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Objective: To survey the fungi contamination of four kinds of feed ingredients in 2013- 2014 from parts of China., Methods: A total of 795 feed ingredients including soybean meal, cottonseed meal, wheat bran and distillers dried grains with soluble( DDGS) were collected from representative enterprises in different parts of China. Food safety national standards GB 4789. 15-2010 microbiological examination of food hygiene enumeration of molds and yeast and GB / T 4789. 16-2003 was used to enumerate, isolate and identify fungi, respectively., Results: A total of 25 genus 54species kinds of fungi were isolated and the fungi from Aspergillus, Penicillium, Fusarium were the common contamination fungi in feed ingredients. Wheat bran was the most serious contaminated feed ingredients by fungi, and the detection rate of fungi contamination in four seasons were all greater than 84. 9%, and the exceeding feed limit rate was amount to 20. 8%. The fungi detection rate and contamination level were relatively lower in cottonseed meal and soybean meal, and the exceeding feed limit rate was 0. 9% and 1. 4%, respectively. There were types of feed ingredients, seasonal and regional differences for Aspergillus flavus and Fusarium moniliforme contamination. The detection rate of Aspergillus flavus in wheat bran was higher in four seasons and all surveyed areas, and autumn and winter and huazhong district were with the highest contamination level. The detection rate of Fusarium moniliforme for soybean meal in autumn and winter and huabei district was higher than others. The detection rate of Aspergillus flavus for DDGS was very low, but the detection rate of Fusarium moniliforme was higher, especially for autumn and huazhong district, the detection rate was 40. 4%and 50. 0%, respectively., Conclusion: The feed ingredients from China were commonly contaminated by fungi. It is recommended that strengthening the fungi contamination monitoring of feed ingredients from summer and autumn, huabei and huazhong district was an important prevention method.

Objective: The Norovirus GII 4 capsid protein was expressed by baculovirus expression system., Methods: The Norovirus GII 4 capsid gene was insert into the HT A plasmid. After sequencing, the recombinant plasmid was transformed into the MAX Efficiency DH10BacT competent cell to express the recombinant capsid protein of Norovirus GII 4. The recombinant capsid protein was purified by Ni-NTA His bind resin affinity chromatography purification column and was identified by Norovirus rapid test kit and SDS-PAGE., Results: The recombinant protein was successfully expressed with the molecular weight about 60 kD, and it has good immunogenicity., Conclusion: The Norovirus GII 4 capsid express plasmid is constructed successfully and the recombinant capsid protein of GII 4 is got in this study.

Objective: The roasted fish fillet sample at the retail collected in Beijing and Qingdao were detected for TTX, and the TTX positive samples was analyzed for fish species identification., Methods: TTX was tested by EUSA method and the cytochrome c oxidase I (COI) genome of TTX-positive samples was extracted and identified by DNA barcode., Results: Totally, 90 samples were tested by EUSA and 58 (64.4%) samples were positive for TTX with the levels ranging from 0.10 mg/kg to 63.81 mg/kg. Among the TTX positive samples, 24 (41.3%) were identified containing toxic puffer fish and 21 (87.5%) were Lagocephalus lunaris, the highly toxic puffer fish., Conclusion: Some roasted fish fillet samples obtained from the retail in two cities were positive for TTX and contained toxic puffer fish. Based on these results, we suggest that roasted fish fillet producers should prevent toxic puffer fish from mixing in the raw material and the I regulators should strengthen the TTX surveillance and product labeling supervision of roasted fish fillet.

Objective: To evaluate the suitability of stx-PCR, Vero cell assay and commercial enzyme immunoassay for detection of Shiga toxin Escherichia coli and to compare sensitivity and specificity of three different methods for detection of Shiga toxin-producing Escherichia coli., Methods: Using stx-PCR, Vero cell assay and commercial enzyme immunoassay to detect 35 Escherichia coli reference strains and 45 strains isolated from food., Results: The three methods all had good specificity. 31 strains gave positive reaction in the Vero cell assay and in the stx-PCR. The consistency between the Vero cell assay and stx-PCR was 100%. Only 38 strains can be detected by commercial enzyme immunoassay., Conclusion: stx-PCR method can serve as a routine rapid detection method in the laboratory. Vero cell assay is recommended to be the gold standard to determine whether the bacteria had the functionally active toxin. Commercial kit was suitable for preliminary rapid detection during clinical testing and outbreaks of food-borne disease.

Objective: To survey the fungi contamination of different feed ingredients in China., Methods: Soybean meal, cottonseed meal, wheat bran and distillers dried grains with soluble (DDGS) were collected from feed enterprises in different part of the country. Feed ingredient samples were diluted and inoculated and the key factors were screened which influenced the isolation., Results: Potato dextrose agar (containing chloramphenicol 0.1 g/L) and 10(-1) dilution were the optimum culture medium and dilution respectively. The range of fungi contamination was from 31% (DDGS) to 88% (wheat bran). The fungi contamination frequencies of feed ingredients varied from region to region, and varied from kind to kind. The contamination of Aspergillus flavus and Fusarium spp. were also different in the regions and sample types. The average contamination percentage of Aspergillus flavus (25%) is higher than Fusarium spp. (11%), and their contamination level is highest in northeast China and lowest in south China, wheat bran and cottonseed meal were the highest and DDGS was the lowest., Conclusion: The fungi contamination, including Aspergillus flavus and Fusarium spp. of feed ingredients all over the country should be pay more attention. It is recommended that prevention of feed ingredients from fungi contamination is needed.

Objective: To develop a real-time PCR method for identification and detection of domestic horse meat (Equus caballus) in animal-origin products., Methods: The primer and TaqMan-probe was designed and synthesized according to the EU reference laboratory and 87 bp fragments was amplified for horse ingredients. The specificity and sensitivity was tested by artificially spiked horse meat into other domestic meat, such as cattle, sheep, pork, chicken, duck and rabbit. 122 samples of cattle and sheep products were random collected in Beijing market and the detection of horse meat was carried out., Results: The real-time PCR in this study has high specificity and sensitivity for horse meat. No cross-reaction was observed between the horse and sheep, pork, chicken, duck and rabbit meat. There was little cross reaction between horse and cattle when the CT value reach 33. 81. The method can detect 0.1% of horse meat mixed with other domestic animal-origin products. No horse meat ingredients were detected in 122 samples in this survey., Conclusion: There was no horse meat mixed into cattle and sheep products in Beijing marked.

Objective: To clone the sequence of Staphylococcus aureus enterotoxin A (SEA) gene, construct its expression vector, and obtain high levels of recombinant Staphylococcus aureus enterotoxin A (rSEA) with high purity., Methods: The enterotoxin A gene was synthesized and inserted into the prokaryotic expressed vector pET28a possessing histiding-tag. The recombinant vector was transfected into E. Coli BL21 (DE3) after it had been verified by DNA sequencing. The strain can express the recombinant protein after the induction by the IPTG. The recombinant protein was purified by Ni-NTA His Bind affinity purification column., Results: The recombinant protein was obtained. SDS-PAGE showed that its molecular mass was about 30kD. The western bolt showed that it can specifically bind rabbit anti-SEA antibody. The BALB/c mouse was immunized by the recombinant protein followed by detection of anti-SEA antibody by ELISA. The results revealed that the protein has reactogenicity and immunogenicity, which provides the foundation for either the preparation of monoclonal antibodies or the further study of the immunological detection of SEA., Conclusion: The rSEA expression vector was constructed successfully and highly expressed the rSEA protein.

Objective: To identify the aflatoxins contamination of corn in China., Methods: Aflatoxins B1, B2, G1 and G2 in 279 corn samples collected from 6 provinces or autonomous regions were determined by HPLC., Results: Aflatoxins were detected in 75.63% of 279 corn samples. The average concentration of positive samples was 44.04 microg/kg, with a range of 0.20 - 888.30 microg/kg. The positive rates of samples from Sichuan, Hubei, Guangxi, Henan, Guangdong and Jilin Provinces were 90.48%, 93.75%, 87.50%, 36.96%, 91.84% and 52.17% respectively, with an average concentration of 107.93, 70.98, 39.65, 8.06, 3.70 microg/kg, and 1.15 microg/kg respectively. AFB1 was detected more frequently and with higher levels than the other three aflatoxins, with a positive rate of 74.55% and an average concentration of 39.64 microg/kg. The positive rate of AFB2, AFG1 and AFG2 was 58.42%, 41.22% and 19.71% respectively, and the average concentration of them was 3.81, 3.47 and 0.51 microg/kg respectively., Conclusion: Corn samples collected from all six regions are contaminated widely with aflatoxins in various degrees. The contamination of aflatoxins in the South was more serious than that in the North of China. AFB1 is the prominent one among the four aflatoxins.

A reversed-phase high performance liquid chromatographic (RP-HPLC) method was developed for the simultaneous determination of the contents of adapalene and the preservatives (2-phenoxyethanol and methyl-4-hydroxybenzoate) in adapalene gels. The chromatographic analysis was carried out on a Tigerkin C18 column (150 mm x 4.6 mm, 5 microm). The mobile phase was 0.02 mol/L ammonium acetate buffer (pH 3.0) and tetrahydrofuran-acetonitrile with gradient elution, and the detection wavelength was set at 270 nm. The calibration curves were linear over the ranges of 10-100 mg/L (r = 0.9999), 4-40 mg/L (r = 0.9999) and 4-40 mg/L (r = 0. 9999) for 2-phenoxyethanol, methyl-4-hydroxybenzoate and adapalene, respectively. The average recoveries of the three substances were within 98.0%-98.6%. The method is simple, reliable and suitable for the simultaneous determination of adapalene, 2-phenoxyethanol and methyl-4-hydroxybenzoate in adapalene gels.

Objective: To study impact of extra waters on immunosystem in mice-alkaline ionized water, mineral-ecology water, activated water, and pure water., Methods: According to Function Assessment and Experiment for Function Food, 1996, the ratio of spain and body weight, the ratio of thymus and body weight, the delayed type hypersensitivity (DTH), the phagocytosing functions by cock RBC, the plaque forming cell (PFC) and HC50 testing were assessment with 120 male Balb/c mice of 17.8 - 23.3 g (group I), the mice were divided into four group, and drank daily the four kinds of waters respectively until 50 days. The lymph cell transformation by ConA and NK cell activity were assessment with other l20 male Balb/c mice of 17.8 - 23.3 g (group II), the mice were divided into four group and drank daily the four kinds of waters respectively until 50 days. The phagocytosing functions by carbon powder were assessment with other 120 female Balb/c mice of 16.7 - 22.0 g (group III) were divided into four group and drank daily the four kinds of waters respectively until 50 days. The data were statisticed by Stata soft., Results: Other three waters compared with the pure water: (1) Alkaline ionized water and activated water can alleviate the body weight increase of male Balb/c mouse (P < 0.01 & P < 0.05), but alkaline ionized water, mineral-ecology water, activated water don't impact on the female Balb/c mouse body weight (P > 0.05). (2) Activated water can remarkably increase the ratio of thymus and body weight (P < 0.05), and increase the phagocytosing ability by cock RBC (P < 0.01), and increase the NK cell activity (P < 0.01). (3) The three extra waters don't impact on other items for the Balh/c mouce., Conclusion: The study must be continued to impact on immunosystem in mice for extra waters.