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Jiang Y.L.,Chinese Academy of Inspection and Quarantine
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui]

A virus was isolated from cultured sick giant salmander (Andrias davidianus ) in a farm, Shanxi Province, China. Skin ulceration and necrosis of the distal limbs are main clinical symptoms. Virus propagated and caused CPE at 10 degrees C to 30 degrees C in BF-2, CO, CHSE, FHM cells. The optimum condition of replication was in BF-2 cells at 25 degrees C. The virus was proved to be senstive to chloroform, heat, pH3 and pH10 treatment. Viral replication was inhibited by 5-Fluoro-2-deoxyuridine (FUDR). These results indicated that the virus possessed an envelope and DNA as the genome. Electron-microscopic observation of thin-section showed numerous hexagonal viral particles measuring 130 nm to 150 nm in diameter orderly arranged in a lattice form in cytoplasm of BF-2 cells. The particles showed typical iridovirus morphology. A 413 bp fragment was amplified from the viral main capsid protein gene by PCR. The fragments was sequenced and analysed. The results showed the isolate shared more than 96% nucleotide identity with some Ranaviruses. We suggested that this virus was named as Andrias davidianus iridovirus (ADIV) tentatively. Source

Jin B.,Shenzhen Entry Exit Inspection and Quarantine Bureau | Xie L.,Shenzhen Entry Exit Inspection and Quarantine Bureau | Guo Y.,Shenzhen Entry Exit Inspection and Quarantine Bureau | Pang G.,Chinese Academy of Inspection and Quarantine
Food Research International

The extensive use of pesticides in modern farming on fruit and vegetables has posed risks to public health and environment. In this study, the methods for extraction and detection of pesticides in juice and fruit wine were reviewed. Sample preparation is an important step in the analytical method, and the advantages of various new extraction techniques over the classical solvent extraction have been highlighted. Current methods involve the use of one or the combination of some of the following techniques for both the sample extraction and clean-up steps: liquid-liquid extraction, solid-phase extraction, solid-phase microextraction, stir bar sorptive extraction, matrix solid-phase dispersion and single-drop microextraction. Determination of low-level pesticide residues in juice and wine has been performed mainly by chromatographic methods employing selective detectors or, in an increasing proportion, coupled to mass spectrometry for the quantification and simultaneous identification of residues. © 2011 Elsevier Ltd. Source

Pang Y.,National Center for Tuberculosis Control and Prevention | Lu J.,Chinese Academy of Inspection and Quarantine | Wang Y.,National Center for Tuberculosis Control and Prevention | Song Y.,National Center for Tuberculosis Control and Prevention | And 2 more authors.
Antimicrobial Agents and Chemotherapy

Rifampin (RIF) susceptibility is a key factor in determining the treatment effectiveness of the standardized treatment regimens. In Mycobacterium tuberculosis, both target gene mutation and the efflux pump play major roles in the resistance to antituberculosis drugs. By eliminating RIF-resistant strains with rpoB mutation, the choice of RIF-monoresistant strains may allow us to identify the RIF-specific efflux pump genes. This study explored the RIF monoresistance mechanism in M. tuberculosis. Data from DNA sequencing and MIC measurements revealed that specific mutations, including Ser531Leu and His526Asp in RpoB, show high-level drug resistance. Three-dimensional structure modeling provided further evidence that the affinity between RIF and RpoB mutants was in accordance with the drug resistance level of the corresponding isolates. Furthermore, transcriptionlevel analysis among the nonmutated isolates indicated that three efflux pumps (Rv0783, Rv2936, and Rv0933) might be involved in exporting RIF from the cell. Compared to 8 g/ml for wild-type Escherichia coli, the MICs for the transgenic E. coli strains with either Rv0783 or Rv2936 were 32 and 16 g/ml, respectively. In conclusion, our study indicated that several RpoB mutant types, including Ser531Leu and His526Asp, show high-level RIF resistance attributed to low affinity between RpoB mutant proteins and RIF. In addition, this work demonstrates that Rv2936 and Rv0783 may be responsible for low-level resistance to RIF by exporting RIF from cells. The predicted structure of RpoB and the newly identified efflux pumps in this study will provide a novel approach to design new drugs and develop novel diagnosis technologies. Copyright © 2013, American Society for Microbiology. All Rights Reserved. Source

Yang Y.,Chinese Academy of Inspection and Quarantine
Zhonghua shi yan he lin chuang bing du xue za zhi = Zhonghua shiyan he linchuang bingduxue zazhi = Chinese journal of experimental and clinical virology

Marburg virus and Ebola virus are acute infections with high case fatality rates. A rapid, sensitive detection method was established to detect Marburg virus and Ebola virus by multiplex real-time fluorescence quantitative PCR. Designing primers and Taqman probes from highly conserved sequences of Marburg virus and Ebola virus through whole genome sequences alignment, Taqman probes labeled by FAM and Texas Red, the sensitivity of the multiplex real-time quantitative PCR assay was optimized by evaluating the different concentrations of primers and Probes. We have developed a real-time PCR method with the sensitivity of 30.5 copies/microl for Marburg virus positive plasmid and 28.6 copies/microl for Ebola virus positive plasmids, Japanese encephalitis virus, Yellow fever virus, Dengue virus were using to examine the specificity. The Multiplex real-time PCR assays provide a sensitive, reliable and efficient method to detect Marburg virus and Ebola virus simultaneously. Source

Wang J.,Beijing University of Chemical Technology | Du Z.,Beijing University of Chemical Technology | Yu W.,Chinese Academy of Inspection and Quarantine | Qu S.,Beijing University of Chemical Technology
Journal of Chromatography A

A liquid-phase microextraction (LPME) methodology based on the use of porous polyvinylidene fluoride (PVDF) hollow fibres was developed for extracting seven pesticides from cucumbers. The seven pesticides include propoxur, carbofuran, atrazine, cyanatryn, metolachlor, prometryn and tebuconazole. The PVDF hollow fibre provides higher extraction efficiency due to its higher porosity and better solvent compatibility. A new desorption methodology was developed since some pesticides were absorbed by the wall pore of the PVDF. Ultra-high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was used for pesticide analysis. In order to obtain high recoveries and enrichment factors of the analytes, several parameters such as method of sealing, acceptor phase (organic solvents), stirring speed, extraction time, salting out effect, desorption mode and time were optimized. A fast, simple method for closing fibre ends was practiced by using mechanical crimping. Pesticides were extracted from the sample to the organic solvent and then desorbed in a mixture of methanol:water (1:1 v/v) prior to chromatographic analysis. Limits of detection (LOD) for the multi-reaction-monitoring (MRM) mode of the method varies from 0.01 to 0.31μg/kg with optimized sample preparation. Calibration curves are linear with R2≥0.991. Enrichment factor of the hollow fibre LPME ranges from 100 to 147. Matrix effect has been considered and is in the range of 76-122%. The relative recoveries from cucumber samples are between 63% and 119% with the relative standard deviation (RSD, n=6) lower than 20%. © 2012 Elsevier B.V. Source

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