Cerebral Toxoplasmosis in Striped Dolphins(Stenella coeruleoalba) Stranded Along theLigurian Sea Coast of Italy

摘要

This article reports the results of necropsy, parasitologic, microbiologic, histopathologic, immunohistochemical, indirect\udimmunofluorescence, biomolecular, and serologic investigations on 8 striped dolphins (Stenella coeruleoalba) found stranded\udfrom August to December 2007 on the Ligurian Sea coast of Italy. Severe, nonsuppurative meningoencephalitis was found in\ud4 animals, as characterized by prominent perivascular mononuclear cell cuffing and macrophage accumulations in neuropil.\udThese lesions were associated with mild lymphocytic–plasmacytic infiltration of choroid plexuses in 1 dolphin. Toxoplasma\udgondii cysts and zoites, confirmed by immunohistochemical labeling, were scattered throughout the brain parenchyma of 2 of\udthe 4 dolphins. No viral inclusions were seen in the brain of any animal. Other findings included severe bronchointerstitial\udpneumonia and pulmonary atelectasis, consolidation, and emphysema. Parasites were identified in a variety of organs, including\udlung (Halocerchus lagenorhynchi). Microbiologic and serologic examinations for Brucella spp were negative on all 8 dolphins. The\ud4 animals with meningoencephalitis had serum antibodies against T gondii (titers ranging from 1:80 to 1:320) but not against\udmorbillivirus. In contrast, the other 4 dolphins were seropositive for morbillivirus (with titers ranging from 1:10 to 1:40) but\udseronegative for T gondii. No morbillivirus antigen or nucleic acid was detected in the tissues of any dolphin. It is concluded\udthat the severe lung and brain lesions were the cause of death and that T gondii was the likely etiologic agent of the cerebral\udlesions. Morbillivirus infection was not considered to have contributed to death of these animals.