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EPIDEMIOLOGY AND LIFE CYCLE OF CYSTIDICOLA FARIONIS (NEMATODA: CYSTIDICOLIDAE), PARASITE OF SALMONIDS SPREADING IN ITALY
No full textA parasitological survey has been carried out in wild and farmed salmonids from northern Italy in order to clarify the current diffusion
of the swimbladder nematode Cystidicola farionis (Nematoda: Cystidicolidae), reported since 2006 in wild salmonids from Adige river
in the Bolzano province. 314
315
P
ARASSITI
DELLA
FAUNA
ACQUATICA
P
ARASSITI
DELLA
FAUNA
ACQUATICA
POSTER 06
POSTER 06
XXVIII Congresso Nazionale SoIPa, Roma 24-27 giugno 2014
XXVIII Congresso Nazionale SoIPa, Roma 24-27 giugno 2014
P06.3
EPIDEMIOLOGY AND LIFE CYCLE OF CYSTIDICOLA FARIONIS (NEMATODA: CYSTIDICOLIDAE),
PARASITE OF SALMONIDS SPREADING IN ITALY
Cavazza G.
[1]
,
Gustinelli A.
*
[1]
, Menconi V.
[1]
, Caffara M.
[1]
, Fioravanti M.L.
[1]
[1]
Department of Veterinary Medical Sciences Alma Mater Studiorum University of Bologna ~ Bologna ~ Italy
INTRODUCTION:
A parasitological survey has been carried out in wild and farmed salmonids from northern Italy in order to clarify the current diffusion
of the swimbladder nematode Cystidicola farionis (Nematoda: Cystidicolidae), reported since 2006 in wild salmonids from Adige river
in the Bolzano province. From July 2012 to September 2013 a total of 103 trouts have been examined, in particular 99 rainbow trout (Oncorhynchus mykiss),
6 wild from Adige river in Bolzano province, 63 and 30 rainbow trout from a farm in Vicenza province (F1) and a farm (F2) located
in Trento province, respectively; and 4 wild brown trout (Salmo trutta fario) from Adige river in Bolzano province. All the fish were
weighted, measured and then subjected to parasitological examination, with more attention to swim bladder. Parasites were isolated,
rinsed in deionized water, fixed in 70% ethanol and clarified by Amman’s lactophenol for morphological studies. Prevalence values (%),
Mean Intensity (MI) and Abundance (A) have been calculated according to Bush et al., 1997, J.Parasitol., 83: 575-583. Sixty-four (64.6%) out of 99 rainbow trout were positive for nematodes (MI=13.4,A=8.64); 35 (55.5%) out of 63 fish (MI=12.6, A=7)
from F1, 26 (86.6%) out of 30 (MI=14.7, A=12.7) from F2 and 3 (50%) out of 6 (MI=53, A=26,5) from the wild. Only 1 (25%) out of
the 4 wild brown trout were parasitized by 31 nematodes. All the parasites were identified as Cystidicola farionis. In F1, 4 samples of
parasite amphipods described as intermediate host of C. farionis, have been collected upstream and within the tanks by a plankton
net. Amphipods were transported alive to the laboratory and then examined for the presence of larval nematodes at the dissection
microscope. The larvae were isolated, fixed in 5% buffered formalin and submitted to morphological study. A total of 4505 amphipods,
all identified as Echinogammarus spp., have been examined. One hundred-four larvae referable mainly to third stage, L3 of C. farionis
were found (MI=1.22, ranging from 1 to 5 larvae/amphipod) in 85 (1.9%) amphipods. A slightly higher positivity (2.1%) for C. farionis
larvae has been observed inside the farm compared to upstream (1.7%), and the highest prevalence value (8.4%) has been observed in
the month of October. In Europe the occurrence of C. farionis is documented in several northern and central European countries, including the European
part of Russia, but its report in Italy is quite recent (Gustinelli et al., 2008, Ittiopatologia, 5:87-97). On the basis of this study C. farionis
spread from Adige river to other water systems involving also trout farms with a potential impact on their commercial value. Infected
farms show common features such as a not-intensive management, with particular reference to low biomass density and integrative
feeding, leading the fish to feed on natural preys as amphipods and allowing the development of C. farionis life cycle.
The increasing presence of C. farionis in Italian salmonid species confirms its stable introduction in both freshwater wild and farming
environments and give a strong warning on the hazard of the introduction of not-monitored fish and their exotic parasites that could
become a risk factor on national scale
FRESHWATER FISH-BORNE PARASITIC ZOONOSES IN ITALY
No full textFish-borne parasitic zoonoses have aroused an increasing interest in Italy over recent years for the changing of culinary habits towards
an increasing consumption of raw/undercooked/marinated fish, in association with the expansion of international commercial trade
in fishery products, globalization and migration flows across world, all factors which have driven to an increased risk of acquiring fish-
borne zoonoses. Several zoonotic helminths can be transmitted through consumption of raw and/or undercooked fish products to
humans, since fishes actively participate to biological cycles of heteroxenous parasites that involve man as definitive or accidental host,
causing different degrees of pathology. Although currently WHO include, with regard to zoonotic fish helminthes, only Opisthorchiidae
(Opisthorchis spp. and Clonorchis spp.) in the priority list of the foodborne parasites “that could produce a substantive burden of
disease” (Torgerson et al., 2014, Trends Parasitol., 30: 20-26) it is undeniable that other fish parasites such as Anisakid nematodes
and Diphyllobothriid cestodes should be taken into account when considering the zoonotic risks linked to European fish products
consumption. In fact, according to EFSA Scientific Opinion on risk assessment of parasites in fishery products (European Food Safety
Authority, 2010, EFSA J., 8, 1543) all wild fish should be considered at risk of containing any viable zoonotic parasites if these products
are to be eaten raw or almost raw, pointing out the need to carry out epidemiological surveys on presence/diffusion of zoonotic
parasites in all fishery grounds. Respect to infections due to Anisakid larvae in marine fish, until recently in Italy a lower attention
has been devoted to the study of zoonotic helminths in freshwater fish populations, such as in primis the cestode Diphyllobothrium
latum and the digenean Opisthorchis felineus. The recrudescence of cases of human Diphyllobothriasis registered in Switzerland,
France and Italy during the last decades (Scholz et al., 2009, Clin.Microbiol.Rev., 22: 146-160) and the recent outbreaks of human
Opisthorchiasis observed in Italy, with more than 200 autochthonous human cases reported from 2004 up to 2011 (Pozio et al., 2013,
Acta Tropica, 126: 54-62), have determined a renewed interest in epidemiology of infections due to zoonotic parasites in freshwater
fish. Concerning Diphyllobothriasis, recent surveys pointed out a widespread presence of D. latum plerocercoids in perch (P. fluviatilis)
populations of Como Lake and, to a lesser extent, in perch from Iseo and Maggiore Lakes, confirming this species as elective second
intermediate host of D. latum in Italy. The occurrence of D. latum plerocercoid larvae was also found in pike (Esox lucius) and burbot
(Lota lota), main paratenic hosts of D. latum, coming from the same sub-alpine lakes, while fish from Garda lake did not show D. latum
infections (Gustinelli et al., 2013, Atti XIX Conv. SIPI, Siracusa, 75). With regard to Opisthorchiasis, although several species of cyprinids
have been described as suitable second intermediate hosts of O. felineus from different endemic countries, so far in Italy only tench
(Tinca tinca) has been found positive from Bolsena, Bracciano and Vico lakes (De Liberato et al., 2011, Vet.Parasitol., 177: 67-71;
Gustinelli et al., 2011, 15th Conf. EAFP, Split, HR, 424), always with high prevalence and intensities. The consumption of raw perch
(“perch carpaccio”) and marinated tench in the positive areas has been identified as the main food source of viable infective stages of
D. latum and O. felineus respectively. In the case of O. felineus, it has to be pointed out that the microscopical size of metacercariae
make their detection impossible through the visual inspection procedures commonly applied for the purpose of detecting parasites
in fishery products, requiring more destructive and time consuming techniques. Anyway, both for Diphyllobothrium plerocercoids
and Opisthorchiid metacercariae, morphology is not sufficient for identification at species level needing the support of molecular
methods. The analysis of risk factors influencing the epidemiology of these zoonotic helminths indicate the lack of efficient urban
wastewater depuration plants around lake shores as the main aspect influencing the maintenance of D. latum cycle, being humans
the elective definitive hosts, together with the influence of abiotic parameters such as temperature and oxygen on development
of Diphyllobothrium first stages (Wicht et al., 2009, Bull.Eur.Ass.Fish Pathol., 29: 58-65). Concerning O. felineus, the presence of
parasitised stray cats, main reservoirs of the infection, and of Bythinia spp. gastropods, suitable first intermediate hosts, seem to be
the key factors in the subsistence of this zoonotic helminth described in Italy since XIX century in dogs and cats (Rivolta, 1884, Giorn.
Anat. Fisiol. Patol. An., 16: 20–28), although the role of fox and other wild animals as reservoirs and the possible involvement of
cyprinids other than tench as second intermediate hosts have to be better studied. Since the maintenance of the complex biological
cycles of these zoonotic helminths is influenced by several biotic and abiotic factors, investigating the interplay of these factors may be
crucial in next future not only for a better understanding of parasite transmission patterns, but also for predictive studies on presence/
maintenance of zoonotic parasites in different fish species in order to map the risks linked to consumption of freshwater fishery
products. At this purpose, further surveys aimed at investigate the possible occurrence of larval stages of other zoonotic helminths
such as the Opisthorchiid Metorchis sp. and the Heterophyid Metagonimus sp. in Italian freshwater fish populations should be carried
out in order to increase the knowledge on epidemiology of fish-borne zoonotic parasites and to prevent outbreaks of new zoonoses.
Furthermore, although so far in Italy the presence of zoonotic helminths has been documented only in wild fish populations, extensive
epidemiological surveys should be conducted on parasites of public health importance in farmed fish species, as required by EFSA and
by current EU food hygiene regulations, in order to confirm as null or negligible the zoonotic risk linked to consumption of national
aquaculture products
A PARASITOLOGICAL SURVEY IN ELASMOBRANCHS FROM ADRIATIC SEA
No full textElasmobranches play a key-role as definitive hosts in the complex life cycle of several parasitic species being at the top of the food
chain. Despite their biological importance, studies on the parasitofauna of sharks and rays are rather difficult to be carried out, as
most of them are endangered species and specimens collection and examination are sporadic and mainly limited to biodiversity and
environmental monitoring research projects. During 2013, in collaboration with the Lab of Marine Biology and Fishery, University of Bologna, located in Fano (Ancona province),
Italy, a parasitological survey has been carried out on elasmobranchs caught in the Adriatic sea for stocks evaluation purposes. A
total of 184 fish from georeferenced fishing stations and belonging to 10 species have been examined: 50 Galeus melastomus, 43
Scyliorhinus canicula, 34 Raja clavata, 27 Squalus acanthias, 11 Mustelus punctulatus, 8 Mustelus mustelus, 5 Raja miraletus, 3
Myliobatis Aquila, 1 Torpedo maculata, 1 Torpedo marmorata. All fish were weighed, measured and submitted to parasitological
examination focused on the gastrointestinal tract. Parasites were cleaned in water and fixed in alcohol 70%, then mounted and clarified
in Amman’s lactophenol for morphological identification. Prevalence (P) values, Mean Intensity (MI) and Abundance (A) have been
calculated according to Bush et al,. 1997, J. Parasitol., 83: 575-583. All the individuals of the remaining species, Galeus melastomus, Myliobatis aquila, Torpedo maculata and Torpedo marmorata were
negative for the presence of parasites.
All the digenean trematodes have been referred to one species, Ptychogonimus megastomus (Rudolphi, 1819), already reported in M.
mustelus and R. clavata but never described in Mustelus punctulatus. This represents to our knowledge a new host-record.
Concerning cestodes, the specimens isolated belongs to two trypanorhinch species, in particolar Nybelinia lingualis in S. canicula and
Eutetrarhynchus ruficollis in M. punctulatus, while the tapeworm isolated from S. canicula was not well preserved and impossible to be
identified.
Nematodes are the most represented endoparasites in our survey as they have been isolated from the intestine of all the six positive
fish species. In S. canicula nematodes were identified as Proleptus obtusus, already reported in this fish species, while in R. clavata,
S. acanthias, M. punctulatus, M. mustelus and R. miraletus, the parasites isolated seem referable to Pseudanisakis spp., but further
morphological analyses need to be carried out to confirm this preliminary study.
In addition in S. acanthias and M. mustelus, the presence of Hysterothylacium sp. and Acanthocheilus sp. has been respectively
observed. The data collected during this survey give a preliminary sight on the parasitofauna present in elasmobranchs species not easy to
be investigated and add new information on the host specificity of some parasitic species,such as Ptychogonimus megastomus, to
our knowledge for the first time reported in M. punctulatus. Furthermore identification at species level and morphological data on
nematodes such as Pseudanisakis spp., should contribute to improve the knowledge on this poorly known genus
First electrosurgical excision of fibrosarcoma in goldfish (Carrassius auratus auratus)
No full textA Carrassius auratus auratus presented for a mass diagnosed as a fibrosarcoma. It was anaesthetised and an electrosurgical device was used and the mass was ablated. There is no previous documentation for electrocautery use in fish oncology. This note provides a safe protocol for electrosurgical excision of neoplasia in fish
A survey on zoonotic helminths in farmed fish to evaluate the safety of Italian aquaculture products
Full text linkIntroduction: 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
INDAGINE PARASSITOLOGICA SULLA PRESENZA DI STADI LARVALI DI NEMATODI ANISAKIDAE IN PESCI MARINI ALLEVATI IN ITALIA
Full text linkL’anisakiasi è 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’EFSA nel 2010 ha pubblicato un parere scientifico sui rischi correlati alla presenza di parassiti zoonotici in prodotti ittici, considerando sicura la pratica d’allevamento 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’allegato 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’EFSA analogamente al salmone atlantico. Appare quindi d’importanza strategica fornire dati scientifici estesi ed attendibili sull’assenza di parassiti zoonotici nei prodotti della maricoltura mediterranea non solo ai fini di una loro migliore qualificazione commerciale ma anche per una più facile applicabilità di tale deroga da parte delle autorità competenti. Nell’ambito delle attività di ricerca previste dal progetto europeo H2020 ParaFishControl “Advanced Tools and Research Strategies for Parasite Control in European farmed fish”, da marzo 2016 a giugno 2017 è stato condotto un esteso monitoraggio parassitologico in spigole (Dicentrarchus labrax) ed orate (Sparus aurata) allevate in Italia. Le attività 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 numerosità campionaria è stata calcolata in modo da ottenere almeno il 95% di probabilità 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 è 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’infestazione 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’infestazione da Anisakis sia da ritenersi trascurabile, aprendo la via ad azioni di qualificazione dei prodotti della maricoltura mediterranea
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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