Streptomyces: a natural source of anti-Candida agents

Abstract

Introduction. There is an urgent need to source new compounds that can combat the current threat of serious infection caused by Candida spp. and contend with the problem of antimicrobial resistance. Gap. A synthesis of the evidence available from the current literature is needed to identify promising antifungal chemotherapeutics. Aim. To highlight anti-Candida compounds derived from Streptomyces spp. (a well-known source of antimicrobial compounds) that could translate to potential candidates for future clinical practice. Methodology. A comprehensive review was conducted across three scientific literature databases spanning a 13-year period. Results. We identified 151 compounds with anti-Candida activity. Amongst these, 40 were reported with very strong inhibitory activity, having minimum inhibitory concentrations (MICs) against Candida spp. of <3.5 µg ml−1, 66 compounds were considered strong inhibitors and 45 compounds exhibited moderate inhibitory potential. From an analysis of the MICs, we deduced that the actinomycin-like compounds RSP01 and RSP02 were probably the most promising anti-Candida compounds. Other antifungals of note included filipin-like compounds, which demonstrated superior inhibition to amphotericin B and activity against Candida glabrata and Candida krusei, and bafilomycin derivatives, which had substantial inhibition against Candida parapsilosis. Conclusion. It is essential to recognize the limitations inherent in the quest for new antifungals, which encompass toxicity, in vivo effectiveness and constraints associated with limited data access. However, further investigation through in-depth study and emerging technologies is of paramount importance, given that there are still many more compounds to discover. This review highlights the importance of antifungal compounds derived from Streptomyces , which demonstrate robust inhibition, and, in many cases, low toxicity, making them promising candidates for the development of novel antifungal agents.