J Infect Dis. 2025 Sep 17:jiaf480. doi: 10.1093/infdis/jiaf480. Online ahead of print.
ABSTRACT
Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are a major antimicrobial resistance threat. Although not standard therapy, azithromycin (AZM) displayed potent activity against ESBL E. coli in vitro, ex vivo, and in vivo. AZM demonstrated multi-fold reductions in MIC, bactericidal activity in supplemented mammalian tissue culture media, and enhanced dose-dependent activity with sodium bicarbonate (NaHCO3). AZM also augmented complement-mediated killing in human serum and improved survival by 50% in a murine bloodstream infection model. These findings underscore the need to revisit antibiotic susceptibility testing-incorporating host defense factors and NaHCO3-and suggest AZM merits further clinical evaluation for ESBL E. coli infections.
PMID:40974066 | DOI:10.1093/infdis/jiaf480
