methods for determining whether a microorganism is potentially resistant to a beta-lactam antibiotic

摘要

methods and means for the characterization of antibiotic resistance in microorganisms. The present invention relates to a method for characterizing the antibiotic resistance of a microorganism comprising the steps of (a) providing a reference mass spectrum of an antimicrobial compound, enzyme modification product, molecular target, or a substrate compound of a modifying enzyme; (b) exposing a microorganism, cell lysate or resulting culture medium supernatant, to said antimicrobial compound or substrate compound in the aqueous liquid to thereby provide an exposed sample; (c) acquire a mass spectrum of the exposed sample; (d) comparing the mass spectrum acquired in step c) with the reference mass spectrum of step (a), and (e) determining, based on the comparison in question, whether a modification of the respective antimicrobial compound has occurred, modifying product or its molecular target or said substrate following said exposure, and establish whether the microorganism in question is potentially resistant to the antimicrobial compound when the modification is observed.