Endophytic Fungi Isolated from Ageratina adenophora Exhibits Potential Antimicrobial Activity against Multidrug-Resistant Staphylococcus aureus

Abstract

Multidrug-resistant bacteria such as <i>Staphylococcus aureus</i> (MRSA) cause infections that are difficult to treat globally, even with current available antibiotics. Therefore, there is an urgent need to search for novel antibiotics to tackle this problem. Endophytes are a potential source of novel bioactive compounds; however, the harnessing of novel pharmacological compounds from endophytes is infinite. Therefore, this study was designed to identify endophytic fungi (from <i>Ageratina adenophora</i>) with antibacterial activity against multidrug-resistant bacteria. Using fungal morphology and ITS-rDNA, endophytic fungi with antibacterial activities were isolated from <i>A. adenophora</i>. The results of the ITS rDNA sequence analysis showed that a total of 124 morphotype strains were identified. In addition, Species richness (<i>S</i>, 52), Margalef index (<i>D</i>^/, 7.3337), Shannon-Wiener index (<i>H</i>^/,3.6745), and Simpson's diversity index (<i>D</i>, 0.9304) showed that <i>A. adenophora</i> have abundant endophytic fungi resources. Furthermore, the results of the agar well diffusion showed that the <i>Penicillium sclerotigenum</i>, <i>Diaporthe kochmanii</i>, and <i>Pestalotiopsis trachycarpicola</i> endophytic fungi's ethyl acetate extracts showed moderate antibacterial and bactericidal activities, against methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) SMU3194, with a MIC of 0.5-1 mg/mL and a MBC of 1-2 mg/mL. In summary, <i>A. adenophora</i> contains endophytic fungi resources that can be pharmacologically utilized, especially as antibacterial drugs.