Cell-mediated and humoral immune responses to a virulent plasmid-cured mutant strain of Salmonella enterica serotype gallinarum in broiler chickens.
One-week-old Salmonella-free broiler chicks were subcutaneously immunized and subsequently boosted two weeks later with 2x10(7)cfu 0.5ml(-1) of an 85-kb virulent plasmid-cured spectinomycin-resistant mutant strain (SG9VP(-)Spc(r)) of Salmonella gallinarum 9 (S. enterica serotype gallinarum 9) along with a control group of mock-immunized chickens. The chicks were subcutaneously challenged at 5 weeks of age with 5x10(10)cfu 0.5ml(-1) (5xLD(50)) of wild-type S. gallinarum var. Duisburg (S. enterica serotype gallinarum var. Duisburg). The cellular and humoral immune responses were measured at weekly intervals post-immunization (PI) and post-challenge (PC) using lymphocyte stimulation test (LST), delayed type hypersensitivity (DTH) test, serum tube agglutination test (STAT) and enzyme-linked immunosorbent assay (ELISA). High stimulation indices suggestive of a potent lymphocyte transformation response and high persistent serum IgG titres were recorded in immunized chickens at the termination of the experiment. These findings indicate that the live attenuated mutant vaccine induced a strong cellular and humoral immunity, which may play a role in the protection of fowl typhoid in broiler chickens.
Rana
Neeraj
N
Department of Veterinary Public Health and Epidemiology, CCS Haryana Agricultural University, Hisar 125 004, Haryana, India. nrana@scientist.com
Kulshreshtha
Ramesh C
RC
D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood; D002645:Chickens; D015169:Colony Count, Microbial / Q000662:veterinary; D007111:Immunity, Cellular; D007117:Immunization, Secondary / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood; D007279:Injections, Subcutaneous / Q000662:veterinary; D008213:Lymphocyte Activation; D009154:Mutation; D010957:Plasmids; D011201:Poultry Diseases / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D011897:Random Allocation; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000276:immunology*; D019779:Salmonella enterica / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D014613:Vaccines, Attenuated / Q000276:immunology; D014774:Virulence
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated