EFFECT OF DIFFERENT ECOSYSTEMS AND MANAGEMENT PRACTICES ON TOXOPLASMA GONDII AND NEOSPORA CANINUM INFECTIONS IN WILD RUMINANTS IN SPAIN.

Toxoplasma gondii and Neospora caninum are two major abortifacient protozoans in domestic small ruminants and cattle, respectively, and they also parasitize a wide range of wildlife. Numerous serosurveys have been conducted in wild ruminants worldwide. However, the potential effect of different ecosystems and management practices on these infections has not been investigated. We studied the prevalence of antibodies to T. gondii and N. caninum in wild ruminants between 2007 and 2012 from four national wildlife reserves: three open space reserves in northwest Spain (Ancares, Mampodre, and Riaño) and a fenced reserve in central Spain (Quintos de Mora). Sera from roe deer ( Capreolus capreolus ) and chamois ( Rupicapra rupicapra ) were collected in Ancares (roe deer), Mampodre (both species), and Riaño (both species), whereas red deer ( Cervus elaphus ) sera were collected only in Quintos de Mora. The results of immunofluorescence antibody tests showed a T. gondii antibody prevalence significantly higher in red deer (13%; 17/131) than in roe deer (2%; 5/228) and chamois (4%; 6/149) (P<0.05, Fisher's exact test). Moreover, N. caninum -specific antibodies were only detected in 1% of animals (2/131 red deer, 2/228 roe deer, and 2/149 chamois). Management measures were implemented in the Quintos de Mora reserve and T. gondii antibody prevalence in red deer decreased from 13% to 2% after 5 yr. In contrast, N. caninum antibody prevalences were very low (<2%) over the years. The results suggest a low frequency of sylvatic life cycles in the hunting reservations studied, so interconnection between sylvatic and domestic life cycles is unlikely. Regardless, a sustainable exploitation of natural resources in wildlife reserves may help to reduce the prevalence of T. gondii infection.

Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution.

The relation between gestational age and foetal death risk in ovine toxoplasmosis is already known, but the mechanisms involved are not yet clear. In order to study how the stage of gestation influences these mechanisms, pregnant sheep of the same age and genetic background were orally dosed with 50 oocysts of Toxoplasma gondii (M4 isolate) at days 40 (G1), 90 (G2) and 120 (G3) of gestation. In each group, four animals were culled on the second, third and fourth week post infection (pi) in order to evaluate parasite load and distribution, and lesions in target organs. Ewes from G1 showed a longer period of hyperthermia than the other groups. Abortions occurred in all groups. While in G2 they were more frequent during the acute phase of the disease, in G3 they mainly occurred after day 20 pi. After challenge, parasite and lesions in the placentas and foetuses were detected from day 19 pi in G3 while in G2 or G1 they were only detected at day 26 pi. However, after initial detection at day 19 pi, parasite burden, measured through RT-PCR, in placenta or foetus of G3 did not increase significantly and, at in the third week pi it was lower than that measured in foetal liver or placenta from G1 to G3 respectively. These results show that the period of gestation clearly influences the parasite multiplication and development of lesions in the placenta and foetus and, as a consequence, the clinical course in ovine toxoplasmosis.

Parásitos del pescado

Documento que contiene: introducción, resultados, ectoparásitos, endoparásitos, especies y número de muestras estudiadas, etc. Permite descargar un fichero con las imágenes que forman parte del libro y descargar el texto completo en word.

Algunos aspectos de la epidemiología y prevención de la anisakiosis

Documento que contiene: introducción, etiología, ciclo biológico, las L3 en los peces hospedadores, anisakiosis en el hombre y prevención y control de la anisakiosis.

Characterization of pathology and parasite load in outbred and inbred mouse models of chronic Neospora caninum infection.

Here, we analyzed histological findings and parasite burden in chronic Neospora caninum infection in BALB/c and ICR mice and studied the correlation between lesion severity and parasite load in brain. To obtain a better understanding of the infection, we examined the influence of various host pathogen factors. Groups of outbred (ICR) and inbred (BALB/c) mice were inoculated using several NC-1 parasite doses (4 x 10(5), 10(6), and 5 x 10(6) tachyzoites), inoculation routes (intraperitoneal and subcutaneous), and 3 immunosuppressive treatments (methylprednisolone, cyclophosphamide, and vinblastine). Lesion severity was analyzed in the liver, lung, heart, and brain tissues, and parasite load was measured by real-time polymerase chain reaction in brain tissue. The results indicated more severe cerebral lesions and higher brain parasite burdens in inbred than in outbred mice. Hepatic tissue was the primary lesion site in immunosuppressed ICR mice. We also observed that increased inoculum size was reflected in greater lesion severity and a higher cerebral parasite load. No difference was observed with respect to inoculation route. The study also showed an association between brain parasite burden and severity of cerebral lesions in BALB/c mice.