Search results for "parasitología"
showing 10 items of 45 documents
POPULATION STRUCTURE OF ANISAKIS SIMPLEX (NEMATODA) IN HARBOR PORPOISES PHOCOENA PHOCOENA OFF DENMARK
2004
The population structure and habitat selection of Anisakis simplex in 35 harbor porpoises off Denmark are described. The nematodes were collected from the stomach and duodenal ampulla and were categorized as third-stage larvae, fourth-stage larvae, subadults, and adults. The porpoises harbored 8,043 specimens of A. simplex. The proportion of adults and subadults increased with infrapopulation size. The number of development stages across infrapopulations covaried significantly (Kendall's test of concordance). Concordance was higher in hosts with the highest intensities than in those with low and medium intensities. All stages occurred mainly in the forestomach, but this trend was stronger f…
Development and pathology of echinostoma caproni in experimentally infected mice
2007
In the present article, several parasitological features of mice, each experimentally infected with 75 metacercariae of Echinostoma caproni (Trematoda: Echinostomatidae), were studied during the first 12 wk postinfection. Moreover, the early pathological responses also were analyzed and compared with data previously published on other host species of E. caproni to gain further insight into the factors determining worm rejection or establishment of chronic infections. The results obtained show that the pattern of E. caproni infection in mice is consistent with a highly compatible host–parasite system. This combination is characterized by a high worm establishment, high egg output, and long s…
Kinetics of echinostoma caproni (trematoda: echinostomatidae) antigens in feces and serum of experimentally infected hamsters and rats
2004
This study reports on the kinetics of antibody production to Echinostoma caproni and the dynamics of antigens in feces and sera in 2 experimental hosts (hamsters and rats) that display different degrees of susceptibility with this echinostome. Echinostoma caproniproduced chronic infections in hamsters, whereas rats lost the infection at 49-56 days postinfection (DPI). Hamsters developed higher antibody responses than rats, probably in relation to different intestinal absorptions of worm antigens in each host species. The levels of coproantigens were indicative of the course of infection in each host. Positive coproantigen levels were detected at 1-2 DPI in both hosts, and the values remaine…
A QUANTITATIVE APPROACH TO THE EXPERIMENTAL TRANSMISSION SUCCESS OF ECHINOSTOMA FRIEDI (TREMATODA: ECHINOSTOMATIDAE) IN RATS
2006
Using a range of parameters, the ability of rats (Rattus norvegicus) to successfully transmit Echinostoma friedi to the next host was examined under experimental conditions. The concept of Experimental Transmission Success (TM), defined as the number of hosts that become successfully infected after exposure to a number of infective stages produced by a previous host per unit of inoculation at which this latter host was exposed, was introduced. Using data for the egg output and miracidium hatching and infectivity, the TM permits us to estimate the ability of a particular defintive host species to successfully transmit a parasite species. This concept may be also useful to compare the transmi…
Gastrointestinal helminths of cuvier’s beaked whales, ziphius cavirostris, From the Western Mediterranean
2004
We examined the gastrointestinal helminth fauna of 2 Cuvier's beaked whales, Ziphius cavirostris, stranded on the Spanish Mediterranean coast. Information regarding intestinal parasites of this species is provided for the first time. Six helminth taxa were identified. Thirty type II larvae of the nematode Anisakis sp. were found in the stomach and the intestine of both hosts; 2 type I larvae of Anisakis sp. were found in the intestine of 1 host. One juvenile of the acanthocephalan Bolbosoma vasculosum was found in the intestine; the metacestode Scolex pleuronectis was found mainly in the terminal colon and the anal crypts of both hosts; adult cestodes of Tetrabothrius sp., which may represe…
Growth and emigration of third-stage larvae of Hysterothylacium aduncum (Nematoda: Anisakidae) in larval herring Clupea harengus
2000
The growth and emigration of Hystherothylacium aduncum in laboratory-reared herring larvae Clupea harengus was studied. Experimental infections of 36-day-old herring larvae resulted in 126 hosts infected with 306 H. aduncum larvae. Regression analyses showed a significant worm emigration from the rectum to the head of the fish, accompanied by an increase in worm body length. The emigration was independent of worm intensity, which suggests an ontogenetic process. Some worms departed from this pattern by moving posteriorly or by penetrating into the muscle, and in 5 cases, the larvae were observed to leave living fish. This individual variation has not been observed in previous studies and mi…
Repeatability of Feather Mite Prevalence and Intensity in Passerine Birds
2014
Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and appro…
Application of molecular topology to the prediction of antiparasitic activity against Giardia intestinalis and Trichomonas vaginalis of 2-Acylamino-n…
2020
Giardia intestinalis y Trichomonas vaginalis destacan por su importancia clínica. G. intestinalis causa la giardiosis, una parasitosis de gran importancia epidemiológica y clínica por presentar una elevada prevalencia. T. vaginalis causa la tricomoniasis, la enfermedad de transmisión sexual (ETS) no viral con mayor incidencia del mundo. Ambas parasitosis comparten el mismo tratamiento farmacológico: los nitroimidazoles. Se ha aplicado la topología molecular en la búsqueda de derivados del 2-Acylamino-nitro-1,3-tiazol con actividad antiparasitaria frente a G. intestinalis y T. vaginalis . Con el análisis lineal discriminante se obtuvo un modelo capaz de clasificar correctamente el 92,85 % de…
Trematodes in Mediterranean coastal habitats: Transmission, life cycles and detection Methods
2015
1. Introducción general Los metazoos trematodos (Platyhelminthes) son componentes ubicuos de los ecosistemas naturales entando temporal o permanentemente presentes en más de la mitad de las especies animales (Bush y col. 2001, Prietrock & Marcogliese 2003). Los parásitos trematodos pueden encontrarse en un amplio rango de condiciones y hábitats, teniendo un gran impacto en los procesos ecológicos: mediante la regulación de las poblaciones de hospedadores (Hudson y col. 2006) y afectando a la estructura de las comunidades y redes tróficas (ej. Mouritsen & Poulin 2002, Thompson y col. 2005, Lafferty y col. 2006, 2008). Son sobre todo, los parásitos que son transmitidos a través de la cadena t…
Interactions of elasmobranchs with other taxa in Iberian waters: parasitism and agonistic relationships
2022
Esta tesis doctoral está dedicada al estudio de las comunidades de helmintos parásitos en elasmobranquios que se encuentran en aguas ibéricas, tanto en el Atlántico como en el Mediterráneo, con comentarios sobre las relaciones agonísticas entre la tintorera (Prionace glauca) y el pez espada (Xiphias gladius), cuestiones que no habían no ha sido abordadas antes por otros investigadores. El presente estudio proporciona, por primera vez, un informe cuantitativo sobre la fauna de cestodos en cuatro especies de elasmobranquios, el tiburón marrajo dientuso (Isurus oxyrinchus); la tintorera (Prionace glauca); la tremielga, (Torpedo marmorata), y el torpedo común (Torpedo torpedo), en aguas ibérica…