Misael Chinchilla

Seroepidemiology of Toxoplasma gondii (Apicomplexa) in meat producing animals in Costa Rica

A serologic screening for Toxoplasma gondii antibodies by IgG indirect fluorescent antibodies test (IgG-IFAT) was carried among 496 swine and 601 cattle serum samples from throughout Costa Rica, to study the possible role of their meat in the transmission of the parasite. The overall prevalence of antibodies was 34.4% in cattle and 43.8% in swine. No significant differences were found in the antibody prevalence between males and females in both animal groups, which acquire the infection early in their lives. Swine did not present significant differences between age groups. In cattle there was a high percent of seropositivity between the first and third years of age. The provinces that showed a greater number of seropositive animals were Limón and Puntarenas for both animals, and Guanacaste for cattle.

Molecular systematics and phylogeography of Cebus capucinus (Cebidae, Primates) in Colombia and Costa Rica by means of the mitochondrial COII gene

We propose the first molecular systematic hypothesis for the origin and evolution of Cebus capucinus based on an analysis of 710 base pairs (bp) of the cytochrome c oxidase subunit II (COII) mitochondrial gene in 121 C. capucinus specimens sampled in the wild. The animals came from the borders of Guatemala and Belize, Costa Rica, and eight different departments of Colombia (Antioquia, Chocó, Sucre, Bolivar, Córdoba, Magdalena, Cauca, and Valle del Cauca). Three different and significant haplotype lineages were found in Colombia living sympatrically in the same departments. They all presented high levels of gene diversity but the third Colombian gene pool was determined likely to be the most ancestral lineage. The second Colombian mitochondrial (mt) haplogroup is likely the source of origin of the unique Central America mt haplogroup that was detected. Our molecular population genetics data do not agree with the existence of two well‐defined subspecies in Central America (limitaneus and imitator). This Central America mt haplogroup showed significantly less genetic diversity than the Colombian mt haplogroups. All the C. capucinus analyzed showed evidence of historical population expansions. The temporal splits among these four C. capucinus lineages were related to the completion of the Panamanian land bridge as well as to climatic changes during the Quaternary Period. Am. J. Primatol. 74:366–380, 2012.

Lack of multiplication of Toxoplasma in macrophages of rats in vitro.

buffer (0.1 M, pH 9.6) of the lyophilized medium, in which larvae were maintained, gave satisfactory results. For the antigen-coating procedure polystyrene plates were incubated uncovered overnight at 37 C, which caused complete evaporation of the liquid phase. Prior to the assay the plates were washed. The sera were tested in a 1:100 dilution and extinction values were measured to express the antibody levels. In Figure 1 a representative example of the results is presented. The extinction values remained unchanged until the second oral infection at 13 wk. After reexposure a rapid and dramatic increase in extinction values was observed with the ES antigen within a week. In parallel, a slow increase in extinction values was observed for 5 wk with the adult toxffer (0.1 M, pH 9.6) of the lyophilized m ocara antigen. We do not know why the first infection did not involve any response to either antigen. Compared to adult T. canis antigen, the ES antigen showed negligible background values until the second infection was given. This may suggest that the first exposure to eggs did not result in an acute infection. Rapid diagnosis can be made within 1 wk after an oral infection. Apparently, the antibodies demonstrated against ES antigen reflect acute and active infection. Antibody formation as a response to repeated immunization with adult antigen is only reflected in the test system using adult T. canis antigen. The use of highly specific ES antigens in combination with a sensitive ELISA method offers a reliable diagnostic tool for toxocariasis. i e . e do not know why the first i ot involve any response to either

Presencia de anticuerpos contra Trypanosoma cruzi en perros de Costa Rica

Trypanosoma cruzi antibody presence was studied in pet and stray dogs from endemic and non endemic zones. Five percent of pet dogs from endemic zones were positive against a 1.6% from non endemic areas. Twelve percent of stray dogs were positive independent of the procedence.

Presencia de ooquistes de Cryptosporidium spp en aguas superficiales en Costa Rica

The presence of Cryptosporidium spp oocysts was determined in seven samples of crude surface water and seven of treated non-chlorinated water from a water plant in San Jose,Costa Rica. Concentration and staining techniques were used to demonstrate the presence of parasites. Cryptosporidium spp oocysts were found in six of seven untreated water samples (85.7%) and in four of the seven treated non-chlorinated samples (57%). The role of water as a transmission vehicle for this parasite in Costa Rica is discussed.

Determination of Toxoplasma gondii in several organs of cattle by carbon immunoassay (CIA) testing

Samples of muscle, heart, liver and lung were tested for the presence of Toxoplasma gondii using mice as a biologic detector and the carbon immunoassay (CIA) for immunological diagnosis. In positive tissues the percentage of samples positive ranged from 10 to 50% which indicates the importance of cattle in the epidemiology of Toxoplasma in Costa Rica. We discuss these findings in relation to the transmission of the parasite in Costa Rica.

Preferencias alimentarias de Triatoma dimidiata (Hemiptera: Reduvíidae) procedente de la meseta central de Costa Rica a finales del siglo XX

RESUMEN Se colectaron 267 ejemplares de Triatoma dimidiata procedentes de comunidades costarricenses ubicadas en tres regiones epidemiologicamente importantes por la Enfermedad de Chagas. A partir de cada insecto, se prepararon extractos de contenido intestinal los cuales fueron utilizados para determinar la presencia de sangres de diferentes vertebrados en un sistema de doble inmunodifusion (Outcherlony). Tambien los insectos fueron sometidos a un analisis de contenido fecal para determinar la posible infeccion con T. cruzi. El 67% de las muestras fue positiva por sangre de humano, lo que constituyo la fuente de alimentacion mas importante (p < 0,05). Tambien fue notable la presencia de sangre de perro en los vectores analizados (49,8%). Las sangres de rata, raton, didelfidos y gallinas se encontraron en porcentajes menores al 15,0%. A pesar de que no se pudo observar una ornitofila manifiesta, cuando las preferencias alimentarias fueron organizadas como cate-gorias exhaustivas y mutuamente excluyentes, la sangre de gallina constituyo la segunda categoria en frecuencia lo que denota que los triatominos pueden utilizar este sustrato alimenticio cuando la sangre humana y canina no estan disponibles. Los porcentajes de infeccion por T. cruzi fueron altamente positivos en los insectos positivos por sangres de didelfidos y ratones, lo que sugiere el papel que estos animales podrian jugar con reservorios silvestres y domicilios de T. cruzi.

Visceral Leishmaniasis in Costa Rica: First Case Report

We describe a 15-month-old eutrophic immunocompetent male who presented with fever, hepatosplenomegaly, pancytopenia, and hypergammaglobulinemia. Leishmania amastigotes were identified in spleen and bone marrow specimens. In addition, tissue culture, animal inoculation, and isoenzyme analysis identified the parasite as Leishmania donovani infantum or Leishmania donovani chagasi. The infant was successfully treated with an antimonial drug. These findings represent the first case of visceral leishmaniasis reported in Costa Rica.

Presencia de Plasmodium brasilianum (Apicomplexa, Plasmodidae) en el mono congo (Alouatta palliata, Primates: Cebidae) de Costa Rica: Importancia epidemiológica en relación con el ser humano

***, OLGA MARTA GUERRERO*,GUSTAVO GUTIERREZ** y RONALD SANCHEZ***** Centro de Investigacion en Enfermedades Tropicales, Departamento de Parasitologia, Facultad de Microbiologia,Universidad de Costa Rica.** Escuela de Biologia, Universidad de Costa Rica.*** Departamento de Investigacion, Universidad de Ciencias Medicas (UCIMED).**** Sede de Occidente, Universidad de Costa Rica.Direccion: Misael Chinchilla Carmona Ph.D. Departamento de de Parasitologia, Facultad de Microbiologia,Universidad de Costa Rica. San Jose, Costa Rica, America Central. Email: chinchillacm@UCIMED.com

COSTA RICAN INTERNATIONAL COOPERATIVE BIODIVERSITY GROUP: USING INSECTS AND OTHER ARTHROPODS IN BIODIVERSITY PROSPECTING

articulo -- Universidad de Costa Rica. Escuela de Quimica, Universidad de Costa Rica. Facultad de Microbiologia. Departmento Parasitologia, Universidad de Costa Rica. Instituto Clodomiro Picado, 1999. Este documento es privado debido a limitaciones de derechos de autor.