Toxoplasma


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Toxoplasma

 

a genus of parasitic protozoa that has one identified species, Toxoplasma gondii. Studies of the life cycle and ultrastructure of T. gondii have shown that it belongs to the order Coccidia.

In the epithelium of the small intestines of cats and other Felidae, the parasites of Toxoplasma proceed through a complex life cycle, which is completed with the formation of minute egglike oocysts similar to those of coccidia of the genus Isospora. Each oocyst contains two spores, each of which develops into four single-celled sporozoites. The mature sporulating oocysts may reinfect felines, in which case the oocysts undergo both asexual and sexual developmental cycles. When the sporulating oocysts enter other mammals, such as mice, as well as birds and man, the oocysts undergo only asexual multiple reproduction.

After entering the macrophages and various organs and tissues, predominantly those of the reticuloendothelial, muscle, and nervous systems, the sporozoites develop into highly fecund mononuclear trophozoites (endozoites) that multiply through a type of internal budding known as endodiogeny. The trophozoites are crescent in shape and measure 4–7 micrometers in length. Their ultrastructure is identical to that of such merozoites as coccidia.

In the chronic form of toxoplasmosis, cysts are formed in a number of organs, including the brain. These cysts contain up to several hundred mononuclear organisms, called cystozoites. The endozoites and cystozoites may infest new hosts, primarily by means of the alimentary tract. Toxoplasma is the source of toxoplasmosis, a severe disease of animals and man.

IU. I. POLIANSKII

References in periodicals archive ?
Positive control DNA (RH) of Toxoplasma was used to detect indigenous toxoplasma DNA.
Toxoplasmosis is caused by an intracellular protozoan parasite, Toxoplasma gondii that may result in life-long colonization in animals and humans (Ali et al.
The results of this work can be used to support the development of public health policies against toxoplasma infection.
Direct and sensitive detection of a pathogenic protozoan, Toxoplasma gondii, by polymerase chain reaction.
Toxoplasmosis is caused by a protozoan parasite Toxoplasma gondii that affects birds and mammals through various routes (Tenter et al.
The serostatus of Toxoplasma infection was screened using a standard enzyme-linked immunosorbent assay commercial kit in accordance with the manufacturer's instructions.
Toxoplasmosis refers to the infection caused by Toxoplasma gondii, an intracellular protozoan (Ryan and Ray, 2004; Klevar, 2007).
Como se ha hecho mencion anteriormente, la toxoplasmosis pasa inadvertida, y los individuos desconocen el hecho de haber estado en contacto con el parasito, a esto se une el hecho de que cause severas lesiones en el feto lo cual hace imperativo el determinar a traves de metodos inmuno-serologicos la primo-infeccion por toxoplasma en mujeres embarazadas, con la finalidad de realizar adecuado tratamiento a la mujer gestante y prevenir danos por toxoplasmosis al feto (4).
Cases underwent investigations and on the bases of positive serum marker for the disease that is toxoplasma IgM antibody and demographic data were collected regarding age, maternal residence and socioeconomic status.
De acuerdo a lo senalado anteriormente, el objetivo del presente estudio fue determinar la seroprevalencia de Toxoplasma gondii en cerdos procedentes de granjas tecnificadas y no tecnificadas de Lima, Peru, asi como identificar las variables epidemiologicas asociadas a su presentacion.
The ubiquitous parasitic protozoan, Toxoplasma gondii, is one of the most successful microorganism on the planet owing to quite a lot of compatibility to many host species, especially mammals, various transmission pathways (e.