Abstract：
Multidrug-resistant (MDR) organisms have been frequently isolated from integumentary lesions of animals, and these lesions are usually infected by more than one pathogen. This study evaluated an in vitro antimicrobial photodynamic therapy (aPDT) using two water-soluble tetra-cationic porphyrins (3-H2TMeP and 4-H2TMeP) against mono and polyculture of MDR bacteria isolated from dogs, cats, and horses. Ten isolates of MDR bacteria (two of each species: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus pseudointermedius) were used to evaluate aPDT against the monoculture using a non-cytotoxic concentration of 3-H2TMeP and 4-H2TMeP porphyrins (40 µM), with 30 min of light irradiation in Gram-positive and 90 min for Gram-negative bacteria. The aPDT using the 4-H2TMeP porphyrin was also tested against five different polycultures (Coagulase positive Staphylococcus (CPS) and Pseudomonas sp.; E. coli and Proteus sp.; Pseudomonas sp. and Proteus sp.; CPS and E. coli; and CPS and Proteus sp.) for 90 min. The efficacy of both treatments was evaluated by plating the solution exposed to light or kept in the dark and counting the colonies forming units after 24 h of incubation at 37 °C. Atomic force microscope analysis was used to map bacteria morphological changes and extract adhesion force parameters from the bacteria membranes. Only the 4-H2TMeP porphyrin had antibacterial activity against MDR bacteria in monoculture, especially S. pseudointermedius and P. aeruginosa. In polyculture, the 4-H2TMeP porphyrin reduced bacterial concentrations (p < 0.05) in the associations of E. coli and S. pseudointermedius, P. aeruginosa and S. pseudointermedius, and P. aeruginosa and P. mirabilis. These results showed that aPDT using 4-H2TMeP is a good option for future associations of aPDT and other therapies or in vivo research.
摘要：
多药耐药（MDR）生物经常从动物的表皮病变中分离出来，这些病变通常被一种以上的病原体感染。这项研究评估了使用两种水溶性四阳离子卟啉（3-H2TMeP和4-H2TMeP）对从狗中分离的MDR细菌的单一和多培养的体外抗菌光动力疗法（aPDT），猫,和马。十种MDR细菌分离物（每种物种中的两种：大肠杆菌，肺炎克雷伯菌,铜绿假单胞菌,粘质沙雷菌,使用非细胞毒性浓度的3-H2TMeP和4-H2TMeP卟啉（40µM），革兰氏阳性菌光辐射30分钟，革兰氏阴性菌光辐射90分钟。还针对五种不同的多培养物（凝固酶阳性葡萄球菌（CPS）和假单胞菌。大肠杆菌和变形杆菌。；假单胞菌。和Proteussp.；CPS和大肠杆菌；以及CPS和变形杆菌。)90分钟。通过将暴露于光或保持在黑暗中的溶液铺板并在37°C下孵育24小时后计数菌落形成单位来评估两种处理的功效。原子力显微镜分析用于绘制细菌形态变化图并从细菌膜中提取粘附力参数。只有4-H2TMeP卟啉在单一培养中对MDR细菌具有抗菌活性，尤其是假中间链球菌和铜绿假单胞菌。在多元文化中，4-H2TMeP卟啉降低了大肠杆菌和假中间链球菌的细菌浓度（p<0.05），铜绿假单胞菌和假中间假单胞菌，还有铜绿假单胞菌和奇异假单胞菌.这些结果表明，使用4-H2TMeP的aPDT是未来aPDT和其他疗法或体内研究的良好选择。
