Large variation in the association between seasonal antibiotic use and resistance across multiple bacterial species and antibiotic classes

Abstract BackgroundUnderstanding how antibiotic use drives resistance is crucial for guiding effective strategies to limit the spread of resistance, but the use-resistance relationship across pathogens and antibiotics remains unclear. MethodsWe applied sinusoidal models to evaluate the seasonal use-resistance relationship across 3 species (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae) and 5 antibiotic classes (penicillins, macrolides, quinolones, tetracyclines, and nitrofurans) in Boston, Massachusetts. ResultsUse of all 5 classes and resistance in 10 of 15 species-antibiotic combinations showed statistically significant amplitudes of seasonality (p < 0.05). While seasonal peaks in use varied by class, resistance in all 10 species-antibiotic combinations peaked in the winter and spring. The correlations between seasonal use and resistance thus varied widely, with resistance to all antibiotic classes being most positively correlated with use of the winter-peaking classes (penicillins and macrolides). ConclusionsThese findings challenge the simple model of antibiotic use independently selecting for resistance and suggest that stewardship strategies will not be equally effective across all species and antibiotics. Rather, seasonal selection for resistance across multiple antibiotic classes may be dominated by use of the most highly prescribed antibiotic classes, penicillins and macrolides.