ENDOPHYTIC FUNGI: SOURCES OF ANTIMICROBIAL COMPOUNDS

Abstract

Antimicrobial resistance represents a major public health challenge and reinforces the need for new substances active against pathogenic microorganisms. In this context, endophytic fungi stand out as promising sources of biologically active secondary metabolites. This study aimed to analyze, through a systematic literature review, the potential of these fungi as sources of metabolites with antimicrobial activity and their contribution to the discovery of new therapeutic agents. Searches were conducted in PubMed, SciELO, ScienceDirect, and Web of Science, supplemented by Google Scholar, considering articles published between January 2015 and December 2025. After applying the eligibility criteria, 16 primary studies were included in the qualitative synthesis. The results revealed a wide diversity of endophytic fungi, host plants, and bioactive metabolites, including representatives of the genera Aspergillus, Penicillium, Talaromyces, Pestalotiopsis, Chaetomium, Neofusicoccum, Diaporthe, Fusarium, and Nigrospora. Different classes of metabolites exhibited in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria and fungal species, including methicillin-resistant Staphylococcus aureus (MRSA). Some compounds showed low minimum inhibitory concentration (MIC) values, indicating significant activity under the evaluated experimental conditions. However, methodological heterogeneity and a predominance of in vitro studies were observed, with limited evidence regarding in vivo efficacy, safety, selectivity, pharmacokinetics, and mechanisms of action. It is concluded that endophytic fungi represent promising sources of antimicrobial metabolites, although further pharmacological and preclinical studies are required to assess their applicability in the development of new therapeutic agents.