|Bearson, Bradley - Brad|
|Lee, I - Hannam University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/21/2014
Publication Date: 5/20/2014
Citation: Bearson, S.M., Bearson, B.L., Loving, C.L., Allen, H.K., Lee, I.S., Kehrli Jr, M.E. 2014. Reduced salmonella fecal shedding in swine administered porcine granulocyte-colony stimulating factor (G-CSF) [abstract]. In: Proceedings of 114th General Meeting of the American Society for Microbiology, Boston, Massachusetts, May 17-20, 2014. p. 204.
Technical Abstract: Salmonella colonization of food animals is a concern for animal health, food safety and public health. Key objectives of pre-harvest food safety programs are to detect asymptomatic Salmonella carriage in food animals, reduce colonization, and prevent transmission of Salmonella to other animals and into the environment. Various obstacles have hindered achievement of these goals, including the ubiquitous nature and numerous serovars of Salmonella; thus, simultaneous implementation of complementary intervention strategies may be required to decrease the incidence of Salmonella in food animals and prevent Salmonella outbreaks in humans. One possible intervention is the pharmaceutical use of biotherapeutic proteins, such as cytokines. Granulocyte-colony stimulating factor (G-CSF) is an immunomodulatory cytokine involved in the production, differentiation, and function of granulocytes that fight infectious disease agents such as viruses and bacteria. Our prior work in pigs has shown that G-CSF administration significantly increased circulating neutrophils. In this study, we evaluated the vectored-delivery of porcine G-CSF as a prophylactic use of a biotherapeutic protein to reduce Salmonella shedding in pigs. Crossbred pigs, five-six weeks of age, were intramuscularly injected with 1010 TCID50/pig of a replication-defective human adenovirus (Ad5) engineered to express porcine G-CSF (Ad5-GCSF; n=9). Control pigs received the same Ad5 vector without an encoded gene (Ad5-empty; n=7). Four days later, all pigs (n=16) were intranasally inoculated with 1 x 107 cfu of Salmonella enterica serovar Typhimurium UK1. Over a 7-day study, rectal temperatures (fever) were monitored, and the level of Salmonella shedding was measured by quantitative bacteriological evaluation of fecal samples. At 2 and 3 days post-challenge with Salmonella, the mock-treated pigs shed significantly more Salmonella (~104-105 cfu/g feces) than the G-CSF-treated pigs (~103 cfu/g feces). No significant difference was observed in the elevated body temperatures between treatment groups. In conclusion, pre-treatment of pigs with G-CSF reduced Salmonella shedding following experimental challenge. Evaluation of prophylactic biotherapeutics as an acceptable alternative to antibiotics in food animals will be further explored.