Argomenti di Patologia Comparata dei Molluschi - Aspetti ecologoci e sanitari.

Questo volume nasce con l’intento di colmare, anche se solo parzialmente, una lacuna che per quanto ci è noto, appare evidente nel contesto della bibliografia scientifica nazionale: la mancanza di testi di riferimento aggiornati, in lingua italiana, di patologia degli organismi acquatici. Tra questi, i molluschi rappresentano organismi modello sempre più considerati rispetto ad altri, sia per la loro importanza bio-medica ed ecologica che per quella socio-economica. Il testo è diretto non solo agli studenti dei corsi di laurea in discipline Biologiche e Veterinarie, ma anche ai professionisti (Biologi, Medici, Veterinari) che lavorano nei settori della Ricerca, della Sanità Pubblica, dell’Acquacoltura, dell’Ecologia. La Patologia comparata dei molluschi, nel contesto del volume, viene sempre trattata nell’ottica di una comprensione più generale del rapporto tra salute e ambiente, oggi aspetto imprescindibile della “filosofia” di fondo che caratterizza le linee guida della Unione Europea per lo sfruttamento sostenibile delle risorse biologiche acquatiche vive e l’ottimizzazione del contributo sostenibile dell’acquacoltura alla sicurezza alimentare. La struttura del libro prevede una prima parte di patologia generale comparata (vertebrati - invertebrati - molluschi) ed una seconda parte di patologia speciale che include una breve trattazione delle principali malattie batteriche, virali, parassitarie e micotiche dei molluschi nonché alcune note legislative redatte dal dott. Giuseppe Arcangeli, Responsabile del Laboratorio di Riferimento Nazionale per le malattie dei Molluschi all’Istituto Zooprofilattico Sperimentale delle Venezie

Disease and Disorders of Freshwater Unionid Mussels: A Brief Overview of Recent Studies

The use of aquatic invertebrates in biomedical research and as environmental sentinels has dramatically grown in recent decades, with an increased need in understanding of comparative pathology. The Unionids freshwater mussels are a group of worldwide distributed bivalves residing small ditches and ponds, lakes, canals and rivers, often used as animal test in eco-toxicological studies. Once one of the most abundant bivalve molluscs in ancient rivers around the world, now many of them are declining in many countries and consequently are nearly extinct in many areas. The causes of this decline are not fully understood but alteration and degradation of the freshwater habitat seemed to play a central role. To date, link causality to the observed losses during episode of mussel die-offs has been more difficult to establish, and disease and pathogen presence have been scarcely considered. In this article we provide a brief overview of unionids freshwater mussel conservation status, also describing reported diseases and pathogens and illustrating a few relatively well-documented studies

Presence of Gambusia affinis (Baird & Girard, 1853) in a freshwater ecosystem of Campania region (Italy)

The western mosquitofish, Gambusia affinis, is a small fish native to the southeastern United States. In the past century this species, and its congener, the eastern mosquitofish, Gambusia holbrooki, have been stocked in permanent and temporary waters throughout the world for mosquito control. These two species, very similar in appearance and biology, quickly became invasive with a strong ecological impact on ecosystems. They are considered responsible for the decline of several native amphibians and small fish in the Mediterranean region. Previous studies on European population conducted from Portugal to Greece reported the presence of only G. holbrooki in Italy, with report on Sicily (Catania) and Tuscany (Coltano) (Vidal, 2010). During an experimental trawl survey in 2010, samples of mosquito fishes were collected with nets from a pond near Cancello Arnone (Campania, Caserta, Italy). In order to define the Gambusia species, identification through dichotomous keys and DNA based methods were conducted. In particular, gonopodia morphology of preserved male individuals along with dorsal and anal fin rays were used to species differentiation (Walters and Feeman, 2000; Veenvliet, 2007), in our case giving uncertain results. For the molecular characterization, DNA from muscle tissue was isolated and two primer sets were used based on the conserved regions of the 12S and 16S rRNA loci as described by Kitano et al. (2007). PCR amplification and sequencing showed a 100% of maximum identity with G. affinis sequences in Genbank. These results, while contributing to unriddle the ambiguities in Gambusia taxonomy (see Vidal, 2010), call for further studies in order to define Gambusia affinis distribution in the Campania region and its impact on freshwater population

On the Fractal Nature of Nervous Cell System

In a detailed study entitled “Morphological development of thick – tufted layer V pyramidal cells in the rat somatosensory cortex, ” an international team of scientists (Romand et al., 2011) reported a series of results pertaining to an analytical investigation of the morphological development of thick-tufted layer V pyramidal cells (also called the principal cells) in the rat somatosensory cortex. At the end of the Introduction Section, the Authors stated “all compartments of a TTL5 cell undergo different developmental changes, supporting the notion that multiple functional compartments receive different inputs an

Epidemiology of Noble Pen Shell (Pinna nobilis L. 1758) Mass Mortality Events in Adriatic Sea Is Characterised with Rapid Spreading and Acute Disease Progression

From May to October 2019, multiple mass mortality events (MMEs) of Pinna nobilis were observed along Croatian coastline starting from the south-east and rapidly progressing in north-western direction. Time dynamics of the MMEs closely followed general speed and direction patterns of surface sea-currents, advancing approximately 350 km in less than 3 months. Surveillance, clinical evaluation, and sample collection were performed on multiple sites with various degrees of mortality rates. Moribund P. nobilis individuals were collected and subjected to pathological, molecular, and microscopical investigation. Affected animals were positive for Mycobacterium in 70% of the individuals, and Haplosporidium pinnae was present in 58% of the cases. Observed pathological lesions were most severe where concurrent presence of both pathogens was confirmed (in 45.8% of moribund individuals). Moderate to strong lesions were observed in animals positive for Mycobacterium only (25% of cases), and lesions were absent or minor to moderate when only H. pinnae was confirmed (16% of cases). Considering the rapid and severe spread of the MMEs, the areas less exposed to major sea currents appeared to be at lower risk of pathogen transmission. Surveillance activities along the Croatian coastline identified several P. nobilis populations in such “lower risk” areas without apparent mortality or clinical symptoms. Such areas are of particular interest as source of potentially healthy individuals to support active recovery actions

Salaria fluviatilis: a Mediterranean, endangered, freshwater blenny

The Mediterranean freshwater ichthyofauna includes many interesting but poorly known species, because of little interest for sport fishing and culinary purposes. Salaria fluviatilis is the most widespread freshwater blenny of the Mediterranean. This species is found in rivers, brooks and low altitude lakes rich in branches and with stone bottom. Average lifespan is up to 5 years; larvae are planktonic until the size of about 1.5 cm and live in quiet waters. They reach a size of 12 cm on average and males are larger than females, and have a small ridge on the head. S. fluviatilis feeds on benthic organisms like small snails and shrimps, on fish and all kinds of insect larvae; it is itself prey of birds (migratory and resident), tortoise (e.g. Emys orbicularis) and snakes (e.g. Natrix spp). The population is very fragmented, and few data are available due to the difficulties to catch or to observe this fish; consequently, it is difficult to know its conservation status. It is included in Annex III of the Bern Convention and is considered a locally endangered species, listed by the IUCN Red List. The species is included in the overall plan of action for the conservation of freshwater Italian fishes. In South Italy, the main threat factors are water pollution, habitat destruction (gravel extraction, damming, canalization of rivers, etc.) and introduction of non-native predatory fish species like catfish (Ameiurus melas), bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides), of two allochthonous decapod crustaceans (Procambarus clarkii and Orconectes limosus) and two Testudines (Trachemys spp.). Due to their important ecological and trophic role of connection between benthic invertebrates, migratory birds and reptiles, we started a monitoring scientific program, capture of breeding animals, setting up of dedicated mesocosms and reproduction as well as rearing of juveniles for, local or in larger scale, restocking purpose allowed by the low genetic divergence of the species

In the wake of the ongoing mass mortality events: Co-occurrence of Mycobacterium, Haplosporidium and other pathogens in Pinna nobilis collected in Italy and Spain (Mediterranean Sea)

Following the Mass Mortality Events (MMEs) of the pen shell P. nobilis in Campania region and Sicily, a survey of moribund P. nobilis specimens was also conducted in other Italian regions (Campania, Tuscany, Sardinia, and Apulia) and Spain (Catalunya). Histopathological and molecular examination of 27 specimens of P. nobils revealed different types of pathogens associated with tissue lesions, morbidity and mortality. Presence of Mycobacterium, Vibrio species, Haplosporidium pinnae and Perkinsus sp. were detected, differently distributed into the areas. The Mycobacterium sp., previously reported in Campania and Sicily samples, was observed in all the analyzed areas and individuals, associated to systemic inflammatory lesions. In Spain, H. pinnae was observed in 36% of cases, always associated to the Mycobacterium sp. Molecular study using hsp65 genes and Internal Transcriber Spacer ITS support that a new species of Mycobacteria is infecting P. nobilis, close to M. triplex and belonging to the group of M. simiae complex with M. sherrisi. Presence of Perkinsus spp. resembling P. mediterraneus was observed in 2 out of 13 Italian individuals whose presence should be addressed as potential risk for shellfish aquaculture of the area. Vibrio spp. were also detected in some case. The preliminary results of this study suggest that Mycobacterium sp., Vibrio spp., H. pinnae and Perkinsus sp. cooperate to disease pathogenesis, being Mycobacterium and Haplosporidium most of the time involved. Vigilant inspection of those areas where MME is now starting, along with continuous systematic surveys, are crucial to define the spatiotemporal progress of mortality and the role of every single pathogen in the disease outcome.info:eu-repo/semantics/publishedVersio

Corrigendum: In the Wake of the Ongoing Mass Mortality Events: Co-occurrence of Mycobacterium, Haplosporidium and Other Pathogens in Pinna nobilis Collected in Italy and Spain (Mediterranean Sea)

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A widespread picornavirus affects the hemocytes of the noble pen shell (Pinna nobilis), leading to its immunosuppression

IntroductionThe widespread mass mortality of the noble pen shell (Pinna nobilis) has occurred in several Mediterranean countries in the past 7 years. Single-stranded RNA viruses affecting immune cells and leading to immune dysfunction have been widely reported in human and animal species. Here, we present data linking P. nobilis mass mortality events (MMEs) to hemocyte picornavirus (PV) infection. This study was performed on specimens from wild and captive populations.MethodsWe sampled P. nobilis from two regions of Spain [Catalonia (24 animals) and Murcia (four animals)] and one region in Italy [Venice (6 animals)]. Each of them were analyzed using transmission electron microscopy (TEM) to describe the morphology and self-assembly of virions. Illumina sequencing coupled to qPCR was performed to describe the identified virus and part of its genome.Results and discussionIn 100% of our samples, ultrastructure revealed the presence of a virus (20 nm diameter) capable of replicating within granulocytes and hyalinocytes, leading to the accumulation of complex vesicles of different dimensions within the cytoplasm. As the PV infection progressed, dead hemocytes, infectious exosomes, and budding of extracellular vesicles were visible, along with endocytic vesicles entering other cells. The THC (total hemocyte count) values observed in both captive (eight animals) (3.5 × 104–1.60 × 105 ml−1 cells) and wild animals (14 samples) (1.90–2.42 × 105 ml−1 cells) were lower than those reported before MMEs. Sequencing of P. nobilis (six animals) hemocyte cDNA libraries revealed the presence of two main sequences of Picornavirales, family Marnaviridae. The highest number of reads belonged to animals that exhibited active replication phases and abundant viral particles from transmission electron microscopy (TEM) observations. These sequences correspond to the genus Sogarnavirus—a picornavirus identified in the marine diatom Chaetoceros tenuissimus (named C. tenuissimus RNA virus type II). Real-time PCR performed on the two most abundant RNA viruses previously identified by in silico analysis revealed positive results only for sequences similar to the C. tenuissimus RNA virus. These results may not conclusively identify picornavirus in noble pen shell hemocytes; therefore, further study is required. Our findings suggest that picornavirus infection likely causes immunosuppression, making individuals prone to opportunistic infections, which is a potential cause for the MMEs observed in the Mediterranean