Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2024
Publication Date: 5/16/2024
Citation: Barnas, M.R., Attuquayefio, W.D., Donovan, D.M., Skory, C.D., Hammond, R.W., Siragusa, G.R., Timmons, J.R. 2024. Yeast Expressing a Phage Endolysin Reduces Endogenous Clostridium perfringens Ex Vivo in 21-Day-Old Broiler Chicken Intestinal Fluids. Avian Diseases. 68(2):129-133. https://doi.org/10.1637/aviandiseases-D-23-00088.
DOI: https://doi.org/10.1637/aviandiseases-D-23-00088

Interpretive Summary: Necrotic enteritis (NE) is a prevalent and often fatal gastrointestinal disease in poultry caused by the bacterium Clostridium perfringens. NE not only impacts the health and welfare of chickens, but global losses have been estimated to cost the poultry industry $6 billion annually. Antibiotics were commonly used for the treatment and prevention of NE. However, alternative antimicrobial solutions are necessary to address rising concerns about antibiotic resistance. In this study, we developed a novel approach to control Clostridium perfringens using an enzyme, called phage endolysin PlyCp41, that has the unique ability to selectively target and destroy the harmful bacterium. This enzyme was produced using modified yeast so that it could eventually be included in animal feed to control NE. We found that this modified yeast was able to eliminate up to 99.99% of the harmful bacteria in laboratory testing and experiments using the contents from chicken intestines. These promising results suggests that incorporating this modified yeast into chicken feed could serve as an effective strategy to control this devastating disease, reducing dependency on antibiotics.

Technical Abstract: The phage endolysin PlyCP41 when purified from Escherichia coli exhibits lytic activity against Clostridium perfringens (Cp) in vitro. The anti-clostridial activity of PlyCP41 endolysin expressed in transgenic yeast (Saccharomyces cerevisiae) was verified in phosphate buffered saline (PBS ) via mixing experiments with cultured Cp and transgenic yeast slurries followed by serial dilution plating and colony counts on TSC (Cp indicator) plates. The transgenic yeast containing PlyCP41 eliminated 99.997% (P<0.01) of the cultured Cp. In addition, this serial dilution plating assay was used to demonstrate that transgenic yeast slurries could reduce the endogenous Cp content in fluids from three different gastrointestinal (GIT) regions (proximal, medial, and distal) from 21-day-old broiler chickens. The transgenic yeast slurries eliminated 90 to 99.99% of the endogenous Cp (P<0.01). These results indicate that the phage endolysin PlyCP41 expressed in S. cerevisiae is highly effective at reducing the endogenous Cp in the presence of gastrointestinal fluids of broiler chickens. Future studies will measure the anti-Cp effect in vivo by administering transgenic yeast to broiler chickens in the feed.