Anti-candida activities of four bacterial endophytic extracts isolated from Urena lobata.

Abstract

Purpose: Most antifungals have drawbacks, including toxicity, efficacy, and cost, and their misuse has led to the emergence of resistant strains. Therefore, more is needed. This study aimed to evaluate the antifungal properties of bacterial endophytic extracts on Candida spp. Materials and Methods: Biological samples were bacterial endophytes from Urena lobata and Candida species isolated from Stool. The Candida species were purified on chromogenic aga medium. The MIC was determined using broth microdilution starting from 200 µg/ml as the highest concentration. The bacterial endophytes were characterised based on morphology and motility. The inhibitory parameters, time kill kinetics assay and probable site of action of the extract were determined using the cell counting method and microscopic observation under methylene blue stain. Results: The characterised Candida species were Candida albicans , Candida glabrata , Candida dubliniensis , Candida parapsilosis , Candida tropicalis and Candida krusei . The selected extracts from screening were A23, A34, A52, A64, A80, and A96. The bacteria producing these extracts were all atypical nonmotile and were Streptobacillus spp. and Bacillus spp. The MIC ranged between 100 µg/ml and 200 µg/ml. The time kill kinetics assay revealed that the cidal effect of the extracts started after 3 to 9 hours of contact with the extracts. The shape of the cells posttreatment revealed that the probable site of action is on the cell membrane for A23 and the cell wall, nucleus, or mitochondria for A52, A64 and A80. Conclusion: Bacterial endophytes have been proven through this study to be a suitable lead compound in antifungal resistance drug development.