Prevalence and Risk Factors for ESBL/AmpC-E. coli in Pre-Weaned Dairy Calves on Dairy Farms in Germany.

Laura Patricia Weber,Katharina Schaufler,Maike Heppelmann,Lisa Bachmann,Timo Homeier-Bachmann,Sylvia Dreyer

doi:10.3390/microorganisms9102135

Abstract

The objectives of this study were to ascertain the fecal ESBL/AmpC-E. coli prevalence and to detect risk factors for their occurrence in young pre-weaned calves and their dams on large dairy farms in Germany. From 2018–2019 we investigated 2816 individual fecal samples from pre-weaned dairy calves and their dams, representing seventy-two farms (mean = 667 milking cows) from eight German federal states. To assess possible risk factors associated with ESBL/AmpC-E. coli prevalence in calves and dams, a questionnaire was performed, collecting management data. We observed an ESBL/AmpC-E. coli prevalence of 63.5% (95% CI: 57.4–69.5) among the sampled calves and 18.0% (95% CI: 12.5–23.5) among the dams. On all farms, at least one positive sample was obtained. To date, this is the highest ESBL/AmpC-E. coli prevalence observed in dairy herds in Europe. Feeding with waste milk was identified as a significant risk factor for a high prevalence of ESBL/AmpC-E. coli in calves. Many calves at large dairies in Germany are fed with waste milk due to the large amounts generated as a result of antibiotic dry-off routines and mastitis treatment with antibiotics. Other notable risk factors for high ESBL/AmpC-E. coli in calves were the general fitness/health of dams and calves, and the quality of farm hygiene. Taken together, these findings suggest that new or improved approaches to animal health management, for example, antibiotic dry cow management (selective dry cow therapy) and mastitis treatment (high self-recovery), as well as farm hygiene, should be researched and implemented.

Highlights

This article is an open access articleThe World Health Organization (WHO) has acknowledged antimicrobial resistance as one of today’s biggest threats to global health, food security and development
The results revealed that the mean farm ESBL/AmpC-E. coli prevalence in calves was almost
14% of the calf-cow pairs were positive for ESBL/AmpC-E. coli

Summary

Introduction

The World Health Organization (WHO) has acknowledged antimicrobial resistance as one of today’s biggest threats to global health, food security and development. In 2015, they launched the Global Action Plan on Antimicrobial Resistance (GAP AMR). One Health approach is essential in order to control the spread of AMR [1]. Among the most critical antibiotic resistant bacteria, extended-spectrum β-lactamases (ESBL)-producing Enterobacteriaceae are listed on the WHO’s Global priority list of antibioticresistant bacteria to guide research, discovery and development of new antibiotics [2]. Resistance to broad-spectrum β-lactams can be mediated by ESBLs and AmpC β-lactamases (AmpC). Both can hydrolyze 3rd- and 4th-generation cephalosporins such as cefotaxime and can either be found separately or in coexistence [3,4]

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