Miró-Canturri Andrea, Ayerbe-Algaba Rafael, Villodres Ángel Rodríguez, Pachón Jerónimo, Smani Younes
Clinical Unit of Infectious Diseases, Microbiology and Preventive Medicine, University Hospital Virgen del Rocío, Seville, Spain.
Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain.
J Antimicrob Chemother. 2020 Jul 1;75(7):1895-1905. doi: 10.1093/jac/dkaa103.
Repurposing drugs provides a new approach to the fight against MDR Gram-negative bacilli (MDR-GNB). Rafoxanide, a veterinary antihelminthic drug, has shown antibacterial activity in vitro against Gram-positive bacteria. We aimed to analyse the in vitro and in vivo efficacy of rafoxanide in combination with colistin against colistin-susceptible (Col-S) and colistin-resistant (Col-R) GNB.
A collection of Col-S and Col-R Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae were used. Chequerboard and time-kill curve analyses were performed to determine the synergy between rafoxanide and colistin. Changes in membrane structure and permeability were analysed using transmission electron microscopy and fluorescence assays. A murine peritoneal sepsis model using Col-R strains of these pathogens was performed to study the efficacy of rafoxanide (10 mg/kg/24 h, IV), colistimethate sodium (CMS) (20 mg/kg/8 h, intraperitoneally) and rafoxanide (10 mg/kg/24 h, IV) plus CMS (20 mg/kg/8 h, intraperitoneally) for 72 h.
Rafoxanide showed MICs ≥256 mg/L for all Col-S and Col-R strains. Chequerboard and time-kill curve analyses showed that rafoxanide (1 mg/L) is more synergistic with colistin against Col-R than Col-S strains. Col-R, but not Col-S, strains treated with rafoxanide demonstrated higher membrane permeabilization. Transmission electron microscopy visualization confirmed that Col-R strains suffer morphological changes. In the murine peritoneal sepsis model with Col-R strains, rafoxanide plus CMS, compared with CMS alone, increased mouse survival to 53.8% and 73.3%, and reduced bacterial loads in tissues and blood between 2.34 and 4.99 log10 cfu/g or mL, respectively.
Rafoxanide repurposing, as monotherapy and in combination with CMS, may address the urgent need for new treatments for infections caused by MDR-GNB.
药物重新利用为对抗多重耐药革兰氏阴性杆菌（MDR - GNB）提供了一种新方法。雷复尼特是一种兽用抗蠕虫药，已在体外显示出对革兰氏阳性菌的抗菌活性。我们旨在分析雷复尼特与黏菌素联合使用对黏菌素敏感（Col - S）和黏菌素耐药（Col - R）革兰氏阴性杆菌的体外和体内疗效。
使用了一组Col - S和Col - R的鲍曼不动杆菌、铜绿假单胞菌和肺炎克雷伯菌。进行棋盘法和时间杀菌曲线分析以确定雷复尼特与黏菌素之间的协同作用。使用透射电子显微镜和荧光测定法分析膜结构和通透性的变化。使用这些病原体的Col - R菌株建立小鼠腹腔败血症模型，以研究雷复尼特（10 mg/kg/24 h，静脉注射）、黏菌素甲磺酸钠（CMS）（20 mg/kg/8 h，腹腔注射）以及雷复尼特（10 mg/kg/24 h，静脉注射）加CMS（20 mg/kg/8 h，腹腔注射）治疗72小时的疗效。
雷复尼特对所有Col - S和Col - R菌株的MIC均≥256 mg/L。棋盘法和时间杀菌曲线分析表明，雷复尼特（1 mg/L）与黏菌素联合使用时，对Col - R菌株的协同作用比对Col - S菌株更强。用雷复尼特处理的Col - R菌株（而非Col - S菌株）表现出更高的膜通透性。透射电子显微镜观察证实Col - R菌株发生了形态变化。在使用Col - R菌株的小鼠腹腔败血症模型中，与单独使用CMS相比，雷复尼特加CMS可使小鼠存活率提高到53.8%和73.3%，并使组织和血液中的细菌载量分别降低2.34至4.99 log10 cfu/g或mL。
雷复尼特重新利用，无论是单一疗法还是与CMS联合使用，都可能满足对抗MDR - GNB引起的感染的新治疗方法的迫切需求。
