Evidence for Expanding the Role of Streptomycin in the Management of Drug-Resistant <i>Mycobacterium tuberculosis</i>



Cohen, Keira A, Stott, Katharine E ORCID: 0000-0001-7079-7957, Munsamy, Vanisha, Manson, Abigail L, Earl, Ashlee M and Pym, Alexander S
(2020) Evidence for Expanding the Role of Streptomycin in the Management of Drug-Resistant <i>Mycobacterium tuberculosis</i>. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 64 (9). e00860-e00820.

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Abstract

In 2019, the WHO tuberculosis (TB) treatment guidelines were updated to recommend only limited use of streptomycin, in favor of newer agents or amikacin as the preferred aminoglycoside for drug-resistant <i>Mycobacterium tuberculosis</i> However, the emergence of resistance to newer drugs, such as bedaquiline, has prompted a reanalysis of antitubercular drugs in search of untapped potential. Using 211 clinical isolates of <i>M. tuberculosis</i> from South Africa, we performed phenotypic drug susceptibility testing (DST) to aminoglycosides by both critical concentration and MIC determination in parallel with whole-genome sequencing to identify known genotypic resistance elements. Isolates with low-level streptomycin resistance mediated by <i>gidB</i> were frequently misclassified with respect to streptomycin resistance when using the WHO-recommended critical concentration of 2 μg/ml. We identified 29 <i>M. tuberculosis</i> isolates from South Africa with low-level streptomycin resistance concomitant with high-level amikacin resistance, conferred by <i>gidB</i> and <i>rrs</i> 1400, respectively. Using a large global data set of <i>M. tuberculosis</i> genomes, we observed 95 examples of this corresponding resistance genotype (<i>gidB-rrs</i> 1400), including identification in 81/257 (31.5%) of extensively drug resistant (XDR) isolates. In a phylogenetic analysis, we observed repeated evolution of low-level streptomycin and high-level amikacin resistance in multiple countries. Our findings suggest that current critical concentration methods and the design of molecular diagnostics need to be revisited to provide more accurate assessments of streptomycin resistance for <i>gidB</i>-containing isolates. For patients harboring isolates of <i>M. tuberculosis</i> with high-level amikacin resistance conferred by <i>rrs</i> 1400, and for whom newer agents are not available, treatment with streptomycin may still prove useful, even in the face of low-level resistance conferred by <i>gidB</i>.

Item Type: Article
Uncontrolled Keywords: Mycobacterium tuberculosis, aminoglycosides, drug resistance mechanisms, multidrug resistance, tuberculosis, whole-genome sequencing
Depositing User: Symplectic Admin
Date Deposited: 01 Feb 2021 15:16
Last Modified: 08 Feb 2024 14:07
DOI: 10.1128/AAC.00860-20
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3115050