Polyphenol Iongel Patches with Antimicrobial, Antioxidant and Anti-Inflammatory Properties.

There is an actual need for developing materials for wound healing applications with anti-inflammatory, antioxidant, or antibacterial properties in order to improve the healing performance. In this work, we report the preparation and characterization of soft and bioactive iongel materials for patches, based on polymeric poly(vinyl alcohol) (PVA) and four ionic liquids containing the cholinium cation and different phenolic acid anions, namely cholinium salicylate ([Ch][Sal]), cholinium gallate ([Ch][Ga]), cholinium vanillate ([Ch][Van]), and cholinium caffeate ([Ch][Caff]). Within the iongels, the phenolic motif in the ionic liquids plays a dual role, acting as a PVA crosslinker and a bioactive compound. The obtained iongels are flexible, elastic, ionic conducting, and thermoreversible materials. Moreover, the iongels demonstrated high biocompatibility, non-hemolytic activity, and non-agglutination in mice blood, which are key-sought material specifications in wound healing applications. All the iongels have shown antibacterial properties, being PVA-[Ch][Sal], the one with higher inhibition halo for Escherichia Coli. The iongels also revealed high values of antioxidant activity due to the presence of the polyphenol, with the PVA-[Ch][Van] iongel having the highest activity. Finally, the iongels show a decrease in NO production in LPS-stimulated macrophages, with the PVA-[Ch][Sal] iongel displaying the best anti-inflammatory activity (>63% at 200 µg/mL).

Intestinal Life Cycle of Eimeria caliginosa (Apicomplexa: Eimeriidae) From the Dusky Rice Rat, Melanomys caliginosus (Rodentia: Cricetidae: Sigmodontinae), In Costa Rica.

The endogenous life cycle of Eimeria caliginosa was studied in experimentally infected dusky rice rats, Melanomys caliginosus. All endogenous stages were located in the epithelial cells of villi in the small intestine. Both Giemsa-stained mucosal scrapings and histological sections were studied for the diagnosis of all the life-cycle stages. Eimeria caliginosa has 3 generations of meronts (M) that differ by size, shape, and number of merozoites (m), which also differ in their size, shape, and location of their nuclei within the cytoplasm of the meronts. The 3 meront types, M1-M3, respectively, had 20-33 (m1), 5-9 (m2), and 13-16 (m3) merozoites. Macrogametocytes and microgametocytes, as well as macrogametes and microgametes, completed the sexual cycle, which concludes with the formation of unsporulated oocysts. This parasite's endogenous development produced severe intestinal lesions in the experimentally infected dusky rice rats. In our ongoing work to understand the biodiversity present in plants and animals of the protected Reserva Biológica Alberto Manuel Brenes (ReBAMB) field station in Costa Rica, we now have discovered 3 new Eimeria species, and this is the second complete life cycle in which we document both the asexual and sexual stages.

Endogenous Life Cycle of Eimeria melanomytis (Apicomplexa: Eimeriidae) from the Dusky Rice Rat, Melanomys caliginosus (Rodentia: Cricetidae: Sigmodontinae) in Costa Rica.

Endogenous stages of the life cycle of Eimeria melanomytis, infecting the peripheral epithelial cells of villi of the small intestine of experimentally infected young dusky rice rats, Melanomys caliginosus , were studied. Giemsa-stained mucosal scrapings and histological sections were examined for all the stages. Eimeria melanomytis has 3 generations of meronts (M), different in size, shape, and number of merozoites (m); and in size, shape, and location of the nuclei within the cytoplasm of the meronts. The 3 meront types, M1-M3, respectively, had 11-14 (m1), 7-10 (m2), and 20-30 (m3) merozoites. Macrogametocytes and microgametocytes, as well as macrogametes and microgametes, complete the sexual cycle forming the unsporulated oocysts. This parasite's endogenous development produced severe intestinal lesions in experimentally infected dusky rice rats.

Endogenous Life Cycle of Eimeria marmosopos (Apicomplexa: Eimeriidae) from the Opossum, Didelphis marsupialis (Didelphimorphia: Didelphidae) in Costa Rica.

The endogenous life cycle of Eimeria marmosopos was studied in experimentally infected young opossums, Didelphis marsupialis . All the endogenous stages were located in the epithelial cells of villi in the small intestine. Giemsa-stained mucosal scrapings and histological sections were studied for the diagnosis of all the life cycle stages. Eimeria marmosopos has 3 generations of meronts (M) that differ by size, shape, and number of merozoites (m), which also differ in their size, shape, and location of their nuclei within the cytoplasm of the meronts. The 3 meront types, M(1)-M(3), respectively, had 8-15 (m(1)), 4-9 (m(2)), and 22-30 (m(3)) merozoites. Macrogametocytes and microgametocytes, as well as macrogametes and microgametes, completed the sexual cycle, finishing with the formation of unsporulated oocysts. This parasite's endogenous development produced severe intestinal lesions in experimentally infected opossums. There are 56 Eimeria species known from all marsupials worldwide, but this is the first complete life cycle in which both the asexual and sexual stages have been documented.

A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from the dusky rice rat Melanomys caliginosus (Tomes) (Mammalia: Rodentia) in Costa Rica.

We collected faecal samples from 24 dusky rice rats, Melanomys caliginosus (Tomes) (Rodentia: Cricetidae: Sigmodontinae), in a Biological Reserve in Costa Rica, and found three (12.5%) to be infected with a species of Eimeria Schneider, 1875, which we describe here as new. Sporulated oöcysts of Eimeria caliginosa n. sp. are almost spheroidal and measure 16-21 × 17-20 (mean 19.6 × 18.2) µm; micropyle, oöcyst residuum and polar granule are absent. Sporocysts are ovoidal, 9-13 × 6-8 (mean 11.2 × 6.7) µm, with small Stieda and sub-Stieda bodies present, but a para-Stieda body is absent; the sporocyst residuum is a compact mass of c.11-15 granules, c.5 µm wide. Sporozoites are crescent-shaped, 5-8 × 2-3 (mean 6.8 × 2.4) µm. This is the third species of Eimeria described from the genus Melanomys Thomas.

Two new Eimeria spp. (Apicomplexa: Eimeriidae) from the dusky rice rat, Melanomys caliginosus, Tome 1860, in Costa Rica.

We collected fecal samples from 9 dusky rice rats, Melanomys caliginosus (Rodentia, Cricetidae, Sigmodontinae), in a Biological Reserve in Costa Rica and found 8 (89%) to be infected with 2 Eimeria species which we describe here as new. Sporulated oocysts (n = 20) of the first, Eimeria melanomytis n. sp., are cylindroidal and measure 20.1 × 13.3 µm (18-23 × 13-15); micropyle and oocyst residuum are both absent, but a bilobular polar granule is present. Its sporocysts are ovoidal, 10.5 × 7.4 µm (10-13 × 6-8) with a small Stieda body, but both substieda and parastieda bodies are absent; a spheroidal sporocyst residuum is present, ≈ 5 µm wide. Sporulated oocysts (n = 20) of the second, Eimeria rebambensis n. sp., are subspheroidal, 21.2 × 17.0 µm (19-23 × 14-18); micropyle and oocyst residuum are both absent, but with a polar granule ≈ 2 µm wide. Sporocysts are elongate-ovoidal, 12.4 × 7.0 µm (11-14 × 6-9) with a distinct knob-like Stieda body, and a substieda body directly beneath it which is about twice as wide, but no parastieda body is present; the sporocyst residuum is an irregular mass composed of 8-10 globules scattered among the sporozoites, which are ≈ 10 × 5 µm, and have 1 refractile body at their wider end and a central nucleus. These are the first eimerians described from this rodent genus.

Infecciones parasitarias del coyote, Canis latrans (Carnivora: Canidae) en un Parque Nacional y una zona agrícola en Costa Rica / Parasitic infections of coyote, Canis latrans (Carnivora: Canidae) in a Costa Rican National Park and a surrounding agricultural area

Parasitic infections of coyote, Canis latrans (Carnivora: Canidae) in a Costa Rican National Park and a surrounding agricultural area. As human populations expand into wild habitats with their pets and livestock, the potential spread of disease to wildlife or vice versa increases. Because, wild and domestic canids may pose as reservoirs or disseminators of infectious diseases (including parasites), coyotes (Canis latrans) may also serve as indicators of ecological health. In Costa Rica, little information exists on coyote parasites, making research necessary to identify potential zoonotic interactions. For this reason, a survey of the coyote parasites was performed in a mixed area of protected woodland and agricultural land, surrounding Irazu Volcano National Park (IVNP) in Cartago, Costa Rica. Over a one-year period, 209 fecal samples were collected directly from the ground. Collection took place on a monthly basis in a trail sectioned into three sub-areas named Irazú (closest to the volcano), potato fields (where potatoes were cultivated), and Prusia (a protected sector of IVNP). Sectioning the trail allowed separate collection and analysis of the samples, where 99 were obtained from Irazú, 11 from potato fields and 99 from Prusia. Using direct examination and mechanical concentration 36.84% positive samples containing at least one helminth were found. The presence of parasites was similar for both woodland areas (33.3% in Prusia and 37.4% in Irazú), but differed from the 63.6% observed in the potato fields. Hookworm parasites (probably Ancylostoma caninum), threadworms (possibly Strongyloides sp.), Toxocara canis, Trichuris sp. and Taenia pisiformis were identified, as well as Hymenolepis diminuta, possible spurious parasite resulting from the ingestion of rodents by coyotes. Seasonal details are discussed, concluding that wet and dry seasons affect presence of parasites. Some remarks are made on the importance of these first findings for Costa Rica, especially considering the systematic way in which the collection of samples was carried out. Rev. Biol. Trop. 60 (2): 799-808. Epub 2012 June 01.

Conforme las poblaciones humanas se expanden hacia los hábitats silvestres con sus mascotas y ganado, el potencial de transmisión de enfermedades hacia los animales silvestres -y viceversa- aumenta, y hace necesario identificar interacciones zoonóticas potenciales. Los cánidos domésticos y silvestres pueden funcionar como reservorios o diseminadores de enfermedades infecciosas (se incluyen parásitos), por lo que el coyote (Canis latrans) puede también servir como indicador de la salud ecológica. Asimismo, se estudiaron los parásitos de 209 muestras de heces de coyotes en una zona mixta de área silvestre protegida y campo agrícola del Parque Nacional Volcán Irazú (PNVI) en Costa Rica. La recolección fue realizada mensualmente durante un año en tres sub-áreas denominadas: Irazú (la más cercana al volcán), papales (por el cultivo de papas), y Prusia (un sector del PNVI). Entonces, se empleó examen directo y concentración mecánica, se obtuvo 36.84% de muestras positivas por al menos un helminto. La presencia de parásitos fue muy similar para ambos sectores boscosos del PNVI (33.3% en Prusia y 37.4% en Irazú), pero contrastó con el 63.63% observado en los papales. También, se identificaron uncinarias (probablemente Ancylostoma caninum), estrongilidios (posiblemente Strongyloides sp.), Toxocara canis, Trichuris sp. y Taenia pisiformis, así como Hymenolepis diminuta, probablemente un parásito espurio proveniente de roedores ingeridos por los coyotes. Se comenta la importancia de estos primeros hallazgos y se concluye que las estaciones seca y lluviosa influyen en la presencia de los parásitos.

In vitro antimalarial activity of extracts of some plants from a biological reserve in Costa Rica

Treatment with the usual antimalarial drugs, have induced parasite resistance, reinforcing the need to finding natural antimalarial components that would be found on plants from the forest. Therefore, we decided to look for these components in Costa Rican plants from a protected forest area. Fresh and dry extracts of roots, bark, leaves, flowers and fruits of 25 plants from a biological reserve in Costa Rica, Reserva Biológica Alberto Manuel Brenes (REBAMB), were studied in vitro for the presence of substances with antimalarial activity. By studying the inhibition of P. berghei schizogony, we assessed the antimalarial activity of several plant extracts: Aphelandra aurantiaca, A. tridentata (Acanthaceae); Xanthosoma undipes (Araceae); Iriartea deltoidea (Arecaceae); Neurolaena lobata (Asteraceae); Senna papillosa, Pterocarpus hayessi, Lonchocarpus pentaphyllus (Fabaceae); Nectandra membranacea, Persea povedae, Cinamomum chavarrianum (Lauraceae); Hampea appendiculata (Malvaceae); Ruagea glabra, Guarea glabra (Meliaceae); Psidium guajava (Myrtaceae); Bocconia frutescens (Papaveraceae); Piper friedrichsthalii (Piperaceae); Clematis dioica (Ranunculaceae); Prunus annularis (Rosaceae); Siparuna thecaphora (Siparunaceae); Solanum arboreum, Witheringia solanácea (Solanaceae); Ticodendrum incognitum (Ticodendraceae); Heliocarpus appendiculatus (Tiliaceae) and Myriocarpa longipes (Urticaceae). We used different parts of the plants as well as fresh and dried extracts for testing IC50. The solid content of the extracts ranged from 1-71.9μg/mL. The fresh extracts showed stronger activity than the dry ones. Since the plants showing the strongest antimalarial activity are very common in Central America, and some similar genera of these plants have shown positives results in South America, we considered important to present these findings for discussion. On the other hand, this is the first systematic study of this kind ever realized in a circumscribed and protected area of Costa Rica. Rev. Biol. Trop. 60 (2): 881-891. Epub 2012 June 01.

El tratamiento con las drogas antimaláricas de uso común han inducido resistencia por parte del parásito, lo que obliga a buscar en las plantas de los bosques, componentes naturales con actividad en contra de esta enfermedad. Por lo tanto, decidimos buscar dichos componentes en plantas de una Reserva Forestal de Costa Rica. Extractos tanto frescos como secos de raíz, corteza, hojas, flores y frutos, de 25 plantas de la Reserva Biológica Alberto Manuel Brenes (REBAMB), fueron estudiados in vitro en busca de sustancias con actividad antimalárica. Las plantas estudiadas fueron: Aphelandra aurantiaca, A. tridentata (Acanthaceae); Xanthosoma undipes (Araceae); Iriartea deltoidea (Arecaceae); Neurolaena lobata (Asteraceae); Senna papillosa, Pterocarpus hayessi, Lonchocarpus pentaphyllus (Fabaceae); Nectandra membranacea, Persea povedae, Cinamomum chavarrianum (Lauraceae); Hampea appendiculata (Malvaceae); Ruagea glabra, Guarea glabra (Meliaceae); Psidium guajava (Myrtaceae); Bocconia frutescens (Papaveraceae); Piper friedrichsthalii (Piperaceae); Clematis dioica (Ranunculaceae); Prunus annularis (Rosaceae); Siparuna thecaphora (Siparunaceae); Solanum arboreum, Witheringia solanacea (Solanaceae); Ticodendrum incognitum (Ticodendraceae); Heliocarpus appendiculatus (Tiliaceae) y Myriocarpa longipes (Urticaceae). Los extractos frescos y secos de las diferentes partes de las plantas fueron estudiadas y se determinó la IC50, el cual osciló entre 1-71.9mg/mL; los extractos frescos mostraron mayor actividad antimalárica. Las plantas que presentaron mayor actividad son muy comunes en Centroamérica y algunos géneros similares, aunque no las mismas especies, han sido encontrados positivos en América del Sur; por esta razón consideramos importante estos resultados como información y materia de discusión en este tema. Además este es el primer estudio sistemático de esta naturaleza realizado en un área boscosa circunscrita y protegida de Costa Rica.

[Parasitic infections of coyote, Canis latrans (Carnivora: Canidae) in a Costa Rican National Park and a surrounding agricultural area]. / Infecciones parasitarias del coyote, Canis latrans (Carnivora: Canidae) en un Parque Nacional y una zona agrícola en Costa Rica.

As human populations expand into wild habitats with their pets and livestock, the potential spread of disease to wildlife or vice versa increases. Because, wild and domestic canids may pose as reservoirs or disseminators of infectious diseases (including parasites), coyotes (Canis latrans) may also serve as indicators of ecological health. In Costa Rica, little information exists on coyote parasites, making research necessary to identify potential zoonotic interactions. For this reason, a survey of the coyote parasites was performed in a mixed area of protected woodland and agricultural land, surrounding Irazú Volcano National Park (IVNP) in Cartago, Costa Rica. Over a one-year period, 209 fecal samples were collected directly from the ground. Collection took place on a monthly basis in a trail sectioned into three sub-areas named Irazú (closest to the volcano), potato fields (where potatoes were cultivated), and Prusia (a protected sector of IVNP). Sectioning the trail allowed separate collection and analysis of the samples, where 99 were obtained from Irazú, 11 from potato fields and 99 from Prusia. Using direct examination and mechanical concentration 36.84% positive samples containing at least one helminth were found. The presence of parasites was similar for both woodland areas (33.3% in Prusia and 37.4% in Irazú), but differed from the 63.6% observed in the potato fields. Hookworm parasites (probably Ancylostoma caninum), threadworms (possibly Strongyloides sp.), Toxocara canis, Trichuris sp. and Taenia pisiformis were identified, as well as Hymenolepis diminuta, possible spurious parasite resulting from the ingestion of rodents by coyotes. Seasonal details are discussed, concluding that wet and dry seasons affect presence of parasites. Some remarks are made on the importance of these first findings for Costa Rica, especially considering the systematic way in which the collection of samples was carried out.

In vitro antimalarial activity of extracts of some plants from a biological reserve in Costa Rica.

Treatment with the usual antimalarial drugs, have induced parasite resistance, reinforcing the need to finding natural antimalarial components that would be found on plants from the forest. Therefore, we decided to look for these components in Costa Rican plants from a protected forest area. Fresh and dry extracts of roots, bark, leaves, flowers and fruits of 25 plants from a biological reserve in Costa Rica, Reserva Biol6gica Alberto Manuel Brenes (REBAMB), were studied in vitro for the presence of substances with antimalarial activity. By studying the inhibition of P berghei schizogony, we assessed the antimalarial activity of several plant extracts: Aphelandra aurantiaca, A. tridentata (Acanthaceae); Xanthosoma undipes (Araceae); Iriartea deltoidea (Arecaceae); Neurolaena lobata (Asteraceae); Senna papillosa, Pterocarpus hayessi, Lonchocarpus pentaphyllus (Fabaceae); Nectandra membranacea, Persea povedae, Cinamomum chavarrianum (Lauraceae); Hampea appendiculata (Malvaceae); Ruagea glabra, Guarea glabra (Meliaceae); Psidium guajava (Myrtaceae); Bocconia frutescens (Papaveraceae); Piper friedrichsthalii (Piperaceae); Clematis dioica (Ranunculaceae); Prunus annularis (Rosaceae); Siparuna thecaphora (Siparunaceae); Solanum arboreum, Witheringia solanacea (Solanaceae); Ticodendrum incognitum (Ticodendraceae); Heliocarpus appendiculatus (Tiliaceae) and Myriocarpa longipes (Urticaceae). We used different parts of the plants as well as fresh and dried extracts for testing IC50. The solid content of the extracts ranged from 1-71.9 microg/mL. The fresh extracts showed stronger activity than the dry ones. Since the plants showing the strongest antimalarial activity are very common in Central America, and some similar genera of these plants have shown positives results in South America, we considered important to present these findings for discussion. On the other hand, this is the first systematic study of this kind ever realized in a circumscribed and protected area of Costa Rica.

Parasitosis intestinal en monos capuchinos cariblancos Cebus capucinus (Primates: Cebidae) de un área protegida en la provincia de Limón, noreste de Costa Rica

Intestinal parasites in white-faced capuchin monkeys Cebus capucinus Primates: Cebidae) inhabiting a protected area in the Limón province of Northeastern Costa Rica. Deforestation of tropical forests is threatening monkey biodiversity and their health status, dependent of an ecologically undisturbed area. To asses this relationship, we analyzed parasite occurrence in their intestines. The study was conducted at the Estación Biológica La Suerte (EBLS), Limón, Costa Rica. The group of white-faced capuchin monkeys (Cebus capucinus) was observed between March and December of 2006. A total of 75 feces samples were obtained. Once a sample was collected, the eaten plant type was identified to family and species level, and feces were processed in the laboratory to determine parasite incidence. Results showed that Moraceae was the most represented family in the samples. Among parasites, Strongyloides spp. and Acanthocephala were the most common. Positive prevalence of parasites was found similar and independent of sex and age of capuchin individuals. Microsporids were mainly reported in feces associated with Piperaceae. A low presence of these parasites was found in samples associated with Myrtaceae, with possible anti-parasite active components. The occurrence of parasites was relatively high in EBLS, when compared to other regions in Costa Rica. The higher occurrence of parasites observed in capuchins at EBLS may be due to the fact that this rain forest is surrounded by areas affected by human activities. We suggest the promotion of research in neotropical primates parasitology, for a better comprehension of the parasite-host relationship, and in a long term, being able to understand the ecosystems where they coexist, and consequently, preserve the biodiversity of the whole region. Rev. Biol. Trop. 58 (4): 1335-1346. Epub 2010 December 01.

La deforestación de bosques tropicales está amenazando la biodiversidad de las especies de primates y su estado de salud, dependiente de un lugar ecológicamente equilibrado. Con el fin de evaluar esta relación, se analizó la presencia de parásitos en los intestinos de esta especie. El estudio se realizó en la Estación Biológica La Suerte (EBLS), Limón, Costa Rica. El grupo de monos capuchinos cariblancos (Cebus capucinus) fue observado entre marzo y diciembre de 2006. Se recolectaron 75 muestras de heces a las que se les identificó las plantas ingeridas, y se procesaron en el laboratorio para evaluar la prevalencia de parásitos. Moraceae fue la familia de plantas más reportada. Strongyloides spp. y acantocéfalos fueron los más comunes. La distribución positiva de las mismas fue similar independientemente del sexo y la edad. Microsporidios se reportaron mayoritariamente en heces asociadas con la familia Piperaceae. Fue encontrada una baja existencia de éstos parásitos en muestras asociadas con Myrtaceae en cuyo género Psidium, se han reportado compuestos activos antiparasitarios. La aparición de parásitos fue relativamente mayor en la EBLS, comparado con muestras de otras regiones más secas de Costa Rica. Por lo tanto, esa expresión parasitaria puede deberse al hecho de ser la EBLS una selva lluviosa, además de estar rodeada por zonas con actividades antrópicas. Se sugiere incrementar las investigaciones de parasitología de campo en primates neotropicales con el fin de entender plenamente las relaciones parásitos-hospederos, para en un largo plazo poder comprender los ecosistemas donde conviven, y en consecuencia, preservar la diversidad biológica.

[Intestinal parasites in white-faced capuchin monkeys Cebus capucinus (Primates: Cebidae) inhabiting a protected area in the Limón province of Northeastern Costa Rica]. / Parasitosis intestinal en monos capuchinos cariblancos Cebus capucinus (Primates: Cebidae) de un área protegida en la provincia de Limón, noreste de Costa Rica.

Deforestation of tropical forests is threatening monkey biodiversity and their health status, dependent of an ecologically undisturbed area. To asses this relationship, we analyzed parasite occurrence in their intestines. The study was conducted at the Estación Biológica La Suerte (EBLS), Limón, Costa Rica. The group of white-faced capuchin monkeys (Cebus capucinus) was observed between March and December of 2006. A total of 75 feces samples were obtained. Once a sample was collected, the eaten plant type was identified to family and species level, and feces were processed in the laboratory to determine parasite incidence. Results showed that Moraceae was the most represented family in the samples. Among parasites, Strongyloides spp. and Acanthocephala were the most common. Positive prevalence of parasites was found similar and independent of sex and age of capuchin individuals. Microsporids were mainly reported in feces associated with Piperaceae. A low presence of these parasites was found in samples associated with Myrtaceae, with possible anti-parasite active components. The occurrence of parasites was relatively high in EBLS, when compared to other regions in Costa Rica. The higher occurrence of parasites observed in capuchins at EBLS may be due to the fact that this rain forest is surrounded by areas affected by human activities. We suggest the promotion of research in neotropical primates parasitology, for a better comprehension of the parasite-host relationship, and in a long term, being able to understand the ecosystems where they coexist, and consequently, preserve the biodiversity of the whole region.

Heterogeneidad en la metaciclogénesis in vitro de clones derivados de una cepa costarricense de Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) / Heterogenity in the vitro metacyclogenesis of clones derived from a Costa Rican strain of Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae)

La metaciclogénesis in vitro fue evaluada en la cepa costarricense de Trypanosoma cruzi denominada TC-4 y en tres clones derivados de la misma como un criterio de heterogeneidad biológica entre clones y cepa parental. Los clones fueron obtenidos de colonias, resultado del cultivo de los parásitos en agar sangre al 40%. Estos clones fueron denominados TC-4 α; TC-4 β; y TC-4 π y fueron mantenidos en agar sangre difásico 40% con infusión cerebro-corazón al 3,7% como fase líquida. La metaciclogénesis fue inducida por incubación de los parásitos en orina artificial de triatomino suplementada con L-prolina (OAT+P) a temperatura constante (27ºC). El progreso en la metaciclogénesis fue diariamente monitoreado determinando el radio tripomastigotos/epimastigotos, el porcentaje de tripomastigotos metacíclicos y la concentración de tripomastigotos metacíclicos (TM/mL). La variabilidad fue evaluada mediante pruebas de ANDEVA para mediciones repetidas (a: 0,05). Los indicadores de metaciclogénesis mostraron sus valores máximos entre las 72 y 96 horas después del inicio del experimento, intervalo donde se observaron diferencias estadísticamente significativas entre algunos de los sistemas celulares (p < 0,05). Estas observaciones pueden sugerir que la composición clonal de cada cepa de T. cruzi puede determinar la infectividad del parásito para el hospedador vertebrado.

Primer hallazgo de Spirometra mansoni en Felis domesticus de Costa Rica / First report of Spirometra mansoni in Felis domesticus from Costa Rica

Se describe un céstodo encontrado en el intestino delgado de gatos provenientes de dos zonas diferentes de Costa Rica (Liberia-Guanacaste y Atenas-Alajuela). De acuerdo con un análisis comparativo morfológico se concluye que los ejemplares hallados corresponden a parásitos del género Spirometra ya que presentan el útero espiralado y huevecillos con los extremos puntiagudos, a diferencia del útero en roseta y huevecillos con extremos redondeados que se encuentran en el género Diphyllobothrium. Dado que presentan un número variable de vueltas en la parte anterior del útero y la vagina es ondulada se clasifican como Spirometra mansoni, siendo éste el primer reporte de este parásito en el país. Se hace una corta revisión de la importancia de este parasito para el ser humano.

Heterogeneidad clonal en epimastigotos de una cepa centroamericana de trypanosoma cruzi / Clonal heterogenity of a central American strain of trypanosoma cruzi

El fenómeno de heterogeneidad clonal fue evaluado en una cepa centroamericana de Trypanosoma cruzi (San Salvador) en un sistema de cultivo en macrófagos. Cuatro clones denominados Clon 9, Clon 10, Clon 11 y Clon 12 fueron obtenidos mediante cultivo en un medio semisólido de agar. Cada clon y la cepa parenteral, fueron subcultivados en medio Schneider suplementado con suero fetal bovino (SFB) al 10 por ciento antes del proceso de infección. Los macrófagos se cultivaron en cubreobjetos y fueron infectados con formas de epimastigotos. La tasa de infección de las células mostró diferencias estadísticamente significativas (p<0,05), pero la carga parasitaria de las células infectadas fue similar para cada uno de los sistemas. La cinética de multiplicación mostró un patrón creciente que fue bastante elevado a las 96 horas en uno de los clones (p<0,05). Los resultados prueban que las interacciones entre las formas parasitarias y las células blanco pueden diferir entre los clones y la cepa parental y que las propiedades de multiplicación intracelular pueden ser diferentes entre los clones individuales