ABSTRACT
In vitro growth kinetics of two Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) clones in myocardial cells from rodents of different susceptibility. Two Trypanosoma cruzi isolates, TCR-4 from Costa Rica and UES-1 from El Salvador, were studied in vitro to compare their infectivity or resistance and intracellular replication in myocardial cells in three strains of mice and rats: NGP white mice, C3 H mice and Sprague Dowley rats. Myocardial cells were cultured on coverslips at 37 degrees C in a humid 10% CO2 atmosphere and then infected at a ratio of one tripomastigote per cell. Samples were studied after 24, 72, 96 and 120 h of infection to determine parasite infection capacity and intracellular multiplication. Both parasites had the highest infection capacity in C3 H mice, followed by NGP mice cells with a very low infection rate. Lastly, almost no Trypanosoma cruzi multiplication was observed in Sprague Dowley rats, suggesting a strong natural resistance in this animal to both strains of the parasite. The UES-1 isolate presented higher multiplication and greater invasion than the TCR-4 strain, showing greater virulence of UES-1 in heart cells, at least in vitro.
Subject(s)
Animals , Mice , Rats , Myocytes, Cardiac/parasitology , Trypanosoma cruzi/growth & development , Kinetics , Costa Rica , Clone Cells/parasitology , Cells, Cultured , El Salvador , Time Factors , Rats, Sprague-Dawley , Trypanosoma cruzi/genetics , Trypanosoma cruzi/pathogenicity , VirulenceABSTRACT
Se hace un análisis general de la literatura y del trabajo de los autores sobre microsporidiosis, una parasitosis que se ha puesto en boga a raíz de los problemas de inmunosupresión, especialmente en personas infectadas con el virus del SIDA. Se hace una revisión histórica, se describe básicamente la morfología de los géneros más importantes de los microsporidios y se comentan algunos aspectos de la epidemiología. Se revisan los cambios patológicos debidos a la infección con estos parásitos, los métodos de diagnóstico más usados, el tratamiento y la prevención contra esta parasitosis. Se enfatiza sobre el hallazgo por primera vez en Costa Rica y probablemente en Centro América, de casos humanos de infección con Enterocytozoon bieneusi y con el género Nosema. Palabras claves: Microsporidia, microsporidiosis, Enterocytozoon, Encephalitozoon, Pleisthphora, Nosema
Subject(s)
Humans , Microsporida/microbiology , Microsporidiosis , Nosema , Parasites/microbiology , Costa RicaABSTRACT
Sigmodon hispidus, a cotton rat, was inoculated with tachyzoites or oocysts of Costa Rican strains of Toxoplasma gondii to demonstrate the resistance to this parasite, as compared with mice, hamster and white rat infection. Susceptibility to tachyzoite inoculation was higher in this animal than in white rats but lower than in the other animals. Independent to the Toxoplasma strain studied, oocyst infection was less lethal for S. hispidus when compared with mice and hamsters; the results were similar to those observed for white rats. There is a probable participation of this wild animal in the natural Toxoplasma life cycle.