Abstract

In the last decade, Acinetobacter baumannii has emerged as a pathogen associated with infections in intensive care units worldwide, especially due to its ability to resist an extensive list of antibiotics. In this context, porphyrins have emerged as an important strategy in photodynamic therapy, since they are a group of tetrapyrrolic compounds with important photochemical and photobiological activities. In this study, the antimicrobial photodynamic activity of meso-tetra(4-N-methyl-pyridyl)porphyrin (H₂TMePyP⁺) and meso-tetra(4-sulfonatophenyl)porphyrin (H₂TPPS^‒) was evaluated against A. baumannii by minimum inhibitory concentration (MIC), anti-biofilm activity, and the interaction with antibiotics after exposure to white-light LED irradiation. The cationic derivative H₂TMePyP⁺ was more potent (MIC = 0.61 µM) than H₂TPPS^‒, with anti-biofilm activity and increased the antimicrobial activity of ciprofloxacin and amikacin. Given these findings, the tetra-cationic porphyrins can be assumed as prototypes to optimize and develop new agents by promoting oxidative stress and inducing free radical production.

摘要

在过去十年中，鲍曼不动杆菌已成为与全球重症监护病房感染相关的病原体，尤其是由于其能够抵抗大量抗生素。在这种情况下，卟啉已成为光动力治疗的重要策略，因为它们是一组具有重要光化学和光生物学活性的四吡咯化合物。在本研究中，对内消旋四(4 -N-甲基-吡啶基)卟啉 ( H ₂ TMePyP ⁺ ) 和内消旋四(4-磺基苯基)卟啉 ( H ₂ TPPS ^- ) 的抗菌光动力活性进行了评估。A. baumannii的最小抑制浓度 (MIC)、抗生物膜活性以及暴露于白光 LED 照射后与抗生素的相互作用。阳离子衍生物H ₂ TMePyP ⁺比H ₂ TPPS ^-更有效（MIC = 0.61 µM） ，具有抗生物膜活性并增加了环丙沙星和阿米卡星的抗菌活性。鉴于这些发现，四阳离子卟啉可以被认为是通过促进氧化应激和诱导自由基产生来优化和开发新试剂的原型。