Discrimination of extended-spectrum beta-lactamases by a novel nitrocefin competition assay
Open Access
- 1 November 1990
- journal article
- research article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 34 (11) , 2184-2192
- https://doi.org/10.1128/aac.34.11.2184
Abstract
We describe a nitrocefin competition assay for determining inhibition profiles as a useful adjunct to existing biochemical methods for the discrimination of beta-lactamases. The hydrolysis rate of nitrocefin was measured with a plate photometer as the change in A480 over 45 min in the presence of 17 inhibitors. Fourteen well-established beta-lactamases and 13 extended-spectrum beta-lactamases were tested. Correlations with data from isoelectric focusing and amino acid sequencing suggested that the inhibition profile reflects alterations in the active-site configuration of beta-lactamases. The method was especially useful in measuring the relative affinities of beta-lactamases against poorly hydrolyzed substrates and in screening large numbers of isolates for the detection of new beta-lactamase types.This publication has 36 references indexed in Scilit:
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