Korean J Vet Res.  2017 Mar;57(1):9-15. 10.14405/kjvr.2017.57.1.9.

Construction of a live attenuated Salmonella strain expressing FanC protein to prevent bovine enterotoxigenic Escherichia coli and evaluation of its immunogenicity in mice

• Won G
• Kim HJ
• Lee JH

• KMID: 2376873
• DOI: http://doi.org/10.14405/kjvr.2017.57.1.9

Abstract

To construct a novel vaccine candidate against bovine enterotoxigenic Escherichia coli (ETEC), FanC, the major subunit of K99 fimbriae adhesion, was inserted into secretion plasmid pYA3560 containing a β-lactamase secretion system. This was then transformed into Δasd Δcrp Salmonella (S.) Typhimurium and designated as JOL950. Secretion of recombinant fanC fimbrial antigens was confirmed by immunoblot analysis. Groups of mice were inoculated with single or double doses of JOL950. Another group was used as a negative control. Compared to control mice, all immunized mice had significantly higher levels (p < 0.05) of serum immunoglobulin (Ig)G, and secretory IgA against FanC. The IgG2a and IgG1 titer assays revealed that immunization highly induced IgG2a compared to that of IgG1, indicating that T helper-1- related cell-mediated immune responses may be elicited by JOL950. The results show that both systemic and mucosal immunities against selected fimbrial antigens of bovine ETEC expressed by a live attenuated S. Typhimurium strain are prominently produced in mice immunized with JOL950 via an oral route.

Keyword

K99 antigen; Salmonella delivery system; bovine enterotoxigenic Escherichia coli

MeSH Terms

Animals
Enterotoxigenic Escherichia coli*
Immunization
Immunoglobulin A, Secretory
Immunoglobulin G
Immunoglobulins
Mice*
Plasmids
Salmonella*
Immunoglobulin A, Secretory
Immunoglobulin G
Immunoglobulins