Gilbert P, Pemberton D, Wilkinson D E
Department of Pharmacy, University of Manchester, UK.
J Appl Bacteriol. 1990 Oct;69(4):585-92. doi: 10.1111/j.1365-2672.1990.tb01552.x.
The antimicrobial activities of four discrete molecular weight fractions of polyhexamethylene biguanides towards a number of Escherichia coli strains have been investigated. Whilst activity of the polymers was observed to increase in proportion to polymerization number, the dependence of activity upon molecular weight was five times greater towards sphaeroplasts than towards whole cells. This suggested that the cell envelope, whilst not conferring complete resistance to the agents, did provide a significant exclusion barrier. Comparison of the activities towards rough and deep-rough lipopolysaccharide strains showed growth inhibitory activity, but not bactericidal activity nor respiratory inhibition, to be enhanced in the rough strains. Uptake studies showed mixed H- and C-type adsorption with significantly greater numbers of high-affinity binding sites being associated with rough than deep-rough lipopolysaccharide. The binding affinity of polyhexamethylene biguanides towards cells was also enhanced in the rough strains. Binding affinity was, in all cases, significantly reduced in the presence of magnesium and suggested a mechanism of self-promoted uptake for these biocides, facilitated through core lipopolysaccharide.
已对聚六亚甲基双胍的四个离散分子量级分对多种大肠杆菌菌株的抗菌活性进行了研究。虽然观察到聚合物的活性与聚合数成比例增加，但对原生质球的活性对分子量的依赖性比对全细胞的依赖性大五倍。这表明细胞膜虽然不能赋予对这些药剂的完全抗性，但确实提供了一个重要的排斥屏障。对粗糙型和深粗糙型脂多糖菌株活性的比较表明，粗糙型菌株的生长抑制活性增强，但无杀菌活性和呼吸抑制作用。摄取研究表明，H型和C型吸附混合，与粗糙型脂多糖相比，深粗糙型脂多糖具有显著更多的高亲和力结合位点。聚六亚甲基双胍对粗糙型菌株细胞的结合亲和力也有所增强。在所有情况下，镁的存在都会显著降低结合亲和力，这表明这些杀菌剂通过核心脂多糖促进了自我促进摄取的机制。
