Glossary of Terms: Antimicrobial Resistance

Publication Summary

NCCID is working with a number of partners to provide current evidence and knowledge on antimicrobial resistance for public health stakeholders. This Glossary of Terms was developed for NCCID by Katrime Integrated Health. The authors conducted a review of peer-review literature and analyzed terminology usage. The intent of this document is to provide public health practitioners and policy makers across disciplines with a lexicon that can lead to consensus. We welcome your comments on this glossary.

Disponible seulement en version anglaise.

Published: 2016

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Project No. 268

NCCID is working with a number of partners to provide current evidence and knowledge on antimicrobial resistance for public health stakeholders. This Glossary of Terms was developed for NCCID by Katrime Integrated Health. The authors conducted a review of peer-review literature and analyzed terminology usage. The intent of this document is to provide public health practitioners and policy makers across disciplines with a lexicon that can lead to consensus. We welcome your comments on this glossary.


Term Definition Source
Active Pharmaceutical Ingredients (API) The biologically active ingredients in a pharmaceutical drug. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada.
Alternative products Strategies or products other than antimicrobials that could be used for either disease prevention or therapy. For example vaccines, phage therapy, lysines, antibodies, probiotics, immune stimulation, and peptides, as well as improved biosecurity practices and sanitation. In agriculture, this would also include improved best practices for management, housing, production systems, and husbandry. O'Neill, J. (2016). Tackling Drug-Resistant Infections Globally: Final Report and Recommendations. Review on antimicrobial resistance to the Government of the United Kingdom. HM Government, London.
Antibiotic resistance The genetically-acquired capacity for bacteria to withstand antibiotic treatment. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Antimicrobial agent A general term for drugs, chemicals, or other substances that either kill or slow the growth of microbes. Different classes exist that are specific to the class of microbe, including: antibacterial drugs (antibiotics) that treat bacterial infections; antiviral agents that treat viral infections; antifungal agents that treat fungi; and antiparasitic agents that treat parasites. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); World Health Organization (2015). Antibiotic Resistance Fact Sheet.
Antimicrobial stewardship Coordinated interventions designed to promote, improve, monitor, and evaluate the judicious use of antimicrobials so as to preserve their future effectiveness and to promote and protect human and animal health. Antimicrobial stewardship encompasses the 5Rs of AMU: responsibility, reduction, refinement, replacement, and review. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Antimicrobial susceptibility tests Used to determine to which specific antimicrobials a particular pathogen is sensitive. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Antimicrobial use (AMU) How antimicrobials are used, including treatment goal, treatment of populations versus targeted individuals, duration of use, route of administration, and species treated (i.e. human, animal, or plant). Ardal, C., et al (2016). International cooperation to improve access to and sustain effectiveness of antimicrobials. Lancet, 387(10015).
Appropriate use AMU that maximizes therapeutic impact while minimizing toxicity and the development of resistance. This should not be interpreted simply as reduced use. Bell, D.M., (2001). Promoting appropriate antimicrobial drug use: perspectives from the Centers for Disease Control and Prevention. Clinical Infectious Diseases, 33(3).
Acquired resistance When a particular microorganism obtains the ability to resist a particular antimicrobial agent to which it was previously susceptible. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Benchmarking AMU Organizing multiple hospitals into networks to allow for inter-hospital comparison of antimicrobial use. Comparison of antimicrobial use by farm or of prescription history by veterinarian. This is considered a valuable national and farm-level management tool in promoting antimicrobial stewardship and reducing AMU. Ibrahim, O.M. and Polk, R.E. (2012). Benchmarking antimicrobial drug use in hospitals. Expert Review of Anti-infective Therapy, 4; Marian, E.H., et al (2015). Antimicrobial prescription patterns of veterinarians: introduction of a benchmarking approach. Journal of Antimicrobial Chemotherapy. Dio:10.1093/jac/dkv104
Broad-spectrum antibiotic Antibiotics that work against a wide range of Gram-positive and Gram-negative bacteria. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Combination therapy Treatment involving more than one drug. A rationale for use of combination therapy has been the lesser likelihood that a pathogen develops resistance to multiple drugs Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Community-acquired infection Infection acquired in the community by someone who has not been recently hospitalized nor had a recent medical procedure. World Health Organization (2014). Antimicrobial Resistance: Global Report on Surveillance.
Community-setting Refers to where antimicrobials are used or prescribed outside of a hospital or emergency-room setting; for example, a private medical or veterinary clinic, pharmacies, or public health centres. Hansen, M.P., et al (2015). Antibiotic resistance: What are the opportunities for primary care in alleviating the crisis? Frontiers in Public Health, 3(35); (PHAC). Public Health Agency of Canada (2015). Canadian antimicrobial resistance surveillance system – Report 2015: protecting Canadians from illness. March 2015.
Computer-based decision support Support programs to provide real-time recommendations on antimicrobial choice that links national or local antimicrobial formularies to computerized systems. Guardabassi, L. and Prescott, J.F. (2015). Antimicrobial stewardship in small animal veterinary practice: from theory to practice. Vet. Clin. North Am. Small Anim, 45.
Critically important antimicrobials A classification system described by the World Health Organization (WHO) and the World Organization for Animal Health (OIE) for medical and veterinary antimicrobials, respectively, that defines the two criteria used to classify antimicrobials by their level of importance. For veterinary antimicrobials, Criteria 1 is that the importance of the antimicrobial class is widely recognized, and; Criteria 2 is that the antimicrobial agents in this class are widely identified as essential for the treatment of serious animal disease and few alternatives are available. For human medical antimicrobials, Criteria 1 is that the antimicrobial agent is used as the sole therapy or one of few alternatives to treat serious human disease, and; Criteria 2 is that the antimicrobial agent is used to treat diseases caused by either a) organisms that may be transmitted via non-human sources or b) diseases caused by organisms that may acquire resistance genes from non-human sources. Both veterinary and human medical antimicrobial agents are thus classified based on whether they meet their respective criteria, i.e. they are classified as: 'critically important' if they meet criteria 1 and 2, 'highly important' if they meet criteria 1 or 2, and 'important' if they meet neither criteria 1 nor 2. World Health Organization (2011). Critically Important Antimicrobials for Human Medicine, 3rd revision.; Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Defined Daily Dose (DDD) Assumed average maintenance dose per day for a drug used for its main indication in its target species. World Health Organization (2003). Introduction to Drug Utilization Research.
Disease prevention Activities designed to protect patients (or other members of the public or animals) from actual or potential health threats and their harmful consequences. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Dose optimization The time course of drugs in the body with reference to their absorption, distribution, metabolism, and elimination. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Drivers of antimicrobial resistance (AMR) Increased and continued transmission of antimicrobial resistance mechanisms to other microbes by standards of infection control, sanitation, access to clean water, access to assured quality antimicrobials and diagnostics, travel, and migration. Although emergence of antimicrobial resistance in microorganisms is a natural phenomenon, antimicrobial resistance selection can be expedited by antimicrobial exposure in healthcare, agriculture, and the environment. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Efflux pump A resistance mechanism that allows bacteria to pump out any antibiotics that penetrate them. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Empirical diagnosis and/or treatment A diagnosis or treatment on the basis of a clinical educated guess in the absence of complete or perfect information. Clinicians use their expertise, intuition and professional judgement to ‘guess’ whether an infection is present and what is likely to be causing it, and thus the most appropriate treatment. O'Neill, J. (2015). Rapid Diagnostics: Stopping Unnecessary Use of Antibiotics. Review on antimicrobial resistance to the Government of the United Kingdom. HM Government, London.
Extended spectrum Beta-lactamase A bacterial enzyme that inactivates some antibiotics, such as penicillin. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Extra-label drug use (ELDU) A process by which Canadian veterinarians are able to prescribe the use of a drug in a way other than the approved uses listed on the label, i.e. to treat a different species or use an alternate dose or route of administration. The veterinarian is responsible for the safety to the animal and end food product, and efficacy of the treatment. The veterinarian must also obtain informed consent from the animal's owner when prescribing ELDU and adhere to Health Canada regulations and guidelines on drugs prohibited for us in food producing animals or other situations. Commonly referred to as 'Off-Label' drug use, e.g., 'I am using this drug off-label to treat this goat.' National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada.
Feed additives Antimicrobials added to animal feed for growth promotion or disease prevention purposes. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
First choice, restricted, and reserve drugs First choice drugs are classified as antimicrobials that can be prescribed without restriction by any authority; Restricted drugs can be prescribed for a specific indication as defined by a policy or with expert consultation; Reserve drugs can be prescribed only after permission from expert consultation or national expert committee. Guardabassi, L. and Prescott, J.F. (2015). Antimicrobial stewardship in small animal veterinary practice: from theory to practice. Vet. Clin. Small North Am. Anim, 45.
Gram stain A laboratory staining technique used to distinguish between two groups of bacteria, Gram-positive and Gram-negative that differ in their cell wall structure. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Growth promotion Administration of an antimicrobial, usually as a feed additive, over a period of time to growing animals that is thought to result in improved physiological performance (i.e. weight gain, feed conversion). Pattern characteristics: long duration of use, group administration in feed. Veterinary example: antibiotics in feed for cattle, pigs, and poultry. No human medical equivalent. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Healthcare associated infection (HAI) See 'nosocomial infection'
Highly important antimicrobials See 'critically important antimicrobials'
Hospital-acquired infection See 'nosocomial infection'
Husbandry The art, science, and tradition that encompass responsible livestock production, which includes providing appropriate facilities that provide for animal comfort, adequate space, proper flooring, ventilation, heating, and access to clean water. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada; Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Important antimicrobials See 'critically important antimicrobials'
Inappropriate antimicrobial use When antimicrobials are used unnecessarily or for non-therapeutic reasons, such as over prescribing or as feed additives in agriculture. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Inappropriate disposal When active antimicrobials are disposed of in such a way that they potentially contaminate the environment, i.e. share their resistance mechanisms with the ‘normal’ bacterial living in that environment. One example would be flushing antimicrobials down a toilet. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Infection prevention and control interventions (IPCI) Interventions intended to minimize the spread of pathogens (including those that are resistant), decrease the likelihood of infection in health-care settings, and reduce the overall need for antimicrobials. The WHO has proposed 4 core areas for health-care facilities, including hand hygiene, environmental cleaning, disinfection and sterilization, and education of staff. Ardal, C., et al (2016). International cooperation to improve access to and sustain effectiveness of antimicrobials. Lancet, 387(10015); Dar, O.A, et al (2016). Exploring the evidence base for national and regional policy interventions to combat resistance. Lancet, 387
Innovation Creating new solutions to counteract loss in antimicrobial effectiveness through research and development. For example, developing new and/or improved rapid diagnostic tests or alternatives to antimicrobials, such as probiotics or vaccinations. Dar, O.A, et al (2016). Exploring the evidence base for national and regional policy interventions to combat resistance. Lancet, 387; National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada.
Intrinsic resistance See 'natural resistance'
Judicial use See 'responsible use'
Mechanisms of antimicrobial resistance The way that a microbe becomes resistant to an antimicrobial drug, e.g. acquisition of resistance genes. Three fundamental mechanisms of antimicrobial resistance are (1) enzymatic degradation of antibacterial drugs, (2) alteration of bacterial proteins that are antimicrobial targets, and (3) changes in membrane permeability to antibiotics. However, there are many mechanisms and the science is continually updated. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).; Dever, L.A., Dermody, T.S. (1991). Mechanisms of bacterial resistance to antibiotics. Arch Intern Med. 151(5).
Medically important antimicrobials Antimicrobials that are considered important to treat either human or animal disease. See also 'critically important antimicrobials.' Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Medically important pathogens Microbes that cause important clinical or economic disease in either animals or humans or both. See also 'priority microbes. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Metaphylaxis Mass treatment of populations currently experiencing any level of disease before the onset of clinical illness. Pattern characteristics: short duration of use, group administration through injection, feed, or water. Veterinary example: control of bovine respiratory disease (BRD) in feedlot cattle through injection of animals with antimicrobials on arrival at the feedlot. Human medical example: risk management for those potentially exposed to a specific pathogen, e.g. Streptococcus pneumonia or highly pathogenic H5N1 avian influenza virus. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Methicillin-resistant Staphylococcus aureus (MRSA) A type of Staphylococcus aureus bacterium resistant to methicillin and other beta-lactam antibiotics. No longer confined to hospitals, MRSA has caused infectious outbreaks in community groups. Gleband et al. (2015). State of the World’s Antibiotics. Center for Disease Dynamics, Economics and Policy. CDDEP: Washington, D.C.
Multi-drug resistant organism A microbe that is resistant to the effect of more than one antimicrobial drug, i.e. multiple distinct drugs do not kill the microbe. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Multiple-drug resistance A phenomenon when one or more micro-organism is resistant to the effects of more than one antimicrobial drug (i.e. the drug no longer works to kill the microbe). Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Natural resistance Innate ability of a bacterial species to resist activity of a particular antimicrobial agent through its inherent structural or functional characteristics, which allow tolerance of a particular antimicrobial drug or class. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Non-therapeutic use of antimicrobials When antimicrobials are used without providing a health benefit to those being treated, e.g. feeding antimicrobials to animals for growth-promotion purposes, a practice that is well-documented to be associated with the emergence of antimicrobial resistance in the animals treated. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Nosocomial infection An infection acquired in the hospital, excluding infections incubating at time of admission. (WHO). World Health Organization (2011). Burden of endemic health care-associated infections worldwide.
Off-label drug use See "Extra-label Drug Use"
'One Health' approach A method of determining policies that bridge human, animal, and environmental health, and accounts for factors relevant to each of these sectors. Dar, O.A, et al (2016). Exploring the evidence base for national and regional policy interventions to combat resistance. Lancet, 387
Optimal duration treatment The ideal length of time for treatment with antimicrobials to prevent disease relapse and antimicrobial resistance, and also to ensure patient safety and cost-effectiveness. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Over the Counter (OTC) Antimicrobials that can be obtained without a medical doctor or veterinary prescription. Lewis, C.A. (2016). Veterinary Drugs, Antimicrobial Resistance and Food Safety: FDA CVM’s Antimicrobial Resistance Policy.
Own Use Importations (OUI) A Canadian regulation that permits animal owners to import antimicrobials without regulatory oversight to be used in their own operation, regardless of the size of the operation. Animals treated with these antimicrobials are permitted to enter the human food chain, even though regulatory agents are not allowed to identify the specific agent or quantify how much is being imported or used on farm. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada.
Priority microbes Micro-organisms considered most important in the spread of antimicrobial resistance, including those important for clinical disease impact, spectrum of resistance, appearing in novel environments or geographical regions, and/or economic consequences. See also 'medically important pathogens.' Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Prophylaxis Administration of an antimicrobial to exposed healthy animals considered to be at risk for developing a disease, but prior to the onset of the disease symptoms and for which no etiologic agent has yet been confirmed by culture or other detection methods. Pattern characteristics: intermediate duration of use, group administration of the antimicrobial through injection, feed, or water. Veterinary example: medicated milk replacer fed to calves to prevent diarrhea; human medical example: antimicrobials given through injection or by oral administration before surgical procedures (pre-operative prophylaxis). Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Prudent use See also 'responsible use'. Sometimes used as shorthand to refer to the 2008 document developed by the Canadian Veterinary Medical Association (CVMA) as guidelines to veterinarians on responsible use of antimicrobials both at the general and species level. Canadian Veterinary Medical Association, (2008). CVMA Antimicrobial Prudent Use Guidelines 2008 for Beef Cattle, Dairy Cattle, Poultry and Swine.
Rapid diagnostic tools A quick and easy-to-perform test for a specific microbe that formerly only laboratory tests could measure; they are intended to provide point of care and same day results to reduce unnecessary antimicrobial use. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Rational antimicrobial use See 'responsible use'
Regulatory maximum discharge A proposed limit to the amount of active pharmaceutical ingredient (API) that may be discharged from a facility, such as a hospital or farm operation. O'Neill, J. (2016). Tackling Drug-Resistant Infections Globally: Final Report and Recommendations. Review on antimicrobial resistance to the Government of the United Kingdom. HM Government, London.
Resistance prevalence The number of cases of a disease caused by antimicrobial resistance that are present in a particular population at a given time. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Resistant (microbe) A microbe that is unaffected by an antimicrobial, i.e. that is able to withstand treatment with antimicrobials. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Responsible use This term implies that activities and capabilities of human and animal health systems are aligned to ensure that patients receive the right treatment at the right time, use these drugs appropriately, and benefit from them. Dar, O.A, et al (2016). Exploring the evidence base for national and regional policy interventions to combat resistance. Lancet, 387
Reversibility of resistance The observed fitness cost of resistance genes and/or mutations to a resistant microbe is a prerequisite for the reversal of antibiotic resistance by reduced antibiotic use. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Ribosomal protection A resistance mechanism that allows bacteria to interfere with an antibiotic's ability to prevent the bacteria to make proteins necessary for their survival. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Selective toxicity A drug's ability to target pathogens such as bacteria or viruses without damaging the host organism. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Societal drugs Drugs whose use and misuse have societal consequences well beyond the individual who is taking them (e.g. Antimicrobials are considered societal drugs because once they become ineffective, they are ineffective for everyone, not just the person taking them. Levy, S.B. (1998). The challenge of antibiotic resistance. Scientific American, March; Levy, S.B. (2002). Factors impacting on the problem of antibiotic resistance. Journal of Antimicrobial Chemotherapy,49.
Spectrum of activity The range of an antimicrobial's effectiveness, i.e. able to kill multiple types of microbes or specialized to target one type of organism. See ‘broad-spectrum antibiotic' Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Squeezing the balloon An analogy used when describing how selection pressure would simply shift to a new antimicrobial without addressing issues of inappropriate use. The uncertainty of whether reducing the rates of resistance to drug X, if accomplished by a switch to the use of drug Y, would result in increased rates of resistance in drug. Y. Bell, D.M., (2001). Promoting appropriate antimicrobial drug use: perspectives from the centers for disease control and prevention. Clinical Infectious Disease, 33(3).
Static activity An antibiotic's ability to disarm bacteria without killing the bacteria. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Stewardship Conserving the effectiveness of existing treatments through infection prevention and control guidelines, education and awareness, regulations, and oversight. The multi-faceted and dynamic approaches required to sustain the clinical efficacy of antimicrobials by optimizing drug use, choice, dosing, duration, and route of administration while minimizing the emergence of resistance and other adverse effects. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada.
Sub-therapeutic Involving or relating to drug dosages administered at too low a level to produce a therapeutic effect, i.e. below the level necessary to treat disease, but the presence of the antimicrobial even at low levels can promote resistance in the microbe population being treated; antimicrobials administered at a level not powerful enough to have a therapeutic effect. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Superbugs Bacteria with resistance to several commonly used antibiotics. World Health Organization (2014). What is antimicrobial resistance Q & A.
Surveillance Detecting and monitoring trends and threats in order to inform strategies to reduce the risks and impacts of antimicrobial resistance (AMR).,National Farmed Animal Health and Welfare Council (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada."
Susceptible (microbes) Microbes that are vulnerable to the therapeutic effect of antimicrobials, i.e. they are destroyed by antimicrobials. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014).
Therapeutic Antimicrobials administered at a level capable of treating disease. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Treatment Administration of an antimicrobial to an animal or person that exhibits frank clinical disease. Pattern characteristics: short duration of use and targeted administration to an individual by injection or orally. Veterinary example: antibiotic injection to treat a cow with foot rot. Human medical example: oral antibiotics to treat a urinary tract infection. Holmes, A.H., et al (2016). Understanding the mechanisms and drivers of antimicrobial resistance. Lancet, 387(10014); Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Unmetabolized antibiotics Antibiotics that are excreted in an active form from animals/humans that enter the environment, including water and sewage systems. Marshall, B.M. and Levy, S.B. (2011). Food animals and antimicrobials: impacts on human health. Clinical Microbiology Reviews, 24; O'Neill, J. (2016). Tackling Drug-Resistant Infections Globally: Final Report and Recommendations. Review on antimicrobial resistance to the Government of the United Kingdom. HM Government, London.
Unnecessary use See 'inappropriate use'
Veterinary Client Patient Relationship (VCPR) A pre-requisite to establish medical need and consequently to prescribe or dispense antimicrobials, a VCPR is an on-going working relationship (not a contractual agreement) between the veterinarian, client, and specific animal patient(s) established on trust. The exact definition is defined by provincial legislation, however Canadian Veterinary Medical Association Antimicrobial Prudent Use Guidelines (2008) considers the following conditions consistent with provincial legislation: 1. The veterinarian has assumed the responsibility for making clinical judgments regarding the health of the animal(s) and the need for medical treatment, and the client has agreed to follow the veterinarian’s instructions. 2. The veterinarian has sufficient knowledge of the animal(s) to initiate at least a general or preliminary diagnosis of the medical condition of the animal(s). This means that the veterinarian has recently seen and is personally acquainted with the keeping and care of the animal(s) by virtue of an examination of the animal(s) or by medically appropriate and timely visits to the premises where the animal(s) are kept. 3. The veterinarian is readily available for follow-up evaluation, or has arranged for emergency coverage, in the event of adverse reactions or failure of the treatment regimen. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada.
Veterinary critically important antimicrobials See 'critically important antimicrobials'
Veterinary Drugs Directive Located in Ottawa, the Veterinary Drugs Directorate (VDD) is part of the Health Products and Food Branch of Health Canada. To protect human and animal health and the safety of Canada's food supply, the Veterinary Drugs Directorate (VDD) evaluates and monitors the safety, quality and effectiveness, sets standards, and promotes the prudent use of veterinary drugs administered to food-producing and companion animals.  hc-sc.gc.ca
Veterinary Feed Directive In the US, a written statement that authorizes the owner or caretaker of animals to obtain and use animal feed containing VFD (veterinary feed directive)-specific drugs to treat their animals in accordance with FDA-approved directions for use. A VFD drug is intended for use in animal feeds, and such use of the VFD drug is permitted only under the professional supervision of a licensed veterinarian. Lewis, C.A. (2016). Veterinary Drugs, Antimicrobial Resistance and Food Safety: FDA CVM’s Antimicrobial Resistance Policy; fda.gov
Veterinary important antimicrobials See 'critically important antimicrobials'
Veterinary oversight A standard definition to apply across provinces and territories is currently being developed by the Canadian Veterinary Medical Association Veterinary Pharmaceutical Stewardship Advisory Group. Generally, includes veterinary guidance during the use of antimicrobials and that there is a current Veterinary Client Patient Relationship. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada; Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).
Withdrawal times The specific period of time from when the last antimicrobial was administered to an animal until the time that it may enter the human food chain. The specific time varies with antimicrobial drug administered, route of administration, and animal species treated. National Farmed Animal Health and Welfare Council, (NFAHWC) 2016. Antimicrobial Stewardship in Food Animals in Canada. Page, S.W., and Gautier, P. (2012). Use of antimicrobial agents in livestock. Rev. Sci. Tech. Off. Int. Epiz.31(1).

Production of this document has been made possible through a financial contribution from the Public Health Agency of Canada through funding for the National Collaborating Centres for Public Health (NCCPH).

The views expressed herein do not necessarily represent the views of the Public Health Agency of Canada. Information contained in the document may be cited provided that the source is mentioned.