Efficacy of β-lactam/β-lactamase inhibitor combination is linked to WhiB4-mediated changes in redox physiology of Mycobacterium tuberculosis.
Saurabh MishraPrashant ShuklaAshima BhaskarKushi AnandPriyanka BaloniRajiv Kumar JhaAbhilash MohanRaju S RajmaniValakunja NagarajaNagasuma ChandraAmit SinghPublished in: eLife (2017)
Mycobacterium tuberculosis (Mtb) expresses a broad-spectrum β-lactamase (BlaC) that mediates resistance to one of the highly effective antibacterials, β-lactams. Nonetheless, β-lactams showed mycobactericidal activity in combination with β-lactamase inhibitor, clavulanate (Clav). However, the mechanistic aspects of how Mtb responds to β-lactams such as Amoxicillin in combination with Clav (referred as Augmentin [AG]) are not clear. Here, we identified cytoplasmic redox potential and intracellular redox sensor, WhiB4, as key determinants of mycobacterial resistance against AG. Using computer-based, biochemical, redox-biosensor, and genetic strategies, we uncovered a functional linkage between specific determinants of β-lactam resistance (e.g. β-lactamase) and redox potential in Mtb. We also describe the role of WhiB4 in coordinating the activity of β-lactamase in a redox-dependent manner to tolerate AG. Disruption of WhiB4 enhances AG tolerance, whereas overexpression potentiates AG activity against drug-resistant Mtb. Our findings suggest that AG can be exploited to diminish drug-resistance in Mtb through redox-based interventions.
Keyphrases
- mycobacterium tuberculosis
- multidrug resistant
- pulmonary tuberculosis
- escherichia coli
- drug resistant
- gram negative
- quantum dots
- klebsiella pneumoniae
- highly efficient
- acinetobacter baumannii
- visible light
- physical activity
- cell proliferation
- pseudomonas aeruginosa
- human immunodeficiency virus
- cystic fibrosis
- transcription factor
- risk assessment
- hepatitis c virus
- climate change
- copy number
- dna methylation
- hiv testing
- label free