title: Protection of piglets against enteric colibacillosis by intranasal immunization with K88ac (F4ac) fimbriae and heat labile enterotoxin of Escherichia coli.
abstract: Enterotoxigenic Escherichia coli (ETEC) is an important diarrheal agent of young domestic animals. Currently, there are no commercially available non-living vaccines to protect weaned pigs from the disease and no major veterinary biologics company markets a postweaning ETEC vaccine of any kind. While efforts have been made to develop a non-living postweaning ETEC vaccine for pigs, studies have been limited to the assessment of immune responses to experimental immunogens. In the present study, we describe a reproducible gnotobiotic piglet model of post-weaning ETEC diarrhea and efficacy tests in that model of subunit vaccines consisting of K88 (F4) fimbriae and/or heat labile enterotoxin (LT) delivered by the intranasal route. We also report antibody responses to the vaccine antigens. Piglets vaccinated with both antigens mounted a substantial immune response with serum and cecal antibody titers to K88 antigen significantly greater than those of controls. Serum anti-LT antibody titers were also significantly greater than those of controls. Piglets vaccinated with both antigens remained healthy following challenge with ETEC. At least some pigs vaccinated with either antigen alone, and most of the control piglets developed dehydrating diarrhea and suffered significant weight loss. The results of this study suggest that an intranasal vaccine consisting of both antigens is highly protective against a vigorous experimental challenge of pigs with K88+ ETEC, while that against either antigen alone is not. The current study provides a system whereby various ETEC antigens and/or combinations of antigens can be tested in exploring strategies for the development of vaccines for ETEC.
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Box 2175, Brookings, SD 57007, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Box 2175, Brookings, SD 57007, United States.
authors.forename: Kristina S
authors.initials: KS
authors.lastname: Mateo
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Box 2175, Brookings, SD 57007, United States; Brookings Biomedical, Inc., 1006 32nd Ave, Suite 106, Brookings, SD 57006, United States.
authors.forename: Mojun
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Box 2175, Brookings, SD 57007, United States.
authors.forename: Alan K
authors.initials: AK
authors.lastname: Erickson
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Box 2175, Brookings, SD 57007, United States.
authors.forename: Nuria
authors.initials: N
authors.lastname: Garcia
authors.affiliation: Department of Mathematics and Statistics, Box 2220, Brookings, SD 57007, United States.
authors.forename: Dong
authors.initials: D
authors.lastname: He
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, AK 68583, United States.
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Moxley
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Box 2175, Brookings, SD 57007, United States; Brookings Biomedical, Inc., 1006 32nd Ave, Suite 106, Brookings, SD 57006, United States. Electronic address: david.francis@sdstate.edu.
authors.forename: David H
authors.initials: DH
authors.lastname: Francis
mesh_terms: D000818:Animals; D000833:Animals, Suckling; D000942:Antigens, Bacterial / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology*; D003967:Diarrhea / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary; D054307:Enterotoxigenic Escherichia coli / Q000276:immunology*; D004768:Enterotoxins / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000276:immunology*; D022361:Escherichia coli Vaccines / Q000008:administration & dosage* / Q000276:immunology; D036781:Fimbriae Proteins / Q000276:immunology*; D010861:Fimbriae, Bacterial / Q000276:immunology; D005856:Germ-Free Life / Q000276:immunology*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines; C026888:K88 antigen, E coli; D014613:Vaccines, Attenuated; D036781:Fimbriae Proteins; C027538:heat-labile enterotoxin, E coli