Relève étoile Jacques-Genest 
July 2019

Dorival Martins Jr.

Postdoctoral fellow in Biochemistry
McGill University

Award-winning publication: Superoxide dismutase activity confers (p)ppGpp-mediated antibiotic tolerance to stationary-phase Pseudomonas aeruginosa

Published in: Proceedings of the National Academy of Sciences


Over 60% of cystic fibrosis patients also suffer from a chronic infection caused by the Pseudomonas aeruginosa (P. aeruginosa) pathogen, which brings about the progressive deterioration of their lungs. In most cases, common antibiotics are unable to eradicate the infection, but overcoming the bacteria's tolerance to antibiotics could help rid patients of the pathogen. The research conducted by Dorival Martins Jr. has shown that P. aeruginosa develops a tolerance to antibiotics when it is deprived of nutrients. The tolerance involves antioxidant enzymes known as superoxide dismutases, which normally prevent oxidative stress in bacteria. However, Martins' findings indicate that the enzymes help P. aeruginosa to reduce the permeability of its membranes, thus significantly limiting the action of the antibiotics. Inhibiting the enzymes could therefore enhance the antibiotic treatments against the persistent infections that affect those suffering from cystic fibrosis.