Spatial Clustering of Escherichia coli with Reduced Susceptibility to Cefotaxime and Ciprofloxacin among Dairy Cattle Farms Relative to European Starling Night Roosts

Summary European starlings (Sturnus vulgaris) have been implicated in the dispersal of zoonotic enteric pathogens. However, their role in disseminating antimicrobial‐resistant organisms through their home range has not been clearly established. The aim of this study was to determine whether starling night roosts served as foci for spreading organisms with reduced susceptibility to antimicrobials among dairy cattle farms. Bovine faecal pats were collected from 150 dairy farms in Ohio. Each farm was visited twice (in summer and fall) between 2007 and 2009. A total of 1490 samples (10 samples/farm over two visits) were tested for Escherichia coli with reduced susceptibility to cefotaxime and ciprofloxacin. Using a spatial scan statistic, focal scans were conducted to determine whether clusters of farms with a high prevalence of organisms with reduced susceptibility to cefotaxime and ciprofloxacin surrounded starling night roosts. Faecal pats 13.42% and 13.56% of samples carried Escherichia coli with reduced susceptibility to cefotaxime and ciprofloxacin, respectively. Statistically significant (P