Antimicrobial resistance (AMR) is the ability of microorganisms to survive in the presence of drugs meant to inhibit or kill them. AMR poses a serious threat to human health, and risks the emergence of untreatable infections.

The key driver of AMR is the widespread use of antimicrobials; even when used appropriately, the use of antimicrobials creates a selective pressure for resistant organisms. In Canada, antibiotic use is largest in the production of food animals, including both livestock and aquaculture to promote growth and treat or prevent disease. Many antibiotics used in animals belong to the same chemical groups as those used in humans, increasing the potential for animals to directly transmit antibiotic resistant pathogens to humans. Antibiotic resistant genes can also be transmitted to other microorganisms, creating a reservoir of resistance genes in the host that could transfer to pathogens.

Human exposure to AMR in the food chain could occur through the following pathways and are applicable to both food grown and animals raised in Canada as well as those that have been imported:

1. Direct contact with treated livestock or fish,
2. Consumption of contaminated meat, poultry, fish, dairy, or eggs; and
3. Consumption of contaminated produce from crops grown in soils fertilized with manure and/or wastewater polluted with sewage or runoff from treated livestock.

Though preventing and controlling AMR is a complex issue involving a multitude of sectors and stakeholders, promoting food safety and hygiene practices is one important way to reduce the transmission of common foodborne illnesses, including those caused by resistant bacteria.

This topic page provides resources on the issue of AMR in the food chain and how transmission of AMR can be reduced. A glossary of terms on antimicrobial resistance can be found here, to explain terms, acronyms, and phrases that may be unfamiliar or unclear.

Selected Resources

AMR in livestock and aquaculture

• Canadian antimicrobial resistance surveillance system report (CARSS) (Public Health Agency of Canada, 2020)
  This report provides an update on surveillance of AMR in Canada for 2020. In particular, the section on ‘Antimicrobial use in animals and on crops in Canada’ provides a valuable overview of national trends in antimicrobial use by animal species.
   
• Consumer exposure to antimicrobial resistant bacteria from food at Swiss retail level (Jans et al., 2018)
  This systematic review assesses the prevalence of antimicrobial resistant bacteria in retail food in Switzerland, and the potential exposure of Swiss consumers to resistant bacteria from retail food.
   
• Antimicrobial drug use in food-producing animals and associated human health risks: what, and how strong, is the evidence? (Hoelzer et al., 2017)
  This systematic review examines the strength of evidence between antimicrobial use in food-producing animals and human health risks, finding compelling scientific evidence that supports the link between antimicrobial use on farms and a public health burden caused by infections with resistant pathogens.
   
• The role of human health and animal health in antimicrobial resistance (National Collaborating Center for Infectious Diseases, 2016)
  This report outlines the various contexts in which antimicrobials are used in health care, livestock production, and agriculture and how inappropriate or excessive antimicrobial use in each of these sectors is contributing to an unprecedented acceleration of antimicrobial resistance.
   
• Comparison of the prevalence of bacterial enteropathogens, potentially zoonotic bacteria and bacterial resistance to antimicrobials in organic and conventional poultry, swine and beef production (Young et al., 2009)
  This NCCEH systematic review and meta-analysis compares the prevalence of zoonotic bacteria or bacteria resistant to antimicrobials in organic and conventional poultry, swine and beef production.
   
• Human health consequences of use of antimicrobial agents in aquaculture (Heuer et al., 2009)
  This review focuses on the use of antimicrobials in aquaculture and the risk this poses to human health through both direct and indirect pathways.
   
• Fishery and aquaculture (FAO, n.d.)
  This webpage discusses ways in which the intensification of production methods in aquaculture, among other factors, has led to an increased spread of pathogens and diseases, and subsequently, increased AMR.

AMR in crops

• Prevalence of Listeria spp. in produce handling and processing facilities in the Pacific Northwest (Jorgensen et al., 2020)
  This peer reviewed article investigates theprevalence and common locations of Listeria monocytogenes in produce-handling and processing facilities in the Pacific Northwest.
   
• FAO/WHO expert meeting on foodborne antimicrobial resistance: Role of environment, crops and biocides (FAO/WHO, 2019)
  This summary report outlines the key discussions of a joint expert meeting by the Food and Agriculture Organization of the United Nations and the World Health Organization on the role of environment, crops, and biocides in contributing to foodborne AMR.
   
• Antimicrobial resistance (AMR) in relation to plant health aspects (FAO, 2019)
  This report explores aspects of plant health and management in relation to AMR and the role pesticides play in exacerbating resistance to antimicrobials.  
   
• Unraveling the role of vegetables in spreading antimicrobial-resistant bacteria: a need for quantitative risk assessment (Hölzel et al., 2018)
  This review provides a critical summary of available information on hazard identification and characterization, exposure assessment, and risk prevention with respect to AMR in the vegetable food chain.

AMR in imported foods

• A review of antimicrobial resistance in imported foods (Jung et al., 2021)
  This review summarizes the literature on the presence of antibiotic resistant organisms and clinically relevant resistance genes in imported foods. It also summarizes the scope of current national surveillance programs from 12 countries, including Canada.
   
• Audacious hitchhikers: the role of travel and the international food trade in the global dissemination of mobile colistin-resistance (mcr) genes (Hassan and Kassem, 2020)
  This peer-reviewed article describes the role of travel and imported foods in the spread of mobile colistin-resistance (mcr) genes to Canada and several other countries. Section 4 specifically highlights numerous examples of mcr transmission through both contaminated animal and plant-based food products.

Curbing transmission of AMR in the food chain

• Role played by the environment in the emergence and spread of antimicrobial resistance (AMR) through the food chain (EFSA Panel on Biological Hazards et al., 2021)
  This qualitative assessment commissioned by the European Food Safety Authority examines environmental sources and transmission routes of AMR in the food chain, identifies the main risk factors leading to their occurrence, and outlines mitigation strategies to address these risks.
   
• Slowing down the superbugs (NCCEH, 2018)
  This NCCEH blog post discusses how resistant bacterial strains can spread to humans through contaminated meat, fish, eggs and dairy products. It also highlights the role of food safety in preventing infection and minimizing the need for antibiotic treatment. 
   
• Tackling antimicrobial resistance and antimicrobial use: a pan-Canadian framework for action (Health Canada, 2017)
  This document outlines a pan-Canadian approach for tackling antimicrobial resistance and antimicrobial use. Section 3 of the document, “Core components” discusses four areas Canada should focus on to address AMR: surveillance, infection prevention and control, stewardship, and research and innovation.
   
• Addressing AMR from a food safety perspective (Clarke et al., 2016)
  This webpage discusses the role of food safety in addressing AMR and suggests resources and methods to encourage food safety across the entire food chain.
   
• Management options for reducing the release of antibiotics and antibiotic resistance genes to the environment (Pruden et al., 2013)
  This review examines environmental management options for reducing the spread of antibiotics and antibiotic resistance genes, including incentives and disincentives for action. Agriculture management and aquaculture management are discussed.