The emergence of multi-drug-resistant Gram-negative pathogens highlights an urgent clinical need to explore and develop new antibiotics with novel antibacterial targets. MreB is a promising antibacterial target that functions as an essential elongasome protein in most Gram-negative bacterial rods. Here, we describe a third-generation MreB inhibitor (TXH11106) with enhanced bactericidal activity versus the Gram-negative pathogens Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa compared to the first- and second-generation compounds A22 and CBR-4830, respectively. Large inocula of these four pathogens are associated with a low frequency of resistance (FOR) to TXH11106. The enhanced bactericidal activity of TXH11106 relative to A22 and CBR-4830 correlates with a correspondingly enhanced capacity to inhibit E. coli MreB ATPase activity via a noncompetitive mechanism. Morphological changes induced by TXH11106 in E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa provide further evidence supporting MreB as the bactericidal target of the compound. Taken together, our results highlight the potential of TXH11106 as an MreB inhibitor with activity against a broad spectrum of Gram-negative bacterial pathogens of acute clinical importance.
多重耐药革兰氏阴性病原体的出现突显了探索和开发具有新型抗菌靶点的新型抗生素的紧迫临床需求。MreB是一种有前途的抗菌靶点,在大多数革兰氏阴性细菌杆中作为必需的延长体蛋白发挥作用。在这里,我们描述了一种第三代MreB抑制剂(TXH11106),与第一代和第二代化合物A22和CBR-4830相比,对革兰氏阴性病原体大肠杆菌、肺炎克雷伯菌、鲍曼不动杆菌和铜绿假单胞菌具有更强的杀菌活性。这四种病原体的大接种量与TXH11106的低耐药率(FOR)相关。TXH11106相对于A22和CBR-4830的增强杀菌活性与通过非竞争机制抑制大肠杆菌MreB ATP酶活性的能力相对应。TXH11106在大肠杆菌、肺炎克雷伯菌、鲍曼不动杆菌和铜绿假单胞菌中引起的形态学变化进一步支持MreB作为化合物的杀菌靶点。综上所述,我们的结果突显了TXH11106作为MreB抑制剂,对急性临床重要性的广谱革兰氏阴性细菌病原体具有活性的潜力。