Waste as an antibacterial weapon.

Intracellular pathogens neutralize and evade macrophage-intrinsic host defenses. In this issue of Cell Host & Microbe, Anaya-Sanchez et al. show that methylglyoxal, a metabolic byproduct of glycolysis, is part of the macrophage arsenal limiting L. monocytogenes and M. tuberculosis infections but is countered by pathogen expression of methylglyoxal detoxification enzymes.