Characterization of a Salmonella Typhimurium ghost carrying an adjuvant protein as a vaccine candidate for the protection of chickens against virulent challenge

摘要: In this study we describe the generation of a safe, immunogenic, genetically inactivated Salmonella Typhimurium ghost vaccine candidate carrying Escherichia coli heat-labile enterotoxin B subunit (LTB) protein as an adjuvant molecule. An asd(+) p15A ori(-) plasmid pJHL187-LTB harbouring E lysis gene cassette and foreign antigen delivery containing eltB was used to transform Δasd (JOL1311) strain construct strain, JOL1499. Incubation mid-logarithmic phase JOL1499 cultures at 42°C resulted in co-expression genes, leading cells LTB (Salmonella Typhimurium-LTB ghost). The production preparations confirmed by western blot analysis, functional activity bind with GM1 receptors determined means enzyme-linked immunosorbent assay. Efficacy evaluated chicken model using 56 chickens 5 weeks old, which were divided into four groups (n = 14): group A designated non-vaccinated control group, whereas birds B, C, D immunized intramuscularly 10(9), 10(8), 10(7) cells, respectively. Compared non-immunized (group A), (groups C D) exhibited increased titres plasma IgG intestinal secretory IgA antibodies. After oral challenge 10(9) colony-forming units virulent vaccinated showed decrease internal organ colonization strain.