title: Influence of route of administration on the humoral response of channel catfish (Ictalurus punctatus) to Yersinia ruckeri.
abstract: Channel catfish were inoculated intraperitoneally, intramuscularly, or intraesophageally with Yersinia ruckeri. Three antigen doses were administered by each route of injection. Four fish from each treatment were sacrificed at 5-day intervals for 40 days. Serum from each individual was tested for antibody activity against Y. ruckeri by indirect enzyme-linked immunosorbent assay (ELISA). High titers of anti-Y. ruckeri antibody were elicited by all doses (10(5) to 10(9) cells/g of fish) regardless of the route of administration. Mean titers for saline injected fish ranged up to 1:64 for each route of inoculation while mean titers for bacteria injected fish ranged up to 1:4096. Mean titers of 1:128 or greater were observed by day 15 post injection; titers peaked about day 30 and diminished thereafter. Channel catfish were most responsive to the antigen (10(7) to 10(9) cells/g of fish) when administered intramuscularly although lower doses (10(5) to 10(6) cells/g of fish) administered intraperitoneally elicited a substantial response. There was little evidence of dose-dependent responses for any of the routes of immunization. The rapid onset of relatively high serum titers suggests that the fish were mounting a secondary response to Yersinia ruckeri.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000008:administration & dosage*; D004797:Enzyme-Linked Immunosorbent Assay; D005399:Fishes / Q000382:microbiology*; D015007:Yersinia / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial