A survey on zoonotic helminths in farmed fish to evaluate the safety of Italian aquaculture products

Introduction: Several zoonotic helminths can be transmitted to humans by consumption of raw, undercooked, marinated or cold smoked fish products, representing a relevant public health concern. Although up to now in Italy the presence of zoonotic helminths has been documented only in wild fish populations, extensive epidemiological surveys are needed in order to assess the possible zoonotic risks linked to consumption of national aquaculture products. At this purpose, a wide parasitological survey has being undertaken on rainbow trout Oncorhynchus mykiss (RBT), gilthead seabream Sparus aurata (GSB) and European seabass Dicentrarchus labrax (ESB) farmed in Italy. Methodology: From spring 2016 to spring 2017 a total of 2347 fish have been examined. In particular, 738 RBT from 4 Italian freshwater trout farms (two farms located in the area endemic for diphyllobothriasis in Northwestern Italy, 1 in the area endemic for opisthorchiasis in Central Italy and 1 in a highly productive area of Northeastern Italy) were subjected to methods aimed to search for larval stages of diphyllobothriid cestodes (visual inspection and candling) and opisthorchiid digeneans (muscular compression/artificial digestion followed by microscopic examination). Furthermore, 781 GSB and 828 ESB from 4 marine farms (3 cage systems and 1 inland farm located in Tyrrhenian and Adriatic seas) were examined for anisakid larvae by UV-press method and artificial digestion. A seasonal periodicity has been applied, sampling 65 specimens/fish species/farm/season in order to reach a statistically significant amount of fish at the end of the survey (258 fish/farm). Results: No zoonotic parasites have been found in all the examined fish at the level of confidence of 99% with a margin of error of 5%. Conclusions: The results so far obtained during this survey are encouraging and seem to confirm that the risks linked to zoonotic helminths in Italian aquacultured fish species are null or negligible, when good farming practices are applied along the production chain

Morphological and molecular characterization of two gastrointestinal parasites in Mustelus mustelus (Linnaeus, 1758) from Adriatic Sea

Specimens of common smooth-hound, Mustelus mustelus, fished as bycatch in the Northwestern Adriatic Sea, were subjected to a complete parasitological examination. Parasites were processed for morphological and morphometric analyses aimed at identifying them to the species level. Parasite identity was confirmed through amplification and sequencing of 28S rDNA. The nematode Acanthocheilus rotundatus was recovered from the stomach and the proximal intestine, while the cestode Calliobothrium verticillatum was collected from the spiral valve. Our results confirm the occurrence of C. verticillatum in M. mustelus from the Mediterranean Sea and provide the first sequence data of A. rotundatus from the same area. Updated knowledge on the parasite fauna of M. mustelus from Adriatic Sea contributes to elucidating aspects of the ecology, biology and health status of elasmobranchs from the Mediterranean Sea, providing useful information for their proper management and conservation

Metacestodes of elasmobranch tapeworms in octopus vulgaris (Mollusca, cephalopoda) from central mediterranean—SEM and molecular data

Cephalopods are intermediate/paratenic hosts in the life cycle of elasmobranch tapeworms, nevertheless most records of infection in this group of mollusks are outdated and fragmentary. The present work aimed to investigate the cestode fauna of the common octopus Octopus vulgaris from the Tyrrhenian Sea (Central Mediterranean). The parasitic stages were characterized by light and Scanning Electron Microscopy (SEM) and sequencing of 28S rDNA. Three cestode taxa were identified to the genus level: the onchoproteocephalidean Acanthobothrium sp. (prevalence 28%), the “tetraphyllidean” Anthobothrium sp. (prevalence 13%) and the trypanorhynch Nybelinia sp. (prevalence 3%). The remarkable prevalence observed for gastrointestinal cestodes highlight a possible important role of O. vulgaris in the transmission of elasmobranch tapeworms, particularly Onchoproteocephalideans. Furthermore, the present work provides, for the first time, detailed morphological (SEM) and molecular support to confirm the occurrence of Anthobothrium sp. in cephalopod hosts. In order to gain higher taxonomic resolution for the identified taxa, we stress the need to collect further morphological and molecular data of adult cestodes infecting their elasmobranch definitive hosts

Anatomy of Tunga trimamillata Pampiglione et al., 2002 (Insecta, Siphonaptera, Tungidae) and developmental phases of the gravid female

This paper deals with some internal anatomical features observed in histological sections and freshly dissected mounts of Tunga trimamillata, a Siphonaptera recently discovered in Andean regions of Ecuador from several mammals, including man. It was possible to study in males and also non-gravid and gravid females, the location and anatomy of several organs not previously described for this species: the testes, epididymis, ganglia, Malpighian tubules, eyes, rectal ampulla with one of its pads and structures which could be interpreted as midgut diverticula, whose presence has not been recorded in the Siphonaptera. The process of neosomy in the female during pregnancy is illustrated by photographs of the consecutive developmental phases, taken at the stereomicroscope. Furthermore, Some details of the exoskeleton, spermatheca during different phases of pregnancy of the gravid female and the presence of a foreign body (parasite?) within the haemocoel have been displayed in specimens cleared with Hoyer's medium

Viral nervous necrosis outbreaks caused by the RGNNV/SJNNV reassortant betanodavirus in gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax)

Mediterranean marine aquaculture has suffered significant economic losses due to viral nervous necrosis (VNN) outbreaks mainly caused by different RGNNV betanodavirus strains. In recent years, the marine aquaculture sector has experienced the emergence of the RGNNV/SJNNV reassortant betanodavirus, harbouring the RNA1 segment of RGNNV genotype and the RNA2 segment of SJNNV genotype. So far, the reassortant strains caused massive mortality outbreaks in gilthead sea bream (Sparus aurata) larvae sparing the European sea bass (Dicentrarchus labrax). In this study, multiple mortality outbreaks occurred in one Italian marine hatchery involving both European sea bass and gilthead sea bream at different life stages were investigated through a complete microbiological and molecular analysis. Gilthead sea bream larvae and juveniles have recorded the highest mortality rates, however, both European sea bass and gilthead sea bream incurred a RGNNV/SJNNV reassortant betanodavirus persistent infection, able to act as asymptomatic carriers and viral source for susceptible fish. These new epidemiological data on nervous necrosis virus (NNV) reassortant infection provide precious advice on how to manage fish to reduce VNN spread in Mediterranean aquaculture. Evidence of interspecies transmission of RGNNV/SJNNV reassortant strains and the persistent infection in both European sea bass and gilthead sea bream, point out the importance to enforce a wide surveillance and a strict biosecurity programme addressing both RGNNV and reassortant RGNNV/SJNNV betanodaviruses in Mediterranean European sea bass and gilthead sea bream farms. Furthermore, the presence assessment of betanoviruses in all newly-introduced fish batches in the farm, regardless of the species and a strict segregation between European sea bass and gilthead sea bream batches within farms can significantly reduce the risk of NNV transmission. Finally, surviving fish can act as carrier fish, and thereby must be segregated from other batches and protected from stress conditions that could trigger a new clinical phase

Helminth infection of the loggerhead sea turtle caretta caretta along the coasts of sicily and the north west adriatic sea

We provide new data on the presence of helminth parasites in 64 individual loggerhead sea turtles Caretta caretta stranded along the coasts of Sicily and the northwest Adriatic Sea between June 2014 and August 2016. The necropsy examination revealed 31 individuals (48.4%) positive for endoparasites, showing a greater prevalence of trematodes than nematodes. In particular, seven species and a single genus of Trematoda (Hapalotrema) and a single species and genus of Nematoda (Kathlania) were identified. Among the Digenea flukes the species with the highest prevalence of infection were Rhytidodes gelatinosus (34.6%) and Hapalotrema sp. (33.3%), while among the Nematoda they were Kathlania sp. (33.3%) and Sulcascaris sulcata (33.3%). Analysis of variance (ANOVA) was applied among the recovery sites of the stranded loggerhead sea turtles and prevalence of endoparasites was used to highlight any relationship between the parasites and the origin of the hosts. ANOVA showed significant differences (p < 0.001) among the data used

A stratified compartmental model for the transmission of Sparicotyle chrysophrii (Platyhelminthes: Monogenea) in gilthead seabream (Sparus aurata) fish farms †

The rapid development of intensive fish farming has been associated with the spreading of infectious diseases, pathogens and parasites. One such parasite is Sparicotyle chrysophrii (Platyhelminthes: Monogenea), which commonly infects cultured gilthead seabream (Sparus aurata)-a vital species in Mediterranean aquaculture. The parasite attaches to fish gills and can cause epizootics in sea cages with relevant consequences for fish health and associated economic losses for fish farmers. In this study, a novel stratified compartmental epidemiological model of S. chrysophrii transmission was developed and analysed. The model accounts for the temporal progression of the number of juvenile and adult parasites attached to each fish, as well as the abundance of eggs and oncomiracidia. We applied the model to data collected in a seabream farm, where the fish population and the number of adult parasites attached to fish gills were closely monitored in six different cages for 10 months. The model successfully replicated the temporal dynamics of the distribution of the parasite abundance within fish hosts and simulated the effects of environmental factors, such as water temperature, on the transmission dynamics. The findings highlight the potential of modelling tools for farming management, aiding in the prevention and control of S. chrysophrii infections in Mediterranean aquaculture

Survey on laboratories and consultants working in the diagnostics of European seabass and gilthead seabream diseases: preliminary results

European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) are prevailing species in Mediterranean marine finfish aquaculture, and despite an increasing demand of the global markets for high-quality seafood, production and technical performance of these two species in the EU has stagnated over the last few years. Two EU Horizon 2020 projects, MedAID and PerformFISH were launched in 2017 to increase the competitiveness and sustainability of the Mediterranean marine fish aquaculture sector. Since the impact of diseases has been one of the factors attributed to the stagnation, both projects envisaged that the concept of healthy fish was a prerequisite for sustainable and profitable aquaculture. A key element of disease surveillance and health management is the availability of fast, reliable, efficient and validated diagnostic techniques capable of detecting the presence of pathogens and timely diagnosis of diseases in fish stocks. Collaborative activities between both consortia launched specific activities to identify all actors involved in diagnostics and to evaluate their diagnostic capacities. An online “Questionnaire on diagnostic capacities in the Mediterranean basin” was carried out. The results obtained showed disproportionate diagnostic capacity between European and non-European Mediterranean countries. European countries in general showed a high level of diagnostic capacity with many advanced or specialised labs dealing with the main diseases of concern for sea bass and sea bream. There was evidence of lower diagnostic capacities in non-European Mediterranean countries in contrast with their high degree of production, which poses a significant regional risk considering the important movement of juveniles in the region. These findings indicate the necessity to address the health management in the region in a more holistic, cooperative and harmonised way. An important finding was a lack of capacity to diagnose viral diseases although VNN has been identified to be the main health threat.Efforts should be engaged in capacity building in the countries missing particular techniques and improvement and training is a priorty. For this purpose, national focal points should be established to create an international network aimed at improving and harmonising all future activities in the field of diagnostics of Mediterranean fish diseases.info:eu-repo/semantics/publishedVersio

Unusual localization of pennella sp. In swordfish (xiphias gladius) hearts

The genus Pennella comprises hematophagous parasites of marine aquatic species, including cephalopods, marine mammals, and pelagic fish. Nine species have been officially included in the genus Pennella plus another six species inquirendae. They are most often found in the host’s musculature, without penetrating internal organs. For the present study, 83 hearts from swordfish (Xiphias gladius) caught in the Mediterranean Sea were sampled and immediately fixed in formalin for histopathological analysis. In total, 10 (12.05%) hearts were found to be parasitized by copepods of the genus Pennella. Macroscopically, there was mild-to-severe fibrinous pericarditis with atrial wall thickening and multiple parasitic nodules. Histologically, the parasitic nodules were surrounded by an inflammatory-necrotizing reaction. Parasitic infestation by Pennella spp. is common in pelagic fish and in swordfish, in particular. Here, however, we report atypical cardiac localization. A future area of focus is the evaluation of cardiac Pennella spp. infestation by histopathology and genetic identification of the parasites

INDAGINE PARASSITOLOGICA SULLA PRESENZA DI STADI LARVALI DI NEMATODI ANISAKIDAE IN PESCI MARINI ALLEVATI IN ITALIA

L\u2019anisakiasi \ue8 una zoonosi parassitaria di origine alimentare sostenuta da larve al terzo stadio (L3) di nematodi appartenenti alla famiglia Anisakidae ed in particolare al genere Anisakis. Soprattutto in seguito alla recente emergenza di sindromi allergiche da Anisakis, l\u2019EFSA nel 2010 ha pubblicato un parere scientifico sui rischi correlati alla presenza di parassiti zoonotici in prodotti ittici, considerando sicura la pratica d\u2019allevamento del salmone atlantico (Salmo salar) in quanto, se allevati partendo da avannotti prodotti in sistemi chiusi e alimentati sempre con mangime inerte, questi animali presenterebbero un rischio di infestazione da larve di Anisakis trascurabile. Su questa base, il Reg. UE n. 1276/2011, che modifica l\u2019allegato III del Reg. CE n. 853\2004, puntualizza la possibile deroga al trattamento di congelamento, obbligatorio per i prodotti della pesca destinati ad essere consumati sotto forma di preparazioni a rischio (crudi, marinati, affumicati a freddo, ecc.), per i prodotti ittici derivanti da allevamento quando vengono rispettati i criteri definiti dall\u2019EFSA analogamente al salmone atlantico. Appare quindi d\u2019importanza strategica fornire dati scientifici estesi ed attendibili sull\u2019assenza di parassiti zoonotici nei prodotti della maricoltura mediterranea non solo ai fini di una loro migliore qualificazione commerciale ma anche per una pi\uf9 facile applicabilit\ue0 di tale deroga da parte delle autorit\ue0 competenti. Nell\u2019ambito delle attivit\ue0 di ricerca previste dal progetto europeo H2020 ParaFishControl \u201cAdvanced Tools and Research Strategies for Parasite Control in European farmed fish\u201d, da marzo 2016 a giugno 2017 \ue8 stato condotto un esteso monitoraggio parassitologico in spigole (Dicentrarchus labrax) ed orate (Sparus aurata) allevate in Italia. Le attivit\ue0 di campionamento hanno coinvolto 4 allevamenti nazionali, di cui 3 in gabbie galleggianti ed uno in vasche a terra, prelevando almeno 258 esemplari per specie/allevamento suddivisi in 4 campionamenti a cadenza stagionale per un totale di 1040 spigole e 1090 orate. La numerosit\ue0 campionaria \ue8 stata calcolata in modo da ottenere almeno il 95% di probabilit\ue0 di evidenziare un esemplare positivo con prevalenza >2%. Per la ricerca di larve di nematodi Anisakidae sono stati associati: esame visivo diretto e mediante transilluminatore di visceri e porzioni muscolari, metodo della UV-press dei filetti e digestione con soluzione cloro- peptica del pacchetto viscerale. Tutti gli esemplari di spigola e orata esaminati sono risultati negativi per la presenza di stadi larvali di Anisakis spp. In un unico esemplare di spigola proveniente da un allevamento in gabbia \ue8 stata evidenziata la presenza di una larva di Hysterothylacium fabri (nematode non zoonotico) incistata sulla superficie del fegato ed identificata a livello di specie mediante PCR-RFLP. Alla luce della trasmissione di questo parassita a pesci predatori per via trofica, similmente ai nematodi Anisakidae zoonotici, nel prossimo futuro verranno condotte indagini mirate ad identificare i fattori di rischio che hanno condotto all\u2019infestazione da H. fabri in allevamento, seppur in un unico esemplare, ed individuare gli eventuali punti critici da monitorare. I risultati ottenuti da questa indagine indicano comunque come nelle spigole e nelle orate allevate in Italia il rischio d\u2019infestazione da Anisakis sia da ritenersi trascurabile, aprendo la via ad azioni di qualificazione dei prodotti della maricoltura mediterranea