title: Protective effects of orally administered, Klebsiella-containing bacterial lysates in mice.
abstract: The efficacy, as oral vaccines, of hepta- and mono-valent, Klebsiella-containing bacterial lysates and a number of control preparations was tested in mice. The preparations were administered during two periods of four days each, interrupted by an interval of 3 days. Fourteen days after the first dose, the animals were challenged either intraperitoneally (i.p.; peritonitis/sepsis model) or intranasally (i.n.; pneumonia model). Animals treated with low doses of Klebsiella lysate, in the form of either a 7-valent lysate or a Klebsiella monolysate, showed enhanced survival in both the peritonitis/sepsis and the pneumonia models. Hexa- and tetra-valent preparations without Klebsiella were not protective in the models tested. Furthermore, it was found that the protection is accompanied by priming for Klebsiella-specific IgG responsiveness (probably at the T cell level) and by significant IgA anti-Klebsiella serum antibody levels in about one third of the animals. The oral efficacy of Klebsiella-containing lysates suggests the presence of an adjacent component that directs Klebsiella antigen(s) to follow a selective intestinal pathway which renders them immunogenic. The identity of this component is under investigation.
authors.affiliation: Eijkman-Winkler Institute for Medical and Clinical Microbiology, Faculty of Medicine, University Hospital, Utrecht, The Netherlands.
authors.forename: J D
authors.initials: JD
authors.lastname: Kuenen
authors.forename: E E
authors.initials: EE
authors.lastname: van Dijke
authors.forename: C
authors.initials: C
authors.lastname: Hol
authors.forename: H J
authors.initials: HJ
authors.lastname: Bootsma
authors.forename: J
authors.initials: J
authors.lastname: Verhoef
authors.forename: H
authors.initials: H
authors.lastname: van Dijk
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007710:Klebsiella Infections / Q000517:prevention & control*; D007711:Klebsiella pneumoniae / Q000276:immunology* / Q000302:isolation & purification; D008297:Male; D051379:Mice; D010538:Peritonitis / Q000517:prevention & control*; D011014:Pneumonia / Q000517:prevention & control*; D018805:Sepsis / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D007070:Immunoglobulin A; D007074:Immunoglobulin G