El estudio, que publica "Science", indica que alrededor de 35 millones de estadounidenses presentan infección crónica por Toxoplasma, aunque sólo las personas con una inmunidad debilitada desarrollan la forma grave de la enfermedad, la cual puede conducir a defectos de nacimiento, inflamación cerebral y problemas de visión.
La infección se adquiere accidentalmente al ingerir esporas, presentes en el suelo contaminado, agua, pelo de gato y objetos que han estado en contacto con heces de gato. También puede adquirirse al consumir carne poco hecha, especialmente pollo, cerdo y cordero.
El parásito responsable de la enfermedad sólo tiene tres cepas principales que, según este estudio, son muy similares genéticamente y se crearon a partir de dos parásitos emparentados. La investigación trata de descubrir cuándo sucedió aquella fusión de genes, y para ello los científicos han secuenciado partes del ADN de las tres cepas para determinar cuántas mutaciones poseen. Según los datos recogidos, las tres cepas proceden de un ancestro común que no tiene más de 10.000 años de antigüedad.
Webs Relacionadas
Science
http://www.sciencemag.org/
Washington University in St.Louis - School of Medicine
http://medicine.wustl.edu
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