Abstract:To investigate the distribution and phenotype characteristics of food borne Aeromonas spp.in Pudong New Area.MethodsAeromonas strains were isolated and identified to species level in 3types of fresh food samples collected from 2markets during May to November in 2011, and the difference of phenotype characteristics among isolates were analyzed. Results74strains of Aeromonas, including 23strains of A.hydrophila, 35strains (12.0%) of A.veronii biovar sobia and 16strains of A.caviae, were isolated from 291samples. The highest isolation rate was 34.1% in meat product, followed by 18.9% in aquatic product and 18.7% in vegetable. Of all the 74isolated strains, 51strains produced β-hemolysin, 59strains produced protease, and 48strains produced both β-hemolysin and protease. Antimicrobial susceptibility tests to 12antibiotics showed most strains were highly susceptible to Cefotaxime, Ceftazidime, Cefepime, Gentamicin, Ciprofloxacin and levoflxacin, while highly resistant to Ampicillin and the antibiotic resistance rate to Amoxicillin-Clavulanic acid had statistical difference among species. Low level of multi-drug resistance(MDR) existed in Aeromonas spp.ConclusionFresh foods in markets were highly contaminated by Aeromonas spp. during prevalent seasons. Aeromonas strains other than A.hydrophila also carried virulence factors. Though resistance to antibiotics was not serious, integrated monitoring of food borne disease based on food chain was necessary.

Abstract:The main purpose of this research was to describe the distribution of V.parahaemolyticus serotypes isolated from diarrhea cases and food in Shanghai and the molecular characteristics of pandemic strains.MethodsGS-PCR was used to recognize pandemic strains. tdh gene, trh gene and orf8 gene of phage f237were detected by PCR after serotyping. PFGE was used to analyze the genetic relationship among isolates. Results1136isolates were divided into 52serotypes (groups). 64.5% of all isolates were GS-PCR positivewhich wasthe pandemic strains. 11serotypes were found in pandemic strains in Shanghai, among which O3∶K6(76.8%), O4∶K68(9.4%), O1∶K25(6.8%), and O1∶K36(4.5%) were the main serotypes. Pandemic strains with serotypes of O10∶K60, O3∶K3and O1∶K33were first reported, and their PFGE patterns were closer to the reported pandemic strains. Most pandemic strains only had tdh gene, and no trh gene positive. Except 5.7% strains, most pandemic strains were positive for orf8gene.PFGE patterns were different among pandemic strains with same serotypes, and isolates with or without orf8 gene could not be distinguished by PFGE.ConclusionNew serovariants of pandemic were emerging, and the results of PFGE and orf8 gene detection suggested there was gene mutation amongpandemic strains.

Abstract:To analyze the molecular epidemiology traits of Vibrio parahaemolyticus in Zhenjiang and surrounding areas.Methods40Vibrio parahaemolyticus strains were collected from the samples of food poison incidents occurred in Zhenjiang and surrounding areas in 2011. Biochemical identification, tdh, trh and toxRS/new gene detection, serotyping and pulse-field gel electrophoresis (PFGE) were applied to these strains. ResultsThe positive rate of tdh, trh, toxRS/new and orf8 were 85.0%, 5.0%, 50.0% and 42.5%, respectively. The prevalent serotype was O3∶K6(32/40). The similarity of PFGE type between group A and B was more than 80%.ConclusionStrains from different regions in Zhenjiang and surrounding areas were mainly O3∶K6pandemic clone and highly homologous.

Abstract:To confirm the feasibility of BN rats as the protein allergy animal model．Methods48female BN rats were randomly divided into 6groups, control group, PAP group, HEWP group, OVA-low group, OVA-middle group, OVA-high group, 8rats in each group. The above groups were administrated 1ml sterilized water, 1mg/ml PAP, 10mg/ml HEWP, 0.1mg/ml OVA, 1mg/ml OVA or 10mg/ml OVA solution, respectively daily for 6weeks by gavage. Blood samples were taken on the 14^th,28^th and 42^nd days from the orbital plexus,and centrifuged to obtain serum for analyzing specific IgG and total IgE．On the 21^st and 35^th days,blood samples were taken to obtain plasma for analyzing histamine．In addition,the changes of blood pressure and gut permeability were determined．ResultsDifferent concentrations of allergen OVA could stimulate allergic reaction in BN rats, including elevated specific IgG and total serum IgE, elevated histamine level, decreased blood pressure, where 1mg/ml OVA was the optimal sensitizing dose. The allergic reactions to Weak allergens (HEWP) was weak, allergic reactions to non allergen (PAP) was negative. Gastrointestinal function had no obvious physiological changesfor all groups.ConclusionBN rat could be a suitable animal model for evaluation of food protein allergy．

Abstract:To study thetime-effectmodel of PTU thyroid disruption and screen sensitive endpoints.MethodsOvariectomized rats were randomly allocated into 3groups, and propylthiouracil was administered at 5mg/kg BW by gavage for 4,8and 12days respectively. An OVX control and a sham control were also included in the study, treated with corn oil. At the end of the study, serum T₃, T_4and TSH levels, activities of liver type I 5′-deiodinase and malic enzyme were measured correspondingly. Histopathology of thyroid was described and thyroid follicular epithelium/colloid ratio was calculated. ResultsCompared with OVX control, animals treated with PTU showed significantly higher serum T₃, and lower TSH levels, while only 8-day and 12-day groups had significantly lower serum T_4levels. The activity of liver type Ⅰ 5′-deiodinase decreased significantly, while malic enzyme did not show any significant difference among the groups. Histopathology results revealed the hypertrophy of thyroid, disappearance of colloid, adding that the ratio of epithelium versus colloid increased significantly. ConclusionPTU could effectively affect the structure and function of thyroid with time-effect trend; thyroid hormone, type I 5′-deiodinase activity and histopathology endpoints were sensitive; 8-day treatment of thyroid disruptor had the optimal observation.

Abstract:To compare the effects of propolis from different origin on the antioxidant function in rats with diabetes mellitus. MethodsDiabetes mellitus was induced in male Wistar rats by intraperitoneal injection of STZ dissolved in citrate buffer solution. Fifty induced rats were divided into five groups, 10rats each, according to fasting blood glucose, i.e.model control group, NO.1Chinese propolis, NO.2Chinese propolis, NO.3Chinese propolis and Brazilian propolis. 10normal male Wistar rats were used as the normal control group. The corresponding propolis suspension was daily administrated for 4weeks to propolis groups, and the same volume of solvent was administrated to normal and model control groups. The fasting glucose level was measured for each groups at the end of the intervention. Plasma, liver and muscle antioxidant capacity, contents of reduced glutathione, malonaldehyde, and antioxidant enzyme activities, including glutathione peroxidase and superoxide dismutase were measured. ResultsAll the propolis could decrease the serum glucose level of the STZ-induced diabetes mellitus rats and improve the antioxidant function to certain degrees. NO.2Chinese propolis could improve the muscle's antioxidant capacity of diabetes rats, better than the others.NO.3Chinese propolis have a better effect on the DM rats liver's antioxidant capacity and contents of glutathione, and could improve the muscle's contents of glutathione and glutathione peroxidase's activity. The Brazilian propolis can better decrease the contents of serum malonaldehyde, increase the contents of serum GSH, and improve the DM rats liver's SOD activity.ConclusionAll the four propolis could decrease the serum glucose level and increase the antioxidant capacity at different level by different ways.

Abstract:To study on the form of coenzyme Q₁₀ (CoQ₁₀) in soft capsule toselect the suitable method. MethodsBased on the chemical property of CoQ₁₀, the existing formsweredetermine in soft capsulethrough chromatography performance of different methods. And then the methods were selected for different forms of CoQ₁₀. ResultsCoQ₁₀ (oxidized form) and reduced CoQ₁₀ co-exist. The methods in China including China National Standard (GB), Chinese Pharmacopoeia (ChP) areboth aimed to the oxidized form.Inthe methods of Association of Official Analytical Chemists (AOAC)and United State Pharmacopoeia (USP), the reduced CoQ₁₀ is transformed to CoQ₁₀ first, and then the total amount is determined.ConclusionCoQ₁₀ (oxidized form) and reduced CoQ₁₀ co-exist in soft capsule and transform to each other under suitable conditions. When testing CoQ₁₀ in soft capsule, the method should considerif there is only the oxidized form or the two formsboth.

Abstract:To establish a rapid method for detection of Shiga toxin-producing Escherichia coli (STEC) O26∶H11 in ground beef using immonomagnetic separation (IMS) and quantitative real-time PCR.MethodsPrimers and TaqMan probe were designed to amplify fragments for wzx gene of STEC O26. Specificity and sensitivity of the method was evaluated. ResultsThe results obtained from qPCR showed that only STEC O26∶H11was positive , while 23other serovars of Escherichia coli and seven species of bacteria other than Escherichia coli were negative. The detection limit for pure colonies by real-time PCR was 5SymboltB@10^2cfu/ml. After 6h enrichment, samples with the initial STEC O26contamination level of 5×10^2cfu/25g were positive by IMS combined with real-time PCR method. The fluorescence signal of enrichment of samples with the initial STEC O26contamination level of 3×10-1 cfu/25g or above could be detected by both IMS-qPCR and qPCR method after 20h enrichment. IMS-qPCR was more sensitive than qPCR only for the lower initial contamination level after a 6h pre-enrichment time. Chromogenic medium combined with IMS had a higher recovery than chromogenic medium only in isolation of STEC O26. Meanwhile, the recovery of STEC O26∶H11 isolated from CHROMagar medium was higher than that from SMAC medium.ConclusionThe improved IMS-qPCR method for detection of E. coli O26∶H11 in ground beef is highly specific, sensitive, simple and fast. It could be used for fast detect of STEC O26∶H11in ground beef.

Abstract:To establish anoptimizedmethodcombination, which was sensitive, accurate and rapid for Escherichia coli enrichment and DNA extraction, so that we can use a real-time qPCR method (TaqMan probe) for detection and enumeration of Escherichia coli in drinking water.MethodsIn membrane filtration-elution step, the bacteria particles were concentrated by three different methods, and the recovery of E.coli was estimated quantitatively by Enumerating CFU on plate agar．In DNA extraction step, the genomic DNA were extracted with four different methods, and the TaqMan PCR assay was used to amplify and measure the recovery of the extracted DNA. ResultsThe recovery of E.coli eluted from the membrane was 76%-93% by using C-method (filtrating with Staph.epidermidis+vortex washing+glass rodscraping). Of the four extraction protocols, Triton-100and beads extraction method had the same linear range (10⁰-10-5), r²:0.998and 0.999respectively. However, the first method had significantly lower cost and time consuming. The recovery of E.coli from water was 79.7%-104.0%, and the sensitivity of qPCR was 1cfu/ml for the whole processing using the optimal methods for DNA extraction.ConclusionThe optimal methodcombination (C method+TritonX-100method) was rapid, accurate and economic for E. colienrichment from water and DNA extraction．

Abstract:To establish a specific and sensitive TaqMan-MGB quantitative real-time PCR assay for the rapid detection of Cronobacter spp..MethodsBased on the conservative sequence of partial macromolecular synthesis operon gene of Cronobacter spp. published on GenBank, specific primers and TaqMan Minor groove binder (TaqMan-MGB) probes were designed, and the rapid real-time PCR assay was estabilished and optimized. The specificity was evaluated with 25strains of other Enterobacteriaceae and some common pathogens. The quantitative standard curve was established with the recombinant plasmids and the sensitivity for the assay was evaluated for recombinant plasmids, pure cultures and contaminated food samples. Comparing with the TaqMan real-time PCR recommended by U.S. FDA, paired-samples t-test for the variables of cycle threshold (Ct) and relative fluorescence intensity (△Rn) was done between the two methods. ResultsThe TaqMan-MGB quantitative real-time PCR assay could be finished detection in 40minutes. It was specific enough to discriminate Cronobacter spp. from all other Enterobacter and non-Enterobacter strains tested. The relative coefficient of the quantitative standard curve was 0.999, and the amplification efficiency of the quantitative standard curve was 99.972%. The sensitivity for the assay was 10copies per reaction for recombinant, 3.8cfu/ml for pure culture, and 38cfu/ml for contaminated food samples,respectively. There were statistical differences between two real-time PCR methods by paired-samples t-test (Ct:t=-14.406, P<0.01and △Rn:t=14.230, P<0.01). The TaqMan-MGB real-time PCR was better than the TaqMan real-time PCR recommended by U.S. FDA in sensitivity and resolution.ConclusionThe TaqMan-MGB quantitative real-time PCR assay targeted the partial macromolecular synthesis operon gene of Cronobacter spp. is rapid, specific and sensitive. It would had a good value in the screening and identification of Cronobacter spp. from infant milk powder for food safety and risk monitor.

Abstract:A method for the determination of 16phthalates in diet samples was developed by isotope-dilution gas chromatography-mass spectrometry with gel permeation chromatography cleanup.MethodsSamples with isotope internal standard solutions were ultrasonically extracted by cyclohexane-saturated acetonitrile and followed by gel permeation chromatography (GPC) cleanup. The components were separated on a DB-5ms capillary column(30m×0.25mm,0.25mm)by GC-MS under selected ion monitoring (SIM) mode,and quantified by the isotope internal standards．ResultsThe average recoveries of the spiked diet samples were in the range of 52.3%-124.7% with the relative standard deviations in the range of 1.6%-16.2%. The limits of detection (LODs) were 0.03-0.06μg/kg.ConclusionThe method is suitable for the determination of 16phthalate esters simultaneously in diet samples with easy operation,high accuracy and precision．

Abstract:To develop a fluoremetric method for rapid screening of fluorescent whitening agents (FWAs) in food packaging paper.MethodsSamples were extracted by ethanol-water (1∶4, V/V) for three times, and the extracts were detected by fluorescence spectrophotometer with the excitation wavelength at 350nm and the emission wavelength at 430nm. C.I.220was used as the standard for quantification. ResultsC.I.220had a good relativity (r=0.9997) within the range of 12.5-400ng/ml and the limit of quantification (LOQ) of this method was 1.2μg/g. Mean recoveries were 84.4%-90.9% at three added levels (1.5,2.5and 6.0μg/g).ConclusionThis method was fast, simple, reliable and could be applied for screening of FWAs in food packaging papers.

Abstract:To developea method for the separation and determination of chromium by the cloud point extraction-graphite furnace atomic absorption spectrometry(CPE-GFAAS).MethodsUsing Triton X-100as surfactant and 8-hydroxyquinoline(8-HQ) as complexing agent, the cloud point extraction rate of the trivalent chromium with graphite furnace atomic absorption spectrometry(GFAAS)was optimized bypH,Triton X-100dosage, temperature, time and other majorfactors. The content of Cr(Ⅵ) was determined by total chromium and Cr(Ⅲ). ResultsThe optimum cloud point extraction condition was pH=9,1.0ml 3% Triton X-100, equilibrium temperature 95℃, equilibrium time 20min. Under this optimum condition, the limit of detection was 0.2μg/L and relative RSD was 4.1%. The spiked recoveries were above 88%-98%.ConclusionThis method has the advantages of low pollution,convenience,accuracy,high sensitivity and high precision．

Abstract:To establish a method for measuring methylmercury and other mercury species in aquatic products by HPLC-AFS. MethodsThe samples were extracted and centrifuged after hydrochloric acid ultrasoundtreatment. 5% of Acetonitrile, 4.62g/L ammonium acetate and 1.2g/L cysteine solution was used as mobile phase. Then the samples, being tested with AFS after C₁₈ seperated, were quantitatively determined by external standard method. There was no need of oxidization or ltraviolet photolysis. ResultsThe best linear range of methylmercury, ethylmercury and inorganic mercury was 0-50μg/L with correlation coefficients above 0.9990, the detection limit was 0.5-1.5μg/L, the precision relative standard deviation was less than 6%, and recovery of spiked samples was 78%-120%. Methylmercury measurement of standard substance in fish was within the reference range.ConclusionThis method was simple, sensitive, accurate and suitable for the determination of mercury species in aquatic products.

Abstract:To find out solutions to the current supervision and management predicament of the tableware disinfection service.MethodsThe historical and current situation of the tableware disinfection service industry was analyzed and summarized. ResultsMajor problems are lack of health requirement for market access, the grey area between different departments, low maneuverability of supervision criteria, low efficiency of execution due to the improper reference, unsuitable laws and rules for supervision.ConclusionIt was suggested to rationalize supervision system and unify the requirement, set up laws and regulations and unify the supervision criteria, improve the related safety standard of manufacture process and production, establish a farm-to-fork supervision system, encourage self-management of the industry, intensify the strength of training and promotion and publicize the supervision information. These would be the effective solutions to the current supervision and management predicament.

Abstract:To investigate the contamination of Shiga toxin-producing Escherichia coli (STEC) in retail meats in Wuhan city.MethodsA total of 196samples were collected from 30open markets and supermarkets during a two-year sampling period (from 2011July to 2012October). Specimens comprised 102pork, 60beef and 34poultry samples. All samples were performed selective incubation, then screened by PCR amplification for the presence of stx1, stx2, rfbO157 and wzyO157 genes. ResultsShiga toxin-producing Escherichia coli (STEC) were frequently detected in beef, pork and poultry products. 18.6% raw meats, 48.4% beef and 2.9% poultry samples had been tested positive for the presence of non-O157STEC. The detection rate of O157type STEC was 13.6% in pork, 6.7% in beef and 2.9% in poultry, respectively. The detection rate of STEC in open markets (35.8%) was a little higher than that in supermarkets (32.4%).ConclusionThe STEC detection rate is a little high in retail meats in Wuhan, and it should be concerned.

Abstract:To investigate the microbiological and heavy metal contamination of pickled raw seafood, and to provide basis for effective supervision measures.MethodsPackaged and bulk pickled raw seafood was collect from all seafood markets in Ruian, and samples were tested according to the national standard. The tests included total bacterial count, coliforms, pathogens(Staphyloc occus aureus, Vibrio parahaemolyticus, salmonella, shigella), lead, arsenic, mercury and cadmium. Results349samples were detected, and the total qualified rate was 57.31%. The qualified rates of packaged products and bulk products were 73.09% and 29.37% respectively. The qualified rates of total bacterial count, coliforms, pathogens, lead, arsenic, mercury and cadmium in pickled raw seafood were 60.46%, 79.94%, 85.67%, 95.70%, 97.99%, 100%, and 97.99%. ConclusionThe commercially available pickled raw seafood was seriously contaminated by microorganism in Ruian. Vibrio parahaemolyticus was the dominate food-borne pathogen. Relevant departments should strengthen the supervision and management to ensure the food safety of pickled raw seafood.

Abstract:To understand the condition of Listeria monocytogens pollution in foods in Xishan County of Kunming, and prevent food poisoning breakout and spread.MethodsSamples were collected according to the national standard (GB 4789.30-2010), and detected by BioMerieux VITEK system. ResultsA total of 406samples of food and food processing tools were detected from May to September in 2012, with an overall detection rate of 2.46%. The detection rate of food processing tools was 2.5%. The detection rate of overall food was 2.46%. The detection rate of vegetables and meat were both 5%.ConclusionThere was a wide spread pollution and high public health risk of Listeria monocytogens in local foods, and the food safety management should be strengthened.

Abstract:To understand the levels of lead, mercury, cadmium and chromium in seafood of Ningbo in 2012and to evaluate the safety for consuming. Methods285samples of 11representative species were collected in Ningbo and analyzed by GB 5009and GB/T 5009. ResultsThe detection rates of lead, mercury, cadmium and chromium were 93.7%, 98.9%, 98.2% and 97.2%, and the violation rates were 2.8%, 0%, 15.4% and 0.4%, respectively. Heavy metal content in descending order was algae, molluscs, crustaceans and fish.ConclusionThe heavy mental contamination in seafood should be highly concerned, and high content of heavy mental was found in some seafood. Environmental protection should be strengthened during the economic development.

Abstract:To investigate Guangzhou consumers’ risk perception on food safety and concern about sources of food safety risk and influential factors.MethodsA questionnaire survey was conducted among 600consumers from markets and supermarkets in Guangzhou. SPSS 15.0was used for data analysis. ResultsConsumer judged ten of the sixteen kinds of food to safety, and five kinds such as edible oil and dairy food to unsafe. The influential factors included the news from government, the reports from news media, brands and manufacturers, labeling and certification, food appearance, purchasing experience, recommendation from friends and gender (F=19.026, P=0.000), cultural degree (F=17.000, P=0.000), background knowledge (F=19.416, P=0.00), per capita monthly income of the family (F=11.143, P=0.00); 8kinds of food risk source were concerned by consumers and there was significant difference in cultural degree(F=6.327, P=0.000), background knowledge (F=10.432, P=0.001), per capita monthly income of the family(F=16.876, P=0.000).ConclusionThe consumers’ risk perception on the food safety deviated from the real situation. Government and media should report the food quality and safety timely and objectively, make greater efforts to strengthen food safety education, and the consumers would be properly guided.

Abstract:To explore the application of space-time permutation scan statistics in bacillary dysentery surveillance, and understand the space-time pattern and the trend of disease. MethodsBased on descriptive analysis, the national bacillary dysentery incidence data of 2910counties during 2008-2009was analyzedby space-time scan statistics using SatScan software. The results were visualized using ArcGIS 10.0software. ResultsThe accumulation time of 2008was from May to October and accumulation space was divided into 7clusters, which included 1113,0, 8,6, 6,0and 6counties respectively. The accumulation time of 2009was August, and the accumulation space was divided into 2clusters which included 1111and 485counties respectively. ConclusionThe space-time scan statistics was more effective for space-time pattern analysis of food borne disease than the classical statistics. Combined with geographic information system, it could be more intuitive, comprehensive to display the hot spot, and provide reference for similar research.

Abstract:To analyze the cadmium level in main food, and preliminarily assess the risk of dietary cadmium exposure of people in Fengtai District.MethodsIn 2011-2012,5samples of 6food categoriess were collected from Fengtai District. Cadmium contents in food were determined by graphite furnace atomic absorption method and the cadmium exposure was estimated by the food consumption data．The health risk was assessed by comparing the cadmium exposure with provisional tolerable monthly intake (PTMI) and the margins of safety (MOS) of cadmium. ResultsThe concentration of cadmium in edible mushrooms and their products was 2.2778mg/kg, which was the highest among the 6food categories being tested. Respectively, in accordance with the mean value of food consumption estimates, the cadmium exposure of Fengtai District residents from 6major food categories were 0.00146mg/kg BW·m, did not exceed PTMI (0.025mg/kg BW·m), and the MOS values were 17.2. The highest contributions were from vegetable products (52.4%), grain and its product (25.8%), edible mushroom and their products (13.4%). Although consumption of edible mushroom and animal visceral was very low, the contribution was high due to the serious cadmium contamination. Therefore, edible mushroom and animal visceral were high risk food for cadmium exposure.ConclusionThe average dietary cadmium exposure from 6food categories did not exceed the PTMI, the MOS was bigger than 1, so the level of dietary cadmium exposure was safe in general. However, more attention should be paid to the possible cadmium contamination in mushrooms and animal visceral.

Abstract:To determine thetoxins and its contentsin food poisoningrapid and accurate, and to provide a scientific basis for emergency response. MethodsAccording to the epidemiological investigation guide of food safety accidents and the trade standard of watermelon (NY/T 584-2002), multiple methods were used for three suspected watermelon samples sent by local CDC. ResultsHigh concentration of aldicarb including aldicarb sulfone and aldicarb sulfoxide were detected in watermelon.ConclusionThis food safety accident was caused by aldicarb.

Abstract:Food-borne diseases caused by parasites have become one of the important factors affecting the food safety. Traditional etiology methods were often subject to the technical proficiency and identification ability of techinician.In addition, the detection efficiency can not be satisfied with the actual needs. Therefore, rapid and accurate detection is a trend to food-borne parasite diagnosis development. The research progress and its application of foodborne parasite detection with some modern detection techniques, such as polymerase chain reaction (PCR), flinders technology associates (FTA), loop-mediated isothermal amplification (LAMP), microarray (DNA chip) and colloidal gold immune chromato-graphy (GICA) technology, including their mechanisms, advantages and disadvantages is reviewed in this paper.

Abstract:The purpose of this study is to introduce the current situation of pollution and possible exposure mechanism of POPs including organochlorine pesticides, dioxin, polychlorinated biphenyls, polybrominated dipheny-lethers, and perfluorinated generation of hydrocarbons, in breast milk of China. Persistent organic pollutants in breast milk have certain load in China, which may have adverse influence on infant's health.