Search results for "Shellfish"
showing 10 items of 44 documents
Toward shrimp consumption without chemicals: Combined effects of freezing and modified atmosphere packaging (MAP) on some quality characteristics of …
2015
The combined effects of freezing and modified atmosphere packaging (MAP) (100% N2 and 50% N2 + 50% CO2) on some quality characteristics of Giant Red Shrimp (GRS) (Aristaeomorpha foliacea) was studied during 12-month storage. In particular, the quality characteristics determined proximal and gas compositions, melanosis scores, pH, total volatile basic-nitrogen (TVB-N), thiobarbituric acid (TBA) as well as free amino acid (FAA). In addition, the emergent data were compared to those subject to vacuum packaging as well as conventional preservative method of sulphite treatment (SUL). Most determined qualities exhibited quantitative differences with storage. By comparisons, while pH and TVB-N sta…
Seasonal and spatial dynamics of enteric viruses in wastewater and in riverine and estuarine receiving waters
2018
International audience; Enteric viruses represent a global public health threat and are implicated in numerous foodborne andwaterborne disease outbreaks. Nonetheless, relatively little is known of their fate and stability in the environment. In this studywe used carefully validatedmethods tomonitor enteric viruses, namely adenovirus (AdV), JC polyomavirus (JCV), noroviruses (NoVs), sapovirus (SaV) and hepatitis A and E viruses (HAV and HEV) fromwastewater source to beaches and shellfish beds. Wastewater influent and effluent, surface water, sediment and shellfish samples were collected in the Conwy catchment (North Wales, UK) once a month for one year. High concentrations of AdV and JCV wer…
Improving efficiency of viability-qPCR for selective detection of infectious HAV in food and water samples.
2017
Aim: To improve the efficacy of intercalating dyes to distinguishing between infectious and inactivated hepatitis A virus (HAV) in food. Methods and Results: Different intercalating dyes were evaluated for the discrimination between infectious and thermally inactivated HAV suspensions combining with the RT‐qPCR proposed in the ISO 15216. Among them, PMAxx was the best dye in removing the RT‐qPCR signal from inactivated HAV. Applied to lettuce and spinach, PMAxx–Triton pretreatment resulted in complete removal of the RT‐qPCR signal from inactivated HAV. Likewise, this study demonstrates that this pretreatment is suitable for the discrimination of inactivated HAV in shellfish without further …
Monitoring programme on cadmium, lead and mercury in fish and seafood from Valencia, Spain: levels and estimated weekly intake.
2008
The study was carried out to determine the current levels of mercury, cadmium, and lead in fish and seafood from the market of Comunitat Valenciana, Spain. Levels of total mercury ranged from 0.02 to 3.15 mg kg⁻¹ w.w. (average = 0.073 mg kg⁻¹ w.w.). Cadmium concentrations ranged from 0.003 to 0.66 mg kg⁻¹ w.w. (average = 0.27 mg kg⁻¹ w.w.) for seafood, and between 0.003 and 0.71 mg kg⁻¹ w.w. (average = 0.01 mg kg⁻¹ w.w.) for marine fish. Concerning lead, concentrations from 0.02 to 0.36 mg kg⁻¹ w.w (average = 0.04 mg kg⁻¹ w.w.) were found in fish, and from 0.02 to 1.02 mg kg⁻¹ w.w. in seafood (average = 0.147 mg kg⁻¹ w.w.). The levels found were, in general, lower than maximum levels propos…
The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals
2015
ABSTRACT The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single o…
Application of viability PCR to discriminate the infectivity of hepatitis A virus in food samples.
2015
Abstract Transmitted through the fecal–oral route, the hepatitis A virus (HAV) is acquired primarily through close personal contact and foodborne transmission. HAV detection in food is mainly carried out by quantitative RT-PCR (RT-qPCR). The discrimination of infectious and inactivated viruses remains a key obstacle when using RT-qPCR to quantify enteric viruses in food samples. Initially, viability dyes, propidium monoazide (PMA) and ethidium monoazide (EMA), were evaluated for the detection and quantification of infectious HAV in lettuce wash water. Results showed that PMA combined with 0.5% Triton X-100 (Triton) was the best pretreatment to assess HAV infectivity and completely eliminate…
The widespread presence of a family of fish virulence plasmids in Vibrio vulnificus stresses its relevance as a zoonotic pathogen linked to fish farms
2021
Vibrio vulnificus is a pathogen of public health concern that causes either primary septicemia after ingestion of raw shellfish or secondary septicemia after wound exposure to seawater. In consequence, shellfish and seawater are considered its main reservoirs. However, there is one aspect of its biology that is systematically overlooked: its association with fish in its natural environment. This association led in 1975 to the emergence of a zoonotic clade within phylogenetic lineage 2 following successive outbreaks of vibriosis in farmed eels. Although this clade is now worldwide distributed, no new zoonotic clades were subsequently reported. In this work, we have performed phylogenetic, ge…
Effects of a phycotoxin, okadaic acid, on oyster heart cell survival
2008
Okadaic acid (OA) is a dinoflagellate toxin which accumulates in shellfish producing diarrhetic shellfish poisoning (DSP) in humans. It was found that OA is a highly selective inhibitor of protein phosphatase types 1 (PP1) and 2A (PP2A) which produces a marked increase in phosphorylation of several proteins, including p38 mitogen-activated protein (MAP) kinase. The cytotoxicity attributed to OA and the effects on p38 MAP kinase and calcium current were examined in the oyster Crassostrea gigas in this study. Data showed that p38 MAP kinase is strongly expressed in oyster heart and that OA bioaccumulated in cultured heart cells. Hence the effects of OA was tested in vitro and in vivo on oyste…
An MLSA approach for the taxonomic update of the Splendidus clade, a lineage containing several fish and shellfish pathogenic Vibrio spp.
2016
A multilocus sequence analysis was undertaken in order to redefine the Splendidus clade of the genus Vibrio, a large group of species containing several pathogenic members that affect fish and shellfish, and are difficult to identify through both phenotypic and genotypic approaches. The study included analysis of partial sequences of recA, gyrB, mreB, rpoD and pyrH genes, as well as the 16S rRNA gene. Seventeen type strain species were included that were complemented with other reference strains and a collection of isolates tentatively identified as members of this clade, as well as a set of other Vibrio species. The clade was well defined and stable in all analyses, and was confirmed to co…
Ribotyping of Vibrio Populations Associated with Cultured Oysters (Ostrea edulis)
2000
The intraspecific variability of Vibrio splendidus, V. harveyi and V. tubiashii recovered from oysters (Ostrea edulis) collected at the Mediterranean coast near Valencia, Spain, was analyzed by ribotyping. The two former species represented the most abundant ones, and the third one was the only species described as pathogenic for oysters. A total of 115 environmental strains were studied, 84 of V. splendidus, 23 of V. harveyi and 8 of V. tubiashii. Chromosomal DNA was digested with KpnI and hybridized with an oligonucleotide probe complementary to a highly conserved sequence in the 23S rRNA gene. Ribotyping among natural populations of the three species rendered 5 to 9 bands, and showed a h…