Patent ID: 7267962

Claim:
A method for detecting an antibiotic-inactivating factor produced by a microorganism, comprising: a) admixing the microorganism with an antibiotic for which inactivation is to be determined and a permeabilizing agent for the microorganism present in a non-growth-inhibiting microorganism-permeabilizing effective amount, to form an assay culture; b) providing a control comprising the microorganism and the antibiotic, without a non-growth-inhibiting microorganism-permeabilizing effective amount of a permeabilizing agent; c) incubating said assay culture and control under appropriate conditions and for a time sufficient to detect said antibiotic-inactivating factor; and d) comparing growth of the microorganism in the assay culture to growth of the microorganism in the control, whereby, significantly more growth or a distortion in a zone of inhibition in the assay culture is indicative of antibiotic-inactivating factor.