Interplay between tolerance mechanisms to copper and acid stress in

Copper (Cu) is an essential trace metal nutrient in health and is increasingly recognized for its role in the control of infection. The pathogen Escherichia coli encounters host niches with mild to high acidity and elevated copper levels. Our study shows that this bacterium can alter its metabolism and harness the amino acid glutamine to suppress the effects of acid stress and copper toxicity. Given the abundance of glutamine in systemic circulation and its importance in the host immune system, our work provides a new insight into the ways in which bacterial pathogens can adapt and survive host-imposed antibacterial strategies.