''Hammondia'' is a genus of

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

alveolates The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major clade and superphylum within Eukarya. They are currently grouped with the stramenopiles and Rhizaria among the protists with tubulocristate mitochond ...

in the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Apicomplexa The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. T ...

History

This genus was created in 1975. Before this date the species of this genus were confused with ''

Toxoplasma gondii ''Toxoplasma gondii'' () is an obligate intracellular parasitic protozoan (specifically an apicomplexan) that causes toxoplasmosis. Found worldwide, ''T. gondii'' is capable of infecting virtually all warm-blooded animals, but felids, such as d ...

'' to which they are closely related. The

canid Canidae (; from Latin, ''canis'', "dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found within the ...

-infecting species, ''H. heydorni'' and ''H. triffittae'', have been split into new genus '' Heydornia'' based on the molecular phylogenetic analysis.

Life cycle

The species in this genus have two vertebrate hosts in their life cycle: a felid (the definitive host) and prey species (the intermediate host), which vary and depend on the local fauna but include mice, deer and others. In the gastrointestinal tract of the definitive host the parasite undergoes sexual reproduction, forms a zygote which after some divisions forms a cyst that is excreted. The cyst is subsequently ingested by the prey species in whom the parasite decysts and invades its tissues wherein it again multiplies and encysts. After ingestion of the tissues of the prey species by the definitive host the parasite again decysts and multiplies. It also undergoes sexual reproduction before encysting again.

Genome

The genome of ''Hammondia hammondi'' has been sequenced.

References

Apicomplexa genera Conoidasida {{Apicomplexa-stub