Bird-livestock interactions associated with increased cattle fecal shedding of ciprofloxacin-resistant Escherichia coli within feedlots in the United States

This research study was conducted to determine if bird depredation in feedlots is associated with the prevalence of ciprofloxacin-resistant Escherichia coli in cattle and to determine if removal of invasive bird species could be an effective management strategy to help reduce ciprofloxacin-resistant E. coli in cattle within the United States. European starlings ( Sturnus vulgaris ) were collected from feedlots within multiple geographic regions within the United States and European starlings within all regions tested positive for ciprofloxacin-resistant E. coli , but prevalence differed by region. Total number of birds on feedlots were positively associated with increased cattle fecal shedding of ciprofloxacin-resistant E. coli . Targeted control of invasive European starlings reduced bird numbers on feedlots by 70.4%, but decreasing populations of European starlings was not associated with corresponding reductions in bovine fecal prevalence of ciprofloxacin-resistant E. coli . These data provide evidence for the role of wild bird depredation in feedlots contributing to fecal shedding of ciprofloxacin-resistant E. coli , but a single month of European starling control in feedlots was not sufficient to impact the fecal carriage of this organism in cattle.