First report of Salmonella 1,4,[5],12:i:- in free-ranging striped dolphins (Stenella coeruleoalba), Italy.

Between 2015 and the beginning of 2018 (January-March), 30 cetaceans were found stranded along the Ligurian Sea coast of Italy. Necropsies were performed in 22 cases and infectious diseases resulted the most common cause of death. Three striped dolphins, showed a severe coinfection involving the monophasic variant of Salmonella Typhimurium (Salmonella 1,4,[5],12:i:-). The isolates were characterized based on antimicrobial resistance, Multiple-Locus Variable-number tandem-repeat Analysis (MLVA) and whole-genome sequencing (WGS). All isolates demonstrated the same multidrug resistant genotype (ASSuT isolates), showed three different MLVA profiles, two of which closely related, and were identified as Sequence Type 34. Moreover, Single nucleotide polymorphisms (SNP) analysis confirmed strong correlations between two out of the three isolates. To our knowledge, S. 1,4,[5],12:i:-, one of the most common serovars in cases of human infection and food sources worldwide, has not previously been described in marine mammals, and reports of Salmonella-associated disease in free-ranging cetaceans are rare. These results highlight the role of cetaceans as sentinel species for zoonotic and terrestrial pathogens in the marine environment, suggest a potential risk for cetaceans and public health along the North Western Italian coastline and indicate cetaceans as a novel potential reservoir for one of the most widespread Salmonella serovars.

Presence of trace metals in aquaculture marine ecosystems of the northwestern Mediterranean Sea (Italy).

Information regarding chemical pollutant levels in farmed fish and shellfish, along with the risks associated with their consumption is still scarce. This study was designed to assess levels of exposure to 21 trace elements in fish (Dicentrarchus labrax), mussels (Mytilus galloprovincialis) and oysters (Crassostrea gigas) collected from aquaculture marine ecosystems of the northwestern Mediterranean Sea. Metal concentrations showed great variability in the three species; the highest values of the nonessential elements As and Cd were found in oysters while the highest levels of Al, Pb and V were found in mussels. The essential elements Cu, Mn and Zn were highest in oysters, but Fe, Cr, Ni, Se, Co and Mo levels were highest in mussels. Fish had the lowest concentrations for all trace elements, which were at least one order of magnitude lower than in bivalves. The rare earth elements cerium and lanthanum were found at higher levels in mussels than in oysters, but undetectable in fish. The maximum values set by European regulations for Hg, Cd and Pb were never exceeded in the examined samples. However, comparing the estimated human daily intakes (EHDIs) with the suggested tolerable copper and zinc intakes suggested a potential risk for frequent consumers of oysters. Similarly, people who consume high quantities of mussels could be exposed to concentrations of Al that exceed the proposed TWI (tolerable weekly intake).

Granulomatous lesions in a wild mullet population from the eastern Ligurian Sea (Italy): mycobacteriosis vs. pseudotuberculosis.

Mycobacterium spp. and Photobacterium damselae subsp. piscicida are recognized as the most frequent causative agents of granulomatous lesions in fish. Although frequent episodes of mycobacterial infections have been reported in wild fish worldwide, only sporadic cases have been documented to date in Italy. To investigate for the presence of lesions referable to mycobacteriosis and to identify the mycobacterial species involved, a total of 159 wild mullets were fished from the eastern coast of the Ligurian Sea, killed and necropsied. Liver and spleen samples were collected from all fish for histopathological and microbiological analyses. Molecular investigations for identification of Photobacterium damselae subsp. piscicida were performed. Gross examination revealed granulomatous lesions in one animal; microscopically, 42.14% of fish displayed granulomas with various histological features, 19.50% resulted positive at Ziehl-Neelsen staining, and were confirmed as mycobacterial lesions by culture. The identified colonies were characterized as M. fortuitum, M. abscessus, M. flavescens, M. chelonae, M. septicum and M. nonchromogenicum. In all, 35% of animals resulted positive for Photobacterium damselae subsp. piscicida. These data suggest widespread mycobacterial infection also by Photobacterium damselae subsp. piscicida infections in wild fish. Moreover, the pathogenicity of some mycobacterial species, previously considered as saprophytic, was demonstrated.

An extensive investigation into the prevalence and the genetic and serological diversity of toxigenic Vibrio parahaemolyticus in Italian marine coastal waters.

The relationship between Vibrio parahaemolyticus strains isolated from the aquatic environment and those isolated from cases of infection in humans is poorly understood due to the low prevalence of tdh- and/or trh-positive strains in the environment. To address this concern, it would be useful to analyse the genetic relationships among environmental and food strains and with reference to clinical isolates, also applying molecular typing methods. The aim of this study was to evaluate the prevalence of toxigenic V.parahaemolyticus in Italian coastal waters and seafood, to examine intra-species variability and to identify, using serotyping and pulsed-field gel electrophoresis (PFGE), relationships among strains from different sources, geographical origin and period of isolation. Of the 192 V.parahaemolyticus strains isolated in different Italian areas and examined in this study, 25 (13.0%) proved to carry the trh gene while none of the strains proved positive to the search by PCR for tdh and Group-Specific-toxRS genes. The prevalence of toxigenic strains in the Tyrrhenian Sea was significantly lower than that calculated for the Ligurian coasts. Regarding the sources of isolation, the higher prevalence of trh-positive V.parahaemolyticus was revealed in fish, followed by clams, plankton, oysters, mussels and lastly seawater. Within the toxigenic strains, 16 serotypes and 20 distinct PFGE patterns were identified. Two clusters, which included a total of 8 V.parahaemolyticus strains, were specifically associated with the North Adriatic Sea area and were stable over time. Our results demonstrate that trh-positive V.parahaemolyticus strains circulated in Italy in the period 2002-2009 with a prevalence higher than that reported from other European and extra-European countries, confirming that toxigenic V.parahaemolyticus is an emerging public health concern in Italy, regardless of its pandemic potential.

Vibrio virulence genes in fishes collected from estuarine waters in Italy.

AIMS: The aim of this study was to investigate the presence of Vibrio vulnificus and potentially pathogenic strains of Vibrio parahaemolyticus in mullets collected from estuarine environment in Italy. METHODS AND RESULTS: Two hundred and ninety-five mullets were analysed by culture using the selective medium thiosulfate citrate bile salt sucrose agar, during a monitoring period of 2 years (2008-2009). Presumptive Vibrio colonies were initially identified by using biochemical tests, and strains identified as V. parahaemolyticus and V. vulnificus were subsequently examined by PCR for the presence of species-specific and virulence genes (toxR, trh, tdh and vvh). V. parahaemolyticus was found in 55% (162/295) of fishes and V. vulnificus in 1% (3/295) with a higher presence in summer months. The trh+/tdh- strains were detected in 16% (47/295) of samples and only one strain resulted trh+/tdh+. One of the V. parahaemolyticus trh+ strains isolated belonged to the O1:KUT (K untypeable), a serotype recently associated to gastroenteritis in Italy. CONCLUSIONS: This is the first report demonstrating a high percentage of potential pathogenic V. parahaemolyticus trh+ strains in estuarine fishes of the Mediterranean area. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings indicate the potential human health risk associated with the presence of pathogenic Vibrio spp. in wild fishes.

Evaluation of Adenovirus and E. coli as indicators for human enteric viruses presence in mussels produced in La Spezia Gulf (Italy).

AIMS: The purpose of this work was to verify whether E. coli is a good indicator of viral contamination in mussels and Adenovirus could represent a better alternative as indicator organism of viral presence to guarantee consumer health protection. METHODS AND RESULTS: Eighty samples of mussels from La Spezia Gulf were analysed for E. coli, Salmonella, Adenovirus, Norovirus and hepatitis A virus with cultural and biomolecular tests. The results of bacterial parameters showed E. coli within the law's limits and the absence of Salmonella. Twelve samples were positive for Adenovirus presence, one for Norovirus genogroup II and two for hepatitis A virus. None of these positive mussels was found to be contaminated with more than one virus at the same time. CONCLUSION: This study showed that there was not a direct correlation between the presence of human pathogenic viruses and bacterial indicators. SIGNIFICANCE AND IMPACT OF THE STUDY: Both E. coli and Adenovirus cannot be considered valid substitutes for the direct research of human pathogenic viruses in mussels. To improve consumer health protection, the European Commission will provide standardized methods for Norovirus and hepatitis A virus detection as soon as possible.

Lichens and moss as bioindicators and bioaccumulators in air pollution monitoring.

In this study, we review research conducted in the La Spezia district during 1989, 1992, and 1994, using lichens and moss as indicators of air pollution. SO2 pollution was examined by means of an Index of Atmospheric Purity (IAP) based on the frequency of epiphytic lichen within a sampling grid. Metal deposits were estimated using the lichen Parmelia caperata and the moss Hypnum cupressiforme as bioaccumulators. IAP maps show progressive air quality improvement from 1989 to 1994. This trend correlates to a decrease in SO2 emissions during recent years that is attributed to the use of methane for residential heating and the closing of a coal-fired power plant. Metal contamination maps show that the most polluted area is now in the southeastern part of the gulf. The pattern of pollution coincides with the location of the chief pollution sources in the area. From 1989 to 1994, the metal concentrations in lichens decreased, but metal deposits in the southeastern area were cause for concern. High concentrations of lead in the area are related to emissions from a waste incinerator and a plant that produces lead oxide. Epidemiological investigations reveal that the area population has the highest levels of lead in their blood. The use of bioindicators and bioaccumulators permits long-term and large-scale monitoring of environmental pollutant levels in full agreement with traditional methods.