[The immunosuppressant effect of T. lewisi (Kinetoplastidae) infection on the multiplication of Toxoplasma gondii (Sarcocystidae) on alveolar and peritoneal macrophages of the white rat]. / Efecto inmunosupresor de Trypanosoma lewisi (Kinetoplastidae) sobre la multiplicación de Toxoplasma gondii (Sarcocystidae) en macrófagos alveolares y peritoneales de rata blanca.

The immunosuppressant effect of T. lewisi infection on the multiplication of T. gondii was compared in peritoneal (MP) and alveolar macrophages (MA) of white rat. Two animal groups were infected with T. lewisi and sacrificed after four days and seven days post infection. A group without infection was maintained as a control. The number of intracellular parasites (tachyzoites) (IT) was counted by light microscopy, calculating the rate infection rate per 100 total cells (TC) and per infected cells (IC) for each group of phagocyte cells. The relation quotient IT, TC or IC multiplied percent, provided a statistical ratio (RE) of the relative number of parasites in both cellular types for each time interval. MA as well as MP obtained after 4 days showed a significant increase in the multiplication of T. gondii with respect to the control. Unlike the MP (which had an increase in the multiplication of T. gondii the fourth day of infection with T. lewisi diminishing towards the seventh day), the MA had an increase in the multiplication of the parasite from the fourth to the seventh day. This difference can be related to the route of infection used for the experiments, that affect the MP directly with a greater effect in comparison with the MA of the lungs. Lung compartment will be affected later, when the infection becomes systemic between the fourth and sixth day of infection. The immunity against T. gondii is similar between both phagocytes, but the time of infection and the compartment where the cells are located, makes the difference in the response time against T. gondii. Supernatants from macrophage cultures or T. lewisi by rat did not induced any immunosuppression.

Efecto inmunosupresor de Trypanosoma lewisi (Kinetoplastidae) sobre la multiplicación de Toxoplasma gondii (Sarcocystidae) en macrófagos alveolares y peritoneales de rata blanca

The immunosuppressant effect of T. lewisi (Kinetoplastidae) infection on the multiplication of Toxoplasma gondii (Sarcocystidae) on alveolar and peritoneal macrophages of the white rat. The immunosuppressant effect of T. lewisi infection on the multiplication of T. gondii was compared in peritoneal (MP) and alveolar macrophages (MA) of white rat. Two animal groups were infected with T. lewisi and sacrificed after four days and seven days post infection. A group without infection was maintained as a control. The number of intracellular parasites (tachyzoites) (IT) was counted by light microscopy, calculating the rate infection rate per 100 total cells (TC) and per infected cells (IC) for each group of phagocyte cells. The relation quotient IT, TC or IC multiplied percent, provided a statistical ratio (RE) of the relative number of parasites in both cellular types for each time interval. MA as well as MP obtained after 4 days showed a significant increase in the multiplication of T. gondii with respect to the control. Unlike the MP (which had an increase in the multiplication of T. gondii the fourth day of infection with T. lewisi diminishing towards the seventh day), the MA had an increase in the multiplication of the parasite from the fourth to the seventh day. This difference can be related to the route of infection used for the experiments, that affect the MP directly with a greater effect in comparison with the MA of the lungs. Lung compartment will be affected later, when the infection becomes systemic between the fourth and sixth day of infection. The immunity against T. gondii is similar between both phagocytes, but the time of infection and the compartment where the cells are located, makes the difference in the response time against T. gondii. Supernatants from macrophage cultures or T. lewisi by rat did not induced any immunosuppression. Rev. Biol. Trop. 57 (1-2): 13-22. Epub 2009 June 30.

El efecto inmunosupresor de la infección de T. lewisi sobre la multiplicación de T. gondii fue comparado en macrófagos peritoneales (MP) y alveolares (MA) de rata. El número de parásitos (taquizoitos) intracelulares (TI) fue contado por microscopía de luz. Los macrófagos alveolares y peritoneales (MP) de animales con 4 días de infección con T. lewisi muestran un aumento significativo en la multiplicación de T. gondii. A diferencia de los MP (que muestran un aumento en la multiplicación de T. gondii al cuarto día de infección con T. lewisi disminuyendo hacia el séptimo día), los MA mantienen un aumento en la multiplicación del parásito desde el cuarto, aumentando hacia el séptimo día de infección. Esta diferencia se puede deber a la ruta de infección utilizada para los experimentos que afectan directamente los MP donde se observa un efecto mayor y más temprano en comparación con los MA aislados de los pulmones, compartimiento afectado cuando la infección se vuelve sistémica entre el cuarto y sexto día de infección. La inmunidad contra T. gondii es similar entre ambas células fagocíticas, pero el tiempo de infección y el compartimiento donde se encuentren las células hace la diferencia en el tiempo de respuesta contra un parásito dado, en nuestro caso T. gondii. No hubo evidencia de que los sobrenadantes de cultivos de macrófagos provenientes de ratas infectadas ni el lisado de tripanosomas indujeran el efecto inmunosupresor.

Parásitos en monos carablanca Cebus capucinus (Primates: Cebidae) de Costa Rica / Parasites of white face monkeys (Cebus capucinus) (Primates: Cebidae) of Costa Rica

Fecal samples of 53 white face monkeys (Cebus capucinus) from some sites of Costa Rica were studied for blood and intestinal parasites. Animals were anesthetized with darts containing Telazol, blood and fecal samples were collected and all the material was studied in the laboratory. For blood parasites, Giemsa stain andKnott concentration was performed. Intestinal parasites were studied by direct examination in 0,85 percent saline solution and a Iodine solution. Haematoxylin stain was used for better protozoa identification. Strongyloides sp, hookworms, acanthocephalid eggs and other nematodes, as well as Tritrichomonas sp (more frequent) and other protozoa were found. The presence of at least one parasites was observed in 33.3 percent to 100 percent of the fecal samples with an average of 73.6 percent. There was not any correlation between sex and infection rate, but the presence of parasite was higher in heavier (older) animals. Microfllarias were the only blood organism detected.The reasons for these high infection rates could be explained for feed diversity, contaminated soil and water contact and sociability of these animals, among other factors.

Se capturaron y anestesiaron un total de 53 primates de la especie Cebus capucinus por medio de dardos con tiletamina de diferentes zonas de Costa Rica. Todos los animales fueron estudiados por la presencia de parásitos sanguíneos e intestinales. En la sangre sólo se encontraron microfilarias (24,5 por ciento) las cuales fueron diagnosticadas usando la concentración de Knott y la tinción de Giemsa. Los parásitos intestinales fueron observados en forma directa y algunos de los protozoos también fueron tejidos con hematoxilina de Heidenhain. Los parásitos encontrados fueron Strongyloides sp, uncinarias, acantocéfalos y otros nemátodos no identificados, en porcentajes que variaron según las zonas de captura. Los índices de infección determinados por la presencia de al menos un parásito fluctuaron entre 33,3 por ciento y el 100 por ciento con una media general del 73,6 por ciento, no existiendo diferencias de infección en cuanto al sexo de los animales. En general se notó un mayor grado de infección en los animales de más peso (más edad) tal y como se ha observado en otros países. Se considera que las infecciones parasitarias son más elevadas en esta especie, posiblemente por tener una alimentación más variada, un mayor contacto con el suelo y aguas contaminadas, así como la gran sociabilidad de estos monos. La presencia de estos parásitos podría ser una de las causas, entre otras para acelerar el riesgo de extinción de los primates en Costa Rica y en América.

Effect of trypanosoma lewisi infection on the toxoplasma gondii multiplication in white rat peritoneal macrophages

Peritoneal macrophages (PM) from normal Wistar rats were treated in vitro with peritoneal supernatant or sera, obtained from rats infected with 106 Trypanosoma lewisi trypomastigotes before the infection with Toxoplasma gondii tachyzoites. In this experimental model, Toxoplasma multiplication in PM was increased, as compared to macrophages treated with supernatant or sera from control rats not infected with T. lewisi. This effect was observed only if the active supernatant or sera came from rats infected with the T. lewisi 3 to 6 d before Toxoplasma inoculation. Furthermore, immunosuppressive activity was only detectable after at least 24 h incubation with the supernatant or sera. These results are in accordance with our in vivo previous studies which demonstrated a clear immunosuppressive effect of T. lewisi during T.gondii infection of the remarkably resistant Wistar rats.

Nosema like organisms found in an immunocompetent human patient: first report in Central América

Stool samples of a immunocompetent hypertense 61 year old woman were stained by the Weber et al. method and studied by electronic microscopy. Mature microsporidia spores were found and according to their diplokaryotic muclei, as well as the typical polar filament with 12 coils, the organisms was classified as Nosema like genus

Método sencillo para determinar la presencia de Toxoplasma gondii (Eucoccidia: Sarcocystidae) en carne / Simplifie method to determinated presence of Toxoplasma gondii in meat

Presence of T. gondii in meat from several sources was determined by traditional methods and by a new simplified method in wich animals are fed meat directly without any previous treatment with artificial gastric fluid. Tissues are ground and the animals ingest them naturally. Determination of Toxoplasma in lungs or brain (as well as by specific antibody test), showed no statistically significant differences between both methods.

Enterocytozoon bieneusi (orden microsporidia, familia entrerocytozoonidae) in Costa Rica: report of the first human case in central america

The first case of microspotidiosis in Central America is describes in en AIDS patient from Costa Rica. Electronic microscopy studies indicate that the spores were not included in a parasitophorous vacuole, but they are in direct contact with the cell cytoptasm. Sporogonic proliferative plasmodial forms presence and localization of the polar tubes in the anterior region of the spore, confirmed the specie Enterocytozoon bieneusi as the cause of this microsporidian infection

Increasing of Toxoplasma gondii (Coccidia, Sarcocystidae) infections by Trypanosoma lewisi (Kinetoplastida, Trypanosomatidae) in white rats

To demonstrate that T. lewisi infection increases T. gondii multiplication in white rats, groups of five Wistar or Sprague Dawley rats were inoculated with 10(6) T. lewisi trypomastigotes and four or seven days later infected with Toxoplasma tachyzoites. Host survival time was monitored, and the presence of T. gondii was confirmed in all dead rats by studying peritoneal exudate smears and lung tissue sections stained with haematoxylin-eosin. The presence of Toxoplasma cysts or antibodies was checked in the brain of surviving rats. The increase is observed four days after trypanosome inoculation and is dependent on rat strain, but not on inoculum size or rat age. Humoral and cellular factors may have a role in the increase as has been reported for other experimental infections with African trypanosomes and T. cruzi

Toxoplasma gondii (Eucoccidia: Sarcoystidae) dissemination pattern in rats after oral infection with oocysts of an avirulent strain

Differences in Toxoplasma gondii dissemination in white rats (Sprague Dowley) and mice (Wistar) after oral oocyst inoculation are described. Groups of five animals (both hosts) wewe infected por os with oocyts of the TCR-2 avirulent strain and the dissemination pattern was compared in brain tissue or by serology. Early disseminationwas similar in both species. One hr after infection the parasite was present in blood and peritoneal exudate as well as in heart, lung, liver, spleen, lymph nodes and brain. However, after five days there were important differences between both hosts and after 30 days, the parasite was detected only in rat heart and brain, while in mice it persisted in fluids and all organs.

Age influence in the natural resistance of white rat and mice to the protozoan Toxoplasma gondii

Groups of 1, 5, 10, 15 and 30 day old rats (Sprague Dawley) and Wistar mice were infected per os with different inocula of Toxoplasma gondii oocysts from an avirulent strain. Infection pattern was followed by determination of survival time, tissue lesions, parasite presence and serology. Although all the animals survived the total experimental period (30 day), there were important differences between both rodents regarding to Toxoplasma natural resistance. Brain cysts, as well as tachyzoites in other organs were regularly present in mice but not in rats. On the other hand, most of the organs from mice presented characteristic T. gondii lesions, while in rats a normal tissues were observed, with the exception of an acute reaction found in the brain of a 15d old animal

Efecto de los corticosteroides sobre la adaptación natural de la rata blanca al Toxoplasma / Effect of corticosteroids on the natural adaptation to Toxoplasma

Ratas adultas normales (Sprague-Dowley) que son naturalmente resistentes a la infección con Toxoplasma gondii, fueron tratadas semanalmente con 10 ó 20 mg de cortisona por 100 grs de peso corporal, previa infección con diferentes concentraciones de Toxoplasma. Grupos de animales fueron infectados con 10**5, 10**6 y 10**7 taquizoitos del parásito. Mientras que los animales testigo inoculados con el Toxoplasma sobrevivieron los 90 días que duró el experimento, aquellas ratas tratadas con 20 mg de cortisona x c/100 g de peso murieron con una toxoplasmosis aguda, independientemente del inóculo empleado. Las ratas infectadas con 10**6 y 10**7 toxoplasmas y tratadas con 10 mg de acetado de cortisona por cada 100 g de peso, también desarrollaron la enfermedad aguda entre 8 y 74 días después de la infección. Este efecto aparentemente inmunosupresor se observó en ratas de 87 + ou - 6 grs no en ratas de 150 g. Estos experimentos indican que los corticosteroides pueden producir una disminución en la resistencia natural contra el Toxoplasma, aspecto que se discute en comparación con infecciones diseminadas en humanos debido al tratamiento con estas drogas