Antibiotic Stewardship: A Way Forward to Ensure Antibiotics Will Continue to be Effective into the Future

By: Dr. Kev Sullivan, Production Animal Consultation Australia

Antibiotics are medicines or compounds that act to selectively kill or inhibit the growth of bacteria. Antibiotics are not effective against viruses and rely on the animal’s immune system to work effectively. Tetracyclines, penicillins, sulphonamides and macrolides are examples of antibiotics.

Antibiotic resistance refers to the acquired ability of bacteria to survive in the presence of an antibiotic that previously was able to kill or inhibit the growth of that bacteria. Resistance can be acquired by the appearance of favorable mutations or by acquiring pre-selected genes for resistance from other bacteria.

Stewardship is a collection of practices that protects valuable resources that belong to everyone, e.g., oceans, forests, rivers and air. The growing crisis of antibiotic resistance in humans has concentrated a lot of attention on the way in which antibiotics are used.

Antibiotic stewardship applies to the protection of antibiotic and other antimicrobial substances to limit antimicrobial resistance (AMR) and preserve their effectiveness so they can continue to work and maintain the health of humans and animals into the future.

In the veterinary space, antibiotic stewardship could be defined as “a multifactorial and dynamic approach to sustain the clinical efficacy of antimicrobials by optimizing drug use, choice, dose, duration and route of administration while minimizing the emergence of resistance and other adverse effects.”

Antibiotic stewardship promotes planning about how to reduce the need to use antibiotics rather than just using them judiciously.

Prudent or judicious use of antibiotics is very important and is an integral part of any stewardship program. Prudent use of antibiotics ensures that antibiotics are used at the correct dose, administered by the correct route for the correct duration to ensure that animals will respond to the treatment. Importantly, prudent use also ensures that there is no risk of antibiotic residues in the products of animals that enter the food chain by observing withdrawal periods in animals that have been treated with antibiotics.

Antibiotic stewardship programs are built around 5 core principles, also known as the 5 Rs. These are:

1. Responsibility

2. Review

3. Reduce

4. Replace

5. Refine

Responsibility: It is crucial that everyone at the feedlot, including managers, administration people, stock crew, feed team and maintenance crew, is on-board in recognizing the need to preserve the effectiveness of antibiotics. Antibiotic stewardship becomes a priority. Management supports the formation of a team to develop and implement an Antimicrobial Stewardship (AMS) plan in consultation with the consultant veterinarian. The veterinarian is an integral part of the AMS team.

Review: A review of the current status of animal health, wellbeing and antibiotic use is undertaken. In the review, areas in need of improvement are identified and a plan is put in place to drive improvement. Outcomes of the AMS plan are monitored and measured. Measurements should include the quantity of each antibiotic used and the quality of their use. The quality of use refers to if the antibiotic has been used appropriately, i.e., if the treatment protocol has been followed.

Reduce: Wherever possible the use of antibiotics should be reduced, without compromising the health and wellbeing of the animals in our care. Preventative measures include procurement policy, preparation of animals prior to feedlot entry, vaccination, animal husbandry, precise nutrition, cattle handling and better diagnosis which when combined ensure that infectious disease incidence and the need for antibiotics is minimized.

Replace: The replacement of antibiotics should be considered whenever available evidence supports the efficacy and safety of an alternative. Many products are promoted as replacement, however rigorous scientific evaluation rarely produces evidence supporting the use of these products.

Refine: Refined use means that the correct diagnosis, the correct drug at the right time, correct dose, route of administration and for the correct length of time. Record this information for analysis of both use and efficiency which will help make future decisions on treatment protocols and use.

This is a continuous cycle of improvement: Responsibility, Review, Reduce, Replace and Refine.

How to develop an Antibiotic Stewardship Plan?

The feedlot industry already has a lot of experience at maintaining high levels of animal health and wellbeing. Quality assurance programs (BQA), National Antibiotic Residue Testing schemes and the Veterinary Feed Directive (VFD) are examples of programs designed to maintain the safety and integrity of beef.

First step: The first step is to recognise and value the benefits of preserving antibiotics and make Antimicrobial Stewardship (AMS) a priority. Form an AMS team and develop a culture of everybody being on-board. It is important that the consulting veterinarian and the feedlot nutritionist are included on the team.

Second step: The next step is to ensure that there is a documented treatment protocol in place. This treatment protocol is a living document and should be reviewed regularly. The treatment protocol must be developed in conjunction with the consultant veterinarian and should cover diseases and conditions that are seen or are likely to be encountered on the feed yard. From this treatment protocol a “Prescribed Drug List” is created and includes the product, drug name, dose rate, withdrawal period and any special conditions that may apply.

Third step: The next step is to review the current antibiotic use for each antibiotic. How much is used? In consultation with your veterinarian, work out what measures are to be used. An example might be grams of Draxxin used per cwt of animals sold per month. Grams per 10,000 head days could be another approach. This is a simple mathematical calculation. Once calculated, it is time to review the usage and develop a plan on how this could be improved.

Examine how well the treatment protocol is followed –the correct drug, dose, route of administration, duration and withdrawal period.

Fourth step: Look for opportunities to change practices that may lead to reducing the need to use antibiotics. For example, improve selection of animals for examination and diagnosis. Review the approach and methods of pen riding and pen checking. Improve the accuracy of diagnosis by using the implementation of technologies such as Whisper®to refine case definition and develop treatment protocols around these case definitions.

Examine and review policies and practices such as procurement of cattle, vaccination, animal handling and husbandry practices.

Fifth step: Once areas of improvement have been identified, set some objectives. An example might be to improve diagnosis of respiratory cases and only treat with antibiotics those animals that actually need antibiotics.

Set a time frame to make progress towards the objective. For example 3, 6 or 12 months. This is a continuous review process.

An AMS plan has two approaches of measuring outcomes.

1. Quantitative – How much antibiotic is being used?

2. Qualitative – How well is the treatment protocol being followed? Correct dose, route of administration, correct timing, correct duration and correct withdrawal period.

To ensure that antibiotics will be effective into the future and to reduce the rate of development of antibiotic resistance, developing and implementing an AMS program is a way forward. This is an ongoing approach that if persisted with will continue to evolve and will produce positive outcomes for not only each feedlot and the feedlot industry but for society.