Antimicrobial resistance profiles of Escherichia coli and prevalence of extended ‐spectrum beta‐lactamase‐producing Enterobacteriaceae in calves from organic and conventional dairy farms in Switzerland

This study compared antimicrobial resistance (AMR) among commensalEscherichia coli of young calves raised on organic and on conventional dairy farms in Switzerland. Proportions of AMR were higher among organically raised calves and calves with antibiotic usage. Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae were found exclusively among calves from conventional dairy farms. AbstractThis study compared the antimicrobial resistance (AMR) among commensalEscherichia coli in the fecal microbiota of young calves raised on organic and on conventional dairy farms in Switzerland. Further, fecal carriage of extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae was assessed for calves from both farming systems. Where possible, data on antimicrobial usage (AMU) were obtained. Antimicrobial susceptibility testing was performed on a total of 71 isolates using the disk diffusion method. ESBL producers were characterized by polymerase chain reaction-based multilocus sequence typing and sequencing of theblaESBL genes. Organically raised calves were significantly more likely to harborE. coli that showed AMR to ampicillin (odds ratio [OR]: 2.78, 95% confidence interval [CI]: 1.02 –7.61,p = 0.046), streptomycin (OR: 3.22, 95% CI: 1.17–8.92,p = 0.046), kanamycin (OR: 11.3, 95% CI: 2.94–43.50,p <  0.001), and tetracycline (OR: 3.25, 95% CI: 1.13–9.31,p = 0.028). Calves with reported AMU were significantly more likely to harborE. coli wit...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research