Godfrey A J, Bryan L E
Antimicrob Agents Chemother. 1984 Oct;26(4):485-8. doi: 10.1128/AAC.26.4.485.
An isogenic set of mutants of Pseudomonas aeruginosa, altered in permeability or permeability plus constitutive production of beta-lactamase, was examined for susceptibility to newer beta-lactam antibiotics. Kinetic data on the chromosomal beta-lactamase and susceptibility studies for the test beta-lactams indicate that permeability was the major mechanism of resistance to the poorly hydrolyzed and nonhydrolyzed antibiotics, e.g., carbenicillin, moxalactam, and cefsulodin. An exception was cefotaxime, with a low Km and a low Vmax, which had reduced efficacy in the permeability mutant and was further affected by the constitutive beta-lactamase. In this case, since the Vmax was low, a nonhydrolytic barrier may provide the additional reduction in susceptibility.
对铜绿假单胞菌的一组同基因突变体进行了研究，这些突变体在通透性或通透性加β-内酰胺酶组成型产生方面发生了改变，以检测它们对新型β-内酰胺抗生素的敏感性。关于染色体β-内酰胺酶的动力学数据以及对测试β-内酰胺类药物的敏感性研究表明，通透性是对水解性差和非水解性抗生素（如羧苄西林、莫西沙星和头孢磺啶）耐药的主要机制。头孢噻肟是一个例外，它具有低Km和低Vmax，在通透性突变体中的疗效降低，并受到组成型β-内酰胺酶的进一步影响。在这种情况下，由于Vmax较低，非水解屏障可能会进一步降低敏感性。
