Edited by
Barbara A. Burleigh
Dominique Soldati-Favre

2008

Subcellular Biochemistry
Volume 47

In biological terms, a parasite can be defined as ’’an organism that grows, feeds and is sheltered on, or in, a different organism while contributing nothing to the survival of the host.’’ This relationship is particularly intimate for parasitic protozoa (and single-celled fungi such as the Microsporidia), many of which not only penetrate tissue barriers, but gain entry into host cells. The entry mechanisms are as diverse as the organisms employing them and are often critical components of their pathogenic profile.