- MDR Multidrug Resistant: R Rifampicin Resistant: IR Isoniazid Resistant: I Isoniazid: R Rifampicin: S Sensitive: Indet Indeterminate: LPA Line Probe Assay: N/A Not Applicable (Pink cells represent results from APM-Reference standard, Grey cells represent results from LPA, Blue cells represent results from GeneXpert MTB/RIF, Yellow cells represent number of tests affected based on results from the reference standard and Red cells represent total number of tests affected by each rapid molecular method)