Reduced use of antimicrobials after vaccination of pigs against porcine proliferative enteropathy in a Danish SPF herd

The present study explored whether the use of group medication with antibiotics in a Danish pig herd was reduced after vaccination of the pigs against proliferative enteropathy (PE) caused by Lawsonia intracellularis. 7900 pigs originating from a single commercial sow herd were vaccinated against L. intracellularis, whereas 7756 pigs were kept as non-vaccinated controls. The pigs were included batch-wise in the study with every second batch being vaccinated. In the vaccinated batches, the consumption of oxytetracykline to treat PE was reduced by 79%, with a significantly lower number of pigs being treated (P < 0.0001). Vaccination also resulted in a highly significant improvement of average daily weight gain (+ 46 g/day; P = 9.55 × 10-31) and carcase weight (+ 1.25 kg; P = 4.54 × 10-05) as well as a shortened fattening period (-8 days; P = 2.01 × 10-45)

Comparing antimicrobial exposure based on sales data

This paper explores the possibilities of making meaningful comparisons of the veterinary use of antimicrobial agents among countries, based on national total sales data. Veterinary antimicrobial sales data on country level and animal census data in both Denmark and the Netherlands were combined with information about estimated average dosages, to make model calculations of the average number of treatment days per average animal per year, at first based on the assumption that the treatment incidence is the same in all species and production types. Secondly, the exposure in respectively animals for meat production and dairy and other cattle (excluding veal and young beef) was estimated, assuming zero use in the dairy and other cattle, and thirdly by assuming respectively 100% oral and 100% parenteral administration. Subsequently, the outcomes of these model calculations were compared with treatment incidences calculated from detailed use data per animal species from the national surveillance programmes in these two countries, to assess their accuracy and relevancy. In Denmark and in the Netherlands, although the computed antimicrobial exposure would seem to be a reasonable estimation of the exposure for all animals as a whole, it differs significantly from the measured exposure for most species. The differences in exposure among animal species were much higher than the overall difference between the two countries. For example, the overall model estimate of 9 treatment days per year for Denmark is a severe overestimation of the true use in poultry (i.e. 3 days), and the overall model estimate of 13 treatment days per year for the Netherlands is a severe underestimation of the true use in veal calves (i.e. 66 days). The conclusion is that simple country comparisons, based on total sales figures, entail the risk of serious misinterpretations, especially if expressed in mg per kg. The use of more precise model calculations for making such comparisons, taking into account differences in dosages and in farm animal demographics, only slightly reduces this risk. Overall model estimates are strongly influenced by animal demographics and a very inaccurate indication of the true differences in exposure, per animal species. To get an appropriate certainty about the true differences in antimicrobial exposure between countries it is an absolute necessity to have reliable information about the use per animal species

The path of least resistance: Paying for antibiotics in non-human uses

Antibiotic resistance is a critical threat to human and animal health. Despite the importance of antibiotics, regulators continue to allow antibiotics to be used in low-value applications - subtherapeutic dosing in animals, and spraying tobacco plants for blue mold, for example - where the benefits are unlikely to outweigh the costs in terms of increased resistance. We explore the application of a user fee in non-human uses of antibiotics. Such a fee would efficiently deter low value uses while also providing funding to support the development of the urgently needed new antibiotics

Veterinary Medicine Needs New Green Antimicrobial Drugs

Given that: (1) the worldwide consumption of antimicrobial drugs (AMDs) used in food-producing animals will increase over the coming decades; (2) the prudent use of AMDs will not suffice to stem the rise in human antimicrobial resistance (AMR) of animal origin; (3) alternatives to AMD use are not available or not implementable, there is an urgent need to develop novel AMDs for food-producing animals. This is not for animal health reasons, but to break the link between human and animal resistomes. In this review we establish the feasibility of developing for veterinary medicine new AMDs, termed green antibiotics, having minimal ecological impact on the animal commensal and environmental microbiomes.We first explain why animal and human commensal microbiota comprise a turnstile exchange, between the human and animal resistomes. We then outline the ideal physico-chemical, pharmacokinetic and pharmacodynamic properties of a veterinary green antibiotic and conclude that they can be developed through a rational screening of currently used AMD classes. The ideal drug will be hydrophilic, of relatively low potency, slow clearance and small volume of distribution. It should be eliminated principally by the kidney as inactive metabolite(s). For oral administration, bioavailability can be enhanced by developing lipophilic pro-drugs. For parenteral administration, slow-release formulations of existing eco-friendly AMDs with a short elimination half-life can be developed. These new eco-friendly veterinary AMDs can be developed from currently used drug classes to provide alternative agents to those currently used in veterinary medicine and mitigate animal contributions to the human AMR problem

In Silico Detection and Typing of Plasmids using PlasmidFinder and Plasmid Multilocus Sequence Typing

In the work presented here, we designed and developed two easy-to-use Web tools for in silico detection and characterization of whole-genome sequence (WGS) and whole-plasmid sequence data from members of the family Enterobacteriaceae. These tools will facilitate bacterial typing based on draft genomes of multidrug-resistant Enterobacteriaceae species by the rapid detection of known plasmid types. Replicon sequences from 559 fully sequenced plasmids associated with the family Enterobacteriaceae in the NCBI nucleotide database were collected to build a consensus database for integration into a Web tool called PlasmidFinder that can be used for replicon sequence analysis of raw, contig group, or completely assembled and closed plasmid sequencing data. The PlasmidFinder database currently consists of 116 replicon sequences that match with at least at 80% nucleotide identity all replicon sequences identified in the 559 fully sequenced plasmids. For plasmid multilocus sequence typing (pMLST) analysis, a database that is updated weekly was generated from www.pubmlst.org and integrated into a Web tool called pMLST. Both databases were evaluated using draft genomes from a collection of Salmonella enterica serovar Typhimurium isolates. PlasmidFinder identified a total of 103 replicons and between zero and five different plasmid replicons within each of 49 S. Typhimurium draft genomes tested. The pMLST Web tool was able to subtype genomic sequencing data of plasmids, revealing both known plasmid sequence types (STs) and new alleles and ST variants. In conclusion, testing of the two Web tools using both fully assembled plasmid sequences and WGS-generated draft genomes showed them to be able to detect a broad variety of plasmids that are often associated with antimicrobial resistance in clinically relevant bacterial pathogens. Copyright © 2014, American Society for Microbiology. All Rights Reserved

Antimicrobial resistance monitoring and surveillance in the meat chain: A report from five countries in the European Union and European Economic Area

Background The emergence of antimicrobial resistance (AMR) in zoonotic foodborne pathogens (Salmonella, Campylobacter) and indicator microorganisms (E. coli, enterococci) is a major public health risk. Zoonotic bacteria, resistant to antimicrobials, are of special concern because they might compromise the effective treatment of infections in humans. Scope and approach In this review, the AMR monitoring and surveillance programmes in five selected countries within European Union (EU) and European Economic Area (EEA) are described. The sampling schemes, susceptibility testing for AMR identification, clinical breakpoints (clinical resistance) and epidemiological cut-off values (microbiological resistance) were considered to reflect on the most important variations between and within food-producing animal species, between countries, and to identify the most effective approach to tackle and manage the antimicrobial resistance in the food chain. Key findings and conclusions The science-based monitoring of AMR should encompass the whole food chain, supported with public health surveillance and should be conducted in accordance with ‘Zoonoses Directive’ (99/2003/EC). Such approach encompasses the integrated AMR monitoring in food animals, food and humans in the whole food (meat) chain continuum, e.g. pre-harvest (on-farm), harvest (in abattoir) and post-harvest (at retail). The information on AMR in critically important antimicrobials (CIA) for human medicine should be of particular importance