Antimicrobial resistance in dairy slurry tanks: A critical point for measurement and control

Multidrug-resistance and extended-spectrum beta-lactamase-producing lactose-fermenting enterobacteriaceae in the human-dairy interface in northwest Ethiopia

“…The dairy farm sewage or slurry waste is an important source of infectious agents including AMR strains. The sewage can contaminate humans directly through contact, or indirectly through sewage-contaminated river water that is used for various purposes including growing vegetables that are consumed by humans or animals [ 20 ].…”

Modelling the impact of wastewater flows and management practices on antimicrobial resistance in dairy farms

“…Liquid slurry is often stored in slurry tanks or lagoons for several months, principally to avoid spreading them on land in autumn and winter due to restrictions to avoid agricultural nitrate pollution. Dairy slurry has been shown to contain bacteria resistant to many antibiotics, including penicillins, cephalosporins, aminoglycosides, quinolones, sulphonamides, phenicols, tetracyclines, and nitrofurans 22 , which have been associated with current or previous farm antibiotic use 23 . Importantly, dairy slurry can include Extended Spectrum Cephalosporin Resistant E. coli (ESCR-EC) 24 , for example AmpC overexpression strains, or Extended Spectrum Beta-Lactamase producing E. coli (ESBL-EC), the WHO’s recommended indicator for global surveillance of AMR 25 .…”

“…However, further reduction in usage of Ab in commercial livestock farming will be extremely challenging for countries such as the UK, that have already made major reductions, due to the need for targeted antibiotic treatment use, whether viewed from an animal welfare or from a farm business perspective. Therefore, it is appropriate to consider whether changes in farm management, infrastructure, or practice, can reduce selection for resistance 23 . Such changes are often difficult to evaluate empirically, because they would need expensive changes to infrastructure, or changes in management practice, with consequent welfare or business risks.…”

“…Such changes are often difficult to evaluate empirically, because they would need expensive changes to infrastructure, or changes in management practice, with consequent welfare or business risks. Mathematical modelling is a powerful tool in such studies, because alternative strategies can be readily evaluated through simulations, and parameters or processes to which adverse outcomes (i.e., proliferation of ARBs) are especially sensitive can be identified, which serve as potential points of control 23 .…”

“…Most mathematical models studying the impact of AMR in dairy farms (or other livestock farm environments) consider a single area of a farm 23 , 33 , 34 , treat the entire farm as a single compartment 35 , or are interested in within-host dynamics of the livestock 36 . While such approaches are undoubtedly useful, to the best of our knowledge, there are no modelling studies that investigate the effects of farm layout, the farm practices associated across different areas of the farm, and the impact these may have upon the emergence and/or spread of AMR across the farm.…”