Abstract: Devices, systems, and methods for strain-specific identification and assessment of susceptibility of microorganisms based on the response of sensors in a colorimetric sensor array to metabolic products of the microorganism. An exemplary method includes culturing a sample containing microorganisms in a medium and in gaseous communication with a colorimetric sensor array. Sensors in the colorimetric sensor array are exposed to volatile organic compounds produced by the microorganism. The method then includes assessing a resistance of the microorganism to at least one substance. The resistance is assessed based on a response of the sensors in the colorimetric sensor array to the volatile organic compounds produced by the microorganism.