Study of the helminth fauna in eagle owl (Bubo bubo) in the south of Spain.

In this study we show the results of the eagle owls' (Bubo bubo) helminthfauna found in Andalusia. A total number of 50 specimens have been analysed in a period of 10 years (from 2011 to 2020). Prevalence ( P % ), mean intensity (IM) and mean abundance (AM) of parasitation have been obtained. The percentage of parasitation in the total sample was 80% (40 out of 50 eagle owls): 78% nematodes, 8% trematodes, 6% cestodes and 4% acantocephalans. 7 species of helminths were identified: 6 nematodes, and 1 trematode. In the case of cestodes and acantocephalans it was not possible to determine species and only the genus was identified. The intestinal nematode Capillaria tenuissima ( P %  = 58% (44-71.2); IM = 11,52 (5.83-28.9)) was the core species whereas Synhimantus laticeps (P% = 16 (7.5-28.8); IM = 4 (1.75-7.25)) and Hartertia hispanica (P% = 16 (7.5-28.8); IM = 1,5 (1-2)) were the secondary species. The remainder species were considered satellite species, with low prevalence and average abundance. Likewise, descriptive parameters of the helminth community were determined: species richness, 1.56 (1.29-1.94), total abundance, 12 (7.24-26.40), Brillouin's diversity index, 0.18 (0.10-0.29) and Berger-Parker dominance index, 0.88 (0.81-0.93). The data from this study show a non-diverse helminthic community, without species dominance with C. tenuissima as the central species, followed by S. laticeps and H. hispanica as secondary species. Worth mentioning is the presence of H. hispanica, which is considered an endemic species in Spain and specifically in Andalusia. To the authors' knowledge, this is the largest population sample taken in parasitological studies about helminths of this raptor in Europe and the first one carried out in the south of Spain (Andalusia).

Pathological and immunohistochemical study of the liver and hepatic lymph nodes in goats infected with one or more doses of Fasciola hepatica.

Lesions produced by Fasciola hepatica in the liver, gall-bladder and hepatic lymph nodes (HLNs) of four groups of five goats are described; in addition, the distribution of CD3+ T lymphocytes and IgG-lambda light chain-bearing cells was analysed in the hepatic lesions and HLNs. One group of goats received a single oral dose of metacercariae, but the other four groups received four or five doses at different intervals over a period of 11 weeks. Animals that survived were killed 53-55 weeks after the first infective dose. Goats were more susceptible to multiple doses than to a single dose, even when the total number of metacercariae was the same. This greater susceptibility was manifested by the occurrence of deaths and the severity of hepatic lesions. CD3+ lymphocytes were sparse in the infiltrate surrounding the acute migratory tracts, suggesting inhibition of the local cell-mediated immune response. Goats with numerous hepatic calcareous granulomas showed the most severe hepatic damage, including marked cirrhosis, with a striking infiltrate of CD3+ T lymphocytes and lambda IgG- plasma cells, replacing extensive areas of hepatic parenchyma, in which hypertrophy of the smooth endoplasmic reticulum of hepatocytes was evident. These findings were observed mainly in the goats given more than one infective dose.

Humoral and cellular immune responses to experimental Fasciola hepatica infections in goats.

Humoral and cellular immune responses to Fasciola hepatica excretory-secretory products (ESPs) in primary and secondary experimental infections in goats were studied. Primary infection induced the development of chronic subclinical fascioliasis that did not affect the establishment of flukes coming from the secondary infection, as the same percentages of recovered flukes were found in both groups. The specific IgG response to F. hepatica ESPs was similar in primary and secondary infections; challenge flukes did not induce any modification in the IgG response. The specific lymphocyte response to F. hepatica ESPs was absent in most of the infected goats, both primarily and secondarily infected. A modulation of the nonspecific cellular responses to mitogens was also observed. All infected goats showed a reduced proliferative response to concanavalin A and phytohemagglutinin. According to our results, humoral and cellular responses to F. hepatica ESPs in goats have no protective effect on the establishment of flukes and the development of disease in either primary or secondary infections.

Detection of antibodies of Fasciola hepatica excretory--secretory antigens in experimentally infected goats by enzyme immunosorbent assay.

An ELISA with excretory-secretory (ES) antigens has been evaluated as a technique for the early detection of specific antibodies in Fasciola hepatica infections in goats. Goats were experimentally infected with 100 or 200 metacercariae of bovine origin and serum samples were taken periodically over 365 days. The ELISA test was performed with ES antigens (10 micrograms mL-1), a single dilution of sera (1:800) and anti-goat IgG conjugate (1:1000). ES specific antigens were detected in all infected goats between 15 and 30 days postinfection (PI) and maximum antibody levels were reached at 90 days PI. Positive antibody levels (significantly different from those of controls) were still found at 365 days PI. No significant differences were observed between goats infected with 100 or 200 metacercariae. In all infected goats, eggs appeared in faeces between 60 and 90 days PI. ELISA with ES antigens could be a feasible method for the early diagnosis of goat fasciolosis.

Ultrastructural colocalization of phosphorylcholine and a phosphorylcholine-associated epitope in first-stage larvae of Trichinella spiralis.

Although the presence of phosphorylcholine (PC) in Trichinella is well established, the structures of the TSL-4 antigens that bear this epitope are unknown. A subset of TSL-4 antigens (TSL-8 antigens) has been reported to be absent from the surface of first-stage T. spiralis larvae. We report experiments with a monoclonal antibody (mAb US2) developed in mice with a relative inability to produce antibodies to PC. In immunoblotting, mAb US2 and anti-PC mAb (BH8) showed apparently identical binding patterns. In addition, we used an immunogold double-labeling technique to study the anatomical distribution of the epitopes recognized by these mAbs; the results obtained indicate close colocalization of epitopes for BH8 and US2 in tissues of T. spiralis first-stage larvae. On the basis of these results, we suggest that US2 probably binds to all T. spiralis TSL-4 antigens, including TSL-8 antigens. We also clarify some conflicting previous reports on the distribution of PC immunoreactivity in first-stage larvae of T. spiralis.