Agafonova Mariya N, Kazakova Renata R, Lubina Anna P, Zeldi Marina I, Nikitina Elena V, Balakin Konstantin V, Shtyrlin Yurii G
Scientific and Educational Center of Pharmaceutics, Kazan (Volga Region) Federal University, Russia.
Scientific and Educational Center of Pharmaceutics, Kazan (Volga Region) Federal University, Russia; I.M. Sechenov First Moscow State Medical University (Sechenov University), Russia.
Microb Pathog. 2020 May;142:104072. doi: 10.1016/j.micpath.2020.104072. Epub 2020 Feb 14.
Miramistin is a widely used antiseptic, disinfectant and preservative, and one of the most popular antimicrobial agents on pharmaceutical market of the Russian Federation (http://www.dsm.ru/en/news/385/). However, there is a lack of reported systematic data on antibacterial efficacy of this agent obtained in accordance with the international standards.
This paper represents a systematic study of antibacterial properties of miramistin. Another objective of this work is to evaluate and compare the exploratory performance of in vitro and in vivo protocols of antiseptics' efficacy testing using miramistin as the reference antiseptic.
Antibacterial activity of 0.1% and 0.2% aqueous solutions of miramistin against two museum strains of S. aureus (ATCC 209p) and E. coli (CDC F-50) was studied. Three standard in vitro laboratory tests (microdilution test, suspension test, and metal surface test), and one in vivo test (on rat's skin) were used. The study was conducted in accordance with the international regulatory documents.
Miramistin showed high bactericidal activity against the studied bacterial pathogens in the standard in vitro tests. Thus, in the microdilution test it showed expressed activity against S. aureus (MIC 8 μg/ml, MBC 16 μg/ml) and E. coli (MIC 32 μg/ml, MBC 128 μg/ml). In the suspension test, miramistin decreased the amount of colony forming units by at least 6 log10 units for S. aureus, and by at least 4.5 log10 units for E. coli. Transition to the metal surface test led to significant decrease of antibacterial activity by 1-3 log10 units as compared to the suspension test. Further dramatic reduction of antiseptic activity (by 3-4 log10 units) was observed in in vivo rat skin test. Addition of a protein contaminant (bovine serum albumin) led to a general decrease in the effectiveness of miramistin against the test pathogens (typically, by 1-2 log10 units). An interesting effect of exposure time-dependent reversal of miramistin's specificity to the studied Gram-positive S. aureus and the Gram-negative E. coli organisms was observed in the metal surface test.
The results of this work provide systematic data on antibacterial efficacy of miramistin. They also underscore the need in relevant in vivo models for evaluation of antiseptics' efficacy. While the existing in vitro methods can be successfully applied at the discovery stages, it is necessary to use more realistic in vivo models at more advanced development stages. The observed selectivity reversal effect should be taken into account when carrying out the antiseptics' efficacy testing and surface disinfection procedures.
咪拉米司汀是一种广泛使用的防腐剂、消毒剂和保鲜剂，是俄罗斯联邦药品市场上最受欢迎的抗菌剂之一（http://www.dsm.ru/en/news/385/）。然而，目前缺乏按照国际标准获得的关于该药剂抗菌效果的系统数据报道。
本文对咪拉米司汀的抗菌特性进行了系统研究。这项工作的另一个目标是评估和比较以咪拉米司汀作为参考防腐剂的体外和体内防腐剂功效测试方案的探索性能。
研究了0.1%和0.2%咪拉米司汀水溶液对两种金黄色葡萄球菌（ATCC 209p）和大肠杆菌（CDC F - 50）标准菌株的抗菌活性。使用了三种标准体外实验室测试（微量稀释试验、悬液试验和金属表面试验）以及一种体内试验（在大鼠皮肤上）。该研究是按照国际监管文件进行的。
在标准体外试验中，咪拉米司汀对所研究的细菌病原体显示出高杀菌活性。因此，在微量稀释试验中，它对金黄色葡萄球菌（MIC 8μg/ml，MBC 16μg/ml）和大肠杆菌（MIC 32μg/ml，MBC 128μg/ml）表现出明显活性。在悬液试验中，咪拉米司汀使金黄色葡萄球菌的菌落形成单位数量至少减少6个对数单位，使大肠杆菌的菌落形成单位数量至少减少4.5个对数单位。与悬液试验相比，过渡到金属表面试验导致抗菌活性显著降低1 - 3个对数单位。在体内大鼠皮肤试验中观察到防腐剂活性进一步大幅降低（3 - 4个对数单位）。添加蛋白质污染物（牛血清白蛋白）导致咪拉米司汀对测试病原体的有效性普遍降低（通常降低1 - 2个对数单位）。在金属表面试验中观察到了咪拉米司汀对所研究的革兰氏阳性金黄色葡萄球菌和革兰氏阴性大肠杆菌生物体的特异性随暴露时间依赖性逆转的有趣效应。
这项工作的结果提供了关于咪拉米司汀抗菌效果的系统数据。它们还强调了在评估防腐剂功效时需要相关的体内模型。虽然现有的体外方法可以在发现阶段成功应用，但在更高级的开发阶段有必要使用更现实的体内模型。在进行防腐剂功效测试和表面消毒程序时应考虑到观察到的选择性逆转效应。
