Héctor Alcaíno

SEROPREVALENCE OF TOXOPLASMA GONDII INFECTION IN SHEEP AND ALPACAS (LLAMA PACOS) IN CHILE

Serum samples from 408 sheep from different regions of Chile and 447 alpacas (Llama pacos) from the north of the country were tested for Toxoplasma gondii antibodies. The indirect haemagglutination test (IHAT) was used in both species and the indirect immunofluorescence test (IIFT) was also used on the sheep samples in order to compare the performance of the tests in that species. In both tests, titers > or = 1:16 were considered diagnostically significant. Sera from 49 sheep (12%) were positive to T. gondii antibodies by the IHAT. When using the IIFT, 114 sheep sera (28%) were positive. The different results obtained in sheep sera between the tests were significant (p < 0.0001). No differences were observed between geographical locations or sex of the sampled sheep regarding serological detection of T. gondii antibodies in sheep. As expected, adult sheep showed higher T. gondii reactivity than young sheep (p = 0.0008). The corrected prevalence of toxoplasmosis in alpaca was 16.3% (32 positive out of 447). The rather low prevalence in alpacas may be associated with their extensive management as well as the extreme climatic conditions of The Andes which apparently would not be favorable for the transmission of the parasite.

Flea species from dogs in three cities of Chile.

The purpose of this study was to establish the pattern of flea infestation in dogs in the cities of Santiago (33 degrees latitude south, 70 degrees longitude west), Concepción (36 degrees latitude south, 73 degrees longitude west) and Osorno (40 degrees latitude south, 73 degrees longitude west), located in different parts of Chile. The only species of fleas found on dogs from the three cities were Ctenocephalides felis felis (41.8%), Ctenocephalides canis (39.4%) and Pulex irritans (18.8%). Although the three species were found in the three cities, differences regarding their frequencies were detected (p<0.05). C. felis was the predominant species found on dogs in Santiago (80.5%). In Concepción, their frequencies followed a similar trend. However in Osorno, the most southern city, the predominant species was C. canis (78.7%).

Parasitos de los animales domésticos en Chile

PARASITES OF DOMESTIC ANIMALS IN CHILE An up-to-date list of the parasites that have been identified in horses, cattle, sheep, goats, llamas, alpacas, pigs, dogs, cats, rabbits, chickens and pigeons in Chile, according to the studies performed at the University of Chile and other Universities and Institutes.

Immunodiagnosis of fasciolosis in horses and pigs using Western blots

Crude and partially purified somatic (S) and excretory-secretory (ES) antigens of Fasciola hepatica were subjected to Western blot analysis in order to identify polypeptides that would enable specific and sensitive immunodiagnosis of horse and pig fasciolosis to be undertaken. Sera from 20 horses and 20 pigs with natural infections of F. hepatica and the same number of uninfected hosts of each species were tested, together with sera from 2 pigs with Cysticercus cellulosae infections. Using crude S antigens, sera from infected horses and pigs reacted specifically with a wide range of polypeptides of 14-19, 22-30, 35-37 and 42 kDa. Likewise, specific reactivity between polypeptides of 14-17, 22-30 and 40-42 kDa in crude ES antigens and sera from infected horses and pigs was obtained. Against the criteria of high sensitivity and specificity, the 22-30-kDa polypeptides would appear to be the most suitable candidate antigens for use in the immunodiagnosis of fasciolosis in horses and pigs.

Gastrointestinal parasite fauna of gentoo penguins ( Pygoscelis papua ) from the Península Munita, Bahía Paraíso, Antarctica

An increase in interest in the diseases of seabirds has developed as a part of a worldwide strategy for environmental conservation (Clarke & Kerry 1993, Jones & Shellam 1999). According to Clarke & Kerry (1993) most studies on penguin enteroparasites were published before 1986 and most of them are post mortem diagnoses. This paper provides new data on the intestinal parasitic fauna of gentoo penguins nesting on the Antarctic Península.

Sarcocystis sp. in guanaco (Lama guanicoe) and effect of temperature on its viability

The biology of the Sarcocystis sp. that infect guanacoes was studied by feeding the infected meat to dogs, cats, rats and mice. Tissues from guanaco, heavily infected with macrocysts, were fed to these animals and their faeces collected daily and examined for the presence or absence of sporocysts. It was shown that only dogs were suitable definitive hosts. The effect of cooking and freezing on the viability of this protozoan organism was also investigated. Freezing to -18 degrees C and -24 degrees C and cooking were effective for inactivating Sarcocystis in guanaco meat. These methods could therefore be used instead of condemning guanaco carcasses infected with Sarcocystis.

Parasitismo gastrointestinal en perros de comunas de Santiago de diferente nivel socioeconómico

The prevalence of canine parasites was estimated in three counties from the Metropolitan Regionwith different socioeconomical conditions which were Providencia (ABC1 level), Quinta Normal (Dlevel) and La Pintana (E level). Faecal samples of 582 dogs were examined by Zinc flotation method,modified Teleman method and staining of faecal smears with Ziehl- Neelsen. A third of the dogs(30.2%) were found positive to some type of parasitism with significant higher prevalence in youngerdogs (3 to 6 months old) with 49% of infection versus 25.6% of older dogs. The percentage of positivesamples was significantly higher in stray dogs than those kept indoors (40% versus 28%). Significantdifferences in the frequency of parasites were also found between La Pintana and Providencia, (oddsratio of 2.61), and between La Pintana and Quinta Normal (odds ratio of 1.85) p < 0.05), but nodifferences were found between Providencia and Quinta Normal. A total of 118 samples werepositive to helminths (67%) and 41samples to protozoa (23.3%), as single infections while mixedinfections were recorded in 17 cases (9.7%).

Inmunodiagnóstico de fasciolosis humana y ovina empleando una fracción de 24-29 kDa de Fasciola hepatica obtenida mediante inmunoadsorción

* Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias. Universidad deChile. Casilla 2 Correo 15, Stgo. Chile.** Escuela de Tecnologia Medica y Departamento de Ciencias Biologicas. Universidad Nacional Andres Bello. Stgo. Chile.MARCOS SILVA**, TEXIA GORMAN* y HECTOR ALCAINO*

Purificación de antígenos de Fasciola hepatica mediante electroelución y su aplicación inmunodiagnóstica mediante Western Blot en la infección animal

La electroelucion implementada en este estudio logro purificar por separado dos polipeptidos, uno de 14 y otro de 29 kDa. La eficiencia diagnostica de cada uno de estos polipeptidos medida a traves de Western blot indico una sensibilidad de 95% y 97,5% respectivamente y ambos una especificidad de 100%. Ademas se concluye que son de utilidad en la pesquisa de infecciones prepatentes

Evaluación diagnóstica de dos proteínas purificadas de Fasciola hepatica mediante ELISA en la fasciolosis ovina

were purified by electroelutionand its diagnostics application through ELISA was evaluated. The sensibility was 60% and 94%, andthe specificity was 100% and 98%, respectively. The 29 kDa polypeptide was efficient for the diagnosisof the sheep fasciolosis, athough the 14 kDa polypeptide was not, when using an ELISA test with it.