''Cytauxzoon'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of parasitic alveolates 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 name is derived from the Greek meaning an increase in the number of cells in an animal.

History

This genus was created in 1948 when Neitz and Thomas proposed the name ''Cytauxzoon'' to accommodate the ''

Theileria ''Theileria'' is a genus of parasites that belongs to the phylum Apicomplexa, and is closely related to ''Plasmodium''. Two ''Theileria'' species, ''T. annulata'' and ''T. parva'', are important cattle parasites. ''T. annulata'' causes tropical ...

'' like parasites with preerythrocytic schizogony in histiocytes. This is in contrast to schizogony in lymphocytes with the latter being characteristic for ''Theileria''. This genus was originally described in

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

n ruminants but is now known to be common in felids including the domestic cat ('' Felis catus''). It was first described in the African grey duiker (''

Sylvicapra grimmia The common duiker (''Sylvicapra grimmia''), also known as the grey or bush duiker, is a small antelope and the monotypic taxon, only member of the genus ''Sylvicapra''. This species is found everywhere in Africa south of the Sahara, excluding the ...

''). ''C. felis'' was first described by Kier in 1979.

Taxonomy

This genus is closely related to ''

'' but differs from it by replicating in

macrophage Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...

s rather than

lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...

Description

Life cycle

The parasites are transmitted by tick bite. After a cat or other host is bitten by an infected tick the parasites infect mononuclear phagocytes. Within these they undergo asexual reproduction ( schizonts). As these leukocytes become engorged with schizonts, they line the lumens of veins and may causing obstruction of blood flow. The schizonts develop into

merozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is ...

s which eventually cause host cell rupture and enter the blood. These intravascular merozoites infect variable numbers of erythrocytes. An infected host is then bitten by a tick. The parasites undergo sexual reproduction in the tick's gut.

Microscopic appearances

The intra erythrocytic forms range in size between 0.8 and 2.3 µm within a mean of 1.64 µm.

Host records

*''C. felis'' — ('' Felis catus'') *''C. felis'' — Florida panther ('' Puma concolor couguar'') *''C. felis'' — bobcat (''

Lynx rufus The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the I ...

'') *''C. felis'' — tiger (''

Panthera tigris The tiger (''Panthera tigris'') is the largest living cat species and a member of the genus '' Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on u ...

'')

Unknown parasite species

*Ocelot (''

Leopardus pardalis The ocelot (''Leopardus pardalis'') is a medium-sized spotted wild cat that reaches at the shoulders and weighs between on average. It was first described by Carl Linnaeus in 1758. Two subspecies are recognized. It is native to the southw ...

'') *Jaguar (''

Panthera onca The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus ''Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the thi ...

'')

Clinical

In cats infection with this parasite is known as

cytauxzoonosis ''Cytauxzoon felis'' is a protozoal organism transmitted to domestic cats by tick bites, and whose natural reservoir host is the bobcat. ''C. felis'' has been found in other wild felid species such as the cougar, as well as a white tiger in c ...

and is commonly fatal.

Vectors

*American dog tick ('' Dermacentor variabilis'') *''

Rhipicephalus appendiculatus ''Rhipicephalus appendiculatus'', the brown ear tick, is a hard tick found in Africa where it spreads the parasite ''Theileria parva'', the cause of East Coast fever East Coast fever, also known as theileriosis, is a disease of cattle which o ...

References

{{Taxonbar, from=Q5201298 Apicomplexa genera