Experimental susceptibility of gilthead sea bream, Sparus aurata, via challenge with Anisakis pegreffii larvae.

The endoscopic and histopathological findings detected in Sparus aurata experimentally infected with third-stage Anisakis larvae without intermediate host are evaluated and discussed. In six fish, live nematode larvae were introduced by gastroscopy into the stomach. The first observation by endoscope, 15 days after challenge, showed the presence of some larvae at the level of gastric mucosa. An explorative celioscopy, performed 60 days after challenge, showed haemorrhages and/or nodules on the gut of two fishes. Necropsy and histology demonstrated parasites in the context of the tissue changes. The finding of live nematode larvae as well as the evidence of tissue change confirm the experimental susceptibility of gilthead sea bream towards Anisakis.

Experimentally induced melanin-like pigmentation (thesaurismosis) related to acorn ingestion in Nero Siciliano pigs.

In this study, an experimental challenge was carried out by feeding Nero Siciliano pigs with acorn to evoke melanin-like pigmentation and support the hypothesis that it is caused by ingested material. Twelve pigs were studied, 6 fed with acorns and 6 fed commercial feed. At slaughter, all the animals fed on acorns showed black discolouration of almost all lymph nodes. The lymph nodes were normal in size and shape. Histochemical tests performed on tissues allowed us to identify and differentiate the pigment. Immunohistochemical staining for macrophage markers showed macrophages containing a variable amount of melanin-like granules. Our data, and the well-known steps of melanin formation, confirm that swine enzymes could act on phenolic substances found in acorns.