Visualizing pyrazinamide action by live single cell imaging of phagosome acidification and Mycobacterium tuberculosis pH homeostasis [article]

Pierre Santucci, Beren Aylan, Laure Botella, Elliott M Bernard, Claudio Bussi, Enrica Pellegrino, Natalia Athanasiadi, Maximiliano G Gutierrez
2021 bioRxiv   pre-print
Mycobacterium tuberculosis (Mtb) segregates within multiple subcellular niches with different biochemical and biophysical properties that, upon treatment, may impact antibiotic distribution, accumulation, and efficacy. However, it remains unclear whether fluctuating intracellular microenvironments alter mycobacterial homeostasis and contribute to antibiotic enrichment and efficacy. Here, we describe a live dual-imaging approach to monitor host subcellular acidification and Mtb intrabacterial
more » ... By combining this approach with pharmacological and genetic perturbations, we show that Mtb can maintain its intracellular pH independently of the surrounding pH in human macrophages. Importantly, unlike bedaquiline (BDQ), isoniazid (INH) or rifampicin (RIF), the drug pyrazinamide (PZA) displays antibacterial efficacy by acting as protonophore which disrupts intrabacterial pH homeostasis in cellulo. By using Mtb mutants, we confirmed that intracellular acidification is a prerequisite for PZA efficacy in cellulo. We anticipate this imaging approach will be useful to identify host cellular environments that affect antibiotic efficacy against intracellular pathogens.
doi:10.1101/2021.12.20.473466 fatcat:s7asqxx5pjfbdnt6eris2e33ou