SUMMARY
Bactericidal antibiotics alter microbial metabolism as part of their
lethality and can damage mitochondria in mammalian cells. In addition,
antibiotic susceptibility is sensitive to extracellular metabolites, but it
remains unknown if metabolites present at an infection site can affect either
treatment efficacy or immune function. Here, we quantify local metabolic changes
in the host microenvironment following antibiotic treatment for a peritoneal
Escherichia coli infection. Antibiotic treatment elicits
microbiome-independent changes in local metabolites but not those distal to the
infection site by acting directly on host cells. The metabolites induced during treatment, such as AMP, reduce antibiotic efficacy and enhance phagocytic killing. Moreover, antibiotic treatment impairs immune function by
inhibiting respiratory activity in immune cells. Collectively, these results
highlight the immunomodulatory potential of antibiotics and reveal the local
metabolic microenvironment to be an important determinant of infection
resolution.