An assessment of health management and biosecurity procedures in marine fish farming in Spain

Marine fish farming in Spain has experienced problems of performance due to losses caused by infectious diseases. Biosecurity and health management are identified by the Food and Agriculture Organization (FAO) as current priorities for proper aquaculture governance. However, they both transcend the responsibility of farmers and require significant resources, concerted action and cooperation. This study presents the analysis of biosecurity practices on marine fish farms, through a questionnaire-based survey on biosecurity procedures and an analysis of health management practices for different stakeholders. The Strengths, Weaknesses, Opportunities, and Threats (SWOT) technique was implemented, which identified the important threats and weaknesses faced by the sector, such as the risk of direct disease transmission between farms, the high likelihood of importing diseases through juvenile shipments, the chronic lack of communication between stakeholders, and the deficient coordination of health strategies. Strengths included awareness of prevention measures and the availability of expertize of health experts at most levels. On the other hand, the availability of experts together with the need to adapt governance to the current production systems were seen as opportunities. Health management measures themselves were actually already found to be adapted to the type of production but they varied between companies (i.e. categorization and diagnosis of mortalities). Nevertheless, the quality of expertize along the value chain provided by private and public laboratories, research institutes, Health Protection Groups, companies and veterinarians was noteworthy. However, there was still a need for all stakeholders involved in marine fish health to improve diagnostics, provide epidemiological information, biosecurity and prevention measures, as well as to promote transparency for better health governance

Evaluation of the performance of three serological tests for diagnosis of Leishmania infantum infection in dogs using latent class analysis

Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum. Serological methods are the most common diagnostic techniques used for the diagnosis of the CanL. The objective of our study was to estimate the sensitivity and specificity of one in-house ELISA kit (ELISA UNIZAR) and three commercially available serological tests (MEGACOR Diagnostik GmbH) including an immunochromatographic rapid test (FASTest LEISH®), an immunofluorescent antibody test (MegaFLUO LEISH®) and an enzyme-linked immunosorbent assay (MegaELISA LEISH®), using latent class models in a Bayesian analysis. Two hundred fifteen serum samples were included. The highest sensitivity was achieved for FASTest LEISH® (99.38%), ELISA UNIZAR (99.37%), MegaFLUO LEISH® (99.36%) followed by MegaELISA LEISH® (98.49%). The best specificity was obtained by FASTest LEISH® (98.43%), followed by ELISA UNIZAR (97.50%), whilst MegaFLUO LEISH® and MegaELISA LEISH® obtained the lower specificity (91.94% and 91.93%, respectively). The results of present study indicate that the immunochromatographic rapid test evaluated FASTest LEISH® show similar levels of sensitivity and specificity to the quantitative commercial tests. Among quantitative serological tests, sensitivity and specificity were similar considering ELISA or IFAT techniques. A leishmaniose canina (Lcan) é uma doença causada pela Leishmania infantum. Os métodos sorológicos são as técnicas diagnósticas mais utilizadas para o diagnóstico da leishmaniose canina. O objetivo do nosso estudo foi estimar a sensibilidade e a especificidade de um kit ELISA interno (ELISA UNIZAR) e de três testes sorológicos disponíveis comercialmente, feitos pelo mesmo fabricante (MEGACOR Diagnostik GmbH), incluindo um teste rápido imunocromatográfico (FASTest LEISH®), um teste de anticorpos imunofluorescentes (Megafluo LEISH®) e um ensaio de imunoabsorção enzimática (Megaelisa LEISH®), utilizando-se modelos de classe latentes numa análise bayesiana. Foram incluídas duzentas e quinze amostras de soro. A maior sensibilidade foi alcançada para Fastest LEISH® (99, 38%), ELISA UNIZAR (99, 37%), Megafluo LEISH® (99, 36%) seguida por Megaelisa LEISH® (98, 49%). A melhor especificidade foi obtida por FASTest LEISH® (98, 43%), seguida por ELISA UNIZAR (97, 50%), enquanto Megafluo LEISH® e Megaelisa LEISH® obtiveram a menor especificidade (91, 94% e 91, 93%, respectivamente). Os resultados do presente estudo indicam que o teste rápido imunocromatográfico, avaliado por FASTest LEISH® mostra níveis similares de sensibilidade e especificidade aos testes comerciais quantitativos incluídos. Entre os testes sorológicos quantitativos, a sensibilidade e a especificidade foram semelhantes, considerando-se as técnicas de ELISA ou IFI

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

A cross-sectional study of Leishmania infantum infection in stray cats in the city of Zaragoza (Spain) using serology and PCR

Background: Feline leishmaniosis is a vector-borne parasitic disease caused by Leishmania spp. Leishmania infection in dogs is prevalent in the Mediterranean basin, but in other animals, such as cats, it could also play a role in the epidemiology of the disease. Information on the geographical distribution and epidemiological features of L. infantum infection in cats is scarce, particularly in urban stray cats living in regions where canine leishmaniosis is endemic. As diagnosis can be challenging, combining different serological and molecular methods is a useful approach. Our aim was to investigate the prevalence of infection of L. infantum in apparently healthy stray cats in an endemic region of Spain (Zaragoza city) using serological and molecular methods, and to compare the results of the different techniques. Methods: The prevalence of Leishmania infection was studied in stray cats captured in urban and peri-urban areas of Zaragoza. Blood was collected from each animal for serology and molecular analysis. Three serological methods, namely the immunofluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and western blot (WB), were used to detect L. infantum antibodies and a real-time PCR (qPCR) assay was used to detect L. infantum DNA. The results were analyzed by Fisher’s exact test and Cohen’s kappa statistic (¿) to assess the level of agreement between the diagnostic techniques. Results: Serological analysis of blood samples from 180 stray cats revealed 2.2% (4/179) Leishmania infection positivity by IFAT, 2.8% (5/179) by ELISA and 14.5% (26/179) by WB. Leishmania DNA was detected by qPCR in 5.6% (10/179) of the cats. Sixteen cats (8.9%) tested positive by only one serological technique and four tested positive by all three serological methods used. The overall rate of infected cats (calculated as the number of cats seropositive and/or qPCR positive) was 15.6%, and only two cats tested positive by all the diagnostic methods. A significant association was found between male cats and a positive qPCR result. Comparison of the techniques revealed a fair agreement in seropositivity between blood qPCR and IFAT (¿ = 0.26), blood qPCR and ELISA (¿ = 0.24), WB and ELISA (¿ = 0.37) and WB and IFAT (¿ = 0.40). The highest agreement between seropositive results was between IFAT and ELISA (¿ = 0.89), and the lowest was between blood qPCR and WB (¿ = 0.19). The prevalence of the feline leukemia virus antigen was 4.49% (8/178 cats) and that of the feline immunodeficiency virus (FIV) antibody was 6.74% (12/178), while co-infection with both retroviruses was observed in one female cat (1/178). Leishmania ELISA and IFAT seropositivity were statistically associated with FIV status by the chi-square test. Conclusions: The results obtained in this study, using serological tests and qPCR, indicate the existence of L. infantum asymptomatic infection in apparently healthy stray cats in the city of Zaragoza, an endemic area in Spain. [Figure not available: see fulltext.

First report on natural infection with Leishmania infantum in a domestic ferret (Mustela putorius furo) in Spain

A pet domestic ferret (Mustela putorius furo) with a papular lesion involving the right pinna was diagnosed with chronic pyogranulomatous dermatitis by histopathologic examination. Intralesional, intracytoplasmic oval microorganisms compatible with Leishmania spp. or Histoplasma spp. were observed in macrophages and multinucleate giant cells. Leishmania infantum (L. infantum) infection was diagnosed by PCR, culture in Novy-MacNeal-Nicolle medium, and immunohistochemistry. Abnormal clinicopathological results included increased alanine transferase, alkaline phosphatase, serum gamma glutamyl transferase and polyclonal gammpathy. Anti-Leishmania antibodies were detected by enzyme-linked immunosorbent assay, immunofluorescence antibody test and western blot using L. infantum antigen. Immunoreactivity against the 16 kDa specific L. infantum antigen fraction was observed by western blot. PCR performed in blood samples obtained from this patient after positive parasite isolation detected L. infantum DNA. To the authors' knowledge, this is the first diagnosis and isolation of L. infantum in a domestic ferret naturally infected in an endemic region (Spain) where canine and feline leishmaniosis is frequently detected. According to these findings, ferrets should be included as potential reservoir hosts of L. infantum. Future investigations should analyze the epidemiological role of ferrets in L. infantum infection including the prevalence of infection

Fish Farms at Sea: The Ground Truth from Google Earth

In the face of global overfishing of wild-caught seafood, ocean fish farming has augmented the supply of fresh fish to western markets and become one of the fastest growing global industries. Accurate reporting of quantities of wild-caught fish has been problematic and we questioned whether similar discrepancies in data exist in statistics for farmed fish production. In the Mediterranean Sea, ocean fish farming is prevalent and stationary cages can be seen off the coasts of 16 countries using satellite imagery available through Google Earth. Using this tool, we demonstrate here that a few trained scientists now have the capacity to ground truth farmed fish production data reported by the Mediterranean countries. With Google Earth, we could examine 91% of the Mediterranean coast and count 248 tuna cages (circular cages >40 m diameter) and 20,976 other fish cages within 10 km offshore, the majority of which were off Greece (49%) and Turkey (31%). Combining satellite imagery with assumptions about cage volume, fish density, harvest rates, and seasonal capacity, we make a conservative approximation of ocean-farmed finfish production for 16 Mediterranean countries. Our overall estimate of 225,736 t of farmed finfish (not including tuna) in the Mediterranean Sea in 2006 is only slightly more than the United Nations Food and Agriculture Organization reports. The results demonstrate the reliability of recent FAO farmed fish production statistics for the Mediterranean as well as the promise of Google Earth to collect and ground truth data

The effect of organic and conventional production methods on sea bream growth, health and body composition: A field experiment

This study aimed to develop a better understanding of organic sea bream aquaculture production in Greece, in particular its consequences for fish growth, health and body composition, and to propose and update standards for sustainable organic sea bream farming. Gilthead sea bream were kept in sea cages at densities of 4 kg m–3 (organic) and 15 kg m–3(conventional), and were fed organically produced feed (45% crude protein, 14% fat) or conventional feed (46% crude protein, 17% fat). The amino acid profile of the conventional diet, particularly the lysine content, which is one of most important dietary amino acids for sea bream, appeared to be unsatisfactory. “Organic” sea bream stored less fat content in their white muscle than the conventional sea bream. The liver lipid content was lower and the hepatosomatic index was higher for the organic sea bream. The microbiological analysis showed that both Enterobacteriaceae and Escherichia coli on the skin were below the enumeration detection limit in both the organic and conventional sea bream. Total viable counts on the skin and muscle of both the organically and conventionally cultured sea bream were approximately 3 log cfu g–1, which is well below the acceptable limit (7 log cfu g–1) for marine species. The results showed that the combination of a low stocking density and feed with a different ingredient composition but similar nutritional value resulted in similar growth rates and nutrient profiles of the final product. Further research on nutrition is required to provide information on setting the appropriate standards for organic sea bream aquaculture to ensure that the final product is in line with the consumers’ preferences

Genetic Resistance to Rhabdovirus Infection in Teleost Fish Is Paralleled to the Derived Cell Resistance Status

Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction - that was not observed in the susceptible cells - and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses

Stimulation of adherent cells by addition of purified proteins of viral hemorrhagic septicemia virus to trout kidney cell cultures

Purified proteins of the virus causing viral hemorrhagic septicemia in the trout were added to cultures on semisolid medium of leukocytes obtained from either healthy or immunized rainbow trout. Adherent cells were specifically stimulated by the glycoprotein of the viral spikes and, to a lesser extent, by the nucleoproteins. In contrast, a specific memory response was associated more with the nucleoproteins than with the glycoprotein when leukocytes from trout immunized with the virus were employed. These results suggest the necessity of employing both proteins in subunit vaccination trials and the possibility of using this assay to select the proper epitopes for genetically engineered proteins during subunit vaccine development