title: Occurrence of cross reactions to foot-and-mouth disease virus in normal swine sera.
abstract: Sera from 101 swine never exposed to foot-and-mouth disease virus were tested by the plaque-reduction neutralization (PRN) and radial immunodiffusion techniques for cross-reactions to 5 types of foot-and-mouth disease viruses. Depending on the group of sera and the virus used, the percentage of sera cross-reacting at low levels varied from 0 to 50% with the PRN technique and 0 to 20% with the radial immunodiffusion technique. 5erum-neutralization tests in mice support the finding of neutralizing antibody by the PRN technique. Ultracentrifugation and 2-mercaptoethanol studies indicate that the cross-reactions are the result of immunoglobulin M or similar macroglobulins.
mesh_terms: D000818:Animals; D005537:Aphthovirus / Q000276:immunology*; D003429:Cross Reactions; D005779:Immunodiffusion; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D051379:Mice; D009500:Neutralization Tests; D013552:Swine / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M