Mechanisms of antimicrobial susceptibility

A kit for determining a mechanism of antimicrobial resistance for a microorganism to an antimicrobial agent comprising:

• an antimicrobial agent, wherein the antimicrobial agent is a compound that kills, inhibits the growth of, or otherwise compromises the viability of the growth of one or more microorganisms;
• a non-replicative transduction particle (NRTP) comprising a reporter nucleic acid molecule encoding a reporter molecule;
• a caged substrate having a structure of
• and
• capable of entering the microorganism and becoming an un-caged substrate in the presence of an enzyme related to a mechanism of resistance to the antimicrobial agent, wherein the un-caged substrate reacts with the reporter molecule to produce a detectable signal, wherein detection of the detectable signal confirms a presence of the microorganism in the sample;
• and
• instructions for using the antimicrobial agent, the NRTP, and the caged substrate to determine the mechanism of antimicrobial resistance for the microorganism to the antimicrobial agent based on the presence or absence of a detectable indication of viability associated with the microorganism when the microorganism is in contact with the antimicrobial agent, the NRTP and the caged substrate, wherein the presence of a detectable indication of viability indicates that the microorganism is viable and that the enzyme related to the mechanism of resistance to the antimicrobial agent is expressed by the microorganism, and wherein the absence of an indication of viability indicates that the microorganism is not viable and that the enzyme related to the mechanism of resistance to the antimicrobial agent is not expressed by the microorganism.