Article

Efficacy of a novel virulence gene-deleted Salmonella Typhimurium vaccine for protection against Salmonella infections in growing piglets

College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, South Korea.
Veterinary Immunology and Immunopathology (Impact Factor: 1.54). 02/2011; 139(2-4):250-6. DOI: 10.1016/j.vetimm.2010.08.010
Source: PubMed

ABSTRACT

We have previously developed a novel attenuated Salmonella Typhimurium (S. Typhimurium) ΔcpxR Δlon vaccine. This study was carried out to examine whether this vaccine could effectively protect growing piglets against Salmonella infection. Attenuated S. Typhimurium secreting the B subunit of Escherichia coli heat-labile enterotoxin was also used as a mucosal adjuvant. Pregnant sows in groups A and B were primed and boosted with the vaccine and mucosal adjuvant, whereas sows in groups C, D and E received PBS. Piglets in groups A and C were intramuscularly primed with formalin-inactivated vaccine and orally boosted with live vaccine, while piglets in groups B, D and E received PBS. Piglets in groups A, B, C, and D were challenged with a wild type virulent S. Typhimurium at the 11th weeks of age. Colostrum sIgA and IgG titers in vaccinated groups A and B sows were approximately 50 and 40 times higher than those of non-vaccinated groups C, D and E sows (P<0.001). Serum IgG titers of group A piglets were also significantly higher than those of groups D and E piglets during the study (P<0.001). Furthermore, no clinical signs were observed in group A piglets during the entire experimental period after the challenge, while diarrhea was observed in many of the piglets in groups B, C, and D. No Salmonella was isolated from fecal samples of the groups A and C piglets on day 14 after challenge, whereas the challenge strain was isolated from several piglets in groups B and D. These results indicate that vaccination of the piglets with the vaccine and mucosal adjuvant in addition to vaccination of their sows induced effective protection against Salmonella infections in the growing piglets.

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    • "Another possible method of on-farm control of Salmonella infections in pigs is vaccination. In most studies the use of Salmonella Typhimurium vaccines significantly decreased clinical signs and excretion of Salmonella (Springer et al., 2001;Roesler et al., 2004Roesler et al., , 2006Eddicks et al., 2009;Farzan and Friendship, 2010;Hotes et al., 2011;Hur et al., 2011). However, Denagamage et al. (2007concluded in their review that the design and reporting deficiencies in many studies (e.g. "
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    • "Heterologous antigens fused with the LTB gene in attenuated Salmonella spp. have been used to induce humoral and cellular immune responses (Qiao et al., 2009; da Hora et al., 2011; Hur et al., 2011). The oral administration of LTB has been shown to promote heterologous protein exposure to the immune system by binding with galactosyl-N-acetylgala-ctosamylsialyl-galactosylglucosylceramide (GM1) ganglioside anchored on the surface of intestinal epithelial cells, thereby producing high titres of serum antibodies in mice (Liu et al., 2011). "
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