Laboratory of Immunology and Molecular Biology, Health Sciences Institute, Universidade Federal da Bahia, Salvador, Bahia State 40110-100, Brazil.
Bioinorganic and Porphyrinoid Materials Laboratory, Department of Chemistry, Universidade Federal de Santa Maria, Rio Grande do Sul State, Santa Maria 97105-900, Brazil.
Photodiagnosis Photodyn Ther. 2023 Jun;42:103343. doi: 10.1016/j.pdpdt.2023.103343. Epub 2023 Feb 18.
Candida spp. is the main fungal genus related to infections in humans, and its treatment has become a challenge due to the production of biofilm and its resistance/multi-resistance profile to conventional antifungals. Antimicrobial photodynamic therapy stands out as a treatment characterized by a broad spectrum of antimicrobial action, being able to induce oxidative stress in pathogens, and porphyrins are photosensitizers with high selectivity to pathogens. Thus, this work aimed to analyze the photoinactivation of different species of Candida by two cationic (4-HTMeP and 3-HTMeP) and one anionic (4-HTPSP) porphyrins.
Microdilution assays were performed to determine the MIC, with subsequent determination of MFC. Determination of oxidative species was done through the use of scavengers, while biofilm morphological features were investigated using the atomic force microscopy.
Cationic porphyrins were significantly efficient in inactivating Candida albicans and non-albicans species with 100% growth inhibition and fungicidal activity (MFC/MIC ≤ 4.0). The cationic porphyrins were also able to interfere in Candida spp biofilm formation. The photo-oxidative mechanism activated by 3-HTMeP in Candida spp. is concurrent with the production of singlet oxygen and oxygen radical species. In the AFM analysis, 3-HTMeP was able to reduce yeast adhesion to the surface.
Cationic porphyrins can photo-inactivate different species of Candida in both planktonic and biofilm-associated forms, and reduce the adhesion of these fungi to the surface.
念珠菌属是与人类感染相关的主要真菌属，由于生物膜的产生及其对常规抗真菌药物的耐药性/多重耐药性，其治疗已成为一个挑战。光动力抗菌疗法作为一种具有广谱抗菌作用的治疗方法脱颖而出，能够诱导病原体产生氧化应激，而卟啉是对病原体具有高选择性的光敏剂。因此，本研究旨在分析两种阳离子（4-HTMeP 和 3-HTMeP）和一种阴离子（4-HTPSP）卟啉对不同念珠菌物种的光灭活作用。
进行微量稀释试验以确定 MIC，随后确定 MFC。通过使用清除剂来确定氧化物种，而使用原子力显微镜来研究生物膜形态特征。
阳离子卟啉对白色念珠菌和非白色念珠菌物种具有 100%的生长抑制和杀菌活性（MFC/MIC ≤ 4.0），因此非常有效。阳离子卟啉还能够干扰念珠菌属生物膜的形成。3-HTMeP 在念珠菌属中激活的光氧化机制与单线态氧和氧自由基的产生同时发生。在 AFM 分析中，3-HTMeP 能够减少酵母对表面的黏附。
阳离子卟啉可以光灭活浮游和生物膜相关形式的不同念珠菌物种，并减少这些真菌对表面的黏附。
