title: Protective immunity by oral immunization with heat-killed Shigella strains in a guinea pig colitis model.
abstract: The protective efficacy of and immune response to heat-killed cells of monovalent and hexavalent mixtures of six serogroups/serotypes of Shigella strains (Shigella dysenteriae 1, Shigella flexneri 2a, S. flexneri 3a, S. flexneri 6, Shigella boydii 4, and Shigella sonnei) were examined in a guinea pig colitis model. A monovalent or hexavalent mixture containing 1 × 10(7) of each serogroup/serotype of heat-killed Shigella cells was administered orally on Days 0, 7, 14 and 21. On Day 28, the immunized animals were challenged rectally with 1 × 10(9) live virulent cells of each of the six Shigella serogroups/serotypes. In all immunized groups, significant levels of protection were observed after these challenges. The serum titers of IgG and IgA against the lipopolysaccharide of each of the six Shigella serogroups/serotypes increased exponential during the course of immunization. High IgA titers against the lipopolysaccharide of each of the six Shigella serogroups/serotypes were also observed in intestinal lavage fluid from all immunized animals. These data indicate that a hexavalent mixture of heat-killed cells of the six Shigella serogroups/serotypes studied would be a possible broad-spectrum candidate vaccine against shigellosis.
authors.affiliation: National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM.
authors.forename: Soumik
authors.initials: S
authors.lastname: Barman
authors.forename: Hemanta
authors.initials: H
authors.lastname: Koley
authors.forename: Thandavarayan
authors.initials: T
authors.lastname: Ramamurthy
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Chakrabarti
authors.forename: Sumio
authors.initials: S
authors.lastname: Shinoda
authors.forename: Gopinath Balakrish
authors.initials: GB
authors.lastname: Nair
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Takeda
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D003092:Colitis / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control*; D004195:Disease Models, Animal; D004405:Dysentery, Bacillary / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control*; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007114:Immunization; D008297:Male; D012760:Shigella / Q000737:chemistry / Q000145:classification / Q000276:immunology*; D022281:Shigella Vaccines / Q000008:administration & dosage / Q000276:immunology*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D022281:Shigella Vaccines; D015164:Vaccines, Inactivated
keywords: heat-killed Shigella cells; hexavalent Shigella immunogen; protective immunity; shigellosis