Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: The Taxonomic Importance of Obligate Heteroxeny: Distinction of Hammondia Hammondi from Toxoplasma Gondii - Another Opinion

item Dubey, Jitender

Submitted to: Parasitology Research
Publication Type: Review Article
Publication Acceptance Date: May 15, 2000
Publication Date: N/A

Technical Abstract: We enumerate identical and divergent findings concerning the obligate heteroxenous Hammondia hammondi and the facultatively homoxenous or heteroxenous Toxoplasma gondii. Differences exist in life cycles, transmission and host range, especially transmissibility to birds and mammals other than rodents, in ultrastructural morphology, immunity and serology in cats and to lesser degree in rodents, in DNA sequences and isoenzymes. Because the recognition of obligate heteroxeny is essential to study these organisms and recognized them as taxa, it is advantageous to give heteroxeny a generic rather than a specific value. Characterization of organisms with the life cycle patterns of Hammondia, Sarcocystis, Frenkelia and Toxoplasma is best achieved by means of the genera presently used.

Last Modified: 4/22/2015