Automatic Identification of Individual rpoB Gene Mutations Responsible for Rifampin Resistance in Mycobacterium tuberculosis by Use of Melting Temperature Signatures Generated by the Xpert MTB/RIF Ultra Assay [Mycobacteriology and Aerobic Actinomycetes]

In this study, we developed an automated algorithm to specifically identify a wide range of mutations in the rpoB RRDR by utilizing the pattern of the Tm of the 4 probes within the 9 windows generated by the Ultra assay. The algorithm builds a RRDR mutation-specific "Tm signature" reference library from a set of known mutations and then identifies the RRDR genotype of an unknown sample by measuring the Tm distances between the test sample and the reference Tm values. Validated using a set of clinical isolates, the algorithm correctly identified RRDR genotypes of 93% samples with a wide range of rpoB single and double mutations. Our analytical approach showed a great potential for fast RRDR mutation identification and may also be used as a stand-alone method for ruling out relapse or transmission between patients. The algorithm can be further modified and optimized for higher accuracy as more Ultra data become available.

Source: Journal of Clinical Microbiology - December 22, 2019 Category: Microbiology Authors: Cao, Y., Parmar, H., Simmons, A. M., Kale, D., Tong, K., Lieu, D., Persing, D., Kwiatkowski, R., Alland, D., Chakravorty, S. Tags: Mycobacteriology and Aerobic Actinomycetes Source Type: research