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1.
J Hazard Mater ; 424(Pt A): 127359, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34601410

RESUMO

The biological mechanism of adverse health outcomes related to exposure to traffic-related air pollution (TRAP) needs elucidation. We conducted a randomized, crossover trial among healthy young students in Shanghai, China. Participants wore earplugs and were randomly assigned to a 4-hour walking treatment either along a traffic-polluted road or through a traffic-free park. We conducted untargeted analyses of plasma exosome transcriptomics, serum mass spectrometry-based proteomics, and serum metabolomics to evaluate changes in genome-wide transcription, protein, and metabolite profiles in 35 randomly selected participants. Mean personal exposure levels of ultrafine particles, black carbon, nitrogen dioxide, and carbon monoxide in the road were 2-3 times higher than that in the park. We observed 3449 exosome mRNAs, 58 serum proteins, and 128 serum metabolites that were significantly associated with TRAP. The multi-omics analysis showed dozens of regulatory pathways altered in response to TRAP, such as inflammation, oxidative stress, coagulation, endothelin-1 signaling, and renin-angiotensin signaling. We found that several novel pathways activated in response to TRAP exposure: growth hormone signaling, adrenomedullin signaling, and arachidonic acid metabolism. Our study served as a demonstration and proof of concept on the evidence that associated TRAP exposure with global molecular changes based on the multi-omics level.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , China , Estudos Cross-Over , Exposição Ambiental/análise , Humanos , Material Particulado/análise , Material Particulado/toxicidade
2.
J Hazard Mater ; 421: 126750, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34339988

RESUMO

The biological mechanisms underlying the associations between atmospheric ozone exposure and adverse cardiometabolic outcomes are yet to be identified. Imbalanced autonomic nervous system (ANS) as well as activations of the sympatho-adrenomedullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axes are among possible early biological responses triggered by ozone, and may eventually lead to cardiometabolic abnormalities. To determine whether acute ozone exposure causes ANS imbalance and increases the secretion of neuroendocrine stress hormones, we conducted a randomized, double-blind, crossover trial, under controlled 2-hour exposure to either ozone (200 ppb) or clean air with intermittent exercise among 22 healthy young adults. Here we found that, compared to clean air exposure, acute ozone exposure significantly decreased the high-frequency band of heart rate variability, even after adjusting for heart rate and pre-exposure to ambient air pollutants and meteorological factors. Ozone exposure also significantly increased the serum levels of stress hormones, including corticotrophin-releasing factor, adrenocorticotropic hormone, adrenaline, and noradrenaline. Metabolomics analysis showed that acute ozone exposure led to alterations in stress hormones, systemic inflammation, oxidative stress, and energy metabolism. Our results suggest that acute ozone exposure may trigger ANS imbalance and activate the HPA and SAM axes, offering potential biological explanations for the adverse cardiometabolic effects following acute ozone exposure.


Assuntos
Poluentes Atmosféricos , Ozônio , Estudos Cross-Over , Frequência Cardíaca , Hormônios , Humanos , Ozônio/toxicidade , Adulto Jovem
3.
Front Microbiol ; 12: 751112, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899637

RESUMO

Herein, we describe a novel bunyavirus, oriental wenrivirus 1 (OWV1), discovered in moribund oriental shrimp (Penaeus chinensis) collected from a farm in China in 2016. Like most bunyaviruses, OWV1 particles were enveloped, spherical- to ovoid-shaped, and 80-115 nm in diameter. However, its genome was found to comprise four segments of (-)ssRNA. These included an L RNA segment (6,317 nt) encoding an RNA-directed RNA polymerase (RdRp) of 2,052 aa, an M RNA segment (2,978 nt) encoding a glycoprotein precursor (GPC) of 922 aa, an S1 RNA segment (1,164 nt) encoding a nucleocapsid (N) protein of 243 aa, and an S2 RNA segment (1,382 nt) encoding a putative non-structural (NSs2) protein of 401 aa. All the four OWV1 RNA segments have complementary terminal decanucleotides (5'-ACACAAAGAC and 3'-UGUGUUUCUG) identical to the genomic RNA segments of uukuviruses and similar to those of phleboviruses and tenuiviruses in the Phenuiviridae. Phylogenetic analyses revealed that the RdRp, GPC, and N proteins of OWV1 were closely related to Wenzhou shrimp virus 1 (WzSV-1) and Mourilyan virus (MoV) that infect black tiger shrimp (P. monodon). Phylogenetic analyses also suggested that OWV1 could be classified into a second, yet to be established, species of the Wenrivirus genus in the Phenuiviridae. These wenriviruses also clustered with Wenling crustacean virus 7 from shrimps and bunya-like brown spot virus from white-clawed crayfish. Of note there were no homologs of the NSs2 of OWV1 and MoV/WzSV-1 in GenBank, and whether other crustacean phenuiviruses also possess a similar S2 RNA segment warrants further investigation. In addition, we established a TaqMan probe-based reverse-transcription quantitative PCR method for detection of OWV1, and it was detected as 1.17 × 102-1.90 × 107 copies/ng-RNA in gills of 23 out of 32 P. chinensis samples without an obvious gross sign. However, the discovery of OWV1 highlights the expanding genomic diversity of bunyaviruses.

4.
Viruses ; 13(12)2021 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-34960649

RESUMO

Global shrimp farming is increasingly threatened by various emerging viruses. In the present study, a novel picornavirus, Penaeus vannamei picornavirus (PvPV), was discovered in moribund White leg shrimp (Penaeus vannamei) collected from farm ponds in China in 2015. Similar to most picornaviruses, PvPV is non-enveloped RNA virus, with a particle diameter of approximately 30 nm. The sequence of the positive single-stranded RNA genome with a length of 10,550 nts was characterized by using genome sequencing and reverse transcription PCR. The existence of PvPV related proteins was further proved by confirmation of viral amino acid sequences, using mass spectrometry analysis. Phylogenetic analysis based on the full-length genomic sequence revealed that PvPV was more closely related to the Wenzhou shrimp virus 8 than to any other dicistroviruses in the order Picornavirales. Genomic sequence conservative domain prediction analysis showed that the PvPV genome encoded a large tegument protein UL36, which was unique among the known dicistroviruses and different from other dicistroviruses. According to these molecular features, we proposed that PvPV is a new species in the family Dicistroviridae. This study reported the first whole-genome sequence of a novel and distinct picornavirus in crustaceans, PvPV, and suggests that further studies of PvPV would be helpful in understanding its evolution and potential pathogenicity, as well as in developing diagnostic techniques.

5.
Phys Chem Chem Phys ; 23(40): 23380-23388, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34636820

RESUMO

The pressure- and temperature-dependent luminescence properties of M'-phase Nd3+:YTaO4 synthesized by a molten salt method are presented. Ten near-infrared emission lines originating from the transitions between the two Stark levels R1,2 of the 3F3/2 state and the five Stark levels Z1,2,3,4,5 of the 4I9/2 state for the doped Nd3+ ions can be clearly identified. All these emission lines are found to shift linearly with pressure in a range up to ∼11 GPa. The R2,1 → Z5 emission lines have larger pressure sensitivities, which are 16.44 and 14.27 cm-1 GPa-1. The intensities of all the emission lines evolve with pressure non-monotonically, and peak at ∼1 GPa. The R1 → Z4,5 and R2 → Z1 emission lines can be obviously narrowed under the hydrostatic pressure, and broadened under the non-hydrostatic pressure, indicating their potential capability for reflecting the characteristic of a pressure environment. The intensity ratio of the R2,1 → Z5 emission lines exhibits a large temperature dependence, with a relative sensitivity between 0.129% and 0.108% K-1 in the physiological temperature range of 290-320 K. Thermal variations of the spectral positions and widths of the R2,1 → Z5 emission lines are also investigated. A high thermal stability for the position of the R2 → Z5 emission line is revealed. Based on the experimental results, the advantages and potential of Nd3+:YTaO4 as a multi-functional sensor for pressure and temperature are discussed.

6.
Opt Lett ; 46(19): 5016-5018, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598256

RESUMO

We report on a high-peak-power electro-optically Q-switched laser emitting a near-diffraction-limited beam profile at 1064 nm by using a gradient-doped Nd:YAG crystal. The gradient-doped crystal features a unique combination of a reduced thermal lens effect through effectively spreading the heat load distribution within its volume. Its performance is compared with those of Nd:YAG crystals with uniform volume doping distribution operating in the Q-switched regime with the same laser configuration, demonstrating the higher average and peak power achievable with the gradient-doped crystal. The maximum average output power amounts to 6.9 W at a pulse repetition rate of 2 kHz, which corresponds to a maximum peak power of ∼585kW. Compared to homogeneous dopant crystals, the slope efficiency and average output power increased by 30.8% and 21.1%, respectively.

7.
Sensors (Basel) ; 21(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34300377

RESUMO

Sensor technology has enabled the development of portable low-cost monitoring kits that might supplement many applications in conventional monitoring stations. Despite the sensitivity of electrochemical gas sensors to environmental change, they are increasingly important in monitoring polluted microenvironments. The performance of a compact diffusion-based Personal Exposure Kit (PEK) was assessed for real-time gaseous pollutant measurement (CO, O3, and NO2) under typical environmental conditions encountered in the subtropical city of Hong Kong. A dynamic baseline tracking method and a range of calibration protocols to address system performance were explored under practical scenarios to assess the performance of the PEK in reducing the impact of rapid changes in the ambient environment in personal exposure assessment applications. The results show that the accuracy and stability of the ppb level gas measurement is enhanced even in heterogeneous environments, thus avoiding the need for data post-processing with mathematical algorithms, such as multi-linear regression. This establishes the potential for use in personal exposure monitoring, which has been difficult in the past, and for reporting more accurate and reliable data in real-time to support personal exposure assessment and portable air quality monitoring applications.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Exposição Ambiental , Monitoramento Ambiental , Hong Kong , Modelos Lineares
8.
Metabolites ; 11(6)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200685

RESUMO

The pathophysiology of nonalcoholic fatty liver disease (NAFLD) is a complex process involving metabolic and inflammatory changes in livers and other organs, but the pathogenesis is still not well clarified. Two mouse models were established to study metabolic alteration of nonalcoholic fatty liver and nonalcoholic steatohepatitis, respectively. The concentrations of metabolites in serum, liver and intestine content were measured by the AbsoluteIDQ® p180 Kit (Biocrates Life Sciences, Innsbruck, Austria). Multivariate statistical methods, pathway analysis, enrichment analysis and correlation analysis were performed to analyze metabolomic data. The metabolic characteristics of liver, serum and intestine content could be distinctly distinguished from each group, indicating the occurrence of metabolic disturbance. Among them, metabolic alteration of liver and intestine content was more significant. Based on the metabolic data of liver, 19 differential metabolites were discovered between DIO and control, 12 between DIO-CCl4 and DIO, and 47 between DIO-CCl4 and normal. These metabolites were mainly associated with aminoacyl-tRNA biosynthesis, nitrogen metabolism, lipid metabolism, glyoxylate and dicarboxylate metabolism, and amino metabolism. Further study revealed that the intervention of obeticholic acid (OCA) could partly reverse the damage of CCl4. The correlation analysis of metabolite levels and clinical parameters showed that phosphatidylcholines were negatively associated with serum alanine aminotransferase, aspartate aminotransferase, NAFLD activity score, and fibrosis score, while lysophosphatidylcholines, sphingomyelins, amino acids, and acylcarnitines shared the reverse pattern. Our study investigated metabolic alteration among control, NAFLD model, and OCA treatment groups, providing preclinical information to understand the mechanism of NAFLD and amelioration of OCA.

9.
Molecules ; 26(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073314

RESUMO

A high-quality Nd0.01:Gd0.89La0.1NbO4 (Nd:GLNO) crystal is grown by the Czochralski method, demonstrating wide absorption and fluorescence spectra and advantage for producing ultrafast laser pulses. In this paper, the tunable and passively mode-locking Nd:GLNO lasers are characterized for the first time. The tuning coverage is 34.87 nm ranging from 1058.05 to 1092.92 nm with a maximum output power of 4.6 W at 1065.29 nm. A stable continuous-wave (CW) passively mode-locking Nd:GLNO laser is achieved at 1065.26 nm, delivering a pulse width of 9.1 ps and a maximum CW mode-locking output power of 0.27 W.

10.
J Fish Dis ; 44(10): 1543-1552, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34152602

RESUMO

A novel pathogenic strain Vibrio 20190611023 was isolated from the hepatopancreas of moribund cultured Penaeus vannamei suffering from black gill disease. This strain was identified as V. brasiliensis based on the phylogenetic analyses of 16S rDNA gene and five other housekeeping genes (i.e., gapA, ftsZ, mreB, topA and gyrB). Some biochemical features of this strain were determined with an API 20NE system, and its haemolytic activity was determined using a sheep blood agar plate. The pathogenicity of this isolate 20190611023 was confirmed by the experimental challenge tests and histopathological examinations. P. vannamei were challenged via reverse gavage with different doses of bacterial suspensions. The calculated median lethal dose (LD50 ) was (3.16 ± 1.78) × 105  CFU/g (body weight). Moreover, antibiotic susceptibility tests were performed, the results of which showed that the strain 20190611023 was sensitive to chloramphenicol, compound sulphamethoxazole, ciprofloxacin, doxycycline and oxacillin, but resistant to erythromycin, kanamycin, gentamicin, cefoperazone, ceftriaxone, cefamezin and piperacillin. To our knowledge, this is the first report for demonstrating V. brasiliensis as a shrimp pathogen, which expands the host range of V. brasiliensis infection. The present study highlights that more attention should be paid to this novel pathogen in intensive shrimp aquaculture.


Assuntos
Farmacorresistência Bacteriana , Penaeidae/microbiologia , Vibrio/classificação , Animais , Antibacterianos/farmacologia , Tipagem de Sequências Multilocus , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Vibrio/efeitos dos fármacos , Vibrio/genética
11.
J Fish Dis ; 44(9): 1315-1324, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34101847

RESUMO

Covert mortality nodavirus (CMNV), a novel aquatic pathogen, causes viral covert mortality disease (VCMD) in shrimps and also known to infect farmed marine fish. To date, there has no report regarding the ability of this virus to infect freshwater fish. In this study, we screened and discovered CMNV-positive freshwater zebrafish individuals by reverse transcription-nested PCR (RT-nPCR). The sequence of CMNV amplicons from zebrafish was found to share 99% identity with RNA-dependent RNA polymerase (RdRp) gene of the original CMNV isolate. Histopathological examination of the CMNV-positive zebrafish samples revealed extensive vacuolation and karyopyknosis lesions in the retina of the eye and the midbrain mesencephalon. CMNV-like virus particles were visualized in these tissues under transmission electron microscope. Different degrees of pathological damages were also found in muscle, gills, thymus and ovarian tissues. Strong positive signals of CMNV probe were observed in these infected tissues by in situ hybridization. Overall, all results indicated that zebrafish, an acknowledged model organism, could be infected naturally by CMNV. Thus, it is needed to pay close attention to the possible interference of CMNV whether in assessment of toxic substances, or in studying the developmental characterization and the nerval function, when zebrafish was used as model animal.


Assuntos
Doenças dos Peixes/virologia , Nodaviridae/isolamento & purificação , Infecções por Vírus de RNA/veterinária , Peixe-Zebra , Animais , Nodaviridae/genética , Nodaviridae/ultraestrutura , Reação em Cadeia da Polimerase , Infecções por Vírus de RNA/patologia
12.
Opt Express ; 29(8): 12471-12477, 2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33985005

RESUMO

In this paper, we present the acousto-optical (AO) Q-switched performance of a holmium (Ho):gadolinium tantalate (GdTaO4) (Ho:GTO) laser pumped by a thulium (Tm)-fiber laser emitting at 1.94 µm. In the efficient continuous wave (CW) regime, a maximum output power of 30.5 W at 2068.8 nm was achieved, corresponding to a slope efficiency of 74.9% with respect to the absorbed pump power. In the Q-switching regime, pulse energies of 2.4 mJ, 1.2 mJ, and 0.9 mJ were obtained with pulse repetition frequencies of 10 kHz, 20 kHz, and 30 kHz, respectively. The minimum pulse widths were 18 ns, 23 ns, and 26 ns, corresponding to peak powers of approximately 133.3 kW, 52.2 kW, and 34.6 kW, respectively.

13.
Viruses ; 13(4)2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33917662

RESUMO

Cross-species transmission of emerging viruses happens occasionally due to epidemiological, biological, and ecological factors, and it has caused more concern recently. Covert mortality nodavirus (CMNV) was revealed to be a unique shrimp virus that could cross species barrier to infect vertebrate fish. In the present study, CMNV reverse transcription-nested PCR (RT-nPCR)-positive samples were identified from farmed sea cucumber (Apostichopus japonicas) in the CMNV host range investigation. The amplicons of RT-nPCR from sea cucumber were sequenced, and its sequences showed 100% identity with the RNA-dependent RNA polymerase gene of the original CMNV isolate. Histopathological analysis revealed pathologic changes, including karyopyknosis and vacuolation of the epithelial cells, in the sea cucumber intestinal tissue. The extensive positive hybridization signals with CMNV probe were shown in the damaged epithelial cells in the in situ hybridization assay. Meanwhile, transmission electron microscopy analysis revealed CMNV-like virus particles in the intestine epithelium. All the results indicated that the sea cucumber, an Echinodermata, is a new host of CMNV. This study supplied further evidence of the wide host range of CMNV and also reminded us to pay close attention to its potential risk to threaten different aquaculture animal species.


Assuntos
Especificidade de Hospedeiro , Nodaviridae/genética , Infecções por Vírus de RNA/veterinária , Pepinos-do-Mar/virologia , Animais , Aquicultura , Hibridização In Situ , Nodaviridae/classificação , Nodaviridae/isolamento & purificação , Nodaviridae/patogenicidade , Filogenia , Infecções por Vírus de RNA/virologia
14.
Chemosphere ; 269: 128724, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33162153

RESUMO

BACKGROUND: The associations between ambient NO2 and diabetes and dyslipidemia have been controversial, and data is especially lacking in developing countries. OBJECTIVE: This study aimed to assess the associations of long-term exposure to NO2 with diabetes and dyslipidemia in China. METHODS: We conducted a cross-sectional study including 13,013 participants from the China Health and Retirement Longitudinal Study (CHRLS). The annual average concentrations of NO2 were estimated based on the residential addresses of participants. We applied logistic regression models to evaluate the associations of NO2 with diabetes and dyslipidemia, and linear regression models to assess the associations with blood biomarkers. RESULTS: A total of 1933 diabetes cases (14.85%) and 1935 (14.87%) dyslipidemia cases were identified. Significant associations were observed between NO2 and risk of diabetes and dyslipidemia independent of PM2.5 and O3. For an interquartile range (IQR) increase in NO2 (12.39 µg/m3), we observed a 13% [odds ratio (OR): 1.13; 95% confidence interval (CI): 1.01, 1.26] increased risk of diabetes, 1.48% (95%CI: 0.51%, 2.46%) increase in glucose, 0.74% (95%CI: 0.19%, 1.29%) increase in glycosylated hemoglobin (HbA1c), 17% (OR: 1.17; 95% CI: 1.05, 1.31) increased risk of dyslipidemia, 4.62% (95%CI: 2.49%, 6.79%) increase in triglyceride, and a decrease of 2.96% (95%CI: 2.13%, 3.79%) in high-density lipoprotein. The associations of NO2 with glucose disorders were stronger among smokers. CONCLUSIONS: Our study indicated long-term exposure to NO2 might contribute to the development of diabetes and dyslipidemia, and the associations were potentially independent of O3 and PM2.5.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Diabetes Mellitus , Dislipidemias , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , China/epidemiologia , Estudos Transversais , Diabetes Mellitus/induzido quimicamente , Diabetes Mellitus/epidemiologia , Dislipidemias/induzido quimicamente , Dislipidemias/epidemiologia , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Humanos , Estudos Longitudinais , Dióxido de Nitrogênio/análise , Material Particulado/análise
15.
Sci Rep ; 10(1): 22265, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33335297

RESUMO

Arachidonic acid (AA) signaling pathway is an important constituent of inflammatory processes. In our previous study, it was found that dihydro-stilbene gigantol relieved hepatic inflammation in mice with CCl4-induced acute liver injury. This study aimed to investigate the involvement of arachidonate metabolic cascade in this process. Our results showed CCl4 activated AA metabolism with the evidence of cPLA2 phosphorylation, which was dependent on the MAPK/JNK activation. Pretreatment with JNK inhibitor SU3327 or gigantol abolished the cPLA2 activation, along with the attenuation of liver damage. Besides, gigantol markedly decreased immune cells activation. Metabolomic analysis revealed that gigantol universally reversed the upregulation of major AA metabolites in injured mouse livers induced by CCl4, especially 12-hydroxyeicosatetraenoic acid (12-HETE). Gigantol also decreased the mRNA and protein expression of platelet-, and leukocyte-type 12-lipoxxygenase (LOX) in the liver. Furthermore, pan-LOX inhibitor nordihydroguaiaretic acid (NDGA) and specific 12-LOX inhibitors baicalein and ML351 attenuated the liver injury to the same extent as gigantol. Overall, our study elucidated a comprehensive profile of AA metabolites during hepatic inflammation caused by CCl4, highlighting the role of 12-LOX-12-HETE pathway in this process. And gigantol alleviated liver inflammation partly through inhibiting the JNK/cPLA2/12-LOX pathway.


Assuntos
Araquidonato 12-Lipoxigenase/genética , Bibenzilas/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Fosfolipases A2 do Grupo IV/genética , Guaiacol/análogos & derivados , Animais , Ácido Araquidônico/metabolismo , Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Guaiacol/farmacologia , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/genética , Inflamação/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metabolômica , Camundongos
16.
Sci Rep ; 10(1): 16484, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020497

RESUMO

The cytochrome cd1-containing nitrite reductase, nirS, plays an important role in biological denitrification. Consequently, investigating the presence and abundance of nirS is a commonly used approach to understand the distribution and potential activity of denitrifying bacteria, in addition to denitrifier communities. Herein, a rapid method for detecting nirS gene with loop-mediated isothermal amplification (LAMP) was developed, using Pseudomonas aeruginosa PAO1 (P. aeruginosa PAO1) as model microorganism to optimize the assay. The LAMP assay relied on a set of four primers that were designed to recognize six target sequence sites, resulting in high target specificity. The limit of detection for the LAMP assay under optimized conditions was 1.87 pg/reaction of genomic DNA, which was an order of magnitude lower than that required by conventional PCR assays. Moreover, it was validated that P. aeruginosa PAO1 cells as well as genomic DNA could be directly used as template. Only 1 h was needed from the addition of bacterial cells to the reaction to the verification of amplification success. The nirS gene of P. aeruginosa PAO1 in spiked seawater samples could be detected with both DNA-template based LAMP assay and cell-template based LAMP assay, demonstrating the practicality of in-field use.


Assuntos
Grupo dos Citocromos c/genética , Técnicas de Diagnóstico Molecular/métodos , Nitrito Redutases/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Pseudomonas aeruginosa/genética , DNA/genética , Primers do DNA/genética , Sensibilidade e Especificidade
17.
Pathogens ; 9(9)2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32927617

RESUMO

A new emerging disease called "translucent post-larvae disease" (TPD) or "glass post-larvae disease" (GPD) of Penaeus vannamei, characterized by pale or colorless hepatopancreas and digestive tract, has become an urgent threat to the shrimp farming industry. Following this clue that treatment of an antibacterial agent could alleviate the disease, systematic investigation of the potential infectious agent of TPD was conducted using bacterial identification and artificial challenge tests to fulfill Koch's postulates. A dominant bacterial isolate, Vp-JS20200428004-2, from the moribund individuals was isolated and identified as Vibrio parahaemolyticus based on multi-locus sequence analysis. However, Vp-JS20200428004-2 differed from the V. parahaemolyticus that caused typical acute hepatopancreatic necrosis disease. Immersion challenge tests revealed that Vp-JS20200428004-2 could cause 100% mortality within 40 h at a dose of 1.83 × 106 CFU/mL, and experimental infected shrimp showed similar clinical signs of TPD. The Vp-JS20200428004-2 could be re-isolated and identified from the experimental infected individuals. Moreover, histopathological analysis of diseased samples indicated that Vp-JS20200428004-2 caused severe necrosis and sloughing of epithelial cells of the hepatopancreas and midgut in shrimp individuals both naturally and experimentally infected. Our present results indicated that Vp-JS20200428004-2 is a highly virulent infectious agent associated with the TPD and deserves further attention.

18.
Virus Res ; 286: 198092, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32659308

RESUMO

The prevalence of covert mortality nodavirus (CMNV) has become one of the major threats to the shrimp farming industry in Asia and South America recently. Here, the genomic RNA1 and RNA2 of CMNV were characterized by using transcriptome sequencing and RT-PCR. Our study revealed that RNA1 is 3228 bp in length, and contains two putative Open Reading Frames (ORFs), one encoding the RNA dependent RNA polymerase (RdRp) of length 1043 amino acids and another encoding the protein B2 with a length of 132 amino acids. RNA2 is 1448 bp in length and encodes a capsid protein of 437 amino acids. CMNV shared the highest similarity of 51.78 % for RdRp with the other known nodaviruses. Phylogenetic analyses on the basis of RdRp, B2 and capsid proteins indicated that CMNV might represent a novel viral species in the family Nodaviridae. This study reported the first genome sequence of CMNV and it would be helpful for further studies of CMNV in relation to its evolution, diagnostic technique and control strategy.


Assuntos
Genoma Viral , Nodaviridae/classificação , Nodaviridae/genética , Penaeidae/virologia , Filogenia , RNA Viral/genética , Animais , Aquicultura , Genômica , Nodaviridae/isolamento & purificação , Fases de Leitura Aberta
20.
J Invertebr Pathol ; 173: 107367, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32251642

RESUMO

Decapod iridescent virus 1 (DIV1) was proven to be the aetiological agent of a disease causing mass die-offs of shrimp, prawn and crayfish. The specific purpose of this study was to develop a new sensitive real-time PCR method for the specific detection of DIV1. A pair of primers that amplify a 142 bp fragment and a TaqMan probe were selected for the major capsid protein gene of DIV1. They were shown to be specific for DIV1 and did not react with other common shrimp pathogens or healthy shrimp DNA. The method could detect as virus levels as low as 1.2 copies of DIV1 plasmid DNA.


Assuntos
Iridoviridae/isolamento & purificação , Penaeidae/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Reação em Cadeia da Polimerase em Tempo Real/instrumentação , Sensibilidade e Especificidade , Carga Viral
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