Effect of Experimental Zinc Deficiency on Immunological Responses in Salmonella -infected Guinea-pigs

Cellular and humoral immune responses to Salmonella dublin infection were studied in guinea-pigs given zinc-deficient (ZnD) or zinc-adequate (ZnA) diet, containing 1.03 or 52.4 mg Zn/kg, respectively. On day 30, each animal of each dietary group was inoculated intraperitoneally with 10(6)viable cells of S. dublin strain 493. On the 15th day after infection, the immune responses were assessed by skin hypersensitivity (SH) tests and enzyme-linked immunosorbent assay (ELISA) for serum antibody with Salmonella -extract antigen. ZnD animals had significantly decreased ability to produce Salmonella -specific immediate and delayed type SH responses. These results were further substantiated by histological examination of skin sections. The ELISA indicated significantly lower Salmonella -specific serum antibody titres in ZnD animals than in ZnA animals. Mean viable counts of S. dublin in the liver and spleen of ZnD animals were significantly higher than those in ZnA animals.