Development of test panel of beta-lactamases expressed in a common Escherichia coli host background for evaluation of new beta-lactam antibiotics.
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.
Bradford
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PA
Department of Medical Microbiology, Creighton University, Omaha, Nebraska 68178, USA.
Sanders
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CC
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology*; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000502:physiology*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D047090:beta-Lactams; D001618:beta-Lactamases