Yeast Expressing a Phage Endolysin Reduces Endogenousin 21-Day-Old Broiler Chicken Intestinal Fluids.

Abstract

The phage endolysin PlyCP41 when purified fromexhibits lytic activity against(CP). The anti-clostridial activity of PlyCP41 endolysin expressed in transgenic yeast () was verified in phosphate buffered saline via mixing experiments with cultured CP and transgenic yeast slurries followed by serial dilution plating and colony counts on tryptose sulfite cycloserine (CP indicator) plates. The transgenic yeast containing PlyCP41 resulted in a log4.5 reduction (99.997%;< 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 regions (proximal, medial, and distal) from 21-day-old broiler chickens. The transgenic yeast treatment of gut slurries resulted in a log1.19, 4.53, and 1.28 reduction in proximal, medial, and distal gut slurries (90% to 99.99% of the endogenous CP;< 0.01), respectively, compared to nontreatment controls. These results indicate that the phage endolysin PlyCP41 expressed inis effective at reducing the endogenous CP in gastrointestinal fluids of broiler chickens. Future studies will measure the anti-CP effectby administering transgenic yeast to broiler chickens in the feed.