Use of immunogold assay for a rapid evaluation of antigens of spotted fever group rickettsiae.

Rabbit-antihuman IgG, yolk immunoglobulins (IgY) and monoclonal antibodies against Rickettsia conorii were adsorbed to colloidal gold. Thus obtained conjugates were found to be active and responded specifically to the agent of the Mediterranean Spotted fever. The suitability of the immunogold assay as a alternative to other known immunoenzymatic or immunofluorescent methods for assessing the presence and/or activity of rickettsial antigens is discussed.