Written by Marta Marcinek
Wrocław University of Environmental and Life Sciences
IVSA Wrocław
Poland
Winner of SCoVE Essay Competition: Veterinary Education
Perspective on One Health
Theme : Veterinary Education Perspective on One Health
Sub-theme : Antimicrobial resistance
The discovery of antibiotics was a major turning point in the history of humanity. However, in a fast-paced world of today, the spread of antimicrobial resistance (AMR), now regarded as a major threat to global health, is fuelled mainly by inappropriate use of these otherwise miraculous drugs. Looking at this problem from a One Health perspective and trying to find ways to address it calls for a better collaboration of all parties involved. The only way to prevent a disaster is to inform and educate those who are responsible for causing it in the first place. Animal health affects human health – we are strongly connected, and so any changes in treating animals are likely to affect all people as well. The key challenge is to improve our knowledge on the matter, but also to alter people’s mindset and attitude towards this subject.
To understand the magnitude of the problem and to establish baseline for taking action, first we need to look at some facts and data. Ever-increasing number of antibiotic-resistant bacteria is mainly of animal origin and one of the reasons for that is inappropriate use of antibiotics in industrial farming. [1] People use antibiotics in food animals to have healthier, more productive farms. This has made possible to increase livestock density but at the same time it has worsened its quality of life – all in the name of decreasing the costs of food production. Large-scale farming often leads to higher levels of stress experienced by animals which result in the weakening of the immune system of livestock which in turn makes it more prone to contracting infections.
This profit-orientation and harsh living conditions of food animals mean that antibiotics are often used prophylactically as they increase muscle growth (about 4-5% more weight) and protein content in meat. To illustrate the scale of the problem, for example in Denmark in 1994 24 000 kg of glycopeptide avoparcin were used in animal feed while in the same time 24 kg of similar vancomycin were used in treating humans. [2] Both have the same mode of action resistance. What is more important, the situation in different countries was very similar. In the 20th century, Australia used 107 times more avoparcin in animal husbandry than vancomycin for human medical purposes. [2] As a result vancomycin-resistant enterococci (VRE) accrued in an alarming rate and considering this pressure it was ever so natural that different kinds of bacteria started to develop some survival mechanisms.
In addition, there are several ways of transmitting these macrobiotics to humans - one way is by food consumption or through direct contact with animals. Also manure permeating into groundwater and surface runoffs play a significant role in antibiotic contamination. Almost 90% of antibiotics meant for livestock have eventually penetrated our environment and in most cases have actively changed its microbiom. [3] Human and animal microbial ecosystems are inextricably intertwined so any animal bacteria can find a human habitat to multiple in and vice versa.
Future prospects don’t look very optimistic. The World Health Organization (WHO) has recognized AMR as one of the top three major threats to global health. [4] Moreover, growing human population – estimated to reach 9.8 billion people by 2050 – is going to lead to higher demand for food production based on livestock. [5] Seemingly the best way out of this predicament is to educate farmers and food producers. In Peru the research [6] shows that because of poor knowledge and lack of communication between veterinarians and farmers there is a lot of antibiotics misuse. In addition, another research [7] shows that in Ghana approximately 9% of antibiotic administration was carried out by veterinary officers. The remaining 91% was based on farmers’ experience only. Also majority (74%) of farmers never had any education on antibiotics and none of the farmers had ever screened manure for the antibiotic residues. It could be changed by strengthening the relationships with veterinarians and improving the diagnostic capacity of the veterinary sector.
Good hygiene and biosafety should be enforced more vigorously - it would decrease creation of new antibiotic resistant bacteria strains in environment and prevent their transmission by human vectors i.e. farm workers. Also improved welfare of food animals should decrease the need of using artificial growth promoters because of similar results. One of the best examples of such changes can be seen in the Netherlands where applying RESET Mindset Model (an interdisciplinary set of tools to promote and implement One Health ideas in food animals industry & veterinary world) led to a significant decrease in use of medicaments for farm animals. [8] Transparency and benchmarking on antibiotic usage at national and local (of a herd) levels were made compulsory. Farmers could improve their knowledge about livestock health, treatments plan and selective dry cow therapy through the dedicated programs led by the veterinarians. It helped to introduce some important changes in animal breeding. Intense cooperation - both mandatory and voluntary – together with a well-developed communication plan between the most important links of the dairy production chain made it possible to decrease antibiotics usage in the Dutch dairy cattle industry. [8] Thanks to RESET program, farmers’ views on antibiotics have changed for the better. If governments from other countries followed the suit and started to encourage farmers to introduce new production methods of breeding without such extensive usage of medicaments, then the problem of antibiotics resistance would be gradually reduced or even eliminated. Furthermore, many people are willing to pay more for their food providing the welfare of animals in production cycle was better. [9]
Unfortunately, animal husbandry isn’t changing fast enough. A growing number of infections has become harder to treat as the antibiotics used to treat them are less effective. This phenomenon has existed for over 35 years because of resistant bacteria spread in agriculture. [3] Once a resistant gene becomes widely disseminated, there is hardly any chance to trace it back to its origin. It has also taken place in hospitals where diseases such as pneumonia, tuberculosis and salmonellosis have gone out of control due to lack of new antibiotics strong enough to treat them. The most notorious example is Staphylococcus aureus. This bacteria is not only common in the environment, but also hazardous to people and as early as in 1961 a strain of MRSA (a strain of methacillin-resistant staphylococcus) was identified and has been spreading all over the world since then. [10] To see the scale of problem one must remember that methicillin to treat infections caused by this bacteria was introduced only two years earlier. S. auresus is now recognized as a major pathogen in hospital infections. In 1980s, after appearance of MRSA, most of drugs such as β-lactam, and glycopeptide antibiotics were ineffective. [11] The only available option to treat it was vancomycin.
Such medicine called avoparcin which was used in 1990s had the same mode of action as the antibiotics used as a growth factor in food animal industry. Consequently, first vancomycin-resistant staphylococcal strain (VRSA) appeared in Japan and shortly after that it was reported in several different countries. [11] Because of antibiotics overuse, E. coli easily disseminated drug resistant genes to other bacteria and as a result our treatment options were drastically limited. Nowadays in hospitals we have to deal with infections caused by gram-Pseudomonas aerugionosa and Acinetobacter baumanii bacteria which are resistant to all β-lactam antibiotics and Streptococcus pneumoniae, the most common etiological factor of pneumonia, which is increasingly resistant to penicillin, macrolides and fluoroquinolones. [12] In addition, populations in developing countries are growing significantly and so a number of animals needed in food industry is also increasing . As a result, it is predicted that the worldwide intake of agricultural antibiotics will increase by 67% in 2030. [2] The key elements which can help to avoid the looming disaster are to decrease chances of spreading bacteria and to limit the use of antibiotics whenever possible.
It is not an exaggeration to claim that human and animal health cannot be viewed separately and thus the concept of One Health should be broadly promoted not only among scientists and veterinarians, but also within the whole society. Holistic approach to One Health will help us understand the complexity of connections between people and the environment. Basic information about antibiotic-resistant bacteria should be passed to as many people as possible – after all, one day we can all be affected by this problem. The WHO has shown the need to focus on this issue by holding the World Antimicrobial Awareness Week. [13] Thanks to such actions people can learn a lot and, most importantly, change their mindset about antibiotics. Veterinarians play a key role in meeting this challenge. Regular updates of the guidelines for antibiotics administration and usage together with increased awareness in veterinary society should help to promote responsible antimicrobial stewardship.
It is essential to invest in research aimed to discover new preventive measures to improve livestock health, its vaccinations, diagnosis and to better technology of animal-based food production. A new generation of veterinary students and scientists can develop new methods of tending to farm animals as well as treating diseases with antibiotics only when necessary. It can also be a chance to show how One Health concept could assist this mission. As an example, we already observe how the usage of different probiotics and feeding strategies can improve animal growth and food production. [14] But finding new ways of optimizing production won’t be possible without scientists’ hard work which in turn will benefit the whole society.
On a farm only qualified veterinarians should be authorized to prescribe antibiotics when treating animals and only when no alternatives are available. They should also focus on better diagnosis before treating bacterial infections, because statistics show that most of antimicrobial drugs are used unnecessary. [2] It would be advisable to create a coherent policy for a better application of this type of medicines. In Sweden, the Swedish Veterinary Association has created a baseline for use of antibiotics. [15] If a group treatment of a herd is necessary, an etiological diagnose should be procured. A veterinarian who notices very high or deviant use of antibiotics on a herd level is required to start an investigation to determine its cause. This mechanism helps to control health of a herd and to reduce overuse of antimicrobial drugs. Such policy can significantly help to improve education of veterinary doctors also by providing them with the most updated information on the subject.
In today’s business-oriented world where antibiotics in farming are vastly overused and AMR is on the rise, the only way to avert the looming catastrophe is to educate the whole society. By promoting good practices at all stages of production (hygiene standards, biosafety etc.) we can reduce antibiotics usage in livestock. Furthermore by better collaboration we can not only improve diagnostics and animal breeding but also increase awareness of antimicrobial stewardship among students, veterinary doctors and as well as farmers and other professionals closely related to the subject. As more knowledge can lead to better solutions, I think it is the only way to address this public health concern and to prevent its escalation.
References and Notes:
Khachatourians G.G. (1998), Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria. Canadian Medical Association.
Witte, W. (1998), Medical Consequences of Antibiotic Use in Agriculture. Science.
Iwu, C. D., Korsten, L., & Okoh, A. I. (2020), The incidence of antibiotic resistance within and beyond the agricultural ecosystem: A concern for public health. Microbiology Open.
O'Neill, J. (2016), Tackling drug resistant infections globally: final report and recommendations. The Review On Antimicrobial Resistance
United Nations - Department of Economic and Social Affairs, Population Division (2017), World Population Prospects: The 2017 Revision, Key Findings and Advance Tables. Working Paper No. ESA/P/WP/248
Benavides, J.A., Streicker, D.G., Gonzales, M.S., Rojas-Paniagua, E., Shiva, C. (2021), Knowledge and use of antibiotics among low-income small-scale farmers of Peru. Preventive Veterinary Medicine vol. 189
Phares, C. A., Danquah, A., Atiah, K., Agyei, F. K., Michael, O.-T. (2020), Antibiotics utilization and farmers’ knowledge of its effects on soil ecosystem in the coastal drylands of Ghana. PLOS ONE
Lam, T. J. G. M., Jansen, J., Wessels, R. J. (2017), The RESET Mindset Model applied on decreasing antibiotic usage in dairy cattle in the Netherlands. Irish Veterinary Journal
Busch, G., Kassas, B., Palma, M. A., & Risius, A. (2020), Perceptions of antibiotic use in livestock farming in Germany, Italy and the United States. Livestock Science
Enright M.C., Robinson D.A., Randle G., Feil E.J., Grundmann H., Spratt B.G. (2002), The evolutionary history of methicillin-resistant Staphylococcus aureus (MRSA). Proceedings of National Academy of Sciences of the USA
Tiwari, H. K., & Sen, M. R. (2006), Emergence of vancomycin resistant Staphylococcus aureus (VRSA) from a tertiary care hospital from northern part of India. BMC Infectious Diseases
Euler, C.W., Ryan, P.A., Martin, J.M., Fischetti, V.A. (2007), M.SpyI, a DNA Methyltransferase Encoded on a mefA Chimeric Element, Modifies the Genome of Streptococcus pyogenes. Journal of Bacteriology
https://www.who.int/news-room/fact-sheets/detail/antibiotic-resistance (accessability: 23.06.2021)
Dowarah, R., Verma, A. K., & Agarwal, N. (2017), The use of Lactobacillus as an alternative of antibiotic growth promoters in pigs. Animal Nutrition
Winding, S. (2019), Swedish dairy farmers’ attitude towards the use of antibiotics. Faculty of Veterinary Medicine and Animal Science