背景:在开发中的非传统抗菌剂中,只有少数针对关键革兰氏阴性菌,如耐碳青霉烯类铜绿假单胞菌,鲍曼不动杆菌或头孢菌素耐药肠杆菌科。Endolysins及其转基因版本符合世界卫生组织的创新标准,有一种新的抗菌作用模式,没有已知的细菌交叉耐药性,并且正在深入研究针对革兰氏阴性病原体的应用。
方法:该研究提出了一种多学科方法,包括LysECD7-SMAP的基因工程和重组内溶素的生产,通过分子动力学模拟和抗菌性能评估,通过晶体结构溶液对其进行分析。配制了两种类型的抗菌剂型,导致冻干粉末注射和羟乙基纤维素凝胶局部给药。他们的疗效估计在治疗脓毒症,和BALB/c小鼠的肺炎模型,瘦素受体缺陷db/db小鼠的糖尿病相关伤口感染和大鼠感染的烧伤伤口。
结果:在这项工作中,我们研究了工程化内溶素LysECD7-SMAP的应用策略及其在临床前研究中评估的剂型.该酶的催化结构域共享内肽酶的保守结构,该内肽酶在多肽链的C末端含有推定的抗微生物肽。内溶素的活性已被证明对一系列病原体,比如肺炎克雷伯菌,A.鲍曼尼,铜绿假单胞菌,溶血葡萄球菌,无色杆菌属,洋葱伯克霍尔德菌和流感嗜血杆菌,包括那些具有多重耐药性的人。候选剂型的功效已在体内研究中得到证实。还讨论了LysECD7-SMAP与细胞壁分子靶标相互作用的一些方面。
结论:我们的研究表明,LysECD7-SMAP疗法可用于系统或局部治疗由易感革兰氏阴性菌引起的感染性疾病,并且对于进行基于LysECD7-SMAP的抗微生物药物试验至晚期至关重要。
BACKGROUND: Among the non-traditional antibacterial agents in development, only a few targets critical Gram-negative bacteria such as carbapenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii or cephalosporin-resistant Enterobacteriaceae. Endolysins and their genetically modified versions meet the World Health Organization criteria for innovation, have a novel mode of antibacterial action, no known bacterial cross-resistance, and are being intensively studied for application against Gram-negative pathogens.
METHODS: The study presents a multidisciplinary approach, including genetic engineering of LysECD7-SMAP and production of recombinant endolysin, its analysis by crystal structure solution following molecular dynamics simulations and evaluation of antibacterial properties. Two types of antimicrobial dosage forms were formulated, resulting in lyophilized powder for injection and hydroxyethylcellulose gel for topical administration. Their efficacy was estimated in the treatment of sepsis, and pneumonia models in BALB/c mice, diabetes-associated wound infection in the leptin receptor-deficient db/db mice and infected burn wounds in rats.
RESULTS: In this work, we investigate the application strategies of the engineered endolysin LysECD7-SMAP and its dosage forms evaluated in preclinical studies. The catalytic domain of the enzyme shares the conserved structure of endopeptidases containing a putative antimicrobial peptide at the C-terminus of polypeptide chain. The activity of endolysins has been demonstrated against a range of pathogens, such as Klebsiella pneumoniae, A. baumannii, P. aeruginosa, Staphylococcus haemolyticus, Achromobacter spp, Burkholderia cepacia complex and Haemophylus influenzae, including those with multidrug resistance. The efficacy of candidate dosage forms has been confirmed in in vivo studies. Some aspects of the interaction of LysECD7-SMAP with cell wall molecular targets are also discussed.
CONCLUSIONS: Our studies demonstrate the potential of LysECD7-SMAP therapeutics for the systemic or topical treatment of infectious diseases caused by susceptible Gram-negative bacterial species and are critical to proceed LysECD7-SMAP-based antimicrobials trials to advanced stages.