially lactobacilli such as L. reuteri may be a suitable solution to inhibit candidiasis.