Drug-resistance testing is also a form of genotypic assay. This testing looks for the genes of circulating RNA in the plasma of patients - to detect mutations that are known to confer specific drug resistance. Examples include:
- NAAT testing of pure cultures of carbapenem-resistant bacteria, or clinical specimens (such as rectal swabs, and direct blood cultures). The tests detect defined carbapenem resistance genes.6
- NAAT testing for the detection of resistant Mycobacterium tuberculosis (MTB). (Rifampin resistance gene rpoB is targeted.)7
6. Tenover FC. Using molecular diagnostics to develop therapeutic strategies for carbapenem-resistant gram-negative infections. FAront Cell Infect Microbiol. 2021;11:715821. Published 2021 Sep 28. doi:10.3389/fcimb.2021.715821