J T Gray1, T J Stabel, P J Fedorka-Cray. 1. USDA, Agricultural Research Service, National Animal Disease Center, Enteric Diseases and Food Safety Research Unit, Ames, IA 50010, USA.
Abstract
OBJECTIVE: To establish the effect of dose on persistence of and immune response to Salmonella choleraesuis in swine. DESIGN: 19 Salmonella-free pigs were allotted to 4 groups. Groups 1 (n = 5), 2 (n = 5), and 3 (n = 5) were inoculated intranasally with 10(9), 10(6), and 10(3) colony-forming units of S choleraesuis, respectively. Group 4 (n = 4) served as uninoculated controls. PROCEDURE: Pigs were monitored for clinical signs of disease and bacterial shedding. Serum and lymphocytes were obtained to measure immune responses. Pigs from groups 1, 2, and 4 were necropsied at postinoculation (PI) weeks 6 and 15. Pigs from groups 3 and 4 were necropsied at PI weeks 6 and 10. RESULTS: Pigs in group 1 shed S choleraesuis through PI week 15 and were tissue positive at PI weeks 6 and 15. Pigs in group 2 were tissue positive for S choleraesuis until PI week 6 and continued shedding through PI week 9. Salmonella choleraesuis was not recovered at any time from pigs in groups 3 or 4. Pigs in groups 1, 2, and 3 had serum IgG and IgM titers to S choleraesuis lipopolysaccharide and soluble antigens. Pigs in all groups had a lymphocyte response to concanavalin A, and pigs in groups 1 and 2 had a lymphocyte response to S choleraesuis endotoxin. Pigs in group 1 had a lower stimulation index in response to both antigens, indicating some form of lymphocyte immunosuppression. CONCLUSIONS: Persistence of S choleraesuis in host tissues is dose dependent. Short-term persistence can occur after a dose as low as 10(6) colony-forming units of S choleraesuis. Higher doses result in development of long-term carrier status, which may be related to the observed lymphocyte immunosuppression.
OBJECTIVE: To establish the effect of dose on persistence of and immune response to Salmonella choleraesuis in swine. DESIGN: 19 Salmonella-free pigs were allotted to 4 groups. Groups 1 (n = 5), 2 (n = 5), and 3 (n = 5) were inoculated intranasally with 10(9), 10(6), and 10(3) colony-forming units of S choleraesuis, respectively. Group 4 (n = 4) served as uninoculated controls. PROCEDURE: Pigs were monitored for clinical signs of disease and bacterial shedding. Serum and lymphocytes were obtained to measure immune responses. Pigs from groups 1, 2, and 4 were necropsied at postinoculation (PI) weeks 6 and 15. Pigs from groups 3 and 4 were necropsied at PI weeks 6 and 10. RESULTS:Pigs in group 1 shed S choleraesuis through PI week 15 and were tissue positive at PI weeks 6 and 15. Pigs in group 2 were tissue positive for S choleraesuis until PI week 6 and continued shedding through PI week 9. Salmonella choleraesuis was not recovered at any time from pigs in groups 3 or 4. Pigs in groups 1, 2, and 3 had serum IgG and IgM titers to S choleraesuislipopolysaccharide and soluble antigens. Pigs in all groups had a lymphocyte response to concanavalin A, and pigs in groups 1 and 2 had a lymphocyte response to S choleraesuis endotoxin. Pigs in group 1 had a lower stimulation index in response to both antigens, indicating some form of lymphocyte immunosuppression. CONCLUSIONS: Persistence of S choleraesuis in host tissues is dose dependent. Short-term persistence can occur after a dose as low as 10(6) colony-forming units of S choleraesuis. Higher doses result in development of long-term carrier status, which may be related to the observed lymphocyte immunosuppression.
Authors: Jennifer Sibley; Binbin Yue; Fei Huang; John Harding; Jill Kingdon; Manuel Chirino-Trejo; Greg D Appleyard Journal: Can J Vet Res Date: 2003-07 Impact factor: 1.310
Authors: Alexander D C Berriman; Damian Clancy; Helen E Clough; Derek Armstrong; Robert M Christley Journal: PLoS One Date: 2013-06-28 Impact factor: 3.240