Zapotoczna Marta, Boksmati Nabila, Donohue Sinead, Bahtiar Baizurina, Boland Ahmad, Somali Hamzah Al, Cox Alysia, Humphreys Hilary, O'Gara James P, Brennan Marian, O'Neill Eoghan
Department of Clinical Microbiology, Education and Research Centre, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin, Ireland.
Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland.
J Med Microbiol. 2017 Mar;66(3):377-387. doi: 10.1099/jmm.0.000446. Epub 2017 Mar 23.
The treatment of device-related infections is challenging and current anti-microbial compounds have poor anti-biofilm activity. We aimed to identify and characterize novel compounds effective in the eradication of Staphylococcus aureus biofilms.
Two novel compounds, MMV665953 {1-(3-chloro-4-fluorophenyl)-3-(3,4-dichlorophenyl)urea} and MMV665807{5-chloro-2-hydroxy-N-[3-(trifluoromethyl)phenyl]benzamide}, effective in killing S. aureus biofilms, were identified by screening of the open access 'malaria box' chemical library. The minimum bactericidal concentrations, half-maximal inhibition concentration (IC50) values and minimal biofilm killing concentrations effective in the killing of biofilm were determined against meticillin-resistant S. aureus and meticillin-sensitive S. aureus. Fibrin-embedded biofilms were grown under in vivo-relevant conditions, and viability was measured using a resazurin-conversion assay and confocal microscopy. The potential for the development of resistance and cytotoxicity was also assessed.
MMV665953 and MMV665807 were bactericidal against S. aureus isolates. The IC50 against S. aureus biofilms was at 0.15-0.58 mg l-1 after 24 h treatment, whereas the concentration required to eradicate all tested biofilms was 4 mg l-1, making the compounds more bactericidal than conventional antibiotics. The cytotoxicity against human keratinocytes and primary endothelial cells was determined as IC50 7.47 and 0.18 mg l-1 for MMV665953, and as 1.895 and 0.076 mg l-1 for MMV665807. Neither compound was haemolytic nor caused platelet activation. MMV665953 and MMV665807 derivatives with reduced cytotoxicity exhibited a concomitant loss in anti-staphylococcal activity.
MMV665953 and MMV665807 are more bactericidal against S. aureus biofilms than currently used anti-staphylococcal antibiotics and represent a valuable structural basis for further investigation in the treatment of staphylococcal biofilm-related infections.
治疗与装置相关的感染具有挑战性，目前的抗菌化合物抗生物膜活性较差。我们旨在鉴定和表征能有效根除金黄色葡萄球菌生物膜的新型化合物。
通过筛选开放获取的“疟疾盒”化学文库，鉴定出两种对金黄色葡萄球菌生物膜有杀灭作用的新型化合物，即MMV665953{1-(3-氯-4-氟苯基)-3-(3,4-二氯苯基)脲}和MMV665807{5-氯-2-羟基-N-[3-(三氟甲基)苯基]苯甲酰胺}。针对耐甲氧西林金黄色葡萄球菌和甲氧西林敏感金黄色葡萄球菌，测定了其最低杀菌浓度、半数最大抑制浓度（IC50）值以及对生物膜有效杀灭的最低生物膜杀灭浓度。在体内相关条件下培养纤维蛋白包埋的生物膜，并使用刃天青转化试验和共聚焦显微镜测量其活力。还评估了耐药性和细胞毒性的发展潜力。
MMV665953和MMV665807对金黄色葡萄球菌分离株具有杀菌作用。处理24小时后，对金黄色葡萄球菌生物膜的IC50为0.15 - 0.58 mg l-1，而根除所有测试生物膜所需的浓度为4 mg l-1，这使得这些化合物比传统抗生素更具杀菌性。MMV665953对人角质形成细胞和原代内皮细胞的细胞毒性测定为IC50分别为7.47和0.18 mg l-1，MMV665807分别为1.895和0.076 mg l-1。两种化合物均无溶血作用，也不引起血小板活化。细胞毒性降低的MMV665953和MMV665807衍生物的抗葡萄球菌活性也随之丧失。
与目前使用的抗葡萄球菌抗生素相比，MMV665953和MMV665807对金黄色葡萄球菌生物膜具有更强的杀菌作用，为进一步研究治疗葡萄球菌生物膜相关感染提供了有价值的结构基础。
