Prevalence of extended-spectrum and AmpC β-lactamase-producing Escherichia coli in Dutch dairy herds

• Published in: Veterinary microbiology Vol. 232; pp. 58 - 64
• Main Authors: Heuvelink, Annet E., Gonggrijp, Maaike A., Buter, Rianne G.J., ter Bogt-Kappert, Carlijn C., van Schaik, Gerdien, Velthuis, Annet G.J., Lam, Theo J.G.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-05-2019; Elsevier BV
• Subjects: Animal husbandry; Antimicrobial resistance; Antimicrobial use; Bacteria; Calves; Cattle; Cefotaxime; Cefoxitin; Ceftazidime; Clavulanic acid; Dairy cattle; E coli; Escherichia coli; Extended-Spectrum β-lactamase; Shedding; Netherlands; Extended-Spectrum β-lactamase; Antimicrobial resistance; Dairy cattle; Antimicrobial use
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2019.04.005

•In 59.6% of Dutch dairy herds ESBL/AmpC-producing E. coli were found.•ESBL/AmpC-producing E. coli prevalence significantly declined between 2011 and 2013.•Animal prevalence of ESBL/AmpC-producing E. coli is highest in young calves.
This study was conducted to assess: (1) a change in between-herd prevalence of extended-spectrum and AmpC β-lactamase-producing Escherichia coli (ESBL/AmpC-EC) between 2011 and 2013, the period during which the antimicrobial policy in animal husbandry in the Netherlands changed significantly, and (2) the prevalence of ESBL/AmpC-EC in individual calves, young stock, and dairy cows in the Netherlands.
In 196 randomly selected conventional dairy herds, faecal samples were collected from calves (maximum n = 15), and randomly selected young stock (n = 5) and dairy cows (n = 15). Additionally, fresh faecal samples were collected from five different places on the floors where the dairy cows were housed. Samples were screened for E. coli with non-wild type susceptibility for cefotaxime and isolates were phenotypically confirmed as ESBL/AmpC-producing by disc diffusion, using cefotaxime and ceftazidime with and without clavulanic acid, and cefoxitin. Samples containing ESBL/AmpC-EC were examined semi-quantitatively.
In 59.6% of the dairy herds one or more samples tested positive for ESBL/AmpC-EC. The between-herd prevalence based on floor samples in 2013 (18.0%) was significantly lower than the prevalence in 2011 based on comparable samples (32.7%). The individual animal prevalence of ESBL/AmpC-EC, with a minimum shedding level of 103 cfu/g of faeces, was 19.3% in calves, 0.9% in young stock, and 0.8% in dairy cows.
Although ESBL/AmpC-EC was found in the majority of dairy herds, the herd prevalence declined significantly between 2011 and 2013. Calves were found to have both, a much higher individual animal prevalence and a higher level of shedding than young stock and cows.