Inactivation of Planktonic Cells and Sessile Biofilm of Candida Auris by Aloe Emodin-mediated Antimicrobial Photodynamic Therapy

Inactivation of Planktonic Cells and Sessile Biofilm of Candida Auris by Aloe Emodin-mediated Antimicrobial Photodynamic Therapy | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Short Report Inactivation of Planktonic Cells and Sessile Biofilm of Candida Auris by Aloe Emodin-mediated Antimicrobial Photodynamic Therapy Mikaela Oliveira da Rosa, Eduarda de Oliveira Pinto, Laura Hoppe Friedrich, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6614954/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This study explored the in vitro potential of Aloe emodin (AE)-mediated antimicrobial photodynamic therapy (aPDT) against the emerging multidrug-resistant fungus Candida auris . While AE alone showed no significant antifungal activity, its activation with visible light (400–780 nm) at 10 µM resulted in a complete (100%) reduction of viable C. auris colony counts after 15 minutes of exposure. Conversely, the dark control group exhibited only a 30% decrease. Furthermore, AE-aPDT demonstrated a notable capacity to inhibit the initial development of C. auris biofilms. These findings highlight the potential of visible light-activated AE as an effective antimicrobial strategy against this resistant pathogen and its biofilms. The rapid and complete eradication of C. auris under these conditions suggests a promising avenue for developing disinfection protocols and potential therapeutic interventions against this critical global health threat. Reactive oxygen species Disinfection Antimicrobial resistance aloe vera visible light Figures Figure 1 Figure 2 INTRODUCTION The escalating global threat of antimicrobial resistance necessitates innovative therapeutic strategies [ 1 ]. The limited effective antifungal drugs and rising resistance contribute to high mortality rates from fungal infections, particularly those caused by Candida ssp. [ 2 ]. C. auris , an emerging multidrug-resistant fungal pathogen [ 3 ], poses a significant health risk with high mortality in systemic infections [ 4 ] and exhibits resistance to multiple antifungal classes [ 5 ], alongside virulence factors like biofilm formation [ 6 ]. Antimicrobial photodynamic therapy (aPDT) presents a promising alternative due to its non-invasiveness and lack of resistance induction [ 7 ], utilizing photosensitizers (PS) activated by light to generate reactive oxygen species [ 8 ]. Natural polyphenolic compounds, such as Aloe emodin (AE), a natural anthraquinone derivative with various pharmacological properties [ 9 ], are being explored as PS in aPDT [ 10 ]. This study aimed to evaluate the efficacy of AE-mediated antimicrobial photodynamic therapy (aPDT) for inactivating both planktonic cells and biofilms of the multidrug-resistant fungal pathogen C. auris . METHODOLOGY The study primarily investigated the AE-antimicrobial in vitro activity and aPDT against the multidrug-resistant fungal pathogen C. auris (CDC B11903). Additionally, the antimicrobial activity of AE was analyzed against other multidrug-resistant bacterial pathogens ( Staphylococcus aureus NTCC 12493, S. aureus ATCC 25923, Escherichia coli ATCC 13486 and E. coli ATCC 25922). aPDT for C. auris involved a 1 × 10⁷ CFU mL⁻¹ suspension incubated with 10 µM of AE for 30 min in the dark, followed by irradiation with 400–780 nm light (25 mW cm⁻², 96 J cm⁻²) for 15 min, with colony counts on PCA plates [11]. C. auris biofilm inhibition was assessed using a 24-hour culture in 96-well plates with AE serial dilutions (1000 − 0.01 µM), quantified by crystal violet staining. C. auris biofilm eradication involved forming a 48-hour biofilm, followed by AE treatment (1000 − 0.01 µM) for 16–20 hours and crystal violet quantification [ 12 ]. Statistical analysis employed two-way ANOVA with Tukey's post hoc test. RESULTS AE alone exhibited no antimicrobial activity against tested strains. However, AE-mediated aPDT with visible light (10 µM, 15 min) achieved 100% eradication of planktonic C. auris cells, significantly greater than the dark control (30% reduction) (Fig. 1 ). This highlights the necessity of light activation for AE's antifungal action, contrasting with some reports of AE's direct antibacterial effects [ 13 ]. Our findings align with previous studies demonstrating aPDT's efficacy against Candida species [ 14 ], likely due to the generation of reactive oxygen species and multi-target action, limiting resistance development [ 15 ]. AE also significantly inhibited C. auris biofilm formation from 1 µM concentration under light, being concentration-dependent (Fig. 2 A), consistent with aPDT's potential against fungal biofilms [ 16 ]. However, AE-aPDT was less effective against established biofilms (Fig. 2 B), suggesting a greater impact on biofilm development than on mature structures. This underscores the potential of AE-aPDT as a promising strategy against planktonic C. auris and for preventing biofilm formation [ 12 ]. In conclusion, this study underscores the significant potential of visible light-activated AE-mediated aPDT for inhibiting Candida auris biofilm formation and eradicating planktonic cells, emphasizing the critical role of light as an environmental factor in disinfection efficacy. AE demonstrates promise as a photosensitizer for aPDT against this resistant fungus, offering a potential strategy for environmental decontamination in healthcare settings and patient decolonization. The rapid and complete elimination of viable C. auris colonies suggests new avenues for treating fungal infections and developing hospital disinfection protocols. Declarations Author contributions M.O.R: data curation , investigation, methodology and Writing – original draft; E.O.P.: Investigation, Methodology; L.H.F: Investigation, Methodology; C.T.M: software; W.L.S: methodology; B.S.V: project administration, supervision, Writing – review and editing. Funding This work was supported by FAPERGS (Foundation for the Supporting of Research in the State of Rio Grande do Sul) under Grant Number 23/2551-0000776-2. Conflicts of interest All authors disclose any financial, business, and/or personal relationships with other people or organizations that could inappropriately influence (bias) the submitted work. Declaration of generative AI and AI-assisted technologies in the writing process During the preparation of this work, the author(s) used Chat GPT-4o mini with the aim of improving the writing to give it a more objective and scientific format. After using this tool/service, the author(s) have reviewed and edited the content as necessary and take full responsibility for the content of the published article. References Berman D, Chandy SJ, Cansdell O, Moodley K, Veeraraghavan B, Essack SY. Global access to existing and future antimicrobials and diagnostics: antimicrobial subscription and pooled procurement. Lancet Glob Health (2022) 10:e293–7. doi: 10.1016/s2214-109x(21)00463-0 Li M, Zhao JP. Research progress on deep fungal drug resistance mechanisms and detection methods. Chin J Mycology (2023) 18(01):90–6. doi: 10.3969/j.issn.1673-3827.2023.01.018 Saris, K., Meis, J. F., and Voss, A. (2018). Candida Auris. Curr. Opin. Infect. Dis. 31, 334–340. doi: 10.1097/QCO.0000000000000469 Chakrabarti, A., and Singh, S. (2020). Multidrug-Resistant Candida Auris: An Epidemiological Review. Expert Rev. Anti-infective Ther. 18, 551–562. doi: 10.1080/14787210.2020.1750368 Garcia-Bustos, V., Salavert, M., Ruiz-Gaitán, A. C., Cabañero-Navalon, M. D., Sigona-Giangreco, I. A., and Pemán, J. (2020). A Clinical Predictive Model of Candidaemia by Candida Auris in Previously Colonized Critically Ill Patients. Clin. Microbiol. Infect. 26, 1507–1513. doi: 10.1016/j.cmi.2020.02.001 Chakrabarti, A., and Singh, S. (2020). Multidrug-Resistant Candida Auris: An Epidemiological Review. Expert Rev. Anti-infective Ther. 18, 551–562. doi: 10.1080/14787210.2020.1750368 JIANG, Jingai et al. Type I Photodynamic Antimicrobial Therapy: Principles, Progress, and Future Perspectives. Acta Biomaterialia, 2024. https://doi.org/10.1016/j.actbio.2024.02.005 PINEGIN, Boris et al. The role of mitochondrial ROS in antibacterial immunity. Journal of cellular physiology, v. 233, n. 5, p. 3745–3754, 2018. https://doi.org/10.1002/jcp.26117 DONG, Xiaoxv et al. Aloe-emodin: a review of its pharmacology, toxicity, and pharmacokinetics. Phytotherapy Research, v. 34, n. 2, p. 270–281, 2020. doi.org/10.1002/ptr.6532 Morales-López, S. E., Parra-Giraldo, C. M., Ceballos-Garzón, A., Martı́nez, H. P., Rodrı́guez, G. J.,Á lvarez-Moreno, C. A., et al. (2017). Invasive Infections With Multidrug-Resistant Yeast Candida Auris, Colombia. Emerg. Infect. Dis. 23, 162–164. doi: 10.3201/eid2301.161497 Horton, M. V., and Nett, J. E. (2020). Candida Auris Infection and Biofilm Formation: Going Beyond the Surface. Curr. Clin. Microbiol. Rep. 7, 51–56. doi: 10.1007/s40588-020-00143-7 LIN, Hai–Dan et al. The effect of aloe–emodin–induced photodynamic activity on the apoptosis of human gastric cancer cells: A pilot study. Oncology letters, v. 13, n. 5, p. 3431–3436, 2017. https://doi.org/10.3892/ol.2017.5915 MA, Wenpeng et al. The effects of aloe emodin-mediated antimicrobial photodynamic therapy on drug-sensitive and resistant Candida albicans. Photochemical & Photobiological Sciences, v. 19, p. 485–494, 2020. DOI: https://doi.org/10.1039/c9pp00352e . Haney EF, Trimble MJ, Hancock REW. Microtiter plate assays to assess antibiofilm activity against bacteria. Nat Protoc. 2021;16(5):2615–2632. doi: 10.1038/s41596-021-00515-3 . Epub 2021 Apr 28. PMID: 33911258. OTIENO, Woodvine; LIU, Chengcheng; JI, Yanhong. AE-mediated photodynamic therapy attenuates sepsis-associated toxins in selected gram-positive bacteria in vitro. Journal of Microbiology and Biotechnology, v. 31, n. 9, p. 1200, 2021. doi: 10.4014/jmb.2105.05024 WANG, Xiaoyun et al. Polyphenolic natural products as photosensitizers for antimicrobial photodynamic therapy: recent advances and future prospects. Frontiers in Immunology, v. 14, p. 1275859, 2023. doi: 10.3389/fimmu.2023.1275859 GANESHKUMAR, Arumugam et al. Current perspectives of antifungal therapy: a special focus on Candida Auris. Journal of Fungi, v. 10, n. 6, p. 408, 2024. https://doi.org/10.3390/jof10060408 BAPAT, Priyanka S.; NOBILE, Clarissa J. Photodynamic therapy is effective against Candida auris biofilms. Frontiers in cellular and infection microbiology, v. 11, p. 713092, 2021. doi.org/10.3389/fcimb.2021.713092 Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6614954","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":473074327,"identity":"e0a7bb1b-8169-4ec5-99c7-3f59913dd172","order_by":0,"name":"Mikaela Oliveira da Rosa","email":"","orcid":"","institution":"Universidade Franciscana – UFN","correspondingAuthor":false,"prefix":"","firstName":"Mikaela","middleName":"Oliveira da","lastName":"Rosa","suffix":""},{"id":473074328,"identity":"a4132bd7-e669-4478-9d77-e35d1cb78e9c","order_by":1,"name":"Eduarda de Oliveira Pinto","email":"","orcid":"","institution":"Universidade Franciscana – 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20:53:04","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6614954/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6614954/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":84984274,"identity":"e79f64d9-1aa3-42d6-b82d-9fe9c0af0ae8","added_by":"auto","created_at":"2025-06-19 14:05:37","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":28504,"visible":true,"origin":"","legend":"\u003cp\u003ePhotodynamic inactivation of planktonic cells of \u003cem\u003eC. auris\u003c/em\u003e by visible light and AE (10µM).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6614954/v1/fd3c350170f47fbc6b6505fb.png"},{"id":84984286,"identity":"b061e54c-7740-4ba8-8144-5e816360a492","added_by":"auto","created_at":"2025-06-19 14:05:38","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":76584,"visible":true,"origin":"","legend":"\u003cp\u003eInhibition and eradication activities of \u003cem\u003eC. auris\u003c/em\u003e biofilm by AE exposed to visible light.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6614954/v1/04be41eb80e7e909a8e3fb39.png"},{"id":88377022,"identity":"9cf0576a-a870-41f8-b852-5a852d229135","added_by":"auto","created_at":"2025-08-05 21:46:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":470980,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6614954/v1/81d3e359-5851-4ca4-9c0f-30335d9fc9cf.pdf"},{"id":84984282,"identity":"cbdbd9cd-b5f2-4c9d-849c-3690e952fc4b","added_by":"auto","created_at":"2025-06-19 14:05:38","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":4581275,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-6614954/v1/1670b8cd085700d95877cff1.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eInactivation of Planktonic Cells and Sessile Biofilm of Candida Auris by Aloe Emodin-mediated Antimicrobial Photodynamic Therapy\u003c/p\u003e","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eThe escalating global threat of antimicrobial resistance necessitates innovative therapeutic strategies [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The limited effective antifungal drugs and rising resistance contribute to high mortality rates from fungal infections, particularly those caused by \u003cem\u003eCandida\u003c/em\u003e ssp. [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. \u003cem\u003eC. auris\u003c/em\u003e, an emerging multidrug-resistant fungal pathogen [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], poses a significant health risk with high mortality in systemic infections [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] and exhibits resistance to multiple antifungal classes [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], alongside virulence factors like biofilm formation [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Antimicrobial photodynamic therapy (aPDT) presents a promising alternative due to its non-invasiveness and lack of resistance induction [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], utilizing photosensitizers (PS) activated by light to generate reactive oxygen species [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Natural polyphenolic compounds, such as \u003cem\u003eAloe emodin\u003c/em\u003e (AE), a natural anthraquinone derivative with various pharmacological properties [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], are being explored as PS in aPDT [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. This study aimed to evaluate the efficacy of AE-mediated antimicrobial photodynamic therapy (aPDT) for inactivating both planktonic cells and biofilms of the multidrug-resistant fungal pathogen \u003cem\u003eC. auris\u003c/em\u003e.\u003c/p\u003e"},{"header":"METHODOLOGY","content":"\u003cp\u003eThe study primarily investigated the AE-antimicrobial in vitro activity and aPDT against the multidrug-resistant fungal pathogen \u003cem\u003eC. auris\u003c/em\u003e (CDC B11903). Additionally, the antimicrobial activity of AE was analyzed against other multidrug-resistant bacterial pathogens (\u003cem\u003eStaphylococcus aureus\u003c/em\u003e NTCC 12493, \u003cem\u003eS. aureus\u003c/em\u003e ATCC 25923, \u003cem\u003eEscherichia coli\u003c/em\u003e ATCC 13486 and E. coli ATCC 25922). aPDT for \u003cem\u003eC. auris\u003c/em\u003e involved a 1 \u0026times; 10⁷ CFU mL⁻\u0026sup1; suspension incubated with 10 \u0026micro;M of AE for 30 min in the dark, followed by irradiation with 400\u0026ndash;780 nm light (25 mW cm⁻\u0026sup2;, 96 J cm⁻\u0026sup2;) for 15 min, with colony counts on PCA plates [11]. \u003cem\u003eC. auris\u003c/em\u003e biofilm inhibition was assessed using a 24-hour culture in 96-well plates with AE serial dilutions (1000\u0026thinsp;\u0026minus;\u0026thinsp;0.01 \u0026micro;M), quantified by crystal violet staining. \u003cem\u003eC. auris\u003c/em\u003e biofilm eradication involved forming a 48-hour biofilm, followed by AE treatment (1000\u0026thinsp;\u0026minus;\u0026thinsp;0.01 \u0026micro;M) for 16\u0026ndash;20 hours and crystal violet quantification [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Statistical analysis employed two-way ANOVA with Tukey's post hoc test.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eAE alone exhibited no antimicrobial activity against tested strains. However, AE-mediated aPDT with visible light (10 \u0026micro;M, 15 min) achieved 100% eradication of planktonic \u003cem\u003eC. auris\u003c/em\u003e cells, significantly greater than the dark control (30% reduction) (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eThis highlights the necessity of light activation for AE\u0026apos;s antifungal action, contrasting with some reports of AE\u0026apos;s direct antibacterial effects [\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e]. Our findings align with previous studies demonstrating aPDT\u0026apos;s efficacy against \u003cem\u003eCandida\u003c/em\u003e species [\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e], likely due to the generation of reactive oxygen species and multi-target action, limiting resistance development [\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e]. AE also significantly inhibited \u003cem\u003eC. auris\u003c/em\u003e biofilm formation from 1 \u0026micro;M concentration under light, being concentration-dependent (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eA), consistent with aPDT\u0026apos;s potential against fungal biofilms [\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e]. However, AE-aPDT was less effective against established biofilms (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eB), suggesting a greater impact on biofilm development than on mature structures. This underscores the potential of AE-aPDT as a promising strategy against planktonic \u003cem\u003eC. auris\u003c/em\u003e and for preventing biofilm formation [\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study underscores the significant potential of visible light-activated AE-mediated aPDT for inhibiting \u003cem\u003eCandida auris\u003c/em\u003e biofilm formation and eradicating planktonic cells, emphasizing the critical role of light as an environmental factor in disinfection efficacy. AE demonstrates promise as a photosensitizer for aPDT against this resistant fungus, offering a potential strategy for environmental decontamination in healthcare settings and patient decolonization. The rapid and complete elimination of viable \u003cem\u003eC. auris\u003c/em\u003e colonies suggests new avenues for treating fungal infections and developing hospital disinfection protocols.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch5\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/h5\u003e\n\u003cp\u003e\u003cstrong\u003eM.O.R:\u0026nbsp;\u003c/strong\u003edata curation\u003cstrong\u003e,\u003c/strong\u003e investigation, methodology and Writing \u0026ndash; original draft; \u003cstrong\u003eE.O.P.:\u003c/strong\u003e Investigation, Methodology;\u003cstrong\u003e\u0026nbsp;L.H.F:\u0026nbsp;\u003c/strong\u003eInvestigation, Methodology; \u003cstrong\u003eC.T.M:\u0026nbsp;\u003c/strong\u003esoftware; \u003cstrong\u003eW.L.S:\u0026nbsp;\u003c/strong\u003emethodology; \u003cstrong\u003eB.S.V:\u0026nbsp;\u003c/strong\u003eproject administration, supervision, Writing \u0026ndash; review and editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by FAPERGS (Foundation for the Supporting of Research in the State of Rio Grande do Sul) under Grant Number 23/2551-0000776-2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors disclose any financial, business, and/or personal relationships with other people or organizations that could inappropriately influence (bias) the submitted work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of generative AI and AI-assisted technologies in the writing process\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDuring the preparation of this work, the author(s) used Chat GPT-4o mini with the aim of improving the writing to give it a more objective and scientific format. After using this tool/service, the author(s) have reviewed and edited the content as necessary and take full responsibility for the content of the published article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBerman D, Chandy SJ, Cansdell O, Moodley K, Veeraraghavan B, Essack SY. Global access to existing and future antimicrobials and diagnostics: antimicrobial subscription and pooled procurement. Lancet Glob Health (2022) 10:e293\u0026ndash;7. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s2214-109x(21)00463-0\u003c/span\u003e\u003cspan address=\"10.1016/s2214-109x(21)00463-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi M, Zhao JP. Research progress on deep fungal drug resistance mechanisms and detection methods. 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Journal of Fungi, v. 10, n. 6, p. 408, 2024. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/jof10060408\u003c/span\u003e\u003cspan address=\"10.3390/jof10060408\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBAPAT, Priyanka S.; NOBILE, Clarissa J. Photodynamic therapy is effective against Candida auris biofilms. Frontiers in cellular and infection microbiology, v. 11, p. 713092, 2021. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003edoi.org/10.3389/fcimb.2021.713092\u003c/span\u003e\u003cspan address=\"10.3389/fcimb.2021.713092\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Reactive oxygen species, Disinfection, Antimicrobial resistance, aloe vera, visible light","lastPublishedDoi":"10.21203/rs.3.rs-6614954/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6614954/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study explored the in vitro potential of Aloe emodin (AE)-mediated antimicrobial photodynamic therapy (aPDT) against the emerging multidrug-resistant fungus \u003cem\u003eCandida auris\u003c/em\u003e. While AE alone showed no significant antifungal activity, its activation with visible light (400\u0026ndash;780 nm) at 10 \u0026micro;M resulted in a complete (100%) reduction of viable \u003cem\u003eC. auris\u003c/em\u003e colony counts after 15 minutes of exposure. Conversely, the dark control group exhibited only a 30% decrease. Furthermore, AE-aPDT demonstrated a notable capacity to inhibit the initial development of \u003cem\u003eC. auris\u003c/em\u003e biofilms. These findings highlight the potential of visible light-activated AE as an effective antimicrobial strategy against this resistant pathogen and its biofilms. The rapid and complete eradication of \u003cem\u003eC. auris\u003c/em\u003e under these conditions suggests a promising avenue for developing disinfection protocols and potential therapeutic interventions against this critical global health threat.\u003c/p\u003e","manuscriptTitle":"Inactivation of Planktonic Cells and Sessile Biofilm of Candida Auris by Aloe Emodin-mediated Antimicrobial Photodynamic Therapy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-19 14:05:33","doi":"10.21203/rs.3.rs-6614954/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8c6cb198-4cb9-40e8-90eb-89055a85110e","owner":[],"postedDate":"June 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-05T21:38:15+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-19 14:05:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6614954","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6614954","identity":"rs-6614954","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}