Indirect immunohistochemistry (IHC) is widely used for the detection of viruses in fixed tissue for the study of the pathogenesis and the diagnosis of viral diseases. In addition, IHC is used for the detection of other agents such as bacteria, protozoa and fungi and for the detection of cell proteins. The technique is rapid, inexpensive, sensitive, specific, safe, and characterized by permanent staining because infectious agents, with the exception of prions, are inactivated by common fixatives. In addition, IHC also allows the simultaneous visualization of histologic and histopathologic features and their correlation to localization of the target. Monoclonal and polyclonal antibodies can be produced against virtually any infectious agent and used for their detection. Dextran polymers and enzyme polymerization are used to increase sensitivity and increase the quality of the staining. The selective or combined use of IHC, PCR, in situ hybridization and conventional isolation of agents will give thebest results, since the techniques are often complementary. Here we briefly describe tissue localization and lesions during natural infection in cattle and small ruminants by several agents that are diagnosed and studied by veterinary pathologists.
展开▼
