Abstract

*Morris Gerard and Steve Crawley

Antigenic variation is a process by which pathogenic micro-organisms escape the immune response of their mammalian hosts. By convergent evolution, protozoal, fungal and bacterial pathogens have developed similar genetic mechanisms for true antigenic variation. In this review article, the biology, the surface antigens and their encoding genes, and the molecular mechanisms of antigenic variation of the protozoa Trypanosoma brucei, Plasmodium falciparum, Babesia bovis, Giardia lamblia, the fungus Pneumocystis carinii, and the bacteria Borrelia hermsii, Anaplasma marginale, Neisseria gonorrhoeae, Mycoplasma bovis and Campylobacter fetus are compared.