Bradford P A, Sanders C C
Department of Medical Microbiology, Creighton University, Omaha, Nebraska 68178, USA.
Antimicrob Agents Chemother. 1995 Feb;39(2):308-13. doi: 10.1128/AAC.39.2.308.
A test panel of 35 different beta-lactamases expressed in a common Escherichia coli host was created to compare the effect that each beta-lactamase had on susceptibility to various beta-lactam antibiotics. A comparison of the MICs obtained with this panel generally reflected differences in the substrate profiles of the various beta-lactamases examined. In addition, several strains of the panel were subjected to selection with porin-specific bacteriophages to obtain mutants lacking either the OmpC or OmpF porin protein. A mutation in either OmpC or OmpF did change the susceptibilities of certain strains expressing beta-lactamase to certain beta-lactam antibiotics. However, the loss of a single porin did not predictably alter susceptibility to any given beta-lactam drug. This panel of strains producing various beta-lactamases was found to be a useful tool for comparing the effects of different beta-lactamases and outer membrane permeability upon susceptibility to beta-lactam drugs.
构建了一个在常见大肠杆菌宿主中表达35种不同β-内酰胺酶的测试组，以比较每种β-内酰胺酶对各种β-内酰胺抗生素敏感性的影响。用该测试组获得的最低抑菌浓度（MIC）比较结果通常反映了所检测的各种β-内酰胺酶底物谱的差异。此外，测试组中的几株菌株用孔蛋白特异性噬菌体进行筛选，以获得缺失OmpC或OmpF孔蛋白的突变体。OmpC或OmpF的突变确实改变了某些表达β-内酰胺酶的菌株对某些β-内酰胺抗生素的敏感性。然而，单一孔蛋白的缺失并不能可预测地改变对任何给定β-内酰胺药物的敏感性。发现该产生各种β-内酰胺酶的菌株测试组是比较不同β-内酰胺酶和外膜通透性对β-内酰胺药物敏感性影响的有用工具。
