• Vaccine Name: deltaphoP/Q S. typhimurium strains expressing PEB1-ss
• Target Pathogen: Campylobacter jejuni
• Target Disease: Campylobacterosis
• Vaccine Ontology ID: VO_0004124
• Type: Recombinant vector vaccine
• Antigen: Campylobacter PEB1 is an adherence factor that is highly immunogenic in humans (Sizemore et al., 2006).
• Preparation: Three live, attenuated deltaphoP/Q Salmonella enteric serovar Typhimurium strains expressing PEB1 minus its signal sequence (PEB1-ss) from three different plasmids were prepared. The three plasmids include a pBR-based asd plasmid, an arabinose-based runaway plasmid, which each expressed PEB1-ss in the bacterial cytosol, and a PEB1::HlyA fusion plasmid that directs secretion of PEB1-ss into the extracellular milieu (Sizemore et al., 2006).
• Virulence: PEB1 is an adherence factor that is highly immunogenic in humans (Sizemore et al., 2006).
• Description: PEB1, the major cell-binding factor of Campylobacter jejuni, is a homolog of the binding component in Gram-negative nutrient transport systems (Prokhorova et al., 2006).

Mouse Response

• Host Strain: Female, BALB/c Mouse Specific Pathogen Free (MSP) 7–9 weeks of age from Taconic
• Vaccination Protocol: Mice that had been acclimated for 5 days were vaccinated with freshly prepared inocula on days 1 and 12 of the experiment by pipet feeding. The target concentration for this experiment was 1–2.5E8 in 50 μl (Sizemore et al., 2006).
• Persistence: MGN4735 was able to colonize the intestine to a high level over the entire test period of 9 days post-inoculation while those mice that survived challenge with 81-176 cleared the infection (Sizemore et al., 2006).
• Immune Response: Serum IgG responses specific for PEB1-ss were induced by pBR-derived and runaway plasmids, with 100 and 90% seroconversion, respectively, at a 1:500 dilution of anti-sera as measured by Western blot analysis, while the PEB1-ss::HlyA fusion plasmid induced serum IgG in only 20% of the mice (Sizemore et al., 2006).
• Side Effects: no adverse side effects were observed
• Challenge Protocol: Challenge of vaccinated BALB/c mice was based on the model developed by Baqar et al. (Baqar et al., 1995b). C. jejuni strain 81-176 served as the challenge strain in the oral model (Sizemore et al., 2006).
• Efficacy: Although significant levels of anti-PEB serum IgG were induced, no protection against oral Campylobacter jejuni challenge was observed (Sizemore et al., 2006).
• Description: Three live attenuated ΔphoP/Q Salmonella enteric serovar Typhimurium strains expressing PEB1 minus its signal sequence (PEB1-ss) from three different plasmids: a pBR-based asd plasmid, an arabinose-based runaway plasmid, which each expressed PEB1-ss in the bacterial cytosol, and a PEB1::HlyA fusion plasmid that directs secretion of PEB1-ss into the extracellular milieu are described above (Sizemore et al., 2006).