Electron-beam-inactivated vaccine against Salmonella enteritidis colonization in molting hens

Authors: JESUDHASAN, PALMY - Texas A&M University; McReynolds, Jackson; Byrd Ii, James - Allen; He, Louis; Genovese, Kenneth - Ken; Droleskey, Robert - Bob; Swaggerty, Christina - Christi; Kogut, Michael - Mike; Duke, Sara; Nisbet, David; PRAVEEN, CHANDNI - Texas A&M University; PILLAI, SURESH - Texas A&M University

Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/7/2015
Publication Date: 1/7/2015
Publication URL: http://handle.nal.usda.gov/10113/61024
Citation: Jesudhasan, P.R., McReynolds, J.L., Byrd II, J.A., He, L.H., Genovese, K.J., Droleskey, R.E., Swaggerty, C.L., Kogut, M.H., Duke, S.E., Nisbet, D.J., Praveen, C., Pillai, S.D. 2015. Electron beam inactivated vaccine against Salmonella enteritidis colonization in molting hens. Avian Diseases. 59:165-170.

Interpretive Summary: Electron Beam (eBeam) technology has a variety of applications in modern society. This study tests the effects of eBeam technology on killing the food safety bacteria, Salmonella. These dead bacteria could serve as a vaccine to control live Salmonella in chickens. Microscopic studies provided evidence that eBeam treatment did not damage the cell membrane of the bacteria. The eBeam vaccine was evaluated by injecting the eBeam-killed Salmonella into the muscle of 50-week old hens. Fourteen days after the hens were vaccinated, the hens were given live Salmonella cells and then tested for invasion into the hen’s organs. Blood was collected from hens in each treatment group on day 0, 14, and 21 after vaccination and the blood was analyzed for the concentration of Salmonella-specific antibodies. Chickens that were vaccinated with the eBeam vaccine had higher Salmonella-specific antibody responses and reduced Salmonella organ colonization. The results provide evidence that eBeam based Salmonella vaccines improve the immune system and are capable of protecting chickens against Salmonella colonization. The eBeam-based vaccine technology avoids the use of chemicals and can be quickly developed for customized vaccines for addressing specific Salmonella problems on chicken farms.

Technical Abstract: Electron Beam (eBeam) ionization technology has a variety of applications in modern society. The underlying hypothesis was that electron beam (eBeam) inactivated Salmonella enterica serovar Enteritidis (SE) cells can serve as a vaccine to control Salmonella colonization and Salmonella shedding in chickens. An eBeam dose of 2.5 kGy (kilograys) was used to inactivate a high-titer (~ 108 CFU) preparation of SE cells. Microscopic studies provided evidence that eBeam irradiation did not damage the cell membrane. The efficacy of the eBeam vaccine was evaluated by administering the eBeam killed S. Enteriditis cells intramuscularly into 50-week old Single Comb White Leghorn hens. On day 14 post-vaccination, the hens were challenged orally with live SE cells (1 X 109 CFU) and SE colonization of organs was determined on day 21. Blood was collected from hens in each treatment group on day 0, 14, and 21 post-vaccination and the sera were analyzed to quantify Salmonella-specific IgG titers. Chickens that were vaccinated with the eBeam vaccine exhibited significantly (p<0.05) higher Salmonella-specific IgG antibody responses and reduced SE organ colonization. The results provide evidence that eBeam based SE vaccines are immunogenic and are capable of protecting chickens against SE colonization. The eBeam-based vaccine technology avoids the use of formalin and can be rapidly employed to develop customized vaccines for addressing specific farms or flocks.