Bacteriophages – scientists' new weapon against antibiotic resistance in bacteria

• The European Union plans to introduce legislative changes that will force poultry farmers to limit the use of antibacterial drugs – it is therefore important to find other methods of limiting the development of microorganisms.
• The use of bacteriophages may soon become the preferred method of fighting bacterial drug resistance.

Antibiotic resistance of bacteria found in farm animals is a growing problem in large-scale meat and egg production, and numerous research teams are working on finding solutions to reduce the presence of drug-resistant microorganisms.

Microorganisms isolated from livestock are increasingly resistant to antibacterial drugs. The mechanisms by which bacteria are resistant to these drugs can be primary as well as acquired. The second type of resistance mechanism – acquired, is becoming a significant issue, because the microorganisms that naturally accompany animals on farms carry genes that determine drug resistance, which are often transferred to pathogenic microorganisms for humans, significantly limiting the possibility of treating infections caused by them.

The Envire project is a response to the challenge put forward by the European Union

– Methods are currently being looked for all over the world to limit the treatment of animals with antibiotics. The increased intensity of research in the European Union is related to plans to introduce legislative changes that will force poultry farmers to limit their use. This mainly concerns the limitation of the use of colistin and enrofloxacin – drugs used both to treat poultry and pigs, and bacterial infections in humans. EU Member States would like to exclude these drugs in order to be able to use them effectively in antibiotic therapy in humans. On the other hand, increasing interest in developing a strategy to reduce the use of antibiotics is associated with the European Green Deal, which assumes a reduction in sales of antimicrobials for farm animals of 50% by 2030 – explains Dr. Maciej Kuczkowski, a poultry disease specialist and member of three Leading Research Teams –  DroPOWER , WET-PPH and Inno-WET.

Dr. Kuczkowski is also a member of an interdisciplinary team led by Dr. Marta Kuźmińska-Bajor, a biotechnologist from the Department of Biotechnology and Food Microbiology, belonging to two LRTs – DroPOWER and BioTech @ Life. Dr. Kuźmińska-Bajor's team is looking for methods to reduce the build-up of drug resistance in poultry farms. This research is part of the international ENVIRE project, which has just received funding under the JPI-AMR Action Call 2021 programme.

The ENVIRE project involves scientists from nine teams from Poland, Germany, France, Lithuania and Tunisia. Members of the scientific consortium have been cooperating for many years, and the research teams were united by a common topic – the problem of drug resistance, which is related to the need to limit the use of antibiotics in poultry treatment and the transfer of resistant bacteria to the environment. Among others, the project is to include studies on the vaccination potential of poultry and methods to reduce the number of drug-resistant bacteria in manure. The Polish team, which was the only one to be given two practical tasks to perform, will research the effectiveness of bacteriophages in reducing microorganisms in litter, as well as conduct a meta-analysis of data from traditional farms and those on which poultry are kept without the use of antibiotics. The meta-analysis will identify specific strategy elements, which may be effective in reducing the number of resistant strains or may be a key factor in the development of non-antibiotic poultry production.

– Bacteriophages are naturally occurring, non-pathogenic viruses that infect bacteria and destroy them. As part of the LIDER project carried out in 2016-2020, we managed to select UPWr1-4 bacteriophages that are capable of eliminating the drug-resistant bacteria that cause poultry diseases. We assume that their use will significantly reduce the number of these bacteria on farms, and their transmission to the natural environment will be significantly reduced – explains Dr. Kuźmińska-Bajor, emphasising that the second, equally important task that her team is to perform is a meta-analysis carried out in cooperation with poultry producers with whom he has been cooperating for years. Using farm samples and information from farmers, the team will identify the good manufacturing practice factors that have the greatest impact on reducing the number of undesirable bacteria in poultry. The research results will become part of an international information platform for poultry producers around the world.

Bacteriophages – a method of fighting bacterial drug resistance

As emphasised by team member Prof. Mariusz Korczyński, head of the Department of Animal Nutrition and Feed Science and leader of the DroPOWER Lead Research Team, some countries in Asia already use bacteriophages, and in the United States they are becoming more and more popular, while in the European Union still no decisions have been made on their widespread use.

– The results of research on this method were negatively opinioned by the EFSA in 2015, but in 2021 there was a breakthrough with the registration of the first bacteriophage preparation in the European Union. There is still a lack of detailed data for a positive opinion, but the research conducted by our team as part of the ENVIRE project will certainly contribute to unambiguously demonstrating the benefits of using bacteriophage preparations, and the entire project will be the culmination of many years of work to date – says Prof. Korczyński, adding that for over two years, together with Dr. Kuczkowski and Dr. Kuźmińska-Bajor they have also been working together at the DroPOWER LRT, which brings together scientists from universities who deal with poultry in every possible aspect – from reproduction, rearing, breeding, through nutrition, prevention, treatment, the environment to the processing of poultry products. As a result, their scientific activities are even more intensified, and active cooperation with the poultry industry provides them with access to the largest producers in the country.

Although scientists are constantly looking for ways to reduce the need for antibiotic use in poultry by introducing innovative antimicrobial solutions, until a method that will fully eliminate pathogens is found, the use of antibiotics will be important to reduce disease development in poultry. At the moment, even with appropriate environmental conditions and compliance of poultry farmers with the regulations, the need to use antibacterial preparations cannot be completely eliminated.