title: Infection and reinfection of chickens with Salmonella typhimurium: bacteriology and immune responses.
abstract: Four-day-old chickens infected orally with a spectinomycin-resistant (Spcr) mutant of a highly invasive avian Salmonella typhimurium strain excreted salmonellae in the feces for at least 10 weeks. When these chickens were reinfected at this time with a nalidixic acid-resistant (Nalr) mutant of the same strain, they excreted this mutant in significantly smaller numbers (P less than 0.01) than did a previously uninfected control group. The Nalr mutant had a shorter survival rate in the tissues of the immunized chickens than in tissues of the control birds. The Spcr mutant stimulated strong IgG, IgA, and IgM responses in serum, small-intestinal contents, and bile. These were detected by enzyme-linked immunosorbent assay (ELISA) against antigens of crude whole bacterial cell protein sonicate, lipopolysaccharide, flagella, and outer-membrane proteins. There was some evidence of an anamnestic response with IgA in bile following reinfection with the Salmonella. The peak response of antibody-producing cells from the spleens of infected chickens, assayed by solid-phase ELISA, occurred at 3 weeks postinoculation. A strong delayed hypersensitivity reaction, detected by foot-pad swelling after inoculation with either whole-cell or outer-membrane proteins, was observed between 2 and 5 weeks after infection with the Spcr mutant. The data indicate that outer-membrane proteins are major immunogens for both humoral and cell-mediated arms of the immune system.
authors.affiliation: Department of Microbiology, Houghton Laboratory, Huntingdon, Cambridgeshire, United Kingdom.
authors.forename: J O
authors.initials: JO
authors.lastname: Hassan
authors.forename: A P
authors.initials: AP
authors.lastname: Mockett
authors.forename: D
authors.initials: D
authors.lastname: Catty
authors.forename: P A
authors.initials: PA
authors.lastname: Barrow
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood; D000921:Antibody-Producing Cells / Q000276:immunology; D001646:Bile / Q000276:immunology; D002432:Cecum / Q000382:microbiology; D002645:Chickens; D005243:Feces / Q000382:microbiology; D006968:Hypersensitivity, Delayed; D007111:Immunity, Cellular; D007136:Immunoglobulins / Q000096:biosynthesis / Q000097:blood; D007422:Intestines / Q000276:immunology; D011201:Poultry Diseases / Q000276:immunology* / Q000382:microbiology; D012008:Recurrence; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000382:microbiology; D012486:Salmonella typhimurium / Q000276:immunology* / Q000302:isolation & purification; D013047:Specific Pathogen-Free Organisms
chemical_list: D000907:Antibodies, Bacterial; D007136:Immunoglobulins