Develop technologies to reduce the use of antibiotics in food animal production in low- and middle-income countries

Why this research is being done

Pakistan is the 11th largest producer of poultry in the word. These products provide a high-quality and affordable source of proteins to communities throughout the country, many of which are protein-deficient. However, Pakistani poultry production faces numerous threats, from endemic and emerging diseases to extreme weather events. Currently, antibiotics are regularly included in poultry feeds to overcome some of these challenges. Here, we aimed to develop non-antibiotic technologies that could afford producers means to control bacterial infections without contributing to growing problem of antibiotic resistance in both veterinary and human medicine.

Results

We (Purdue University, Sargodha Univesity [Sargodha, Pakistan], University of the Punjab [Lahore, Pakistan]) focused on utilizing bacteriophages to target bacteria associated with fowl typhoid (Salmonella Gallinarum) and colibacillosis (avian pathogenic E. coli [APEC]). Bacteriophages are viruses that are very specific to bacteria; they infect bacteria, replicate, and cause the bacterial cell to burst. The newly replicated phages can then go on to infect and destroy other bacteria. To create prototypes, we isolated bacteriophages from waste water, sewage, and poultry waste in both the US and Pakistan. We characterized these bacteriophages in terms of: 1) the ability of these bacteriophages to kill Salmonella Gallinarum and APEC isolates obtained from diseased chickens in Pakistan; 2) growth of the bacteriophages under different extreme conditions (e.g., low pH); and 3) their genetic sequences. The antibacterial efficacy of the two prototypes was then measured in live animals receiving experimental Salmonella Gallinarum or APEC infections. In both cases, the prototypes reduced colonization of the targeted bacteria by up to 99.999%. Importantly, chickens receiving the phage prototypes grew at rates equal or greater than untreated chickens and the prototypes caused no significant changes in the overall chicken microbiome. Finally, we found that chickens do not produce an appreciable antibody response to the phages, indicating that the treatment could be used multiple times during the broiler production cycle.

In collaboration with agricultural economists, we also conducted a national-level willingness-to-pay study to better guide commercialization of the prototypes. We found that Pakistanis are very accepting of the use of "viruses" to control bacterial infections in poultry and would pay a premium for products from chickens treated with bacteriophages instead of antibiotics.

Conclusions

Working with Purdue's Office of Technology Commercialization, we have submitted to full patent applications for the two prototypes (fowl typhoid and colibacillosis) and we are currently working with potential licensees to commercialize both of them. The project was chosen for a second round of funding where we will measure the efficacy of the bacteriophage prototypes in combination with other compounds (e.g., phytochemicals from agro-wastes) to prevent fowl typhoid and colibacillosis in large-scale animal trials taking place in Pakistan. At the same time, we are using behavior theory to identify barriers to adoption of the technology and how those barriers can be lowered.

Contact information

Paul Ebner pebner@purdue.edu | 765-494-4820