Yi Kaifang, Liu Shuobo, Liu Peiyi, Luo Xingwei, Zhao Jinfeng, Yan Fengbin, Pan Yushan, Liu Jianhua, Zhai Yajun, Hu Gongzheng
College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
Biomed Pharmacother. 2022 May;149:112873. doi: 10.1016/j.biopha.2022.112873. Epub 2022 Mar 26.
It has been recognized that colistin resistance is a growing problem that seriously impairs the clinical efficacy of colistin against bacterial infections. One strategy that has been proven to have therapeutic effect is to overcome the widespread emergence of antibiotic-resistant pathogens by combining existing antibiotics with promising non-antibiotic agents. In this work, antibiotic susceptibility testing, checkerboard assays and time-kill curves were used to investigate the antibacterial activity of the individual drugs and the potential synergistic activity of the combination. The molecular mechanisms of tetrandrine in combination with colistin were analyzed using fluorometric assay and Real-time PCR. To predict possible interactions between tetrandrine and MCR-1, molecular docking assay was taken. Finally, we evaluated the in vivo efficacy of tetrandrine in combination with colistin against MCR-positive Salmonella. Overall, the combination of tetrandrine and colistin showed significant synergistic activity. In-depth mechanistic analysis showed that the combination of tetrandrine with colistin enhances the membrane-damaging ability of colistin, undermines the functions of proton motive force (PMF) and efflux pumps in MCR-positive bacteria. The results of molecular docking and RT-PCR analyses showed that tetrandrine not only affects the expression of mcr-1 but is also an effective MCR-1 inhibitor. Compared with colistin monotherapy, the combination of tetrandrine with colistin significantly reduced the bacterial load in vivo. Our findings demonstrated that tetrandrine serves as a potential colistin adjuvant against MCR-positive Salmonella.
人们已经认识到，黏菌素耐药性是一个日益严重的问题，严重损害了黏菌素对细菌感染的临床疗效。一种已被证明具有治疗效果的策略是将现有抗生素与有前景的非抗生素药物联合使用，以克服抗生素耐药病原体的广泛出现。在这项研究中，使用抗生素敏感性测试、棋盘法和时间杀菌曲线来研究单一药物的抗菌活性以及联合用药的潜在协同活性。使用荧光测定法和实时聚合酶链反应分析了粉防己碱与黏菌素联合使用的分子机制。为了预测粉防己碱与MCR-1之间可能的相互作用，进行了分子对接试验。最后，我们评估了粉防己碱与黏菌素联合使用对MCR阳性沙门氏菌的体内疗效。总体而言，粉防己碱与黏菌素的联合使用显示出显著的协同活性。深入的机制分析表明，粉防己碱与黏菌素的联合使用增强了黏菌素的膜损伤能力，破坏了MCR阳性细菌中质子动力势（PMF）和外排泵的功能。分子对接和逆转录聚合酶链反应分析结果表明，粉防己碱不仅影响mcr-1的表达，而且是一种有效的MCR-1抑制剂。与黏菌素单药治疗相比，粉防己碱与黏菌素联合使用显著降低了体内细菌载量。我们的研究结果表明，粉防己碱可作为一种潜在的黏菌素佐剂，用于对抗MCR阳性沙门氏菌。
