{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T14:27:11Z","timestamp":1780324031901,"version":"3.54.1"},"reference-count":46,"publisher":"Public Library of Science (PLoS)","issue":"5","license":[{"start":{"date-parts":[[2022,5,11]],"date-time":"2022-05-11T00:00:00Z","timestamp":1652227200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Urinary tract infections (UTIs) are common bacterial infections. The global emergence of multidrug-resistant uropathogens in the last decade underlines the need to search for new antibiotics with novel mechanisms of action. In this regard, exploring endophytic fungi inhabiting medicinal plants used locally against urinary tract infections could be a promising strategy for novel drug discovery. This study investigates crude metabolites from endophytic fungi isolated from <jats:italic>Annona muricata<\/jats:italic> as potential sources of antibiotic drugs to fight against uropathogens and reduce related oxidative stress. Crude ethyl acetate extracts from 41 different endophytic fungi were screened against three bacterial strains using the broth microdilution method, and fungi producing active crude extracts were identified using ITS1-5.8S rRNA-ITS2 nucleotide sequences. The antibacterial modes of action of the five most active extracts were evaluated using <jats:italic>Staphylococcus aureus<\/jats:italic> ATCC 43300 and <jats:italic>Klebsiella oxytoca<\/jats:italic> strains. The DPPH and FRAP assays were used to investigate their antioxidant activity, and their cytotoxicity against the Vero cell line was evaluated using the MTT assay. Out of the 41 crude extracts tested, 17 were active with minimum inhibitory concentrations (MICs) ranging from 3.125 \u03bcg\/mL to 100 \u03bcg\/mL and were not cytotoxic against Vero cell lines with a cytotoxic concentration 50 (CC<jats:sub>50<\/jats:sub>) &gt;100 \u03bcg\/mL. The more potent extracts (from <jats:italic>Fusarium waltergamsii<\/jats:italic> AMtw3, <jats:italic>Aspergillus<\/jats:italic> sp. AMtf15, <jats:italic>Penicillium citrinum<\/jats:italic> AMf6, <jats:italic>Curvularia<\/jats:italic> sp. AMf4, and <jats:italic>Talaromyces annesophieae<\/jats:italic> AMsb23) significantly inhibited bacterial catalase activity, lysed bacterial cells, increased outer membrane permeability, and inhibited biofilm formation, and the time-kill kinetic assay revealed concentration-dependent bactericidal activity. All seventeen extracts showed weak ferric iron-reducing power (1.06 to 12.37 \u03bcg equivalent NH<jats:sub>2<\/jats:sub>OH\/g of extract). In comparison, seven extracts exhibited DPPH free radical scavenging activity, with RSA<jats:sub>50<\/jats:sub> ranging from 146.05 to 799.75 \u03bcg\/mL. The molecular identification of the seventeen active fungi revealed that they belong to six distinct genera, including <jats:italic>Aspergillus<\/jats:italic>, <jats:italic>Curvularia<\/jats:italic>, <jats:italic>Fusarium<\/jats:italic>, <jats:italic>Meyerozyma<\/jats:italic>, <jats:italic>Penicillium<\/jats:italic>, and <jats:italic>Talaromyces<\/jats:italic>. This investigation demonstrated that fungal endophytes from Cameroonian <jats:italic>Annona muricata<\/jats:italic>, a medicinal plant used locally to treat bacterial infections, might contain potent antibacterial metabolites with multiple modes of action. The antibacterial-guided fractionation of these active extracts is currently ongoing to purify and characterise potential antibacterial active ingredients.<\/jats:p>","DOI":"10.1371\/journal.pone.0267246","type":"journal-article","created":{"date-parts":[[2022,5,11]],"date-time":"2022-05-11T18:48:13Z","timestamp":1652294893000},"page":"e0267246","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":11,"title":["Crude metabolites from endophytic fungi inhabiting Cameroonian Annona muricata inhibit the causative agents of urinary tract infections"],"prefix":"10.1371","volume":"17","author":[{"given":"Lorette Victorine","family":"Yimgang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2144-0710","authenticated-orcid":true,"given":"Rufin Marie","family":"Kouipou Toghueo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ines Michele Kanko","family":"Mbekou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Darline","family":"Dize","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabrice Fekam","family":"Boyom","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2022,5,11]]},"reference":[{"key":"pone.0267246.ref001","doi-asserted-by":"crossref","first-page":"549","DOI":"10.3389\/fimmu.2019.00549","article-title":"Infectious Disease Threats in the Twenty-First Century: Strengthening the Global Response","volume":"10","author":"DE Bloom","year":"2019","journal-title":"Front Immunol"},{"key":"pone.0267246.ref002","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1056\/NEJMoa2001017","article-title":"A Novel Coronavirus from Patients with Pneumonia in China, 2019","volume":"382","author":"N Zhu","year":"2020","journal-title":"N Engl J Med"},{"key":"pone.0267246.ref003","first-page":"9486","article-title":"Assessment of practices in screening and treating women with bacteriuria","volume":"25","author":"EL Ditkoff","year":"2018","journal-title":"Can J Urol"},{"key":"pone.0267246.ref004","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1038\/nrmicro3432","article-title":"Urinary tract infections: epidemiology, mechanisms of infection and treatment options","volume":"13","author":"AL Flores-Mireles","year":"2015","journal-title":"Nat Rev Microbiol"},{"key":"pone.0267246.ref005","doi-asserted-by":"crossref","first-page":"S1","DOI":"10.1086\/318850","article-title":"Urinary Tract Infections: Disease Panorama and Challenges","volume":"183","author":"WE Stamm","year":"2001","journal-title":"J INFECT DIS"},{"key":"pone.0267246.ref006","doi-asserted-by":"crossref","DOI":"10.1093\/ofid\/ofw281","article-title":"The Increase in Hospitalizations for Urinary Tract Infections and the Associated Costs in the United States, 1998\u20132011","volume":"4","author":"JE Simmering","year":"2017","journal-title":"Open Forum Infectious Diseases"},{"key":"pone.0267246.ref007","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2020\/2176569","article-title":"Predictors of Urinary Tract Infections in Children and Antibiotic Susceptibility Pattern in the Buea Health District, South West Region, Cameroon","volume":"2020","author":"CP Nji","year":"2020","journal-title":"BioMed Research International"},{"key":"pone.0267246.ref008","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1056\/NEJMcp1104429","article-title":"Uncomplicated Urinary Tract Infection","volume":"366","author":"TM Hooton","year":"2012","journal-title":"N Engl J Med"},{"key":"pone.0267246.ref009","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1080\/1120009X.2017.1380395","article-title":"Multi-drug-resistant Gram-negative bacteria causing urinary tract infections: a review","volume":"29","author":"A Mazzariol","year":"2017","journal-title":"Journal of Chemotherapy"},{"key":"pone.0267246.ref010","doi-asserted-by":"crossref","first-page":"e0220265","DOI":"10.1371\/journal.pone.0220265","article-title":"The burden of antimicrobial resistance among urinary tract isolates of Escherichia coli in the United States in 2017","volume":"14","author":"IA Critchley","year":"2019","journal-title":"PLoS ONE"},{"key":"pone.0267246.ref011","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1159\/000504415","article-title":"Changes in Antimicrobial Resistance of Urinary Tract Infections in Adult Patients over a 5-Year Period","volume":"104","author":"H Caskurlu","year":"2020","journal-title":"Urol Int"},{"key":"pone.0267246.ref012","doi-asserted-by":"crossref","first-page":"1934","DOI":"10.3390\/microorganisms8121934","article-title":"Untapped Potentials of Endophytic Fungi: A Review of Novel Bioactive Compounds with Biological Applications","volume":"8","author":"MC Manganyi","year":"2020","journal-title":"Microorganisms"},{"key":"pone.0267246.ref013","first-page":"13","article-title":"ON THE ANTIBACTERIAL ACTION OF CULTURES OF A PENICILLIUM, WITH SPECIAL REFERENCE TO THEIR USE IN THE ISOLATION OF B","author":"A. Fleming","journal-title":"INFLUENZ?1E"},{"key":"pone.0267246.ref014","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1016\/j.cell.2014.06.034","article-title":"Insights into Secondary Metabolism from a Global Analysis of Prokaryotic Biosynthetic Gene Clusters","volume":"158","author":"P Cimermancic","year":"2014","journal-title":"Cell"},{"key":"pone.0267246.ref015","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/21501203.2019.1645053","article-title":"Bioprospecting endophytic fungi from Fusarium genus as sources of bioactive metabolites","volume":"11","author":"RMK Toghueo","year":"2020","journal-title":"Mycology"},{"key":"pone.0267246.ref016","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1007\/s13205-020-2081-1","article-title":"Endophytic Penicillium species and their agricultural, biotechnological, and pharmaceutical applications","volume":"10","author":"RMK Toghueo","year":"2020","journal-title":"3 Biotech"},{"key":"pone.0267246.ref017","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1590\/2175-7860201566403","article-title":"The World Flora Online 2020 project: will Cameroon come up to the expectation?","volume":"66","author":"JM Onana","year":"2015","journal-title":"Rodrigu\u00e9sia"},{"key":"pone.0267246.ref018","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.jep.2019.02.010","article-title":"Antiplasmodial potential and GC-MS fingerprint of endophytic fungal extracts derived from Cameroonian Annona muricata","volume":"235","author":"RMK Toghueo","year":"2019","journal-title":"Journal of Ethnopharmacology"},{"key":"pone.0267246.ref019","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1016\/j.arabjc.2016.01.004","article-title":"Annona muricata: A comprehensive review on its traditional medicinal uses, phytochemicals, pharmacological activities, mechanisms of action and toxicity","volume":"11","author":"AV Coria-T\u00e9llez","year":"2018","journal-title":"Arabian Journal of Chemistry"},{"key":"pone.0267246.ref020","first-page":"315","article-title":"AMPLIFICATION AND DIRECT SEQUENCING OF FUNGAL RIBOSOMAL RNA GENES FOR PHYLOGENETICS","author":"Elsevier","year":"1990","journal-title":"PCR Protocols"},{"key":"pone.0267246.ref021","doi-asserted-by":"crossref","first-page":"146","DOI":"10.1016\/j.sajb.2016.12.021","article-title":"Enzymatic activity of endophytic fungi from the medicinal plants Terminalia catappa, Terminalia mantaly and Cananga odorata","volume":"109","author":"RMK Toghueo","year":"2017","journal-title":"South African Journal of Botany"},{"key":"pone.0267246.ref022","unstructured":"Cockerill FR, Clinical and Laboratory Standards Institute, editors. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically: approved standard\u2014ninth edition. Wayne, Pa: CLSI; 2012."},{"key":"pone.0267246.ref023","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2021\/6697973","article-title":"Antibacterial and Mode of Action of Extracts from Endophytic Fungi Derived from Terminalia mantaly, Terminalia catappa, and Cananga odorata","volume":"2021","author":"MIK Mbekou","year":"2021","journal-title":"BioMed Research International"},{"key":"pone.0267246.ref024","doi-asserted-by":"crossref","first-page":"630","DOI":"10.1111\/jam.13048","article-title":"Antibacterial activity and proposed action mechanism of a new class of synthetic tricyclic flavonoids","volume":"120","author":"C Babii","year":"2016","journal-title":"J Appl Microbiol"},{"key":"pone.0267246.ref025","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1186\/s12866-018-1321-6","article-title":"Defining conditions for biofilm inhibition and eradication assays for Gram-positive clinical reference strains","volume":"18","author":"CD Cruz","year":"2018","journal-title":"BMC Microbiol"},{"key":"pone.0267246.ref026","doi-asserted-by":"crossref","first-page":"e0237076","DOI":"10.1371\/journal.pone.0237076","article-title":"Garcinia kola (Heckel) and Alchornea cordifolia (Schumach. & Thonn.) M\u00fcll. Arg. from Cameroon possess potential antisalmonellal and antioxidant properties","volume":"15","author":"F Djague","year":"2020","journal-title":"PLoS ONE"},{"key":"pone.0267246.ref027","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/0022-1759(83)90303-4","article-title":"Rapid colorimetric assay for cellular growth and survival: Application to proliferation and cytotoxicity assays","volume":"65","author":"T. Mosmann","year":"1983","journal-title":"Journal of Immunological Methods"},{"key":"pone.0267246.ref028","doi-asserted-by":"crossref","first-page":"65","DOI":"10.3390\/pathogens5040065","article-title":"Microbial Biofilms in Urinary Tract Infections and Prostatitis: Etiology, Pathogenicity, and Combating strategies","volume":"5","author":"C Delcaru","year":"2016","journal-title":"Pathogens"},{"key":"pone.0267246.ref029","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1179\/2047773215Y.0000000030","article-title":"Antimicrobial resistance: a global multifaceted phenomenon","volume":"109","author":"F Prestinaci","year":"2015","journal-title":"Pathogens and Global Health"},{"key":"pone.0267246.ref030","doi-asserted-by":"crossref","first-page":"1404","DOI":"10.3389\/fmicb.2019.01404","article-title":"A Review of the Microbial Production of Bioactive Natural Products and Biologics","volume":"10","author":"JV Pham","year":"2019","journal-title":"Front Microbiol"},{"key":"pone.0267246.ref031","doi-asserted-by":"crossref","first-page":"731","DOI":"10.4014\/jmb.1901.01015","article-title":"Bioprospecting of Novel and Bioactive Metabolites from Endophytic Fungi Isolated from Rubber Tree Ficus elastica Leaves","volume":"29","author":"Z Ding","year":"2019","journal-title":"J Microbiol Biotechnol"},{"key":"pone.0267246.ref032","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1007\/978-3-030-03589-1_12","volume-title":"Advances in Endophytic Fungal Research","author":"F Uzma","year":"2019"},{"key":"pone.0267246.ref033","doi-asserted-by":"crossref","first-page":"231","DOI":"10.5941\/MYCO.2012.40.4.231","article-title":"Molecular Identification of Endophytic Fungi Isolated from Needle Leaves of Conifers in Bohyeon Mountain, Korea","volume":"40","author":"J-J Yoo","year":"2012","journal-title":"Mycobiology"},{"key":"pone.0267246.ref034","doi-asserted-by":"crossref","first-page":"992","DOI":"10.1039\/C8NP00010G","article-title":"Diversity of biologically active secondary metabolites from endophytic and saprotrophic fungi of the ascomycete order Xylariales","volume":"35","author":"SE Helaly","year":"2018","journal-title":"Nat Prod Rep"},{"key":"pone.0267246.ref035","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1007\/s11101-020-09679-4","article-title":"Endophytes from Gingko biloba: the current status","volume":"19","author":"RMK Toghueo","year":"2020","journal-title":"Phytochem Rev"},{"key":"pone.0267246.ref036","doi-asserted-by":"crossref","first-page":"70","DOI":"10.3390\/jof4020070","article-title":"Antiplasmodial Properties and Cytotoxicity of Endophytic Fungi from Symphonia globulifera (Clusiaceae)","volume":"4","author":"J Ateba","year":"2018","journal-title":"JoF"},{"key":"pone.0267246.ref037","doi-asserted-by":"crossref","first-page":"2473","DOI":"10.1007\/s00436-018-5936-1","article-title":"Conditioned media and organic elicitors underpin the production of potent antiplasmodial metabolites by endophytic fungi from Cameroonian medicinal plants","volume":"117","author":"RMK Toghueo","year":"2018","journal-title":"Parasitol Res"},{"key":"pone.0267246.ref038","doi-asserted-by":"crossref","first-page":"E2100","DOI":"10.1073\/pnas.1401876111","article-title":"Antibiotics induce redox-related physiological alterations as part of their lethality","volume":"111","author":"DJ Dwyer","year":"2014","journal-title":"Proc Natl Acad Sci U S A"},{"key":"pone.0267246.ref039","first-page":"1","article-title":"Catalase Activity and Hydrophobicity Test of Bacteria Susceptible to Extracts of Cleistopholis Patens and Piliostigma Reticulatum","author":"AO Daniels","year":"2020","journal-title":"EJBIO"},{"key":"pone.0267246.ref040","first-page":"175","article-title":"The revival of micro-organisms sublethally injured by chemical inhibitors","author":"P. Gilbert","year":"1984","journal-title":"Soc Appl Bacteriol Symp Ser"},{"key":"pone.0267246.ref041","doi-asserted-by":"crossref","first-page":"2474","DOI":"10.1128\/AAC.49.6.2474-2478.2005","article-title":"Mechanisms of antibacterial action of three monoterpenes","volume":"49","author":"D Trombetta","year":"2005","journal-title":"Antimicrob Agents Chemother"},{"key":"pone.0267246.ref042","doi-asserted-by":"crossref","first-page":"1824","DOI":"10.1128\/AAC.35.9.1824","article-title":"Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria","volume":"35","author":"RH Eng","year":"1991","journal-title":"Antimicrob Agents Chemother"},{"key":"pone.0267246.ref043","doi-asserted-by":"crossref","first-page":"81","DOI":"10.26438\/ijsrbs\/v6i3.8186","article-title":"Assessment of endophytic fungal isolates for its Antibiofilm activity on Pseudomonas aeruginosa","volume":"6","author":"AY Dawande","year":"2019","journal-title":"IJSRBS"},{"key":"pone.0267246.ref044","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1186\/s13568-020-01143-y","article-title":"Prospecting the antimicrobial and antibiofilm potential of Chaetomium globosum an endophytic fungus from Moringa oleifera","volume":"10","author":"N Kaur","year":"2020","journal-title":"AMB Expr"},{"key":"pone.0267246.ref045","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1186\/s12906-021-03269-3","article-title":"Extracts of endophytic fungi from leaves of selected Nigerian ethnomedicinal plants exhibited antioxidant activity","volume":"21","author":"M Ibrahim","year":"2021","journal-title":"BMC Complement Med Ther"},{"key":"pone.0267246.ref046","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1002\/mnfr.200500156","article-title":"Green tea catechins as brain-permeable, natural iron chelators-antioxidants for the treatment of neurodegenerative disorders","volume":"50","author":"S Mandel","year":"2006","journal-title":"Mol Nutr Food Res"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0267246","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,5,11]],"date-time":"2022-05-11T18:48:52Z","timestamp":1652294932000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0267246"}},"subtitle":[],"editor":[{"given":"Guadalupe Virginia","family":"Nev\u00e1rez-Moorill\u00f3n","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2022,5,11]]},"references-count":46,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2022,5,11]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0267246","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,5,11]]}}}