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1.
Nat Commun ; 13(1): 2383, 2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35504907

RESUMO

Historical ecology has revolutionized our understanding of fisheries and cultural landscapes, demonstrating the value of historical data for evaluating the past, present, and future of Earth's ecosystems. Despite several important studies, Indigenous fisheries generally receive less attention from scholars and managers than the 17th-20th century capitalist commercial fisheries that decimated many keystone species, including oysters. We investigate Indigenous oyster harvest through time in North America and Australia, placing these data in the context of sea level histories and historical catch records. Indigenous oyster fisheries were pervasive across space and through time, persisting for 5000-10,000 years or more. Oysters were likely managed and sometimes "farmed," and are woven into broader cultural, ritual, and social traditions. Effective stewardship of oyster reefs and other marine fisheries around the world must center Indigenous histories and include Indigenous community members to co-develop more inclusive, just, and successful strategies for restoration, harvest, and management.


Assuntos
Pesqueiros , Ostreidae , Animais , Ecologia , Ecossistema , Alimentos Marinhos
2.
Int J Med Mushrooms ; 24(1): 27-40, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35442593

RESUMO

Numerous studies have reported the vast medicinal values of proteins from mushrooms. The present study aimed to investigate the potential of protein extracts from the sclerotium of Pleurotus tuber-regium (Fr.) Singer for antitumor activities against a breast cancer cell line. Protein from P. tuber-regium sclerotium was fractionated using ammonium sulphate at concentrations of 30%, 60%, and 90% and designated as PS30, PS60, and PS90, respectively. All protein extracts were assessed for cytotoxicity toward breast cancer cell line MDA-MB-231 and normal lung fibroblast cell line MRC-5 in the MTT assay. The ability of the protein extracts to inhibit cellular migration was evaluated using the antimigration assay. The most promising protein extract against MDA-MB-231 cells was PS60, with a half-maximal inhibitory concentration of 0.75 ± 0.57 µg/mL and a selectivity index of 14.00. Cytotoxicity and antimigration effects on cancer cells were best exhibited by PS60, with absolute migration capability values between 5.4142 ± 0.6916 and 5.6581 ± 0.2015 nm/h. PS60 was shown to exert cytotoxic effects associated with the induction of apoptosis and cell cycle arrest in MDA-MB-231 cells at G1/G0 and S phase. In conclusion, PS60 protein of P. tuber-regium sclerotium has good potential to be developed into a novel antitumor drug against breast cancer.


Assuntos
Antineoplásicos , Ascomicetos , Neoplasias da Mama , Ostreidae , Pleurotus , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Humanos
3.
Water Environ Res ; 94(4): e10714, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35445485

RESUMO

Fe-Mn binary oxide (FMBO) is a promising adsorbent for As(III) removal through combined adsorption and oxidation. The calcined oyster shell-supported Fe-Mn binary oxide (FMBO/OS) adsorbent was synthesized by the co-precipitation method. Results indicated that the calcined oyster shell, as a carrier, improved the stability of FMBO and its adsorption capacity for As(III). The maximum adsorption capacity of FMBO/OS on As(III) reached 140.5 mg·g-1 . Under pH 5.0 and 25°C, the removal efficiency of FMBO/OS to As(III) solution (C0 = 10 mg·L-1 ) reached 87% within 12 h. Moreover, based on the characterization analyses, the removal mechanisms of As(III) were deduced to include the combined adsorption and oxidation process of FMBO and the synergistic effect of oyster shells. This work provides new insights into synthesizing efficient and green adsorbents to remove aqueous As(III). Meanwhile, it provides technical support for reusing waste biomass materials such as the oyster shell. PRACTITIONER POINTS: FMBO/OS was prepared by a simple hydrothermal co-precipitation method. The carrier alleviates the agglomeration of Fe-Mn oxides. The adsorbent shows a strong adsorption capacity of As(III) and good selectivity. The good results benefit from the synergistic effect of calcium arsenate generation. The prepared adsorbent can adsorb arsenic in real samples.


Assuntos
Arsênio , Ostreidae , Poluentes Químicos da Água , Purificação da Água , Adsorção , Animais , Arsênio/química , Concentração de Íons de Hidrogênio , Ferro/química , Óxidos/química , Água , Poluentes Químicos da Água/química , Purificação da Água/métodos
4.
Dis Aquat Organ ; 148: 153-166, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35445663

RESUMO

Agapollen is a traditional heliothermic marine oyster lagoon in western Norway, representing the northernmost site of any Marteilia sp. protists detected in Europe. The semi-closed lagoon is a unique site to study the life cycle and development of M. pararefringens in naïve mussels. Two baskets with uninfected mussels were deployed in the lagoon outlet in May and October 2018, respectively, and sampled every 6 wk. The parasite was first detected in the mussels by PCR in early July and by histology in late August. By then, M. pararefringens had developed into mature stages, indicating a rapid development during mid-summer. Sporulation occurred during autumn. Mussels deployed in October never became infected, indicating that transmission was restricted to the warmest period of the year. Pronounced pathology was observed in infected mussels, including degenerated digestive tubules and infiltration of haemocytes. Mussel mortality was observed in the baskets, but whether this was due to infections of M. pararefringens or other environmental factors could not be determined. Plankton samples from the lagoon were also collected for PCR analysis. These samples, dominated by copepods, were positive for M. pararefringens in summer. In sorted samples, M. pararefringens was detected in the Acartia spp. and Paracartia grani fractions between July and October. These plankton copepods are therefore potentially involved in the life cycle of M. pararefringens.


Assuntos
Copépodes , Mytilus edulis , Mytilus , Ostreidae , Parasitos , Animais , Copépodes/parasitologia , Eucariotos , Mytilus/parasitologia , Mytilus edulis/parasitologia
5.
Mar Drugs ; 20(4)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35447907

RESUMO

The marine pennate diatom Haslea ostrearia has long been known for its characteristic blue pigment marennine, which is responsible for the greening of invertebrate gills, a natural phenomenon of great importance for the oyster industry. For two centuries, this taxon was considered unique; however, the recent description of a new blue Haslea species revealed unsuspected biodiversity. Marennine-like pigments are natural blue dyes that display various biological activities-e.g., antibacterial, antioxidant and antiproliferative-with a great potential for applications in the food, feed, cosmetic and health industries. Regarding fundamental prospects, researchers use model organisms as standards to study cellular and physiological processes in other organisms, and there is a growing and crucial need for more, new and unconventional model organisms to better correspond to the diversity of the tree of life. The present work, thus, advocates for establishing H. ostrearia as a new model organism by presenting its pros and cons-i.e., the interesting aspects of this peculiar diatom (representative of benthic-epiphytic phytoplankton, with original behavior and chemodiversity, controlled sexual reproduction, fundamental and applied-oriented importance, reference genome, and transcriptome will soon be available); it will also present the difficulties encountered before this becomes a reality as it is for other diatom models (the genetics of the species in its infancy, the transformation feasibility to be explored, the routine methods needed to cryopreserve strains of interest).


Assuntos
Cosméticos , Diatomáceas , Ostreidae , Animais , Antioxidantes/farmacologia , Diatomáceas/fisiologia , Pigmentação
6.
BMC Genomics ; 23(1): 211, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35296243

RESUMO

BACKGROUND: The diversified aquaporin (AQP) family that was derived from gene duplication and subsequent functional differentiation play critical roles in multiple physiological processes and in adaptation to the dynamic environments during the evolutionary process. Oysters are a group of bivalve fauna in Mollusca that were widely distributed around the world and show extraordinary adaptation to harsh environments. However, knowledge is lacking with the diversity and evolution of the AQP family in oysters, even in molluscs. RESULTS: Here, we performed a comprehensive analysis of the AQP family in three geographical isolated oyster species that are native to different environments. Genome distribution and phylogenetic analysis revealed that the expansion of the AQP family in oysters were attributed to tandem duplication. Synteny analysis indicated that large-scale inversions lead to the independent duplication or deletion of the AQPs after speciation. As a consequence, these independent duplication events contributed to the diversification of the AQP family in different oysters. Pore pattern analysis suggested that the duplicated AQPs in oysters were highly diversified in inner surface profiles, implying the subsequent functional differentiation. The comparison conducted based on the transcriptome data demonstrated that the functional differentiated AQP family members in oysters may play critical roles in maintaining the balance between the stationary homeostasis and dynamic environments. CONCLUSIONS: Our observation provides evidence for the correlation between the duplicated and functional differentiated AQP family and the adaptation to stationary life under dynamic environments in oysters. Additionally, it also broadens our knowledge of the evolution of AQP family in molluscs.


Assuntos
Aquaporinas , Ostreidae , Animais , Aquaporinas/genética , Duplicação Gênica , Genoma , Ostreidae/genética , Filogenia
7.
Food Chem ; 385: 132603, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35259621

RESUMO

Oyster protein hydrolysate (OPH) has high bioactivity and excellent performance, but its application in food formulation is still limited due to poor flavor and instability. In the present study, OPH was prepared by enzymatic hydrolysis and loaded into nanoliposomes. Then, the effects of chitosan coating (0, 0.25, 0.5, and 1.0%) on the physical properties, stability, and antioxidant activity were evaluated. The results showed that 1% chitosan-coated nanoliposomes had high encapsulation efficiency (EE) and physical stability. Additionally, chitosan coating slowed the release rate of nanoliposomes and increased the retention rate of antioxidant activity of OPH. The stability of the uncoated/coated nanoliposomes in a maltodextrin matrix by spray/freeze drying was evaluated. FTIR spectrum showed that hydrogen bonds, hydrophobic, and electrostatic interactions had been formed between chitosan-coated nanoliposomes and maltodextrin. Chitosan coating significantly improved the physical stability and antioxidant activity retention of nanoliposomes during powder reconstitution.


Assuntos
Quitosana , Ostreidae , Animais , Antioxidantes/química , Quitosana/química , Liofilização , Ostreidae/metabolismo , Tamanho da Partícula , Hidrolisados de Proteína/química
8.
Commun Biol ; 5(1): 250, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318453

RESUMO

Habitat engineers make strong and far-reaching imprints on ecosystem processes. In intertidal mudflats, the dominant primary producer, microphytobenthos (MPB), often forms high biomass patches around oyster reefs. We evaluate multiple hypotheses linking MPB with oyster reefs, including oyster biodeposition, meiofaunal grazing, and abiotic factors, aiming to help predict effects of reef removal or proliferation. We quantify spatial patterns of an Atlantic mudflat community and its environment around two large Crassostrea reefs before experimentally sacrificing one reef via burning. MPB biomass was enriched surrounding living oyster reefs although infaunal biomass and individual sizes were low. Structural equation modelling best supported the hypothesis that crab predation intensity, which decayed with distance from the reefs, locally freed MPB from grazing. Our results suggest that Crassostrea reef expansion may enrich local MPB patches and redirect trophic energy flows away from mudflat infauna, with potential implications for the sustainability of local fisheries and bird conservation.


Assuntos
Braquiúros , Ostreidae , Animais , Ecossistema , Pesqueiros , Comportamento Predatório
9.
Mar Environ Res ; 176: 105594, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35279515

RESUMO

Despite the effective remediation efforts following the end of the metallurgic activity thirty years ago upstream the Lot River watershed, the levels of cadmium (Cd) accumulated in wild oysters from the downstream Gironde Estuary still exceed nowadays the admissible human consumption limit (5 mg/kg, d.w.). The main goal of this work is to quantify the role of sediments as long-term intra-estuarine sources or sinks of Cd and the transport of this contaminant towards the estuary mouth taking as case study the example of the highly turbid Gironde Estuary. The original estimation for the annual net fluxes of the suspended particulate matter ( [Formula: see text] and particulate Cd ( [Formula: see text] ) presented in this work between 1990 and 2020 indicates that 80% of the Cd discharged into the ocean is in dissolved form (Cdd). The values of [Formula: see text] vary proportionally to those of [Formula: see text] and ranged between 0.1 and 1.4 t/y, with a ten-year average decreasing from 0.8 to 0.6 t/y for the past 30 years. The differences between ten-year total (Cdp + Cdd) gross and net fluxes show that Cd has effectively been stored in estuarine sediments. This Cd storage was of about 43, 22 and 13 t for the 1990s, 2000s and 2010s, respectively. However, during years of low gross fluxes, estuarine sediments act as additional, secondary sources of bio-available/dissolved Cd into the water column, potentially relating to the continued observations of high Cd concentrations in wild oysters at the estuary mouth. In addition to the natural solubility of Cdp along the salinity and turbidity gradients of the estuary, natural and anthropogenic remobilization of bottom sediment particles further contribute to its mobilization from the particle phase, along with other numerous inorganic/organic pollutants. The mass balances presented in this work could support a new sediment management policy potentially more beneficial to the estuarine ecosystem.


Assuntos
Ostreidae , Poluentes Químicos da Água , Animais , Cádmio , Descontaminação , Ecossistema , Monitoramento Ambiental , Estuários , Sedimentos Geológicos , Humanos , Ostreidae/metabolismo , Poluentes Químicos da Água/análise
10.
Oecologia ; 198(4): 1031-1042, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35279725

RESUMO

Understanding how habitat edges affect ecological processes is crucial given widespread and increasing modifications to natural landscapes. Resource specialization is a key factor affecting among-species edge responses, but we know little about how intraspecific resource use variation mediates edge utilization. Here, we integrate stomach content analysis, geometric morphometrics and feeding experiments to explore the role of resource polymorphism in mediating marsh crab (Panopeus obesus) foraging within the marsh-oyster reef boundary. Stomachs of edge individuals contained a greater proportion of morphologically defended edge prey (bivalves) compared to core marsh individuals, and edge individuals possessed relatively tall and robust claw morphology for manipulating such prey. We further show experimentally that phenotypic changes of edge P. obesus are associated with enhanced feeding efficiency on small, but not large edge prey. Morphological and ecological traits of edge P. obesus overlapped with the edge-occurring congener, P. herbstii, suggesting some degree of functional convergence despite the potential for interspecific competition within edges. Though this polymorphism is likely plastic, the success of P. obesus along edges could subsidize predator production within marshes and alter top-down pressure across mosaic estuarine landscapes. More generally, our study reveals polymorphism as a driver of edge utilization, while yielding new insight into the processes that maintain or erode spatial niche differentiation within predator guilds.


Assuntos
Braquiúros , Ostreidae , Animais , Braquiúros/genética , Ecossistema , Humanos , Comportamento Predatório/fisiologia , Áreas Alagadas
11.
Sci Total Environ ; 826: 154061, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35231523

RESUMO

Leaf oysters (Isognomon ephippium) are large intertidal bivalves that form shellfish reefs. They have a patchy and restricted distribution in estuaries in northern New South Wales, Australia, where the water quality is impacted by a range of anthropogenic stressors from coastal agriculture, urbanisation, industry and recreational activities, along with natural stochastic events such as flooding. Little, however, is currently known about the tolerance of leaf oysters to poor water quality. This study investigated the condition of leaf oyster populations in four estuaries, by assessing the density, size-frequency and condition index. These biological parameters were modelled against habitat water quality parameters including nutrient loads, organic and inorganic carbon, algal biomass, sedimentation and total alkalinity. The water quality assessments were replicated during dry conditions and after rain in two estuaries. Leaf oyster density, size, and body condition significantly differed among the four estuaries. Density ranged from as few as 0.04 oysters per m2 in the heavily impacted Richmond River, up to 267 oysters per m2 in the Tweed River. Overall water quality was also significantly different among the four estuaries, and significant declines in water quality were observed after rain. Distance based linear models revealed significant correlations between biological indicators of leaf oyster reef health and a range of water quality parameters. Leaf oysters with higher condition occur in locations with high dissolved oxygen and salinity levels, whereas low pH and high nutrient run-off were associated with low density and poorer oyster condition. Nevertheless, dense populations were found to persist in areas with pH below 7.9, in high turbidity (over 27 NTU) and areas dominated by fine silt. Their ability to form dense reefs on estuarine soft muddy bottom habitats with low water flow, suggests that leaf oysters could be used to complement rock oysters in future intertidal shellfish reef restoration programs.


Assuntos
Ostreidae , Qualidade da Água , Animais , Austrália , Estuários
12.
Appl Environ Microbiol ; 88(8): e0236021, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35348387

RESUMO

Contamination of oysters with a variety of viruses is one key pathway to trigger outbreaks of massive oyster mortality as well as human illnesses, including gastroenteritis and hepatitis. Much effort has gone into examining the fate of viruses in contaminated oysters, yet the current state of knowledge of nonlinear virus-oyster interactions is not comprehensive because most studies have focused on a limited number of processes under a narrow range of experimental conditions. A framework is needed for describing the complex nonlinear virus-oyster interactions. Here, we introduce a mathematical model that includes key processes for viral dynamics in oysters, such as oyster filtration, viral replication, the antiviral immune response, apoptosis, autophagy, and selective accumulation. We evaluate the model performance for two groups of viruses, those that replicate in oysters (e.g., ostreid herpesvirus) and those that do not (e.g., norovirus), and show that this model simulates well the viral dynamics in oysters for both groups. The model analytically explains experimental findings and predicts how changes in different physiological processes and environmental conditions nonlinearly affect in-host viral dynamics, for example, that oysters at higher temperatures may be more resistant to infection by ostreid herpesvirus. It also provides new insight into food treatment for controlling outbreaks, for example, that depuration for reducing norovirus levels is more effective in environments where oyster filtration rates are higher. This study provides the foundation of a modeling framework to guide future experiments and numerical modeling for better prediction and management of outbreaks. IMPORTANCE The fate of viruses in contaminated oysters has received a significant amount of attention in the fields of oyster aquaculture, food quality control, and public health. However, intensive studies through laboratory experiments and in situ observations are often conducted under a narrow range of experimental conditions and for a specific purpose in their respective fields. Given the complex interactions of various processes and nonlinear viral responses to changes in physiological and environmental conditions, a theoretical framework fully describing the viral dynamics in oysters is warranted to guide future studies from a top-down design. Here, we developed a process-based, in-host modeling framework that builds a bridge for better communications between different disciplines studying virus-oyster interactions.


Assuntos
Gastroenterite , Herpesviridae , Norovirus , Ostreidae , Animais , Vírus de DNA , Gastroenterite/epidemiologia , Humanos
13.
Artigo em Inglês | MEDLINE | ID: mdl-35168502

RESUMO

Abstract: Vibrio infection was rarely reported in Tasmania prior to 2016, when a multistate outbreak of Vibrio parahaemolyticus associated with Tasmanian oysters was identified and 11 people reported ill. Since then, sporadic foodborne cases have been identified following consumption of commercially- and recreationally-harvested oysters. The increases in both foodborne and non-foodborne Vibrio infections in Tasmania are likely associated with increased sea water temperatures. As oyster production increases and climate change raises the sea surface temperature of our coastline, Tasmania expects to see more vibriosis cases. Vibriosis due to oyster consumption has been reported in other Australian states, but the variability in notification requirements between jurisdictions makes case and outbreak detection difficult and potentially hampers any public health response to prevent further illness.


Assuntos
Doenças Transmitidas por Alimentos , Ostreidae , Vibrioses , Vibrio parahaemolyticus , Animais , Austrália/epidemiologia , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Vibrioses/epidemiologia
14.
Chemosphere ; 295: 133824, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35150702

RESUMO

This study aims to assess the potential toxicity of (1) nanoplastics (NPs) issued from the fragmentation of larger plastic particles collected on the Caribbean marine coast (NP-G), and (2) polystyrene NPs (NP-PS), commonly used in the literature, on Caribbean swamp oysters (Isognomon alatus). Oysters were exposed to 7.5 and 15 µg.L-1 of each type of NPs, combined or not with arsenic (As) at 1 mg.L-1 for one week before molecular analyses at gene levels. Overall, the NP-G triggered more significant changes than NP-PS, especially when combined with As. Genes involved in the mitochondrial metabolism were strongly up-regulated in most of the conditions tested (up to 11.6 fold change for the NP-PS exposure at 7.5 µg.L-1 for the 12s). NPs in combination with As or not triggered a response against oxidative stress, with an intense repression of cat and sod1 (0.01 fold-changes for the NP-G condition at 7.5 µg.L-1). Both NP-G and NP-PS combined or not with As led to an up-regulation of apoptotic genes p53 and bax (up to 59.3 fold-changes for bax in the NP-G condition with As). Our study reported very innovative molecular results on oysters exposed to NPs from environmental sources. Our results suggest that the composition, surface charge, size, and the adsorbed contaminants of plastics from the natural environment may have synergic effects with plastic, which are underestimated when using manufactured NPs as NP-PS in ecotoxicological studies.


Assuntos
Nanopartículas , Ostreidae , Poluentes Químicos da Água , Animais , Microplásticos/toxicidade , Nanopartículas/toxicidade , Ostreidae/metabolismo , Plásticos/toxicidade , Poliestirenos/metabolismo , Poliestirenos/toxicidade , Poluentes Químicos da Água/toxicidade
15.
Zhonghua Liu Xing Bing Xue Za Zhi ; 43(1): 92-97, 2022 Jan 10.
Artigo em Chinês | MEDLINE | ID: mdl-35130658

RESUMO

Objective: To evaluate the application of real-time RT-PCR and semi-nested RT-PCR in the detection of norovirus in oysters and analyzing the genetic characteristics of the isolates. Methods: Real-time fluorescent RT-PCR and semi-nested RT-PCR were used to detect norovirus GⅠ/GⅡ in fresh oysters collected from the markets in Beijing from November 2014 to October 2015. The detection rate of the parallel test was also analyzed. In addition, the reliability of semi-nested RT-PCR was evaluated by agreement rate and consistency test (Kappa value). The positive products of norovirus GⅠ/GⅡ capsid protein region gene by semi-nested RT-PCR were sequenced. Software BioEdit 7.0.9.0 was used for sequence alignment, and software Mega 6.0 was used to construct the evolutionary tree. Results: In 72 samples, the detection rate of norovirus was 31.94% (23/72) by real-time RT-PCR, 38.89% (28/72) by semi-nested RT-PCR and 48.61% (35/72) by parallel test. The coincidence rate of the two methods was 73.61%, a moderate degree (Kappa value =0.43). A total of 13 norovirus strains were successfully sequenced, and 11 strains (7 GⅡ.17 strains, 2 GⅡ. 4 Sydney_ 2012 strains, 1 GⅡ. 1 strain and 1 GⅡ. 21 strain) were obtained from norovirus positive samples by two RT-PCR methods, two strains (1 GⅡ. 17 strain and 1 GⅡ. 3 strain) were obtained from real-time RT-PCR negative samples which were positive for norovirus by semi-nested RT-PCR. The similarity between these strains and reference strains from diarrhea patients, environmental sewage, and shellfish products were 84.4% - 100.0%. Conclusions: The parallel test of norovirus in oysters by two RT-PCR methods can improve the detection rate and detect more genotypes. Norovirus strains in oysters were highly homologous with reference strains from diarrheal patients, environmental sewage, and shellfish products. Therefore, surveillance, prevention and control for norovirus should be carried out in people who have frequent contacts with oysters and related environments.


Assuntos
Norovirus , Ostreidae , Animais , Pequim , Humanos , Norovirus/genética , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Microbiol Spectr ; 10(1): e0191321, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35171011

RESUMO

Vibrio vulnificus is a naturally occurring, potentially lethal pathogen found in coastal waters, fish, and shellfish. Sewage spills in coastal waters occur when infrastructure fails due to severe storms or age, and may affect bacterial populations by altering nutrient levels. This study investigated effects of sewage on clonal and natural V. vulnificus populations in microcosms. Addition of 1% sewage to estuarine water caused the density of a pure culture of V. vulnificus CMCP6 and a natural V. vulnificus population to increase significantly, by two to three orders of magnitude, whether measured by quantitative PCR (qPCR) or culture and in batch and continuous cultures. Changes in the transcription of six virulence- and survival-associated genes in response to sewage were assessed using continuous culture. Exposure to sewage affected transcription of genes that may be associated with virulence, i.e., it modulated the oxidative stress response by altering superoxide dismutase transcription, significantly increasing sodB transcription while repressing sodA. Sewage also repressed transcription of nptA, which encodes a sodium-phosphate cotransporter. Sewage had no effect on sodC transcription or the putative virulence-associated genes hupA or wza. The effects of environmentally relevant levels of sewage on V. vulnificus populations and gene transcription suggest that sewage spills that impact warm coastal waters could lead to an increased risk of V. vulnificus infections. IMPORTANCE Vibrio vulnificus infections have profound impacts such as limb amputation and death for individuals with predisposing conditions. The warming climate is contributing to rising V. vulnificus prevalence in waters that were previously too cold to support high levels of the pathogen. Climate change is also expected to increase precipitation in many regions, which puts more pressure on wastewater infrastructure and will result in more frequent sewage spills. The finding that 1% wastewater in estuarine water leads to 100 to over 1,000-fold greater V. vulnificus concentrations suggests that human exposure to oysters and estuarine water could have greater health impacts in the future. Further, wastewater had a significant effect on gene transcription and has the potential to affect virulence during the initial environment-to-host transition.


Assuntos
Esgotos/microbiologia , Transcrição Genética , Vibrio vulnificus/crescimento & desenvolvimento , Vibrio vulnificus/genética , Animais , Peixes , Regulação Bacteriana da Expressão Gênica , Humanos , Ostreidae/microbiologia , Alimentos Marinhos , Vibrioses/microbiologia , Vibrio vulnificus/patogenicidade , Virulência/genética
18.
Food Chem ; 382: 132329, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35134723

RESUMO

Proteins and polysaccharides commonly coexist in the food system, forming complexes and coacervates to make tailor-made food. In this study, the effects of κ-carrageenan on the rheological behavior, network structure, textures, and molecular force of oyster protein (OP treated with high-pressure homogenization were investigated. Rheological results showed that κ-carrageenan improved the storage modulus of OP, and the higher concentration of κ-carrageenan accelerated the gelation of OP. The second derivative of infrared spectroscopy revealed that κ-carrageenan contributed to the formation of ß-sheet in OP. Molecular force and texture analysis showed that κ-carrageenan might promote the increase of hydrophobic bonds and disulfide bonds, which was helpful to enhance gel strength. The microstructure showed that the OP gel with 1.5% κ-carrageenan had a compact network structure with abundant minor mesh and sheet edge. This study reveals the gelation mechanism of OP/κ-carrageenan and provides the theoretical basis for developing innovative oyster products.


Assuntos
Ostreidae , Proteínas , Animais , Carragenina/química , Géis/química , Proteínas/química , Reologia
19.
J Food Prot ; 85(5): 786-791, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35226753

RESUMO

ABSTRACT: Vibrio parahaemolyticus is a major cause of foodborne diseases and a significant threat to human health worldwide. Most of the infections caused by V. parahaemolyticus are usually associated with the consumption of raw or undercooked seafood. This study was conducted to determine the prevalence, quantitative load, and antimicrobial resistance of V. parahaemolyticus in retail seafood in Hanoi, Vietnam. A total of 120 seafood samples consisting of marine fish (n = 30), oysters (n = 30), shrimp (n = 30), and squid (n = 30) were purchased from different traditional markets in Hanoi between May and October 2020. Isolation of V. parahaemolyticus was based on ISO/TS 21872-1:2017, and the most-probable-number (MPN) method was used for quantification. The disk diffusion method was applied for antimicrobial susceptibility testing. Overall, V. parahaemolyticus was detected in 58.33% of the samples. V. parahaemolyticus was most commonly isolated in shrimp samples, with a prevalence of 86.67%, followed by fish (53.33%), squid (53.33%), and oysters (40%). One V. parahaemolyticus isolate from an oyster carrying the trh gene was detected. Of the positive samples, 27.14% contained V. parahaemolyticus counts of less than 2 log MPN/g, whereas 44.29% ranged from 2 to 4 log MPN/g and 28.57% contained more than 4 log MPN/g. Regarding antimicrobial resistance, 85.71% of V. parahaemolyticus isolates were resistant to at least one antibiotic tested. The highest rate of resistance was observed against ampicillin (81.43%), followed by cefotaxime (11.43%), ceftazidime (11.43%), trimethoprim-sulfamethoxazole (8.57%), and tetracycline (2.86%). The results demonstrate the high prevalence and quantitative load and the antimicrobial resistance of V. parahaemolyticus isolated from seafood sold in the study area.


Assuntos
Ostreidae , Vibrio parahaemolyticus , Animais , Antibacterianos/farmacologia , Crustáceos , Farmacorresistência Bacteriana , Alimentos Marinhos , Vietnã
20.
Sci Total Environ ; 824: 153891, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35182647

RESUMO

To evaluate the effect of pyrolyzed crushed oyster shells (PCOS) on the remediation of sediments and microbial diversity, a field study was conducted in Buksin Bay, Tongyeong City, Republic of Korea. It was observed that after treatment with PCOS, the concentration of H2S in the sediment of the control site was 287 mg/L. Furthermore, it decreased up to 0 mg/L and remained so until the end of the field study, that is for a period of six months. Moreover, the concentrations of NO2-N + NO3-N, NH4-N, and PO4-P decreased sharply, and the oxidation-reduction potential (ORP) increased after PCOS treatment in pore water and overlying water. Regarding the diversity of microbial communities, the predominance of bacteria from phylum Chlorobi was observed in highly reduced (-410 mV; ORP) sediment, which is well known for the production of H2S. After PCOS treatment, the relative abundance of Chlorobi was sharply suppressed. On the other hand, the predominance of bacteria from the phyla Proteobacteria and Bacteroidetes was observed, and their relative abundance in the PCOS-treated sediment increased throughout the experiment, based on 16S rRNA sequencing. The results demonstrate that the abundance of bacterial communities in the PCOS-treated sediments of Buksin Bay is important for marine ecological functioning, especially for pollutant transformation.


Assuntos
Microbiota , Ostreidae , Síndrome do Ovário Policístico , Animais , Bactérias/genética , Sedimentos Geológicos/microbiologia , RNA Ribossômico 16S/genética , Água
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