ABSTRACT
This chapter focuses on a particular aspect/group of foodborne microbes and toxins, namely Cystoisospora belli, in relation to their biology, epidemiology, clinical aspects, diagnosis, treatment and prevention. Taxonomic repositioning of the formerly known Isospora belli to Cystoisospora belli has been based on biological and phylogenetical characters of the diplosporocystic, tetrasporozoic oocyst-producing coccidian protozoa recognized as a human pathogen almost a century ago. The presence of tissue cyst in the genus Cystoisospora favors phylogenetic rather than phonetic classification. Developmental stages of Cystoisospora comprise asexual multiplication, sexual reproduction, and sporogony. Definite diagnosis of cystoisosporiasis relies on identification of characteristic oocysts in stool or intestinal content. Oocysts of Cystoisospora belli can be seen by direct smear of duodenal content or the acid-fast staining procedure. A number of animals have been tested for the susceptibility of infection with orally administered oocysts of Cystoisospora belli.
