Vaara M, Vaara T
Nature. 1983;303(5917):526-8. doi: 10.1038/303526a0.
A major virulence factor of bacteria that cause generalized infections is their resistance to the lytic action of the complement cascade, an important defence mechanism of the host. Invasive Gram-negative enteric bacteria, which cause about one-third of all bacteraemic infections, are completely resistant to lysis by complement, even in the presence of hyperimmune serum. The same bacteria are also resistant to many antibiotics that are effective therapeutic agents against other bacteria, as the outermost surface layer (the outer membrane) of the bacteria functions as a permeability barrier. Here we show that it is possible to sensitize such bacteria to both complement and antibiotics by using an agent that binds to the outer membrane. This agent is a nontoxic derivative of polymyxin which by itself has no bactericidal action.
引起全身性感染的细菌的一个主要毒力因子是它们对补体级联反应的溶解作用具有抗性，而补体级联反应是宿主的一种重要防御机制。引起约三分之一菌血症感染的侵袭性革兰氏阴性肠道细菌对补体介导的溶解完全具有抗性，即使在存在超免疫血清的情况下也是如此。这些细菌还对许多对其他细菌有效的治疗性抗生素具有抗性，因为细菌的最外层（外膜）起着渗透屏障的作用。在这里，我们表明，通过使用一种与外膜结合的试剂，可以使这类细菌对补体和抗生素都敏感。这种试剂是多粘菌素的无毒衍生物，其本身没有杀菌作用。
