LAUSR

OBJECTIVE To describe the genome sequences of 38 antibiotic-resistant Escherichia coli from veal calves. MATERIALS AND METHODS The isolates were recovered in 2015 from nine veal farms in the eastern United States and were screened for antibiotic sensitivity using an automated microdilution procedure. The draft genomes were sequenced on an Illumina NextSeq 500 platform and assembled using SPAdes. RESULTS In total 294 resistance genes, categorized into 40 unique genes, and conferring resistance to seven different antibiotic classes were detected. Extended spectrum β-lactamase (ESBL) genes, blaCTX-M and blaCMY, and azithromycin resistance gene, mph(A), were detected in multiple genomes. Further, mutations in gyrA, parC, and parE, conferring resistance to fluoroquinolones, were detected as were mutations in the ampC promoter that are responsible for hyperproduction of β-lactamases. We identified 25 unique sequence types, including STs that are associated with extraintestinal infections. CONCLUSIONS Results of this study indicate a high level of diversity among multidrug-resistant E. coli isolates from veal operations. The identification of multiple isolates encoding resistance to β-lactams, macrolides, and fluoroquinolones, as well as virulence factors responsible for human infections warrants more study on the ecology of antibiotic resistance on veal operations.