Annalisa Zaccaroni

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

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

Potential adverse effects of inorganic pollutants on clinical parameters of loggerhead sea turtles (Caretta caretta): results from a nesting colony from Cape Verde, West Africa.

A large number of nesting loggerhead sea turtles (n = 201) were sampled to establish the blood levels of 11 elements (Cu, Mn, Pb, Zn, Cd, Ni, Cr, As, Al, Hg, and Se). Almost all of the samples showed detectable levels of these 11 elements, and Zn and Se exhibited the highest concentrations (median values as high as 6.05 and 2.28 μg/g, respectively). The median concentrations of the most toxic compounds, As, Cd, Pb, and Hg, were relatively low (0.38, 0.24, 0.06, and 0.03 μg/g, respectively). We also determined the haematological and biochemical parameters in a subsample of 50 turtles to evaluate the potential effects of these contaminants on clinical parameters and found several associations. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements and their adverse effects on blood parameters in sea turtles.

Thyroid hormones as a potential early biomarker of exposure to 4-nonylphenol in adult male shubunkins (Carassius auratus) ☆

Nonylphenol, an estrogenic-like compound, can induce vitellogenin synthesis in males and immature Teleostean species, but little is known about its effects on thyroid hormones balance. The present study evaluated the potential effects of a single acute exposure to nonylphenol (i.p. injected) on the thyroid and reproductive axis of 250 shubunkins (Carassius auratus). Plasma levels of thyroid hormones were quantified immunoenzymatically by ELISA assay. Nonylphenol induced a significant decrease of thyroxin levels, whereas no effect on triiodothyronine concentrations was detected. No histopathological changes were detected in thyroid or testes. The toxicological data confirmed that nonylphenol exerts an estrogenic effect on male fish. In addition, nonylphenol was suspected to inhibit the thyroid hormones balance, suggesting the thyroid should be included among the other endocrine glands susceptible to endocrine disruption.

Influence of the rehabilitation of injured loggerhead turtles (Caretta caretta) on their blood levels of environmental organic pollutants and elements.

We monitored the levels of 57 organic pollutants and 11 elements in the blood of 61 live stranded loggerhead sea turtles at the beginning and end of the rehabilitation period with the goal of evaluating whether recuperation of normal physiological conditions has an influence on the circulating levels of these pollutants from the blood. According to our results, several pollutants (OCPs, PCBs and toxic elements) are mobilized from storage tissues to the blood in sick turtles, and this is more evident in the subgroup of cachectic animals. We observed a significant decrease in the concentrations of some contaminants at the end of the rehabilitation period, probably due to redistribution processes. In contrast, an increase in the levels of the essential elements selenium and zinc was observed after a period of correct feeding and supplementation during hospitalization.

TOXICITY OF SEA ALGAL TOXINS TO HUMANS AND ANIMALS

Marine algal toxins are responsible of more than 60000 intoxication/year, with an overall mortality of about 1.5%. Human intoxications are due to consumption of seafood and respiratory exposure to aerosolized toxins. Algal toxins are also responsible for extensive die-offs of fish and shellfish, as well as mortality in seabirds, marine mammals and other animals depending on marine food web. Lots of information are available concerning acute intoxications, while little is known about environmental health effects of chronic exposure to low levels of algal toxins. Toxins are produced by two algal groups, dinoflagellates and diatoms, representing about 2% of known phytoplankton species (60–80 species out of 3400–4000) and can reach humans directly (via consumption of shellfish) or through food web transfer to higher trophic levels (zooplankton and herbivorous fish). Most toxins are neurotoxins and all are temperature stable, so cooking does not ameliorate toxicity in contaminated seafoods; five seafood poisoning syndromes exists: paralytic shellfish poisoning, neurotoxic shellfish poisoning, ciguatera fish poisoning, diarrhetic shellfish poisoning, and amnesic shellfish poisoning.

Post-mortem investigations on a leatherback turtle Dermochelys coriacea stranded along the Northern Adriatic coastline

Leatherback sea turtles Dermochelys coriacea are regularly reported in the Mediterranean Sea but rarely reach the northern Adriatic Sea. In the summer of 2009, a well-preserved carcass of an adult female of this species was found dead along the coast of Lido di Venezia. A complete necropsy was carried out, along with evaluation of levels of tissue trace elements. The the post-mortem revealed acute severe bacterial gastroenteritis caused by Photobacterium damselae ssp. piscicida, an opportunistic agent that infected an apparently debilitated animal weakened by ingested plastic debris. High levels of heavy metals (Hg, Pb, Cd and As) found in the liver and kidneys might have contributed to the animals demise. These findings support previous indications that marine debris is one of the major threats to marine animals, particularly for critically endangered species such as the leatherback turtle.

Toxicity of Fresh Water Algal Toxins to Humans and Animals

Algae and cyanobacteria are responsible of the presence of toxins in fresh waters. Algae are considered less dangerous than cyanobacteria, because even if they can proliferate quite intensively in eutrophic fresh waters, they rarely accumulate to form dense surface blooms like blue-green algae do. Thus the toxins they produce do no accumulate to levels high enough to become hazardous to human and animals health.

METAL CONCENTRATIONS IN THE LIVER AND KIDNEY OF RAPTOR SPECIES FROM THE CALABRIA REGION, ITALY

We have focused our study on the concentrations of non essential trace metals Pb, Cd and Cr and essential heavy metals Zn and Cu, in the liver and kidney of raptor species from different areas of the Calabria region in Italy, with the aim of obtaining information concerning the quality and the contamination level of their habitat. No significant differences related to sampling areas and gender were found, while significant differences were found in metal concentrations among species. Mean Cd concentrations in the kidneys were generally 1.5-10 fold higher than hepatic ones, while Pb was mostly concentrated in the liver; a different pattern in tissue Cr concentration was observed between species. Referring to essential metals, Cu levels were higher in the liver, whereas higher Zn concentrations were constantly present in the kidneys. The ratio between kidney and liver metal concentrations (K:Ls) was also evaluated. The measured concentrations in toxic elements can be considered as indicative of chronic exposure to low amounts of pollutants. The essential metal concentrations were in the range of physiological values and did not show the presence of any deficiency or excess of metal. The present study can be considered as a starting point in the study of a possible correlation between levels of pollutants and the appearance of any adverse effects in raptor species in the Calabria area.

Vitellogenin (VTG) conservation in sea turtles: anti-VTG antibody in Chelonia mydas versus Caretta caretta.

Vitellogenin (VTG) is considered as a marker of endocrine disruption. A Western blot method for VTG quantification in Caretta caretta turtle plasma was developed using anti‐VTG antibody for Chelonia mydas. A screening of samples (n = 61) collected in the southern Mediterranean Sea around Lampedusa Island, Italy, was performed. The antibody showed a good cross‐reactivity with C. caretta VTG, suggesting a certain conservation of the core of the protein in different sea turtle species. The optimal operative condition for Western blot analysis consists of using diluted plasma at 1:50. In field samples, a certain mismatch with morphological sexing was observed, and VTG was detected in young animals. These results suggest the possibility of a precocious activation of VTG‐encoding genes before sexual maturation and/or exposure to endocrine disrupter substances.

Trace metal concentration in wild avian species from Campania, Italy

AbstractThis study was conducted to determine heavy metals concentrations in tissues of 94 birds belonging to different species from coastal areas of Naples and Salerno (Southern Italy) in order to provide baseline data concerning trace element levels in wild birds living in or close to an area characterized by high anthropogenic impact. Additional aim of this study was to verify if diet influenced metal accumulation, so birds were classified as birds of prey, fish eating birds and insectivorous birds.Kidney was the primary organ for Cd accumulation in all groups considered, Pb was accumulated preferentially in bone, whereas Hg showed high values in liver of fish eating birds. Zn showed the highest mean concentrations, while Cu levels were one order of magnitude less. The variance analysis with respect to feeding habits disclosed only a lower accumulation of Hg in insectivores with respect to the other groups. For all metals, the concentrations measured in tissues should be considered indicative of chronic exposure to low, “background” environmental levels and/or to the presence of low bioavailable metals in the environment. In addition, metal levels were not of toxicological concern, being always well below the toxic thresholds defined for each metal.