Mass spectrometric measurement of beta-lactamase resistances

摘要

The invention relates to the determination of resistances of microorganisms which produce ²-lactamases, in particular "extended spectrum ²-lactamases" (ESBL). The invention provides a method whereby the microbial resistance can be measured very simply and quickly by means of the catalytic effect of the microbially produced ²-lactamases on ²-lactam antibiotics, which consists in a hydrolytic cleavage of the ²-lactam ring. The method determines the resistance of the bacteria a few hours after a suitable substrate, either a ²-lactam antibiotic or a customized ²-lactam derivative, has been added to a suspension of the microbes, by direct mass spectrometric measurement of the substrate breakdown caused by the ²-lactamases.