ANSES's activities in the area of antimicrobial resistance and veterinary antimicrobials
The multiplication of bacterial strains that are resistant to antibiotics calls into question the efficacy of these treatments. The issue of antimicrobial resistance presents a major challenge for both human and animal health. ANSES carries out several missions in this area relating to animal health, food and the environment.
Antimicrobial resistance: a major issue for animals and humans
The extensive use of antibiotics over the past few decades has led to the selection of micro-organisms with genes giving them the ability to resist these drugs. These bacteria pose a significant threat to both animal and human health, because antibiotics effective against pathogenic bacteria are diminishing in number, and are even non-existent for certain multidrug-resistant strains. Particular attention is now being paid to resistance to so-called "critical" antibiotics, which are mainly used as a last resort in human medicine when the first antibiotics prescribed have failed to cure a patient.
ANSES's role in combating antimicrobial resistance in animal health
ANSES is responsible for monitoring antimicrobial resistance in veterinary medicine, whether it relates to livestock farming or food of animal origin intended for humans.
Monitoring and studying the presence of bacterial resistance in animals
- The National Reference Laboratory for antimicrobial resistance
The Fougères and Ploufragan-Plouzané-Niort laboratories share the mandate of National Reference Laboratory (NRL) for antimicrobial resistance. As such, they monitor the resistance of bacteria that can contaminate humans via food of animal origin, as part of harmonised European monitoring plans.
In addition, the NRL implements annual monitoring plans, overseen by the Ministry of Agriculture and Food, which keep an eye on developments at national and European level. The NRL also validates authorised methods for testing the resistance of bacteria of animal origin to antibiotics of critical importance to humans.
How does the NRL's monitoring plan work?
Monitoring focuses on "indicator" bacteria such as Escherichia coli, which enable the reservoir of circulating resistance to be estimated, as well as bacteria such as Salmonella and Campylobacter that cause human infections. Samples are collected from healthy food-producing animals.
Depending on the bacterium and farming sector, samples are collected on the farm (surface sampling), at the slaughterhouse (in intestinal contents) or at distribution (in meat). Sampling is random and takes place throughout the year and across the country. Each year, the results are published in France by the Directorate General for Food (DGAL) and at European level by the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC).
- RESAPATH: a network for monitoring antimicrobial resistance
Since 1982, the French Surveillance Network for Antimicrobial Resistance in Pathogenic Bacteria of Animal Origin (RESAPATH) has been monitoring changes in resistance to antibiotics for all domestic animal species in France.
The RESAPATH network's objectives are to:
- monitor trends in antimicrobial resistance in bacteria of importance to animal health (including Escherichia coli),
- detect the emergence of antimicrobial resistance and characterise its mechanisms at the molecular level,
- provide all its stakeholders with methodological and scientific support.
How does RESAPATH work?
The network is coordinated by ANSES's Lyon and Ploufragan-Plouzané-Niort laboratories and encompasses more than 100 volunteer veterinary testing laboratories. As part of their practitioner activity, veterinarians are required to collect samples from diseased animals, in order to isolate bacteria and perform antibiotic resistance tests (antibiograms). These data are then sent to RESAPATH. Monitoring focuses primarily on the Escherichia coli bacterium, which is indicative of antimicrobial resistance since it is a known reservoir of resistance genes, which it can transmit to other bacteria.
- Monitoring exposure to antimicrobials and assessing the risks associated with antimicrobial resistance as part of the marketing of veterinary antimicrobials
The French Agency for Veterinary Medicinal Products (ANMV), part of ANSES, grants marketing authorisation for veterinary antimicrobials in France. Its monitoring of sales of veterinary antibiotics also enables the authorities to assess animal exposure to antibiotics and monitor changes in practices for different animal species. The information gathered is one of the essential elements, together with monitoring of bacterial resistance, needed for assessing the risks associated with antimicrobial resistance. These data also make it possible to recommend measures for managing these risks and monitor the effects of these measures.
- Investigating the presence of antibiotics and resistant bacteria in the environment
While antimicrobial resistance in humans and animals is a well-researched phenomenon, its dissemination in the environment is less well known. This is despite the fact that certain resistance genes that are currently a problem in medicine come from bacteria in the environment. In November 2020, ANSES published an expert appraisal report on the presence of resistant bacteria and antibiotics in the environment, the first review of knowledge on this topic.
- Conducting research to better monitor and understand antimicrobial resistance
ANSES's laboratories also conduct a great deal of research that helps further knowledge of antimicrobial resistance.
Some projects may aim to improve the monitoring of antimicrobial resistance, for example by enhancing the methods used to detect resistant bacteria or improving the functioning of monitoring systems.
Other projects aim to better understand how antibiotic-resistant bacteria are selected and spread. To do so, they use an overall approach, taking into account humans, animals and the environment.
Research is also carried out into alternatives to antibiotics. The aim is to reduce the use of these drugs and get around the resistance of certain bacteria to antibiotics.
- Participating in European and international reference work on antimicrobial resistance
ANSES is a Collaborating Centre of the World Organisation for Animal Health (WOAH) for veterinary medicinal products and a Reference Centre for antimicrobial resistance of the Food and Agriculture Organization of the United Nations (FAO). Under these mandates, the Agency provides advice to these institutions and support to Member States to ensure the rational use of antibiotics in veterinary medicine and reduce antimicrobial resistance.
ANSES's recommendations for improving monitoring and control of antimicrobial resistance
- Favour an overall approach, including humans, animals and the environment
Some resistant bacteria can be transmitted from animals to humans, and vice versa. Bacteria carrying antimicrobial resistance genes are also found in the environment. Combating antimicrobial resistance therefore requires an overall approach, encompassing humans, animals and the environment.
- Create a European network for monitoring antimicrobial resistance in veterinary medicine
Currently, only the monitoring of antimicrobial resistance in healthy animals and in meat is harmonised at European level. Several countries, including France, also monitor antimicrobial resistance in sick animals. Scientists have shown that trends may differ when comparing surveillance data from healthy and sick animals. ANSES, together with other European institutes, is calling for the creation of a European antimicrobial resistance surveillance network in veterinary medicine (EARS-Vet). Just like the national monitoring conducted by RESAPATH, it would keep track of resistance levels of bacteria collected from diseased animals. Its creation would help better define the appropriate use of veterinary antibiotics in Europe.
- Study new bacteria
Currently, the only bacteria that are monitored regularly are those that can be transmitted from animals to humans, such as Salmonella or Campylobacter, or that are considered to provide a good indication of the general level of antimicrobial resistance, such as Escherichia coli. However, other bacteria could also benefit from this type of monitoring, such as those responsible for diseases causing significant livestock losses and requiring the use of medication. ANSES is therefore exploring the possibility of monitoring the resistance of bacteria, such as mycoplasmas, that are not currently covered by monitoring systems.
- Improve monitoring of environmental contamination
Following the November 2020 publication of an initial expert appraisal on the presence of antibiotics and resistant bacteria in the environment, ANSES recommended that all studies on antimicrobial resistance in the environment should include monitoring of a set of indicators including antibiotics, a resistant bacterium and a resistance gene. It also recommended taking into account the fate of this drug residue contamination over time and in space.