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The levels of six non-dioxin-like polychlorinated biphenyls (PCBs 28, 52, 101, 138, 153, and 180) were determined in the liver of 84 loggerhead turtles (Caretta caretta) stranded along the coasts of the Tyrrhenian Sea in Campania Region (Southern Italy), from 2017 to 2021. The average value of the sum (∑

Non-essential toxic metals are environmental pollutants that contaminate the marine ecosystem due to their extensive use and long-range transport (by rivers and air). Their presence into the environment is often linked to the human activity, with an expected bioaccumulation in the food chain. Within the marine animals, sea turtles may be considered as potential sentinel species for environmental assessment because of their long lifetime, habitat use and migratory nature. In this study, non-essential toxic metals in the coastal of Tyrrhenian Sea were monitored, during the 2017–2018 period, using the Mediterranean loggerhead sea turtle (Caretta caretta) as indicator species. The levels of Cadmium (Cd), Arsenic (As), Mercury (Hg) and Lead, (Pb) were determined in 30 turtles stranded in different locations along the coasts of Campania region of Southern Italy. After morphometric analysis, the non- essential toxic metal accumulation in loggerhead sea turtle muscle and organs have been measured analysing the total concentrations of metals in samples of liver, kidney, and muscle by Atomic Absorption Spectrophotometry (AAS) after microwave assisted digestion with nitric acid and hydrogen peroxide. The pattern of contaminants revealed a similar distribution for Pb and total mercury, that were not significantly high in all the analysed matrices. On the contrary, elevated concentrations of total As were found out in all matrices, mainly in muscle (25.7 mg/kg w.w.), and of Cd in liver (1.23 mg/kg w.w.) and kidney (6.82 mg/kg w.w.). These studies allow us to estimate the exposure degree to which these species are subjected.

Sulcascaris sulcata Rudolphi 1819 is a gastric nematode parasite of sea turtles. Here, we report the occurrence and describe for the first time the pathological changes caused by S. sulcata in the Mediterranean loggerhead sea turtle (Caretta caretta) stranded along the Tyrrhenian coast and northern Adriatic coast of Italy. Prevalence of infection was significantly higher in loggerhead sea turtles from the Adriatic Sea. Both prevalence and abundance of infection showed an increasing trend along with host age classes from both geographical localities. Nevertheless, while many small loggerhead sea turtles were found infected from the Adriatic Sea, only bigger individuals were infected from the Tyrrhenian Sea. The most common gross pathological change was a mucous gastritis with focal to multifocal raised ulcerous lesions roundish to irregular in shape ranging from 1 to over 20 cm in length, and cream-yellowish to greenish in color. The severity grade of gastritis increased with higher number of S. sulcata individuals. Microscopic pathological changes ranged from atrophic gastritis with heterophilic infiltration in the lamina propria to the destruction of the mucosal and sub-mucosal surfaces and necrosis. Results here obtained demonstrate that S. sulcata may cause ulcerous gastritis in both samples of loggerhead sea turtles studied from the Mediterranean Sea. Observed differences in S. sulcata infection among the different host age classes and between the two studied basins are likely linked to the differences of regional habitat and intermediate prey host availability.

We summarized the neuropathologic findings in 60 cetaceans stranded along the Italian coastline from 2002 to 2014. The following neuropathologic changes were detected in 45% (27/60) of animals: nonsuppurative meningo-encephalitides (30%, 18/60), nonspecific lesions (12%, 7/60), suppurative encephalitis (2%, 1/60), and neoplasm (2%, 1/60). No histologic lesions were found in 47% (28/60) of the specimens. Five (8%, 5/60) samples were unsuitable for analysis. Analysis with PCR detected Brucella spp., morbillivirus, and Toxoplasma gondii infection in one, six, and seven individuals, respectively. Immunohistochemical analysis confirmed positivity for morbillivirus and for T. gondii infection in three cases each. No evidence of the scrapie-associated prion protein PrPSc was detected. Our findings underscore the importance of an adequate surveillance system for monitoring aquatic mammal pathologies and for protecting both animal and human health.

This study reports the results of seroepidemiological investigations carried out against Morbillivirus, Toxoplasma gondii and Brucella spp. on blood serum samples collected from 70 cetacean specimens found stranded along the Italian coastline between 1998 and 2014. A total number of 23 serum samples (32.8%) obtained from Stenella coeruleoalba, Tursiops truncatus, Balaenoptera physalus and Globicephala melas harboured anti-Morbillivirus neutralizing antibodies. Ten sera (16%) collected from S. coeruleoalba and T. truncatus were found positive against T. gondii, while no antibodies against Brucella spp. were found. These data reveal that stranded cetaceans provide a unique opportunity for monitoring the health status of free-ranging animals living in the Mediterranean Sea, in order to investigate the level of exposure of cetacean populations to selected infectious agents representing a serious threat for aquatic mammals.

An unusual mortality event involving cetaceans, mainly striped dolphins Stenella coeruleoalba (Meyen, 1833), occurred along the Tyrrhenian Sea coast of Italy during the first 3 mo of 2013. Based on post-mortem analyses carried out according to body condition on 66 dolphins (54% of stranded animals), several hypotheses to explain the causes of this mortality event were proposed. Although no definitive conclusions can be drawn, dolphin morbillivirus was deemed the most likely cause, although other infectious agents (including Photobacterium damselae damselae and herpesvirus) or environmental factors may also have contributed to this recent mortality event.

Morbilliviruses are recognized as biological agents highly impacting the health and conservation status of free-ranging cetaceans worldwide, as clearly exemplified by the two Dolphin Morbillivirus (DMV) epidemics of 1990-1992 and 2006-2008 among Mediterranean striped dolphins (Stenella coeruleoalba). After these two epidemics, morbilliviral infection (MI) cases with peculiar neurobiological features were reported in striped dolphins stranded along the Spanish coastline. Affected cetaceans showed a subacute-to-chronic, non-suppurative encephalitis, with brain lesions strongly resembling those found in human "subacute sclerosing panencephalitis" and "old dog encephalitis". Brain was the only tissue in which morbilliviral antigen and/or genome could be detected. Beside a case of morbilliviral encephalitis in a striped dolphin's calf stranded in 2009, we observed 5 additional MI cases in 2 striped dolphins, 1 bottlenose dolphin (Tursiops truncatus) and 2 fin whales (Balaenoptera physalus), all stranded in 2011 along the Italian coastline. Noteworthy, 3 of these animals (2 striped dolphins and 1 bottlenose dolphin) showed immunohistochemical (IHC) and/or biomolecular (PCR) evidence of morbilliviral antigen and/or genome exclusively in their brain, with 1 striped dolphin and 1 bottlenose dolphin also exhibiting a non-suppurative encephalitis. Furthermore, simultaneous IHC and PCR evidence of a Toxoplasma gondii coinfection was obtained in 1 fin whale. The above results are consistent with those reported in striped dolphins after the two MI epidemics of 1990-92 and 2006-2008, with evidence of morbilliviral antigen and/or genome being found exclusively in the brain tissue from affected animals.