scholarly journals Negligible risk of zoonotic anisakid nematodes in farmed fish from European mariculture, 2016 to 2018

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Maria Letizia Fioravanti ◽  
Andrea Gustinelli ◽  
George Rigos ◽  
Kurt Buchmann ◽  
Monica Caffara ◽  
...  

Background The increasing demand for raw or undercooked fish products, supplied by both aquaculture and fisheries, raises concerns about the transmission risk to humans of zoonotic fish parasites. This has led to the current European Union (EU) Regulation No 1276/2011 amending Annex III of Regulation (EC) No 853/2004 and mandating a freezing treatment of such products. Zoonotic parasites, particularly anisakid larvae, have been well documented in wild fish. Data on their presence in European aquaculture products, however, are still scarce, except for Atlantic salmon (Salmo salar), where the zoonotic risk was assessed as negligible, exempting it from freezing treatment. Aim To evaluate the zoonotic Anisakidae parasite risk in European farmed marine fish other than Atlantic salmon. Methods From 2016 to 2018 an observational parasitological survey was undertaken on 6,549 farmed fish including 2,753 gilthead seabream (Sparus aurata), 2,761 European seabass (Dicentrarchus labrax) and 1,035 turbot (Scophthalmus maximus) from 14 farms in Italy, Spain and Greece. Furthermore, 200 rainbow trout (Oncorhynchus mykiss) sea-caged in Denmark, as well as 352 seabream and 290 seabass imported in Italy and Spain from other countries were examined. Fish were subjected to visual inspection and candling. Fresh visceral organs/fillet samples were artificially digested or UV pressed and visually examined for zoonotic anisakid larvae. Results No zoonotic parasites were found in any of the fish investigated. Conclusions The risk linked to zoonotic Anisakidae in the examined fish species from European mariculture appears negligible. This study laid the groundwork for considerations to amend the current EU regulation.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Alicia C. Bertolotti ◽  
Ryan M. Layer ◽  
Manu Kumar Gundappa ◽  
Michael D. Gallagher ◽  
Ege Pehlivanoglu ◽  
...  

Abstract Structural variants (SVs) are a major source of genetic and phenotypic variation, but remain challenging to accurately type and are hence poorly characterized in most species. We present an approach for reliable SV discovery in non-model species using whole genome sequencing and report 15,483 high-confidence SVs in 492 Atlantic salmon (Salmo salar L.) sampled from a broad phylogeographic distribution. These SVs recover population genetic structure with high resolution, include an active DNA transposon, widely affect functional features, and overlap more duplicated genes retained from an ancestral salmonid autotetraploidization event than expected. Changes in SV allele frequency between wild and farmed fish indicate polygenic selection on behavioural traits during domestication, targeting brain-expressed synaptic networks linked to neurological disorders in humans. This study offers novel insights into the role of SVs in genome evolution and the genetic architecture of domestication traits, along with resources supporting reliable SV discovery in non-model species.


2014 ◽  
Vol 23 (4) ◽  
pp. 435-442 ◽  
Author(s):  
Mokhtar Ibrahim Khalil ◽  
Ismail Saad El-Shahawy ◽  
Hussein Saad Abdelkader

The present study was the first attempt to survey the diversity of fish zoonotic parasites in the southern region of Saudi Arabia, particularly the Najran area, from October 2012 to October 2013. Approximately 163 fish representing seven species (two of freshwater fish and five of marine fish) were examined for fish-borne trematode metacercariae using the compression technique, and for zoonotic nematode larvae. Adult flukes were obtained from cats experimentally infected with the metacercariae on day 25 post-infection The prevalence of each parasite species was recorded. The parasites found belonged to two taxa: Digenea (Heterophyes heterophyes and Haplorchis pumilio) in muscle tissue; and nematodes (larvae of Capillaria sp.) in the digestive tract. The morphological characteristics of the fish-borne trematode metacercariae and their experimentally obtained adults were described. This is the first report of these parasites in fish in Saudi Arabia. Moreover, Myripristis murdjan presented higher prevalence of Capillaria sp. infection (22.7%), while Haplorchis pumilio was the dominant metacercarial species (7.9%). Although the number of documented cases continues to increase, the overall risk of human infection is slight. The increasing exploitation of the marine environment by humans and the tendency to reduce cooking times when preparing seafood products both increase the chances of becoming infected with these parasites. Furthermore, our results indicate that certain fish production systems are at risk of presenting fish zoonotic parasites, and that control approaches will benefit from understanding these risk factors.


2013 ◽  
Vol 33 (7) ◽  
pp. 851-854 ◽  
Author(s):  
Bruno H. Ueda ◽  
Letícia C. Karling ◽  
Ricardo M. Takemoto ◽  
Gilberto C. Pavanelli

This paper presents a science metric study of parasites of fish farming in Brazil, including a significant review of the literature. The methodology used was based on researching articles in three different databases, carried out on May 2012: ISI (Institute for Scientific Information), SciELO (Scientific Electronic Library Online), and Google Academic. The number of articles on fish parasites is mounting (currently over 110), having much increased since 1995. However, the quantity is still low compared with the amount of papers on parasites of fish from natural environments. In Brazil, the farmed fish that have been studied the most are pacu, tilapia and tambaqui. Monogeneans represent the most prevalent group, followed by protozoa and crustaceans. The regions most researched were the southeast and south, making up 84% of the total literature. The main issue addressed in articles was pathology, followed by treatment and record. In conclusion, the treatment of parasitic diseases of farmed fish in Brazil is still incipient, highlighting the importance and usefulness of management practices to prevent the occurrence of health problems.


2021 ◽  
Vol 17 (8) ◽  
Author(s):  
Clarissa Maia de Aquino ◽  
Gracienhe Gomes dos Santos ◽  
Maur´ício Laterça Martins ◽  
Vildes Maria Scussel

The skipjack tuna (Katsuwonus pelamis) is commonly found in the tropical waters of the oceans. It is a fishing resource of high economic value and available for national and international markets. Therefore, it is important to know the fish parasites for a correct sanitary inspection, as the pathogenesis in humans can occur through spoliative, toxic or mechanical action. This study aimed to identify the zoonotic parasitic fauna that infects the beautiful-striped using morphological methods. A total of 06 samples were analyzed. The fish were necropsied for parasitological evaluation of the musculature and internal organs. The samples were visually inspected and the structures with morphology combining with parasitic shapes were analyzed both in stereoscopic and microscope. The parasites found were fixed in 70% alcohol for later identification. All samples showed the presence of zoonotic parasites for humans. Two genera of zoonotic parasites have been found for humans that have beautiful tuna as their hosts, namely Anisakis sp. (Nematoda) and Trypanorhyncha (Eucestoda). A 100% of the infections occurred in the muscles and 66.6% in the liver. The results reinforced the importance of inspection by responsible organisms on the importance of evisceration as quickly as possible to avoid migration of larvae to the muscle.


2021 ◽  
Vol 2 ◽  
Author(s):  
Caitlin L. Stockwell ◽  
Ramón Filgueira ◽  
Jon Grant

The health and welfare of farmed fish are highly dependent on environmental conditions. Under suboptimal conditions, the negative impact on welfare can cause changes in fish behaviour. Acoustic tags can provide high resolution and high frequency data to monitor fish positioning within the cage, which can be used to infer swimming behaviour. In this study, implanted acoustic tags were used to monitor the three-dimensional positioning of Atlantic salmon (Salmo salar) at a commercial farm in Nova Scotia, Canada. The one-month study period allowed the characterisation of background behaviour and changes in behaviour in relation to different environmental conditions, namely, water characteristics in terms of dissolved oxygen and temperature caused by the fall overturn, storm conditions, and feeding activity. The three-dimensional position of 15 fish was recorded using high temporal resolution (3 s). Fish movement was characterised by calculating four fish variables: distance from the centre of the cage [m], depth [m], velocity [ms−1], and turning angle [°]. The population swam in a counterclockwise swimming direction around 4 ± 2 m depth at an average speed of 0.61 ± 0.38 ms−1. After the fall overturn, the population moved significantly towards cage centre while decreasing velocity, and non-significant differences in depth and turning angle were observed. During feeding periods, a significant increase in depth and velocity, as well as a reduction in turning angle were observed. The storm event did not cause any significant change in the four fish variables. While some of the behavioural changes were difficult to assess with respect to causation, the high resolution, high frequency data provide unique detailed positioning information to further our understanding of the swimming behaviour of farmed fish.


Author(s):  
Alicia C. Bertolotti ◽  
Ryan M. Layer ◽  
Manu Kumar Gundappa ◽  
Michael D. Gallagher ◽  
Ege Pehlivanoglu ◽  
...  

AbstractStructural variants (SVs) are a major source of genetic and phenotypic variation, but remain challenging to accurately type and are hence poorly characterized in most species. We present an approach for reliable SV discovery in non-model species using whole genome sequencing and report 15,483 high-confidence SVs in 492 Atlantic salmon (Salmo salar L.) sampled from a broad phylogeographic distribution. These SVs recover population genetic structure with high resolution, include an active DNA transposon, widely affect functional features, and overlap more duplicated genes retained from an ancestral salmonid autotetraploidization event than expected. Changes in SV allele frequency between wild and farmed fish indicate polygenic selection on behavioural traits during domestication, targeting brain-expressed synaptic networks linked to neurological disorders in humans. This study offers novel insights into the role of SVs in genome evolution and the genetic architecture of domestication traits, along with resources supporting reliable SV discovery in non-model species.


2019 ◽  
Vol 7 (8) ◽  
pp. 233 ◽  
Author(s):  
Shruti Gupta ◽  
Jorge Fernandes ◽  
Viswanath Kiron

The intestinal microbiota of certain farmed fish are often exposed to antimicrobial substances, such as antibiotics, that are used to prevent and treat bacterial diseases. Antibiotics that kill or inhibit the growth of harmful microbes can rapidly alter intestinal microbial diversity and composition, with potential effects on the host health. In this study, we have elucidated the impact of two antibiotics, florfenicol and oxolinic acid, by employing a high-throughput 16S rRNA gene amplicon sequencing technique on the distal and mid intestinal microbial communities of Atlantic salmon (Salmo salar). For this, Atlantic salmon were offered diets with or without antibiotics. We then investigated the bacterial communities in the intestinal mucus of the fish. Our results showed that antibiotic exposure shifts the intestinal microbial profile differentially. In addition, the bacterial compositions of the control and antibiotic-fed groups were significantly different. Antibiotic feeding altered the composition and abundance of the dominant bacterial phyla, namely Proteobacteria, Actinobacteria, Firmicutes, Spirochaetes, Bacteroidetes, Tenericutes, and Thermotogae. The bacterial association network analysis also indicated the differential pattern of co-occurrence of bacteria in the three study groups. The results regarding the differences in the structure and association of the intestinal microbiota of Atlantic salmon after florfenicol and oxolinic acid feeding can be employed to attenuate the adverse effects of antibiotic feeding on fish.


2015 ◽  
Vol 89 (18) ◽  
pp. 9348-9367 ◽  
Author(s):  
Mona C. Gjessing ◽  
Natalya Yutin ◽  
Torstein Tengs ◽  
Tania Senkevich ◽  
Eugene Koonin ◽  
...  

ABSTRACTPoxviruses are large DNA viruses of vertebrates and insects causing disease in many animal species, including reptiles, birds, and mammals. Although poxvirus-like particles were detected in diseased farmed koi carp, ayu, and Atlantic salmon, their genetic relationships to poxviruses were not established. Here, we provide the first genome sequence of a fish poxvirus, which was isolated from farmed Atlantic salmon. In the present study, we used quantitative PCR and immunohistochemistry to determine aspects of salmon gill poxvirus disease, which are described here. The gill was the main target organ where immature and mature poxvirus particles were detected. The particles were detected in detaching, apoptotic respiratory epithelial cells preceding clinical disease in the form of lethargy, respiratory distress, and mortality. In moribund salmon, blocking of gas exchange would likely be caused by the adherence of respiratory lamellae and epithelial proliferation obstructing respiratory surfaces. The virus was not found in healthy salmon or in control fish with gill disease without apoptotic cells, although transmission remains to be demonstrated. PCR of archival tissue confirmed virus infection in 14 cases with gill apoptosis in Norway starting from 1995. Phylogenomic analyses showed that the fish poxvirus is the deepest available branch of chordopoxviruses. The virus genome encompasses most key chordopoxvirus genes that are required for genome replication and expression, although the gene order is substantially different from that in other chordopoxviruses. Nevertheless, many highly conserved chordopoxvirus genes involved in viral membrane biogenesis or virus-host interactions are missing. Instead, the salmon poxvirus carries numerous genes encoding unknown proteins, many of which have low sequence complexity and contain simple repeats suggestive of intrinsic disorder or distinct protein structures.IMPORTANCEAquaculture is an increasingly important global source of high-quality food. To sustain the growth in aquaculture, disease control in fish farming is essential. Moreover, the spread of disease from farmed fish to wildlife is a concern. Serious poxviral diseases are emerging in aquaculture, but very little is known about the viruses and the diseases that they cause. There is a possibility that viruses with enhanced virulence may spread to new species, as has occurred with the myxoma poxvirus in rabbits. Provision of the first fish poxvirus genome sequence and specific diagnostics for the salmon gill poxvirus in Atlantic salmon may help curb this disease and provide comparative knowledge. Furthermore, because salmon gill poxvirus represents the deepest branch of chordopoxvirus so far discovered, the genome analysis provided substantial insight into the evolution of different functional modules in this important group of viruses.


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