Protection against neonatal Escherichia coli diarrhea by vaccination of sows with a novel multivalent vaccine candidate expressing E. coli adhesins associated with neonatal pig colibacillosis

摘要: In this study, we investigated the optimal condition of a novel multivalent Escherichia coli vaccine candidate for protection efficacy against E. colibacillosis in piglets via booster strategy using oral and intramuscular administration routes. The was constructed an expression secretion plasmid attenuated Salmonella delivery system as described earlier. Pregnant sows were divided into four groups three each immunized with mixture individual strains. Sows primed boosted at 8 11 weeks pregnancy. Group A intramuscularly orally. B C orally boosted. D PBS control. serum IgG IgA levels to adhesin antigens elevated compared controls, colostral all sows. addition, from significantly increased. These data suggest that systemic immune responses highly induced by vaccination candidate. After challenge virulent strain coli, clinical signs such diarrhea mortality not observed suckling sows, while affected 100% 25% control group piglets, respectively. findings indicate immunization irrespective routes can effectively protect their neonatal diarrhea.