rpoB Mutations and Effects on Rifampin Resistance in Mycobacterium tuberculosis

Abstract

To investigate the mutations within the whole rpoB gene of Mycobacterium tuberculosis and analyze their effects on rifampin (RIF) resistance based on crystal structure. Methods: We sequenced the entire rpoB gene in 175 tuberculosis isolates and quantified their minimum inhibitory concentrations using microplate-based assays. Additionally, the structural interactions between wild-type/mutant RpoB and RIF were also analyzed. Results: Results revealed that a total of 34 mutations distributed across 17 different sites within the whole rpoB gene were identified. Of the 34 mutations, 25 could alter the structural interaction between RpoB and RIF and contribute to RIF resistance. Statistical analysis showed that S450L, H445D, H445Y and H445R mutations were associated with high-level RIF resistance, while D435V was associated with moderate-level RIF resistance. Conclusion: Some mutations within the rpoB gene could affect the interaction between RpoB and RIF and thus are associated with RIF resistance. These findings could be helpful to design new antibiotics and develop novel diagnostic tools for drug resistance in TB.

Frequency of rpoB, katG, and inhA Gene Polymorphisms Associated with Multidrug-Resistant Mycobacterium tuberculosis Complex Isolates among Ethiopian TB Patients: A Systematic Review

“…Resistance to RIF is the most important indicator of MDR-TB and serves as a surrogate marker for the detection of MDR-TB [ 8 ]. The primary mechanism of RIF resistance is due to the mutations in the rpoB gene that encode the DNA-dependent RNA polymerase β -subunit [ 19 , 20 ]. RIF resistance is largely associated with the most common mutations of the rpoB gene within 81-bp fragment of RIF resistance determining region (RRDR) or hot-spot region at codon rpoB 531, rpoB 526, and rpoB 516 between codons 507 and 533 [ 17 , 18 , 21 ].…”

Whole genome sequencing analysis to evaluate the influence of T2DM on polymorphisms associated with drug resistance in M. tuberculosis

“…In the T2DM group four specific rpoB gene variants were found: H445L, S441L, Q432P, and Q432L. These variants have been reported in studies where comorbidities are not specified [16][17][18][19]. According to the recent Catalogue of mutations related with drug resistance in Mycobacterium tuberculosis complex of WHO, these mutations have a low prevalence (1.17%, 0.26%, 0.29% and 0.21% respectively), and have been classified as SNPs associated with phenotypic resistance against rifampicin [20].…”

“…Also with relation to RIF resistance, the rpoB Q432L, and rpoB Q432P mutations have been identified in isolates with a high minimum inhibitory concentration (MIC), while rpoB Legend shows resistance classification. The scale represents the number of substitutions per site for each position of the alignment S441L, and rpoB H445L showed medium, and low MIC respectively [18]. Likewise, pharmacokinetics studies have found that individuals with T2DM had 25% lower average plasma concentration, and an increase in time to reach the maximum concentration of rifampicin [3].…”

Whole genome sequencing analysis to evaluate the influence of T2DM on polymorphisms associated with drug resistance in M. tuberculosis

“…Also with relation to RIF resistance, the rpoB Q432L, and rpoB Q432P mutations have been identi ed in isolates with a high minimum inhibitory concentration (MIC), while rpoB S441L, and rpoB H445L showed medium, and low MIC respectively. [17]. Likewise, pharmacokinetics studies have found that individuals with T2DM had 25% lower average plasma concentration, and an increase in time to reach the maximum concentration of rifampicin [3].…”

“…In the T2DM group four speci c rpoB gene variants were found: H445L, S441L, Q432P, and Q432L. These variants have been reported in studies where comorbidities are not speci ed [15][16][17][18]. According to the recent Catalogue of mutations related with drug resistance in Mycobacterium tuberculosis complex of WHO, these mutations have a low prevalence (1.17%, 0.26%, 0.29% and 0.21% respectively), and have been classi ed as SNPs associated with phenotypic resistance against rifampicin [19].…”