FACTOID # 14: North Carolina has a larger Native American population than North Dakota, South Dakota and Montana combined.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Toxoplasma" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Toxoplasma
Toxoplasma gondii
Scientific classification
Kingdom: Protista
Phylum: Apicomplexa
Class: Conoidasida
Subclass: Coccidiasina
Order: Eucoccidorida
Family: Sarcocystidae
Genus: Toxoplasma
Species: T. gondii
Binomial name
Toxoplasma gondi
(Nicolle & Manceaux), 1908

Toxoplasma gondii is a species of parasitic protozoa, belonging to the Apicomplexa, that can cause the disease toxoplasmosis in humans. The life cycle of Toxoplasma gondii has two phases. The sexual part of the lifecycle takes place only in cats, the definitive host of Toxoplasma gondii. The asexual life cycle can take place in any warm-blooded animal, like other mammals and birds. In these intermediate hosts, the parasite invades cells forming a so-called parasitophorous vacuole. Within this vacuole T. gondii propagates by a series of binary fissions until the infected cell bursts. This fast replicating form of the asexually reproducing T. gondii is called tachyzoite. Additionally, a slow replicating form exists, the bradyzoite. Bradyzoite vacuoles can form tissue cysts in the infected animals/humans. Resistance to antibiotics varies, but the cysts are very difficult to erradicate entirely. The immune system of the host does not detect these cysts, while free tachyzoites are efficiently cleared by the immune response. Scientific classification - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Typical phyla Rhodophyta (red algae) Chromista Heterokontophyta (heterokonts) Haptophyta Cryptophyta (cryptomonads) Alveolates Pyrrhophyta (dinoflagellates) Apicomplexa Ciliophora (ciliates) Excavates Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Amoebozoa Choanozoa Many others; classification varies Protists are a heterogeneous group of living things, comprising those eukaryotes which are neither animals, plants, or fungi. ... Classes & subclasses Class Conoidasida    Gregarinasina    Coccidiasina Class Aconoidasida    Haemosporasina    Piroplasmasina The Apicomplexa are a large group of protozoa, characterized by the presence of an apical complex at some point in their life-cycle. ... In biology, binomial nomenclature is a standard convention used for naming species. ... A parasite is an organism that lives in or on the living tissue of a host organism at the expense of that host. ... Protozoa (in Greek protos = first and zoon = animal) are single-celled creatures with nuclei that show some characteristics usually associated with animals, most notably mobility and heterotrophy. ... Classes & subclasses Class Conoidasida    Gregarinasina    Coccidiasina Class Aconoidasida    Haemosporasina    Piroplasmasina The Apicomplexa are a large group of protozoa, characterized by the presence of an apical complex at some point in their life-cycle. ... Binomial name Homo sapiens Linnaeus, 1758 Subspecies Homo sapiens idaltu (extinct) Homo sapiens sapiens Human beings define themselves in biological, social, and spiritual terms. ... Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing, e. ... Trinomial name Felis silvestris catus Schreber, 1775 The cat (also called domestic cat or house cat) is a small feline carnivorous mammal. ... Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing, e. ... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals primarily characterized by the presence of mammary... Orders Many - see section below. ...


Tissue cysts can be ingested by a cat, e.g. by feeding on an infected mouse. The cysts survive passage through the digestive system of the cat and the parasites infect epithelial cells of the small intestine where they undergo sexual reproduction and oocyst formation. Oocysts are shed with the feces. Animals and humans that ingest oocysts (e.g. by eating unwashed vegetables etc.) become infected. The parasite enters macrophages in the intestinal lining and is distributed via the blood stream throughout the body. Infection is normally asymptomatic. However, in immune compromised patients toxoplasmosis can develop. During pregnancy Toxoplasma can lead to abortion or hydrocephalus. Diagram showing the small intestine In biology the small intestine is the part of the gastrointestinal tract between the stomach and the large intestine (colon). ... Macrophages (Greek: big eaters) are cells found in tissues that are responsible for phagocytosis of pathogens, dead cells and cellular debris. ...


It is currently discussed, that infected rats and mice are less fearful of cats, leading to a propagation of the lifecycle (see references). This is an article about wild rats; for pet rats, see Fancy rat Species 50 species; see text *Several subfamilies of Muroids include animals called rats. ...


Human prevalence

In the U.S. NHANES III national probability sample, 22.5% of 17,658 persons >12 years of age had Toxoplasma-specific IgG antibodies, indicating that they had been infected with the organism. There is some research to suggest that infection in humans can lead to slower reactions and an increase in risk-taking behaviors. Schematic of antibody binding to an antigen An antibody is a protein complex used by the immune system to identify and neutralize foreign objects like bacteria and viruses. ...


References

  • M. Berdoy, J. Webster, D. Macdonald: "Fatal Attraction in Rats Infected with Toxoplasma gondii", Proceedings of the Royal Society of London, B267, pp 1591 - 1594, August 7, 2000.
  • CDC document: Toxoplasma gondii Infection in the United States, 1999–2000 (http://www.cdc.gov/ncidod/eid/vol9no11/03-0098.htm)

The sci-fi author William Sleatoruses an alien version of toxoplasma gondii in his book Parasite Pig. William Sleator is a noted science fiction author who writes primarily for the so-called junior adult audience (pre-teens and adolescents), but has also occasionally written for younger audiences. ...


  Results from FactBites:
 
Toxoplasma gondii - Wikipedia, the free encyclopedia (1044 words)
Toxoplasma is a species of parasitic protozoa whose definitive host is cats but which can be carried by the vast majority of warm-blooded animals, including humans.
Acute stage toxoplasma infections can be asymptomatic, but often gives flu-like symptoms in the early acute stages, and like flu can become, in very rare cases, fatal.
Toxoplasma infection causes damage to astrocytes in the brain, and such damage is also seen in schizophrenia.
Toxoplasmosis - Wikipedia, the free encyclopedia (1884 words)
Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii.
Toxoplasma is one of a number of parasites that may alter their host's behaviour as a part of their life cycle.
Although some researchers have found potentially important associations with toxoplasma, it is possible that these associations merely reflect factors that predispose certain types of people to infection (e.g., people who exhibit risk-taking behaviors may be more likely to take the risk of eating undercooked meat).
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m