Award details

Understanding the role of host-pathogen interactions and the impact of management system on antimicrobial resistance in Brazilian livestock systems

Reference	BB/R022739/1
Principal Investigator / Supervisor	Dr Caroline Rymer
Co-Investigators / Co-Supervisors	Dr Partha Pratim Ray
Institution	University of Reading
Department	Sch of Agriculture Policy and Dev
Funding type	Research
Value (£)	74,037
Status	Completed
Type	Research Grant
Start date	01/05/2018
End date	30/04/2019
Duration	12 months

Abstract

unavailable

Summary

The Brazilian beef industry is immense, and is a vital source of foreign revenue for the country. Brazil is the second largest producer of beef in the world, and has the world's largest commercial herd of approximately 200 million head produced on 1.8 million farms ranging from small enterprises (<500 head p.a.) to commercialised beef production enterprises (>4000 head p.a.). Most animals are produced on pasture, many of them on soils of low to medium fertility in the cerrado (similar to savannas, an important biome in Brazil) with <7% of slaughtered animals being produced on feedlots. Despite this extensive system of beef production, antimicrobial consumption is high. In 2010, Brazil was ranked third highest in the world for antimicrobial consumption by food producing animals, and accounted for 9% of total global farm animal antimicrobial consumption. This high consumption of antimicrobials by farm animals increases the risk of the development of antimicrobial resistant (AMR) bacteria in the host animal's microbiome (the microbial population living in the animal's gut). There are many factors which might encourage the proliferation of AMR bacteria in the host gut, and the hypothesis on which this proposal is based is that changes in the host microbiome may affect the maintenance and prevalence of AMR strains of bacteria. Identifying interventions that may then encourage the development of a microbiome that suppresses AMR bacteria could then help control the development and spread of AMR in Brazilian beef cattle. We hypothesise that beef finished on pasture in Brazil will have a lower prevalence of faecal AMR bacteria compared with those finished in feedlots, because of the less intensive nature of the pasture based production system. Much of the pasture grazed in Brazil is suitable either for the growth of tropical grasses or, in more intensively managed pastures, legumes. Both tropical grasses and forage legumes contain tannins, which are known to haveantimicrobial properties and antibiotic resistance modifying properties. However, the efficacy and mode of action of tannins as antimicrobials depends on their concentration and composition. Elucidating the relationship between tannin composition and intake, and the effect this has on the host animal's microbiome (and susceptibility to AMR bacteria) will be investigated in this project. In the first stage of the project, we will conduct a survey to determine the effect of animal age (yearling and finishing animal) and production system (cerrado grazing, more intensively managed pasture, feedlot) on the prevalence of AMR bacteria in faecal samples taken from beef cattle in Brazil. We will also determine the composition of the microbial population in the animal's gut (from the faecal sample) to investigate whether there are patterns of bacterial species which are associated with a lower prevalence of AMR bacteria. We will also take samples of the forages consumed by the animal and investigate whether the amount and composition of tannin that the animal consumes can explain differences in its gut microbiome and the prevalence of AMR bacteria. This will then enable us to develop management and feeding strategies (that would be investigated in the second stage of the project) that might reduce the prevalence of AMR bacteria in Brazilian beef cattle, improving the health status of the cattle themselves and improving the safety and marketability of the meat.

Impact Summary

Brazil is one of the largest consumers of antimicrobials for use in food producing animals, and use across the livestock sector is projected to keep rising. Brazil is the second largest producer of beef (9.6 million tonnes) in the world, over 90% of which are raised in pasture based systems. However, in the absence of any data on AMR status on Brazilian beef farms it can only be predicted that emergence and spread of AMR has increased due to increasing antimicrobial use. Therefore, this project aims to determine the prevalence of AMR (both phenotypic and genotypic) in beef cattle raised under different management systems (e.g. pasture based vs intensive system, grass vs legume based pasture, low vs high antimicrobial use) and identify drivers of AMR within each management system (e.g. antimicrobial use, tannin intake, tannin composition in forages). This project will also gain insight into the relationship between the gut microbiome and AMR. The outputs of this project will be vital in developing strategies to reduce AMR on beef farms in Brazil and thus will help minimise the environmental impact of Brazilian beef production systems. In addition to academic beneficiaries, we expect the following could benefit from this research: Farmers: Prevalence of resistant bacteria and genes will allow farmers to assess the status of AMR on their farms. Identification of drivers of AMR on farms will provide farmers with information required to identify and adopt management strategies that will minimise the threat of AMR to animal and human health. This will also allow farmers to show that they are proactive in avoiding practices that could harm animal and public health. This will also allow farmers to claim and label their beef as 'AMR safe'. Information on the content and composition of tannin in forages and their association with the gut microbiome or prevalence of AMR will help farmers to selectively include or exclude certain species of forage to reduce the likelihood of emerging AMR on farms. Veterinarians: Understanding of how on-farm management practices such as feeding practice or antimicrobial use could contribute to the emergence of AMR in animals' gut will allow veterinarians to include information in herd health plan regarding antimicrobial use and feeding management at different stages of life to reduce the threat of AMR. Policymakers: The outcomes of our project will inform government agencies (e.g. Ministry of Agriculture and the Environment) about the status of AMR on Brazilian beef farms and potential opportunities to change on-farm management practices to reduce the threat of emerging AMR in food producing animals. This information could form the basis of forming new policy or guidelines or farm and food standards scheme (e.g. Red Tractor Scheme in the UK but equivalent for AMR in Brazil) to contain AMR. Society: Identification of on-farm management practices that could contribute to ever-growing threat of AMR to animal and human health will facilitate changes in practice or development of alternative strategies and thus will reduce the selection for AMR on beef farms. Reduced AMR on farms will reduce the likelihood of AMR getting into the food chain. Feed companies: By knowing the relationship between the gut microbiome and AMR, interventions could be identified to alter the gut microbiome such that it does not facilitate the development of resistance or its spread between bacterial hosts. Feed companies could develop feed additives containing tannin to modulate gut microbiome to reduce the emergence of AMR in animals' gut. Brazilian Beef Exporters Association: The outcome of this project could drive changes in on-farm management practices, which in turn could reduce the emergence of AMR on beef farms. This will allow achievement of key objectives of Brazilian Beef Project i.e. to strengthen the image of Brazilian beef and to expand Brazilian participation in the world beef market by making beef more 'AMR safe'.

Committee	Not funded via Committee
Research Topics	Animal Health
Research Priority	X – Research Priority information not available
Research Initiative	Newton Fund - BBSRC-FAPESP Joint Pump-Priming Awards for AMR in Agriculture (NFBRAZILAMR) [2017]
Funding Scheme	X – not Funded via a specific Funding Scheme

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