Use of recombinant antigens for detection of Toxoplasma gondii infection in swine.

Five recombinant Toxoplasma gondii antigens, designated B427, C51, C55, V22, and MBP30 were assessed for their potential use in an enzyme-linked immunoassay (EIA) for detection of T. gondii infection in swine. The antigens were evaluated with sera from young pigs that had been fed 1-10,000 T.

Development of a simple enzyme immunoassay for blood haptoglobin concentration in cattle and its application in improving food safety.

Objective: To verify the role of haptoglobin, a major acute-phase reactant protein in cattle, as a marker to identify health/disease status in cattle and further assess its potential in improving food safety.

Sample Population: Serum samples from various cattle groups: clinically normal cattle comprising steers (n = 157) and culled dairy cows (n = 92) before death (antemortem [AM]); retained carcasses (n = 57) railed off the line during postmortem (PM) inspection; and apparently AM normal culled dairy cows (n = 57).

Procedure: Efficacy of the simplified monoclonal antibody-based enzyme immunoassay was established by comparing results of haptoglobin tests performed independently on aliquots of serum samples by 3 laboratories.

Toxoplasma gondii recombinant antigens H4 and H11: use in ELISAs for detection of toxoplasmosis in swine.

Toxoplasma gondii recombinant antigens H4 and H11 were assessed for their potential for use in ELISA for diagnosis of toxoplasmosis in swine. The antigens were evaluated with sera from young pigs experimentally infected with T. gondii.

Food Safety and Regulatory Aspects of Cattle and Swine Cysticercosis.

Using slaughter disposition data maintained by the Food Safety and Inspection Service (FSIS) of the U.S. Department of Agriculture, prevalence of cattle cysticercosis ( Cysticercus bovis ) for a l0-year period from 1985 through 1994 is reported.

Role of sodium azide in reducing nonspecific color development in enzyme immunoassays.

Improved enzyme immunoassay (EIA) procedures achieved by incorporating sodium azide during predilution of serum samples in a solid-phase EIA for the detection of anti-Toxoplasma antibody in swine using a peroxidase conjugate and in all washes of a bovine brucellosis rapid card test EIA using alkaline phosphatase conjugate are reported. Without this modification, substantial background interference was encountered that showed direct correlation with the degree of hemolysis of the serum samples. Anti-Toxoplasma gondii antibody-negative samples, separated by subjective groupings based on degree of hemolysis, into "clear", "slight", and "gross/total" samples, had a mean +/- standard deviation of 0.