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Xue F.,Plant and Food Inspection Center
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2010

OBJECTIVE: To characterize the genes of Campylobacter jejuni isolates and to genotype the strains from chicken, cow, duck, pig and red-crowned Crane during 2006 to 2008 by multilocus sequence typing (MLST). METHODS: To choose 7 pairs Campylobacter jejuni home-keeping gene, gltA, aspA, glnA, glyA, pgm, tkt and uncA as target gene, PCR was applied to detect 42 samples in East China between 2006-2008. Sequencing, analysis and comparation of the genes were done. RESULT: Typing the 42 isolates by MLST and finding 24 new sequence typing types. CONCLUSION: MLST is a useful method to evuluate Campylobacter jejuni genes and gene evolution. Source


Wu S.,Jiangnan University | Duan N.,Jiangnan University | Zhu C.,Plant and Food Inspection Center | Ma X.,Jiangnan University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2011

A novel and sensitive immunoassay for the simultaneous detection of aflatoxin B 1 (AFB 1) and ochratoxin A (OTA) in food samples was developed by using artificial antigen-modified magnetic nanoparticles (MNPs) as immunosensing probes and antibody functionalized upconversion nanoparticles (UCNPs) as signal probes. NaY 0.78F 4:Yb 0.2, Tm 0.02 and NaY 0.28F 4:Yb 0.7,Er 0.02 UCNPs were prepared and functionalized, respectively, with immobilized monoclonal anti-AFB 1 antibodies and anti-OTA antibodies as signal probes. Based on a competitive immunoassay format, the detection limit for both AFB 1 and OTA under optimal conditions was as low as 0.01ngmL -1, and the effective detection range was from 0.01 to 10ngmL -1. The proposed method was successfully applied to measure AFB 1 and OTA in naturally contaminated maize samples and compared to a commercially available ELISA method. The high sensitivity and selectivity of this method is due to the magnetic separation and concentration effect of the MNPs, the high sensitivity of the UCNPs, and the different emission lines of Yb/Tm and Yb/Er doped NaYF 4 UCNPs excited by 980nm laser. Multicolor UCNPs have the potential to be used in other applications for detecting toxins in the field of food safety and other fields. © 2011 Elsevier B.V. Source


Zhang Z.,Nanjing Medical University | Lu H.,Nanjing Medical University | Lu H.,Plant and Food Inspection Center | Huan F.,Nanjing Medical University | And 5 more authors.
International Journal of Cancer | Year: 2014

Cytochrome P450 2A13 (CYP2A13), mainly expressed in human respiratory tract, is highly efficient in the metabolic activation of aflatoxin (AF) B1 (AFB1) and is assumed to play a role in human lung tumorigenesis in airborne AFB1 exposure. To validate the assumption, we exposed human bronchial epithelial (BEAS-2B) cells stably expressing CYP2A13 (B-2A13), CYP1A2 (B-1A2) and CYP2A6 (B-2A6) to 0.1-10 nM AFB1 for 30-50 passages. B-2A13 cells showed increased sensitivity to 0.1 nM AFB1-induced neoplastic transformation and the formation of tumors in nude mice were observed at passage 30 (P30) while it occurred at P50 B-1A2 cells. B-2A6, similar to vector control, showed no neoplastic transformation in this condition. Additionally, AFB1-DNA adducts and 8-OHdG significantly increased in transformed P40 B-2A13, in parallel with the upregulation of p-ATR, p-BRCA1, Mre11, Rad50 and Rad51. However, the apoptosis of P40 cells was near normal, while the expression of Bax, C-Caspase 3 and C-PARP increased passage-dependently. Inhibition of ATR (ATR siRNA or NU6027) reversely increased the apoptosis of P40 B-2A13 cells in parallel with the upregulation of Bax, C-Caspase 3 and C-PARP, suggesting that ATR plays an important role in maintaining cell survival via antiapoptosis. Additionally, activation of ATR was necessary to neoplastic transformation since blockage of ATR in P40 cells inhibited DNA damage repair response and anchorage-independent growth. Our data demonstrated that CYP2A13 played a critical role in AFB1-induced neoplastic transformation. ATR-mediated the dysfunction of apoptosis and DNA damage repair might be involved. These results help establish a linkage between airborne AFB1 and human respiratory carcinoma. What's new? Produced by certain foodborne fungi, aflatoxin B1 (AFB1) floats through the air in dust and enters the lungs, particularly in people who work in food processing. Cytochrome P450 2A13 (CYP2A13) helps metabolize AFB1 and is thought to play a role in causing lung tumors in the presence of AFB1. To test whether this is true, the authors took cells expressing CYP2A13 and exposed them to AFB1. Compared with cells expressing other enzymes, those expressing CYP2A13 were more likely to become cancerous and form tumors in mice. In those cells, the authors found signs of DNA damage, as well as dysregulation of damage repair and apoptosis, suggesting a possible mechanism for how the tumors are getting started. © 2013 UICC. Source


Peng C.,Jiangnan University | Duan X.,Jiangnan University | Song S.,Jiangnan University | Xue F.,Plant and Food Inspection Center
International Journal of Molecular Sciences | Year: 2013

It is challenging to detect 7-aminonitrazepam (7-ANZP) residue in animal tissues simply and sensitively by the enzyme-linked sorbent immunoassay (ELISA) method. This paper demonstrates that utilizing a bioconjugate of gold nanoparticles and enzyme-labeled antibody as a signal probe increases the sensitivity of a traditional ELISA for 7-ANZP by nearly 20 times. The sensitivity of this ELISA for 7-ANZP was 5.6 pg/mL in buffer, and the limit of detection (LOD) of 0.18 μg/kg for 7-ANZP in urine could be achieved after the urine samples were simply hydrolyzed and diluted by buffer. This simple and sensitive method has potential application for improving the sensitivity of ELISA methods against various small molecules. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source


Xue F.,Hefei University of Technology | Xue F.,Plant and Food Inspection Center | Wu J.,Hefei University of Technology | Chu H.,Hefei University of Technology | And 7 more authors.
Microchimica Acta | Year: 2013

We present an electrochemical aptasensor for rapid and ultrasensitive determination of the additive bisphenol A (BPA) and for screening drinking water for the presence of BPA. A specific aptamer against BPA and its complementary DNA probe were immobilized on the surface of a gold electrode via self-assembly and hybridization, respectively. The detection of BPA is mainly based on the competitive recognition of BPA by the immobilized aptamer on the surface of the electrode. The electrochemical aptasensor enables BPA to be detected in drinking water with a limit of detection as low as 0. 284 pg mL-1 in less than 30 min. This extraordinary sensitivity makes the method a most powerful tool for on-site monitoring of water quality and food safety.[Figure not available: see fulltext.] © 2012 Springer-Verlag Wien. Source

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