Abstract:To investigate the antioxidant activity of recombinant human lactoferrin (rhLF). Methods The 1,1-diphenyl-2-picryl hydrazyl free radical (DPPH) inhibiting rate, hydroxyl free radical inhibiting rate, superoxide anion radical inhibiting rate, reducing capacity and inhibiting of lipid peroxidation in rat liver were tested to evaluate the antioxidant activity of rhLF and bovine lactoferrin (bLF) in vitro. Results The concentration of rhLF and bLF were correlated with the inhibiting rate of 1,1-diphenyl-2-picryl hydrazyl free radical, hydroxyl free radical, superoxide anion radical and reducing capacity. There was significantly dose-response relationship and the difference had statistical significance(P＜0.05). There was no interaction between sample and concentration, the trend of the value was the same in different concentrations of rhLF and bLF. Antioxidant effect of rhLF and bLF had significant difference in rat liver homogenate, different concentrations of rhLF and bLF had significant difference(P＜0.05). Conclusion Bovine lactoferrin and rhLF have antioxidant activity, and could be added to health food or cosmetics as a natural antioxidant.

Abstract:To investigate the effect of lanthanum nitrate on immune development of offspring rats, which exposed to pregnant rats, by measuring the level of interferon, interleukin, and the proliferation of spleen T lymphocyte, spleen B lymphocyte and natural killer (NK) cells. Methods Pregnant SD rats were randomly divided into control group, low dose group, middle dose group and high dose group,with 10 rats in each group. The rats were treated with lanthanum nitrate at of 0,2, 20, and 60 mg/kg BW respectively, from gestation day 7 to gestation day 16. On postnatal day 4 (PND4), the number of rats was reduced to 4(2 male and 2 female per litter), about 160 rats in the four groups. One male and one female from each litter were chosen as A queue, and the other one male and one female were B queue. On postnatal day 52 (PND52), rats of the A queue were observed including body weight, peripheral blood lymphocyte typing and serum γ-interferon (γ-IFN), interleukin-2 (IL-2), IL-4, IL-1α, IL-10, and tumor necrosis factor (TNF) content. The rats of B queue were detected T-dependent antigen response and lymphocytes proliferation on postnatal day 55 (PND55). Offspring rats were weighed every week during the experiment. Results There was no significant difference between the experimental groups and the control group (P>0.05), including the relative weight of liver, kidney, lung, brain, spleen and thymus. Spleen T lymphocyte proliferation in male rats of the high dose group was higher than the control group (P<0.05), with a dose-response relationship. The number of blood NK cells in female rats of the experimental groups were more than the control group (P<0.05) with, a dose-response relationship. The results show that benchmark dose lower bound was 0.21 mg/kg BW. Conclusion Exposure to lanthanum nitrate during pregnant period had a slight stimulation on NK cell and spleen T lymphocytes, however, there was no significant toxicity on the immune system development of rats offspring.

Abstract:The single toxicity and joint toxicity of disthylstilbestrol(DES), dibutyl phthalate(DBP)and propyl thiouracil(PTU)to the proliferation of GT1-7 cells were investigated. Methods The dose of DES was 0.1,1, 10,0 and 1 000 μmol/L, the dose of DBP was 0.01,1, 10,0 and 1 000 μmol/L, and the dose of PTU was 0.000 1,0.01,1,100 and 1 000 μmol/L. The dose of joint toxicity were DES(0.1-1 000 μmol/L), DBP(0.01 μmol/L) and PTU(0.000 1 μmol/L). The cell counting Kit-8 was used to evaluate the viability of GT1-7 cells under DES, DBP and PTU alone or combined exposure. Results When DES and DBP exposed alone, the viability of GT1-7 cells increased at first and then decreased with the higher dose. Compared with the control group ,the viability of GT1-7 cells exposed to PTU increased and maintained at a certain level. When the concentration of DES, DBP and PTU was below 10,0 and 1 000 μmol/L, the viability of GT1-7 cells was above 90%. When DES and DBP, DES and PTU combined exposed to GT1-7 cells, the viability was increased first and then decreased with the increase of DES concentration. When DBP and PTU combined exposed, then cell viability had the same change. When 0.01 μmol/L DBP and 0.000 1 μmol/L PTU added to 0-10 μmol/L DES, the cell viability increased obviously, and the difference was significant(P＜0.05).But when concentration increased to 100 μmol/L DES, the cell viability was decreased from 80% to 4%, and the difference was significant(P＜0.05). Conclusion When DES, DBP and PTU was exposed to GT1-7 cells, the cell proliferation increased at first and then decreased. When they were combined at a certain concentration, it showed a joint effect of cell proliferation on GT1-7 cells.

Abstract:To verify the related risk factors of crayfish-related rhabdomyolysis outbreak using animal experiment, and to provide positive samples by animal experiment screening for the confirmation of the pathogenic factors of crayfish-related rhabdomyolysis. Methods Based on the result of epidemiological investigations and the traceability information of 48 crayfish-related rhabdomyolysis cases in Guangdong Province in 2016, suspected crayfish samples were screened and separated as meat and hepatopancreas, which were given to mice by gavage to trigger crayfish-related rhabdomyolysis through observing the indicators of serology and skeleton histopathology. Results The main clinical symptoms of the cases were muscle soreness, fatigue, dyspnea and chest distress, and the blood biochemistry test showed that the abnormal percentage of creatine kinase(CK), creatine kinase isoenzyme(CKMB)and myoglobin(MB)were above 85%, accordance with the diagnosis of haff disease. The crayfish-related rhabdomyolysis was related with the batch and intake of crayfish, as well as the individual physical difference. In 36 incidents, there were two restaurants (restaurant A and restaurant B) reported 2 incidents respectively, others only reported one. 30 g/kg BW of female hepatopancreas from restaurant A could induce increase of serum CK and CKMB in mice. After giving the highest dose (30 g/kg BW) of hepatopancreas from restaurant A, serum CK and CKMB were all higher than other dose groups (10,3.3,1.1 g/kg BW). 30 g/kg BW crayfish meat from restaurant A and B could both induce increase of serum CKMB, MB, aspartate aminotransferase(AST), lactate dehydrogenase(LDH)and creatinine(CR). The abnormal increase of rhabdomyolysis related indicators CK, CKMB, MB, LDH, glutamic pyruvic transaminase(ALT)and AST were positively correlated in the same animal. The rhabdomyolysis pathological manifestations, such as inflammatory cell infiltration, eosinophilic in bicepsfemoris muscle, and cross striations unclear and disappear were mainly observed in animals with serum CK, CKMB abnormal increase. Conclusion Crayfish-related rhabdomyolysis could be triggered in mice, and was associated with the batch and dose of the crayfish, which was consistent with the result of human epidemiological investigation.

Abstract:To investigate the antibiotic resistance and the distribution of virulence genes in Enterococcus faecalis isolated from meat and meat products collected from food market in Zigong City, Sichuan Province, and to observe sequence typing(ST)identified by multilocus sequence typing (MLST) among multi-drug resistant Enterococcus faecalis. Methods Enterococcus faecalis strains were isolated from 147 meat samples including raw meats and cooked meats from 17 to 21 April,2013. The antimicrobial susceptibilities of Enterococcus faecalis isolates were determined by automatic bacteriology identification. The presence of four virulence genes (cylA, asa1, gelE and esp) were investigated by polymerase chain reaction(PCR), and ST types were detected in multi-drug resistant isolates. Results A total of 65 isolates were obtained from 147 samples, 58.5%(38/65)of the isolates were resistant to at least one drug. Of all isolates, resistance to tetracycline was the highest (41.5%,27/65), and resistance to rifampicin, chloramphenicol and erythromycin was also fairly high. Moreover, resistance to high concentrations of streptomycin and gentamicin in Enterococcus faecalis isolates were 15.4%(10/65) and 12.3%(8/65), respectively. Strains resistant to penicillin, glycopeptides and lipopeptides were failed to acquire in this study. Four virulence genes which were common in Enterococcus faecalis were distributed in all 65 isolates, and the positive rates of gelE , asa1, esp and cylA were 56.9%(37/65),21.5%(14/65),9.2%(6/65) and 7.7%(5/65), respectively. There were 14 isolates, which showed resistance to three or more antibiotics, belonged to 9 STs mainly comprised of ST16 (n=4), ST81 (n=2) and ST480 (n=2). The profile of resistance and virulence genes were similar in the Enterococcus faecalis isolates with same STs. Conclusion The same ST type of Enterococcus faecalis strains from meat and meat products in Zigong City harbored similar virulence genes and multi-drug resistant pattern, which should be paid attention to the potential threat to human health.

Abstract:This study was to compare and assess the accuracy of species-level identification methods for Enterococcus spp., and to understand the species distribution and antimicrobial susceptibility characteristics of Enterococcus spp. collected of raw pork from a free trade market in Beijing. Methods By using matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS)and 16S rRNA gene analysis, the species of Enterococcus spp. were identified, and the inconsistent results were further identified by API 20 Strep, 16S rRNA and 23S rRNA gene analysis. Moreover, the susceptibility of isolated Enterococcus spp. to 10 antibiotics was analyzed at species level. Results Among the five identification methods, 16S rRNA gene analysis showed 100.0% consistence with the final species identification results, but the VITEK 2 COMPACT showed the lowest consistence of only 4.0%(1/25). The most prevalent species in Enterococcus spp. was Enterococcus faecalis, accounting for 82.6% (71/86) followed by Enterococcus hirae 14.0% (12/86). Enterococcus faecalis strains showed higher antimicrobial susceptibility than Enterococcus hirae to ciprofloxacin, tetracycline, high-level streptomycin and high-level gentamicin (ciprofloxacin: χ²=10.751, P<0.01; tetracycline:χ²=3.865, P>0.05; high-level streptomycin:χ²=1.608, P>0.05; high-level gentamicin:χ²=0.553, P>0.05), but showed apparently lower antimicrobial susceptibility on erythromycin and chloramphenicol than Enterococcus hirae (erythromycin:χ²=20.244, P<0.01; chloramphenicol:χ²=14.139, P<0.01). Conclusion The 16S rRNA gene analysis and MALDI-TOF-MS have higher accuracy at species level identification for Enterococcus spp.. Different species of Enterococcus spp. showed various antimicrobial susceptibility characteristics. This study was important for the effective monitoring of drug-resistant enterococci spread and prevalence.

Abstract:To investigate the association between the multilocus sequence tying(MLST)of Listeria monocytogenes and its antibiotic susceptibility, and to determine the presence of some clonal strains with high pathogenic potential.Methods Susceptibility tests were performed through the Kirby-Bauer (K-B) method and E-test method with fourteen antibiotics; and then 50 Listeria monocytogenes strains were genotyped by MLST. Results The antibiotic resistant rate of Listeria monocytogenes was 22.00%(11/50), and multi-resistant strains appeared during the tests. The 50 Listeria monocytogenes strains were divided into 12 types based on MLST typing with ST9 and ST121 was being the dominant types. Conclusion Specific STs could transfer to particular strains during food production processes. The resistant strains were found in both foodborne and human source Listeria monocytogenes. There was a possibility of the transmission of antibiotic-resistant genes, thus the monitoring of potentially pathogenic ST-type was quite important to reduce Listeria monocytogenes.

Abstract:To explore the correlation between Vibrio parahaemolyticus (VP) contamination of aquatic products and clinical diarrhea cases. Methods Totally 654 aquatic product samples and 8 112 clinical diarrhea cases were collected in Huzhou City between 2014 to 2016. Aquatic products and faecal or anal swab specimens of clinical diarrhea cases were tested for VP, O group of serum and the virulence gens tdh and trh, respectively. The distribution characteristics of VP in aquatic products and clinical diarrhea cases was analyzed and compared. Results The detection rate of VP in aquatic products was 28.02% (183/653), of which freshwater products and seafood counted for 33.67% (132/392) and 19.54% (51/261) respectively, and the difference was statistically significant (χ²=14.823, P<0.001). The detection rate of VP in clinical diarrhea cases was 4.87% (395/8 112), and 15.40% (170/1 104) of them had exposure to aquatic and its products. In the time distribution, the detection rate of VP in aquatic products and clinical diarrhea cases were basically the same, and the detection rates were relatively high in July to September. In the serotype distribution, O3 and O4 were the two main serotypes both in aquatic products and clinical diarrhea cases. In the virulence genotype distribution, the tdh()/trh() was predominant (60.51%, 239/395) in clinical diarrhea cases, while the tdh()/trh() was the predominant one (42.08%, 77/183) in aquatic products. Conclusion There was a certain correlation between VP contamination in aquatic products and clinical diarrhea cases in the time distribution and biological characteristics. Therefore, it is necessary to further strengthen the monitoring and management of VP in aquatic products.

Abstract:To investigate the drug susceptibility of Cronobacter spp. isolated from formula milk powder, infant rice powder, and clinical cases in Sichuan Province.Methods The drug susceptibility test of 109 strains of Cronobacter spp. was conducted with minimum broth dilution method. Results All the strains were sensitive to ciprofloxacin, nalidixic acid, cefotaxime, gentamicin, trimethoprim/sulfamethoxazole, tetracyclin and chloramphenicol, while 53 strains were resistant tocefoxitin, and the resistance rate was 48.6%(53/109). The minimum inhibitory concentration value of trimethoprim/sulfamethoxazole and chloramphenicol increased year by year. Conclusion Strains of Cronobacter spp. in this study had higher resistance to the second generation cephalosporins, and further study was needed to understand the mechanism. It was necessary for clinician to refer the drug sensitivity of Cronobacter spp. so as to select antibiotics correctly, and also for controlling the rapid evolving of multi-drug resistant strains of Cronobacter spp..

Abstract:To establish a method for rapid detection of Vibrio parahaemolyticus producing thermostable direct haemolysin (TDH) by immunochromatography technology of the labeled magnetic fluorescent nanoparticles combined with antibody. To establish a method for rapid detection of Vibrio parahaemolyticus producing thermostable direct haemolysin (TDH) by immunochromatography technology of the labeled magnetic fluorescent nanoparticles combined with antibody.Methods The gene fragment of Vibrio parahaemolyticus producing TDH was constructed and amplified. The product was ligated with plasmid vector (pET-28a) and expressed in Escherichia coli to prepare antibody. The antibody was conjugated with the labeled magnetic fluorescent nanoparticles to prepare an immunochromatographic test strip. The samples were mixed with different concentrations of standard strain and negative control samples respectively with the fluorescent nanoparticle-monoclonal antibody conjugate, incubated on the strip for 5 min, and observed with naked eyes under UV light.Experimental test was conducted for sensitivity, specificity, reproducibility and sample simulation. The gene fragment of Vibrio parahaemolyticus producing TDH was constructed and amplified. The product was ligated with plasmid vector (pET-28a) and expressed in Escherichia coli to prepare antibody. The antibody was conjugated with the labeled magnetic fluorescent nanoparticles to prepare an immunochromatographic test strip. The samples were mixed with different concentrations of standard strain and negative control samples respectively with the fluorescent nanoparticle-monoclonal antibody conjugate, incubated on the strip for 5 min, and observed with naked eyes under UV light.Experimental test was conducted for sensitivity, specificity, reproducibility and sample simulation.Results The recombinant plasmid vector could efficiently and efficiently express the soluble protein with molecular weight of 26 kD in Escherichia coli BL21 (DE3). The monoclonal antibody and the magnetic fluorescent particles were well coupled. The resulting conjugate was reacted with the lowest concentration at 10 CFU/ml positive strain, and the negative control strains had no reaction. The recombinant plasmid vector could efficiently and efficiently express the soluble protein with molecular weight of 26 kD in Escherichia coli BL21 (DE3). The monoclonal antibody and the magnetic fluorescent particles were well coupled. The resulting conjugate was reacted with the lowest concentration at 10 CFU/ml positive strain, and the negative control strains had no reaction.Conclusion The magnetic fluorescent nanoparticles coupled with the TDH virulence gene expression product of Vibrio parahaemolyticus was prepared in the experiment.Testing process was simple with high sensitivity, strong specificity, good repeatability and short detection time. The magnetic fluorescent nanoparticles coupled with the TDH virulence gene expression product of Vibrio parahaemolyticus was prepared in the experiment.Testing process was simple with high sensitivity, strong specificity, good repeatability and short detection time.

Abstract:The colloidal gold immunochromatographic strip was developed to detect aflatoxin B₁ (AFB₁), zearalenone (ZEN) and deoxynivalenol (DON) in grains. Methods The pH of colloidal gold solution and the dosage of the specific antibody and antigen were optimized through three combinations. The limit of quantitation, accuracy, specificity and the stability of the detection strip were investigated. Results The optimal pH of colloidal gold solution for AFB₁, ZEN and DON was 7.5,7.5 and 7.0, respectively. The optimal concentration of antibody marking was 4.2,7.2 and 9.6 μg/ml, respectively. The optimal concentration of the specific antigen was 1.0,1.4 and 0.8 mg/ml, respectively. Sixty samples were detected through instrument method and colloidal gold immunochromatographic method simultaneously, and the results were consistent with each other. No cross-reaction was observed with other analogue and mycotoxins, and the triple strip could be stored at room temperature for 12 months. Conclusion The triple strip was a simple, accurate and stable method for monitoring AFB₁, ZEN and DON in grains, and had good application foreground in field analysis.

Abstract:To establish a detection method for paraquat residues in bamboo shoots by ultra performance liquid chromatography-tandem with triple quadrupole mass spectrometry. Methods Samples were extracted with methanol-0.1 mol/L hydrochloric acid solution(1∶1,V/V). After cleaned up with Oasis WCX solid phase extraction columns(60 mg/3 ml), samples were separated in UPLC BEH HILIC column(100 mm×2.1 mm,1.7 μm). The analytes were detected with mass spectrometer in multiple reaction monitoring mode with external standard. Results It showed good linearity with the correlation coefficients of 0.998 2 in the range of 10-500 μg/L. The limit of detection was 2 μg/kg and the limit of quantitation was 5 μg/kg. Under 5,0 and 200 μg/kg spiked levels, the recoveries ranged from 82.2% to 104.8% with the relative standard deviation (RSD) of 8.3%-10.9%. Conclusion The results indicated that this method was simple, rapid, sensitive and suitable for the determination of paraquat residues in bamboo shoots.

Abstract:A method for the determination of eleven quinolones drug residues in chicken and egg by the ultra performance liquid chromatography-electrospray ionization tandem quadrupole mass spectrometry (UPLC-ESI-MS/MS) was established. Methods The analytes in chicken and egg were extracted by 1% acetic acid-acetonitrile, and the fat were separated by centrifugation and extraction using hexane. The eleven analytes were separated by the mobile phase of 10 mmol/L ammonium acetate (contain 0.1% formic acid)-methanol on gradient elution. The identifications were achieved by electrospray ionization in positive mode (ESI+) using multiple reaction monitoring (MRM). The quantifications were performed by the matrix matched isotope-labelled internal standards. Results The calibration curves of the eleven analytes showed a good linearity in the range of 0.05-50.0 μg/L with R² above 0.997 4. Recoveries were between 82.4% and 104.3% with RSD less than 15.0%. The limits of detection were 0.05-0.10 μg/kg. Conclusion The method had the advantages of simple pretreatment and low matrix effects, which was suitable for the rapid, high-throughput quantitative analysis of quinolones drug residues in poultry food.

Abstract:To set up the model for evaluation of the food safety supervision on large-scale event. Methods The safety level of food producers was evaluated by Delphi method. The other factors which might affect food safety such as age and personnel source were screened and identified. The evaluation model of composite index was developed by analytic hierarchy process. Results The model was constituted of 5 dimensions (age, weather, personnel source, food type and the producer's safety level) in a large-scale event. The scores weight were 3.96%, 9.85%, 7.14%, 35.99% and 43.06%, respectively. The score of alert for restaurant was 60,8 for fast food services, and 59 outdoor catering. Conclusion This study was helpful for supervision department to conduct food safety risk assessment and choose safe food producers and ensure food safety in a large-scale event.

Abstract:Aiming at the American food enterprise inspector management system, this paper analyzed the American food company system from several aspects, such as the inspection basis, constitute and qualification management, duties and tasks, training and the management of the inspectors. The paper analyzed the characteristics and experience of the American food enterprise inspector management system. It can provide some references for establishing China's food enterprise inspectors system.

Abstract:To investigate the attitude of food industries on GB 14880-2012 Standard on the Use of Food Nutritional Fortification Substances and the impact of its implementation on food industries. Methods A questionnaire survey was designed and carried out in 25 provinces on food industries in 2014, and 686 valid questionnaires were collected. Descriptive analysis and chi square test were used for statistical analysis. Results The awareness rate of food industries for the standard was 87.61% (601/686), the average score of maneuverability was 4.325 points at a 5 points scale, and the score of rationality was 4.293 points. 92.15% (552/599) of the food industries had taken different actions to implement the new standard, and it had played a positive role, however it also increased the cost of inspection for food industries. Conclusion The awareness rate of food industries was high, and food industries had high satisfaction score for maneuverability and rationality on GB 14880-2012. The new standard played a positive role for the food industries. However, the implementation of new standards also brought inspection cost for food industries.

Abstract:To investigate the status of dietary nutrients intake of the residents in Shunyi District, Beijing in 2015. Methods Using stratified cluster sampling method, Shunyi District was divided into urban and rural areas, according to the level of economic development and geographical location. Two communities or villages were randomly selected in each type of areas. Three hundred households and 817 objects were randomly selected from each community or village. All members of each household were investigated about food consumption, dietary nutrients intake and food sources of nutrition. Results The consumption of grain and egg was at the reasonable level, but the intake of potato, fruit, vegetable, soyabean and nut was low, only reached 60.8%, 52.3%, 83.0% and 63.2% of the recommended intake, respectively. Milk and aquatic product were far below the recommended values, only reached 16.8% and 34.3% of the recommended intake. Meat, edible oil and salt had exceeded the recommended values at 10.3%, 63.7% and 100.0%, respectively. Energy supply was basically adequate. There were 52.1%(426/817)、72.1%(589/817)、83.8%(685/817)、88.6%(724/817)、97.2%(794/817)、10.0%(82/817) and 45.9%(375/817) of the population with protein, vitamin A, B₁, B₂, calcium, iron and zinc deficiency, respectively. 91.6%(748/817) of the residents reached the appropriate level of sodium intake. The proportion of energy from fat should be reduced and the quality of protein be improved. Conclusion Unreasonable food consumption and deficient of some micronutrients might be the important factors influencing the health of Shunyi residents..

Abstract:The microbiological quality control test for the centers for disease control and prevention was conducted at the provincial, municipal and county level, and the detection capability against six foodborne pathogenic bacteria was evaluate. Methods Six bacteria under test were Listeria monocytogenes, Bacillus cereus, Enterobacter sakazakii, Escherichia coli, Salmonella and Staphylococcus aureus. According to the bacterium combination designed in 2011 and 2012, the samples were prepared by adding the fresh blended culture of pathogenic bacteria into radiation-sterilized milk powder carrier. Six samples of I-VI were prepared in 2011 while ten sample of A-J in 2012. The results of qualification were evaluated using the point-score method. The rate of detection was analyzed with Pearson ² or likelihood ratio². Results The overall qualification rate of 2011 and 2012 were 86.5%(268/310)and 84.3%(375/445), respectively. The lowest qualification rate in 2011 was blank sample VI(68.0%,17/25), while the lowest in 2012 was sample G(0.0%,0/8). In both 2011 and 2012, Escherichia coli was the main false negative bacterium and accounted for 85.7%(60/70)of total false negatives in 2012. The most frequent false positive results among in 2011 were Staphylococcus aureus and Bacillus cereus which were not accounted for the evaluation. In 2012, the highest false positive result was Staphylococcus aureus which accounted for 36.8%(7/19)of the total. In Enterobacter sakazakii and Escherichia coli composite samples of the two years both showed that the false negative rate of Escherichia coli increased significantly. The serotyping accuracy of Salmonella and Escherichia coli were as low as 41.5%(95/229)and 45.1%(105/233), respectively. The false identification occurred on Listeria monocytogenes versus Listeria innocua, Bacillus cereus versus Bacillus mycoides, and Enterobacter sakazakii versus Enterobacter amnigenus. Conclusion More than 80% of the centers possessed qualified detection capability against six foodborne pathogenic bacteria, which satisfied the requirements of food safety risk surveillance. The highest detection capability was toward Salmonella. Staphylococcus aureus had lower false negative results but was easy to produce false positives. The detection capability of Enterobacter sakazakii had improved significantly comparing with the results of 2010.

Abstract:To provide constructive suggestions for the further improvement of the national standard (GB 4789) by evaluating the current food microbiological examination methods system. Methods The study was conducted by the means of questionnaire surveys in 19 provinces and municipalities which were located in the central and western regions of China. The subjects of the study were mainly the government inspection agencies, the enterprise inspection departments and the third party laboratories. The data was collected through an online system and analyzed by SPSS 22.0 and Microsoft Excel 2013. Results A total of 1 056 valid questionnaires were collected in the survey. The government and the enterprises were the subjects of the investigation. The overall score from different agencies were above 4 within a 5 point scale, and the enterprise inspection department’ score was higher than that of the government inspection agency (P<0.05). It was believed that 93.8% (991/1 056) of the respondents thought that the current standard system could fully or basically meet their needs. In terms of the improvement of standard system, 50.7% (535/1 056) of the respondents thought that it was urgent to revise the sample pretreatment method; in the aspect of increasing specific examine methods, different institutions had different ideas (P<0.05); as for rapid test method, 92.4% (976/1 056) of the respondents thought that it was necessary to include rapid test method in the microbiological examination methods system. Conclusion Food microbiological examination standards (GB 4789) system was frequently used, and the overall evaluation was good. It was suggested that the authorities should make clear the position of the rapid test method in the national food safety standard system and provide guidance for its development.

Abstract:To improve the record system of enterprise food safety standards, and promote the harmonious development of food industry in Hunan Province by studying the status of enterprise food safety standard records. Methods The enterprise food safety standard recorded in Health and Family Planning Supervision Bureau of Hunan Province in 2010-2015 were collected. The time of record, the location of the enterprise, the product category as well as the reasons of refusals were analyzed by SPSS 19.0. Results From 2010 to 2015, totally 5 036 enterprise food safety standards were recorded in Hunan Province, and the average annual increase rate was 35.6%, showing an increasing trend year by year. Among the 29 food categories, most records were the beverage products, accounting for 27.3%(1 377/5 036). Changsha City accounted for 43.5%(2 190/5 036)of the records. The main reasons for unsuccessful application were improper use of raw materials, unmatched “requirements”, no necessity with the existing standards and violation of GB 7718-2011. Improper use of raw materials accounted for the highest proportion(30.2%,42/139). Conclusion In the work of enterprise food safety standard record, more attention should be paid to the preparation of instructions, and more trainings should be carried out for related personnel.

Abstract:To investigate the residue levels of semicarbazide (SEM) in baked foods and assess the dietary exposure and health risk for Shaanxi residents. Methods A total of 160 representative baked foods were collected and determinied with liquid chromatography-electrospray tandem mass spectrometry. The margin of exposure (MOE) method was used to assess the risk of SEM intake from baked foods for Shaanxi residents. Results The average detection rate of SEM in baked foods was 56.3%(90/160) and the highest residue level was 2 364.0 μg/kg. Bread had the highest detection rate of 80.2%(69/86). On the average consumption of baked foods and the content level of SEM, the exposurel of men from different age groupsranged from 0.043 to 0.270 μg/kg BW, and the MOE ranged from 92 734 up to 582 065. The exposure of women from different age groups ranged from 0.045 to 0.232 μg/kg BW, and the MOE ranged from 107 542 to 551 345. At the highest content level of SEM, the MOE of male and femal adults was 68 228 and 64 627, respectively. Conclusion The contamination of SEM in baked foods was quite common but it may cause little health risk for human body.

Abstract:To investigate the distribution and drug resistance of Campylobacter spp. from slaughters and markets in Shijiazhuang City.Methods Chicken samples including anal swab before slaughter, ketones smear, chicken and liver were collected. Campylobacter spp. were isolated and identified according to GB/T 4789.9-2014 and multiplex polymerase chain reaction(PCR)method. The antibiotics susceptibility testing was conducted by the method of Kirby-Bauer with 12 kinds of antibiotics of 6 categories. Results Totally 17 strains of Campylobacter spp. were detected from 439 samples and the detection rate was 3.9%(17/439). The resistance rates of Campylobacter jejuni to nalidixic acid, levofloxacin, ciprofloxacin and tetracycline were 85.7%(6/7).All Campylobacter jejuni isolates were susceptible to gentamicin, streptomycin, amikacin, azithromycin and florfenicol. Furthermore, the resistance rate of Campylobacter coli to azithromycin, doxycycline and florfenicol was less than 50.0%, while was up to 80.0% to ciprofloxacin, levofloxacin, nalidixic acid, gentamicin, amikacin, tetracycline, streptomycin and clindamycin. The multi-drug resistance rate of Campylobacter was 70.6%(12/17), which showed 11 resistance patterns. The drug resistance patterns from market isolates were more than those from the slaughterhouse, and both had different dominant drug resistance profiles. Conclusion There was a certain degree of Campylobacter contamination in the slaughter and market in Shijiazhuang. The multi-drug resistance of the isolates was serious.

Abstract:To provide reference for the prevention and control of food poisoning caused by Vibrio parahaemolyticus by investigating a food poisoning event in a temple. Methods Food poisoning field hygienic investigation, epidemiological investigation and laboratory detection were conducted. Through case control study and statistical analysis, the causes of poisoning and prevention countermeasures were put forward. Results This poisoning confirmed 28 cases, including 24 monks, 4 employees and visitors, and the attack rate of 5.6%(28/500). Field survey on July 20th found cross contamination during dinner process, and there was no difference (P>0.05) between the patients and the others. Patients, including the employees in the cafeteria, anal swab samples and the cooking tools were positive for Vibrio parahaemolyticus of serotypes O3∶K6, which was the cause of food poisoning. The possible explanation was the pathogen carried by the employees in the cafeteria and improper operation during that dinner. Conclusion This incident was a Vibrio parahaemolyticus food poisoning. Relevant departments should pay attention to the food poisoning risk in temple and strengthen the regulatory monitoring and early warning to secure monks and visitors.

Abstract:Risk ranking is one of the most effective risk assessment approaches, which is employed to proceed quantitative classification of risks from different chemical hazards to give a rapid identification and screen the high-risk food and chemical hazards through comprehensive analysis and consideration of the factors including the levels of contamination, dietary exposures, and hazardous effects to public health. This paper reviews the primary published risk ranking frameworks and models including risk ranking matrix, priority index and semi-quantitative food risk classification model, and integrally analyzed the theories of risk ranking, methods and characteristics of different approaches to offer the references of methodology for setting the priority of the chemical hazards in food during the risk management to solve the ranking problem of food risk hazards in practical work and to assiste formulate the specific risk management measures.

Abstract:Mycotoxin contamination in crops and food seriously affects human health, monitoring and prevention of mycotoxin is an important part of food safety assurance system. With the superiorities of rapidness, lable-free, high throughput and sensibility, surface plasmon resonance (SPR) has been widely used in drug screening, food testing, environment monitoring, clinical diagnosis and other fields. In this paper, the application of SPR biosensor in rapid screening of mycotoxins in food was reviewed.