Abstract:Objective To investigate the genomic and virulence characteristics of seven invasive non-typhoidal Salmonella (iNTS) isolates. Methods Based on the collection of seven iNTS strains, whole genome sequencing were performed. The serotypes, genomes and virulence factors were identified, annotated and analyzed according to the comparison of genome data and relevant databases. Results Among the seven tested iNTS isolates, six were monophasic, including one Salmonella Typhimurium and two Salmonella I 4, [5], 12∶i∶-(ST34 type), whose MLST types were ST34 two Salmonella Enteritidis, one Salmonella Corvallis and one unknown serotype with the antigenic formulae of I 4, [5], 12∶d∶- (ST279 type). No consistent rule was found in genomic components and relevant the component parameter differences varies much between different serotypes than those of the same serotype from different sources. The distribution of virulence factors (VF) was significantly different among different Salmonella serotypes, but the common VF characteristics in iNTS strains were not found, though Capsule/Immune evasion, toxin, peritrichous_flagella and Salmochelin may be associated with high invasiveness. All tested isolates contained type III and type VI secretion systems. The number of secretion protein, type III for S. Corvallis and type VI for Salmonella I 4, [5], 12∶d∶-was respectively the highest among the seven isolates. Pseudogenization of the secreted effector SseI may exist among some Salmonella serotypes which may contribute to the enhancement of Salmonella invasiveness. Conclusion The common characteristic differences of virulence factor between iNTS and gastroenteritis NTS were not observed at the moment, and highly invasive pathogenic mechanisms still require further analysis and research at the functional transcriptome and proteomic levels to determine the genetic basis of iNTS occurrence and transmission.

Abstract:Objective To investigate the etiology of a small outbreak of gastroenteritis caused by Vibrio parahaemolyticus in Guangzhou, 2017. Methods Serotype identification, antimicrobial susceptibility test, polymerase chain reaction (PCR) test of virulence genes (tdh, trh, tlh), toxRS/new gene, orf8 gene, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were analyzed. On the basis of epidemiological investigation, the serology, virulence, antimicrobial susceptibility and molecular characteristics of a total of 14samples Vibrio parahaemolyticus samples were tested.Results The serotype O8∶K21 of 14 strains of Vibrio parahaemolyticus was identified. All isolates were sensitive to ceftriaxone, ciprofloxacin, chloramphenicol, cotrimoxazole, sulfonamide complex, amikacin, nalidixic acid, streptomycin, tetracycline and gentamicin, and resistant to apart from ampicillin and trimethoprim. The PCR detection of virulence gene showed that all the strains were positive for tdh (thermostable direct hemolysin) and tlh (themolabile hemolysin), but negative for trh (tdh-related hemolysin), and carried toxRS/new and orf8 genes. According to PFGE cluster analysis, they were considered it was judged to be a highly related strains. According to MLST analysis, the results were all ST479 type. Conclusion The reason for the small outbreak of gastroenteritis was due to Vibrio parahaemolyticus O8∶K21, which shared common genetic characteristics. It harbored the Positive for both the tdh gene which was gene and group-specific polymerase chain reaction is the key characteristic of pandemic strains, and additional surveillance should be conducted to facilitate control of the transmission of this pathogen.

Abstract:Objective To investigate the infection status, main virulence genes and drug resistance of diarrheagenic Escherichia coli (DEC) in the diarrhea population in Huzhou, Zhejiang Province. Methods DECs were isolated from fecal specimens from patients with diarrhea in three sentinel hospitals from 2018 to 2020. All clinical isolates were then further identified using multiplex real-time fluorescence quantitative polymerase chain reaction (PCR). The microbroth dilution method was used for drug sensitivity testing. DECs were isolated from fecal specimens collected from 2018 to 2020 from patients with diarrhea in three sentinel hospitals. All clinical isolates were then further identified using multiplex real-time fluorescence quantitative PCR. The microbroth dilution method was used for drug sensitivity testing. Results A total of 293 DEC positive cases were detected, and 294 strains were isolated. Enteroaggregative Escherichia coli (EAEC) accounted for 55.4% (163/294), and Enterotoxigenic Escherichia coli (EPEC) accounted for 29.6% (87/294). Enteropathogenic Escherichia coli (EPEC) accounted for 11.2% (33/294), Enteropathogenic Escherichia coli (EPEC) accounted for 11.2% (33/294), Enteroinvasive Escherichia coli (EIEC) accounted for 3.4% (10/294) and Enterohemorrhagic Escherechia coli (EHEC) accounted for 0.3%(1/294). The antimicrobial resistance rates of 117 randomly selected strains to AMP ampicillin, NAL nalidixic acid, AMS ampicillin-Sulbactam and TET tetracyclin AMP, NAL, AMS and TET were 70.9%, 60.7%, 53.8% and 51.3%, respectively. The multidrug resistance rate reached 55.6%. The sensitivity rates to IMP imipenem, CAZ ceftazidime, AMC amoxicillin clavulanic acid and CFX cefoxitin IMP, CAZ, AMC and CFX were 99.1%, 92.3%, 92.3% and 91.5%. DEC cases had a peak in July to August, and the main infected population was between 20 and 39 years old. strains of DEC were randomly selected to AMP, NAL, AMS and TET were 70.9%, 60.7%, 53.8% and 51.3%, respectively. The multidrug resistance rate reached 55.6%. The sensitivity rates to IMP, CAZ, AMC, and CFX were 99.1%, 92.3%, 92.3% and 91.5%. DEC cases had a peak in July to August, and the main infected population is between 20 and 39 years old. Conclusion The DEC genotypes of the patients with diarrhea in Huzhou, Zhejiang Province were mainly EAEC and ETEC, with multiple antibiotic resistance. The distribution of cases was obviously seasonal, and the infected population was mainly young adults.

Abstract:Objective To study the toxic effects of Galerina sulciceps on mice. Methods The poisonous mushrooms collected from food poisoning were identified as Galerina sulciceps. The detected α-amanodexin peptide (α-AMA) was 1 690 μg/g. The mice were designed into 4 dose groups of 464,215, 100,46.4 mg/kg BW. After intraperitoneal injection, heart, liver, spleen, lung, kidney, brain, and intestine of mice were taken for pathological diagnosis. ResultsIn animal experiments, the median lethal dose(LD₅₀) of female mice was 108 mg/kg BW (confidence limit:74.1-157 mg/kg BW). The pathology of the liver of mice showed that with the increase of dose, hepatocyte swelling and necrosis, accompanied by bleeding and inflammatory cell infiltration, the pathological changes gradually worsened. Conclusion Galerina sulciceps mainly contains α-AMA, which causes liver damage to humans and animals. Studying the toxic mechanism of Galerina sulciceps has great significance to improve the survival rate of poisoned patients.

Abstract:Objective To investigate the prevalence and drug resistance of Staphylococcus aureus in pig slaughterhouse pigs in He'nan Province. Methods Samples of nasal swabs and body surface swabs under different conditions, along with scalding water and air samples were collected, and were then cultured and inspected for Staphylococcus aureus isolation, through a procedure based on the national standard GB 4789.10-2016. Drug resistance of the staphylococcal isolates were tested by means of microbroth dilution method, following the antimicrobial susceptibility test standard of the American Institute of Clinical and Laboratory(CLSI) standards. Results The result showed that 96 strains of Staphylococcus aureus were isolated from 625 samples, accounting for 15.36%, among which the most positive ones were from samples of pigs to be slaughtered(33.00%,33/100), electronarcosis(25.83%,31/120) and decapitation(22.00%,22/100), while isolation rates were fairly low or even null in samples from depilation body surface, chilling body surface, split half body surface, air and water processes. The drug resistance result indicated that all the 96 Staphylococcal aureus strains presented resistance to the 8 kinds of test antimicrobials, especially florfenicol(98.96%,95/96). Almost all the strains (96.88%,93/96) showed multiple resistance to chloramphenicol, macrolides, lactams, lincoamines and other antimicrobials, and isolates resistant to all 7 kinds of tested drugs as accounted for 34.38% (33/96), and those resistant to 5 or plus drugs 76.04%(73/96). Conclusion There are different degrees of Staphylococcus aureus contamination in some slaughterhouses in He'nan Province, in which the pollution in waiting for slaughtering, hemp electricity and decapitation is more serious, which should be paid more attention. The overall drug resistance of Staphylococcus aureus isolates is serious, and there is a common phenomenon of multiple drug resistance, so the relevant departments need to strengthen the supervision of the use of antibiotics.

Abstract:Objective To establish a recombinase polymerase amplification (RPA) method for the detection of Listeria monocytogenes(L.monocytogenes) in food. Methods Based on the hlyA gene of L. monocytogenes, a set of RPA primers was selected for constructing RPA test, and its specificity and sensitivity were then tested.Results The RPA assay could be finished in 30 min at 37 ℃. The primers used in RPA were specific. Experiments confirmed a detection limit of DNA template as low as 0.5 ng/μL. L. monocytogenes in the artificially-contaminated meat could be detected at the limit of 10⁴ CFU/2.5 g. Conclusion The RPA method for detecting L. monocytogenes has strong specificity and high sensitivity, which is easy to operate, and can be performed under normal temperature without depending on the expensive equipment. It is suitable for field detection and application in the basic laboratory.

Abstract:Objective To develop a plasmid DNA reference material for rapid and comprehensive identification of Listeria monocytogenes. To develop a plasmid DNA reference material for rapid and comprehensive identification of Listeria monocytogenes.Methods The synthetic DNA fragment contained the hlyA, plcB and inlA, which were currently used for the detection of Listeria monocytogenes, was cloned into vector PUC57 to construct the plasmid reference material (pDNA Listeria). The quantity, homogeneity and stability of pDNA Listeria were evaluated by ultraviolet spectrophotometry (UV). real time quantitative polymerase chain reaction(qPCR) was used to evaluate the applicability of pDNA Listeria. The synthetic DNA fragment contains the hlyA, plcB, and inlA, which currently used for the detection of Listeria monocytogenes, was cloned into vector PUC57 to construct the plasmid reference material (pDNA Listeria ). The quantity, homogeneity and stability of pDNA Listeria were evaluated by ultraviolet spectrophotometry (UV). qPCR was used to evaluate the applicability of pDNA Listeria. Results The results showed that the fixed value of pDNA Listeria was 29.85 μg/mL,which had traceable values, reliable homogeneity and good stability.The pDNA Listeria could be staored at -20 ℃ for more than one year. The pDNA Listeria also provided comparable sensitivity and reliability to the genomic references material. The result showed that the fixed value of pDNA Listeria was 29.85 μg/mL,which had traceable values, reliable homogeneity and good stability.The pDNA Listeria could be staored at -20 ℃ for more than one year.The pDNA Listeria also provides comparable sensitivity and reliability to the genomic references material.Conclusion The pDNA Listeria could be used not only to identify Listeria monocytogenes but also to describe the biological characteristics such as virulence, pathogenicity, and invasiveness of Listeria monocytogenes at the same time. Importantly, the study proved the application of rapidly synthesized multiple targets plasmid serving as qPCR standard for pathogen identification. The pDNA Listeria could be used not only to identify Listeria monocytogenes but also to describe the biological characteristics such as virulence, pathogenicity, and invasiveness of Listeria monocytogenes at the same time. Importantly, the study proves the usefulness of rapidly synthesized multiple targets plasmid serving as qPCR standards for pathogen identification.

Abstract:Objective To establish a new quantitative accuracy method for detection of Staphylococcus aureus in food by droplet digital polymerase chain reaction PCR polymerase chain reaction (ddPCR). Methods A pair of primers and probe for both qPCR and ddPCR was selected according to the single copy gene of nuc in Staphylococcus aureus. The specificity, sensitivity, accuracy and repeatability of this method were analyzed. Results The limit of detection (LOD) and limit of quantitation (LOQ) of ddPCR method were determined to be 110 CFU/mL by gradient dilution of pure culture of Staphylococcus aureus. The LOQ of ddPCR was 1 000 CFU/g in the artificial contaminated experiment, and the maximum deviation of detection result of four spiked addition levels was 4.77%, and the coefficient of variation of 5 parallel repeats was less than 20%, showing good accuracy and repeatability. Conclusion The established method has good specificity, high sensitivity and accurate result, which provides a reference for rapid quantitative detection of Staphylococcus aureus.

Abstract:Objective To analyze the familial aggregation of college students′ self-reported food allergy in college students, provide baseline information on the prevalence of food allergy in college students and theoretical basis for preventing, treating and managing food allergy. Methods In 2019, cross-sectional study was done through 2 538 college students from 6 universities in Nanchang selected by multi-stage cluster random sampling. The investigation contents included the food allergy status, main influencing factors and family history of food allergy, etc. Data was analysed statistically with SPSS 17.0 software. Results 2 313 valid questionnaires were collected. The incidence of self-reported food allergy was 15.69%(363/2 313).Most of them was rapid food allergy. About half students did not know about food allergy, and more than 70% of them did not pay attention to food labels. The FA had obvious familial aggregation.There was a significant difference between the incidence of food allergy among students with positive family history and those with negative family history (χ²=28.696, P<0.05).There was a significant difference in the incidence of food allergy between students with one or both parents of food allergy and those without both parents (χ²=26.184, P<0.05).The heritability of food allergy in first-degree relatives (parents) was 44.4%, stratified by exposure to smoke, the heritability of food allergy in first-degree relatives (parents) in smoke environment was 73.8%, and the heritability in smoke-free environment was 15.2%. Conclusion The rate of self-reported food allergy among college students was 15.7%. Food allergy had obvious familial aggregation, which was influenced by genetic factors. The students were lack of understanding of food allergy, so it is necessary to strengthen relevant knowledge publicity and health education among college students.

Abstract:Objective To study the drug resistance characteristics of Salmonella isolated from diarrheal patients in Shunyi, Beijing. Methods Collected stool samples of diarrheal patients in Shunyi, Beijing 2013-2018. Isolation, bacterial identification and serotyping were tested for Salmonella strains. To analyze Drug resistance rate, non-drug sensitivity rate, multi-drug resistance rate and drug resistance profile of Salmonella strains to 26 antibacterial drugs were analyzed by broth dilution test method. Results The prevalence of Salmonella in diarrhea patients was 5.44% (113/2 076). Twenty-six serotypes were identified in 114 Salmonella strains, and the dominate serotypes were Salmonella enteritidis and Salmonella typhimurium with the composition ratio value of 32.46% (37/114) and 27.19% (31/114), respectively. The multi-drug resistance rates of Salmonella spp., S. enteritidis and S.typhimurium were 44.74% (51/114), 67.57% (25/37) and 45.16% (14/31), respectively. Salmonella spp., S.enteritidis and S.typhimurium were distributed 62,29 and 20 kinds of drug resistance profiles, respectively. Conclusion The drug resistance of Salmonella isolated from diarrhea patients was serious, and the distribution of drug resistance profile showed large diversity. It is necessary to continued high-quality pathogenic surveillance of Salmonella, so as to provide basis for scientific prevention and treatment of Salmonella infection.

Abstract:Objective To understand the drug resistance and homology of diarrheagenic Escherichia coli(E.coli), from food in Jiamusi, and to provide basis for effective control of food borne diseases and clinical treatment. Methods Multiple polymerase chain reaction(PCR) was used to detect diarrheagenic E.scherichia coli in food. Drug resistance of diarrheagenic E.coli isolated from food in Jiamusi was analyzed by Sensitire microbial sensitivity analysis system, and the homology of isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Results Fifty one strains of diarrheagenic E.coli were isolated from 1 320 samples with a total positive rate of 3.86%. Twenty one strains of them were resistant to drugs (41.18%), among which 3 were single drug-resistant and other 18 were multi drug-resistant. A total of 49 different PFGE fingerprints were obtained from 51 strains of diarrheagenic E.coli, and the homology was 38.6%～100%. Conclusion The multi drug-resistant of diarrheagenic E.coli from food in Jiamusi is obvious. The homology is polymorphic.

Abstract:Objective To analyze the incidence and epidemiological characteristics of Vibrio parahaemolyticus infection in Liaoning Province, and to provide scientific basis for prevention and control measures. To analyze the incidence and epidemiological characteristics of Vibrio parahaemolyticus infection in Liaoning Province, and to provide basis for the scientific formulation of prevention and control measures. Methods The case information of Vibrio parahaemolyticus infection in Liaoning from 2014 to 2019 was collected, and the stool samples of patients were collected for detection. SPSS 17.0 software was used for statistical analysis. The Mantel-Haenszel was used to calculate the OR and 95%CI of different sex, age, occupation and regions. The case information of Vibrio parahaemolyticus infection in Liaoning from 2014 to 2019 was collected, and the stool samples of patients were collected for Vibrio parahaemolyticus detection. SPSS 17.0 software was used for statistical analysis.The Mantel-Haenszel was used to calculate the OR and 95%CI of Vibrio parahaemolyticus test for deferent patients of the sex, age, occupation, and regions.Results Detection rate of Vibrio parahaemolyticus was 4.37% from 2014 to 2019 in Liaoning Province. There were significant differences in the patients of Vibrio parahaemolyticus among different regions (5.59% and 2.86%, χ²= 87.627, P<0.01), age (χ²=122.612, P<0.01) and occupations (χ² =139.107, P<0.01). 376 cases were between 25 and 44 years old with the proportion of 43.37% (376/867). There were obvious seasonal characteristics, and the peak time of detection rate was in summer. Main exposed food were aquatic animals and their products (52.14%, 390/748), meat and their products (12.97%, 97/748). There were significant differences in the patients of Vibrio parahaemolyticus among different regions (5.59% and 2.86%, χ²=87.627, P<0.01), age (χ²=122.61, P<0.01) and occupations (χ²=139.107, P<0.01). 376 case of patients were between 25 and 44 years old, with the proportion of 43.37% (376/867).There were obvious seasonal characteristics, and the peak time of detection rate was in summer. Main exposed food were aquatic animals and their products (52.14%, 390/748)and aquatic animals and their products(12.97%, 97/748). Conclusion Vibrio parahaemolyticus is one of the important pathogens of foodborne diseases in Liaoning Province. Vibrio parahaemolyticus is one of the important pathogens of foodborne diseases in Liaoning Province.

Abstract:Objective To construct a set of scientific, reasonable and operable index system for municipal food safety supervision, level evaluation index system, to provide a reference for the precise evaluation of food safety supervision level of various cities. Methods Based on the experience of establishing food safety demonstration counties in Zhejiang province, the evaluation index system was determined by using balanced scorecard theory and network analytic hierarchy process (AHP) through field research method, literature and expert interview. The system was applied to evaluate 11 cities in Zhejiang province. Results The weights of the four first-level indicators of work performance, relevant stakeholders, internal management and learning and growth are 0.107 6,0.343 9,0.488 3 and 0.062 1 respectively. Under the first-level indicators, there are 10 second-level indicators and 51 third-level indicators. The evaluation result of 11 cities are consistent with the evaluation result of Zhejiang food safety work in 2020. Conclusion The evaluation index system can scientifically and objective ly evaluate and reflect the level of food safety supervision in each city.

Abstract:The risk assessment and risk management of new substances in food contact materials (FCMs) are of great significance for ensuring food safety and promoting industry innovation. This study compares the advantages and disadvantages of FCMs risk management institutions, regulatory framework, raw material management mode and risk assessment of new substances to be used in FCMs in China and the EU, sorts out the strengths of the EU mode, and makes recommendations for optimizing the risk assessment and risk management mode of new substances to be used in FCMs in China.

Abstract:Objective To analysed nutritious and harmful elements found in liquid milk marketed in different regions across China, analyzed the intake of elements from drinking milk, assessed exposure to elements and health risks in adults, and provided basis for relevant standards. Methods As many as 110 milk samples were collected in seven geographic regions across China. A total of 15 elements, Mg, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd and Pb, were determined with microwave digestion - inductively coupled plasma mass spectrometry to analyze regional differences. Recommended Nutrient Intake (RNI) and Adequate Intake (AI) were used to assess nutrition status while Margin of Exposure (MOE) and Provisional Tolerable Monthly Intake (PTMI) were used to assess health risks. Results The result showed that milk generally has high level of Ca (430-939 mg/kg). The levels of 9 elements, namely Fe, Cr, Co, Mn, V, Ni, Pb, As and Cd, varied geographically. The measured concentrations of As, Pb and Cr in liquid milk were all lower than the limits of the Chinese standards. According to the result of exposure assessment, the RNIs of Mg, Ca, Se and Mo were higher than 10%. The MOE of Pb was much higher than 1. The PTMI of Cd was lower than 0.1 μg/kg BW/month, and the MOE of Ni was much higher than 10. Conclusion Milk contains abundant nutritious elements and is an important supplementary to human nutrition. In addition, milk generally contains low levels of harmful elements, which poses low risk to human health.

Abstract:Objective To understand the consumption, free sugar intake and its energy proportion ration of baked food among urban residents aged 3 and above in China. Methods According to stratified multistage cluster random sampling,this study selected the consumption of baked food of 13 083 people aged 3 and above in 18 provinces in China by three non-consecutive 24 h dietary recalls. The data of sugar content in baked food comes from the special monitoring of baked food carried out by China National Center for Food Safety Risk Assessment. The simple distribution model was used to calculate individual free sugar intake and its energy proportion ratio of baked food per day. Results The consumption rate of baked foods of urban residents aged 3 years and above in China was 24.11%, with that of women (25.69%) was slightly higher than that of men (22.42%). With the increase of age, the overall consumption rate of baked foods in all age groups showed a downward trend,with the highest consumption rate in the group of 3-5 years old (39.09%), and the lowest consumption rate in the group of over 60 years old (17.57%). The average consumption of baked foods in general population was 10.25 g/d, which was slightly higher in women than that in men (10.58 g/d and 9.92 g/d, respectively);the average consumption of baked foods in 13-17 years old group was the highest, which was 16.36 g/d, followed by 6-12 years old group and 3-5 years old group, which were 15.22 g/d and 13.25 g/d respectively. The average free sugar intake via baked foods among general population was 1.54 g/d, and its energy proportion ratio was 0.37% (0.37%TE), which was higher in women than that of men (1.60 g/d, 0.41%TE, 1.47 g/d, 0.33% TE, respectively);The highest intake of free sugar was 2.21 g/d (0.52% TE) in 13-17 years old group, followed by 2.14 g/d (0.59%TE) in 6-12 years old group and 1.94 g/d (0.65% TE) in 3-5 years old group. The average energy proportion ratio of baked foods among consumers was 1.53%TE (1.43%TE-1.67%TE), and the P₉₅ value of consumers was 3.86%. The average free sugar intake of general population via bread and pastry was 0.68 g/d and 0.73 g/d respectively, which was much higher than that of biscuit 0.13 g/d. Conclusion The consumption rate, free sugar intake and free sugar energy proportion ratio via baked foods among Chinese urban residents aged 3 and above were all higher in woman than men, and the level of free sugar intake through baked food was low. When it comes to reducing the sugar content of baked foods, it is suggested to focus on the people aged 3-5,6-12 and 13-17, and focus on bread and pastry.

Abstract:Objective To analyze the current status of the use of salt and condiments in restaurant dishes in 6 provinces, including the use rate, usage amount and sodium contribution rate of salt and condiments in restaurant dishes. Methods The data is from the composition information of 8127 dishes in 192 restaurants in the baseline survey of “Action on Salt China-Restaurant Salt Reduction Project”. The median and quartiles are used to describe the use of salt and condiments in dishes and its sodium content. The usage rates of salt and condiments in dishes were compared by chi-square test, and the usage was compared between groups using Kruskal-Wallis nonparametric test. Results The usage rates of salt and condiments in the surveyed dishes in the 6 provinces surveyed exceed 50% and 25% respectively. The median amounts of salt, chicken essence/MSG, chicken powder, soy sauce, and other condiments in the dishes were 0.82 g/100 g, 0.86 g/100 g, 1.42 g/100 g and 3.66 g/100 g. The median sodium content of total sodium and salt in dishes, chicken essence/monosodium glutamate/chicken powder, soy sauce and other seasonings are 505.89 mg/100 g, 322.22 mg/100 g, 106.72 mg/100 g, 86.46 mg/100 g and 2.57 mg/100 g. Sodium in restaurant dishes is mainly from condiments (85%-90%), of which salt is the condiment with the highest sodium contribution, rate, accounting for 32%-58%. Conclusion The use of salt and condiments in restaurants is different among 6 provinces. Targeted strategy should be adopted to reduce salt as well as reducing the use of other condiments, in order to control the total sodium content in restaurant dishes.

Abstract:Objective To understand the trend and influencing factors of vitamin A status among students from the pilot area of the “Nutrition Improvement Program for Compulsory Education Students in Rural Areas”( Shorten as “Program”) in Hainan Province from 2014 to 2017. Methods From 2014 to 2017, a total of 2 603 students were selected from Qiongzhong county in Hainan Province through stratified cluster random sampling method. The serum retinol and other indicators were detected and questionnaire survey were carried out. Results In 4 years, the average serum retinol concentration of students was (333.4±81.9)-(370.9±88.1) ng/mL, with an overall variation trend of decline and then increase (P<0.05 ) ; The subclinical vitamin A deficiency (SVAD) rate of students was 18.0% to 31.5%, which increased first and then decreased (P<0.05) ; and the vitamin A deficiency (VAD) rate was 0.8% to 2.0%, without significant change in 4 years (P>0.05). From 2014 to 2017, The serum retinol concentration of junior high school students was higher than that of primary school students (P<0.05), except for 2015, there was no statistically significant difference between different genders (P>0.05) ; and the SVAD rate of junior high school students was lower than that of primary school students (P<0.05). The minority nationality (OR=2.290) and anemia (OR=2.373) were risk factors for SVAD or VAD, the junior middle school students (OR=0.235) and daily outdoor activity time≥30 min (OR=0.554) were protective factors. Conclusion The nutritional status of vitamin A among students in the region had been improved, but the SVAD was still a striking problem, the minority nationality and pupils were at higher risk, and improving anemia and increasing outdoor activity might help reduce the risk of SVAD or VAD in students. To understand the trend and influencing factors of vitamin A status among students from the pilot area of the “Nutrition Improvement Program for Compulsory Education Students in Rural Areas” (Shorten as “Program”) in Hainan Province from 2014 to 2017. Methods From 2014 to 2017, a total of 2 603 students were selected from Qiongzhong county in Hainan Province through stratified cluster random sampling method. The serum retinol and other indicators were detected and questionnaire survey were carried out. Results In 4 years, the average serum retinol concentration of students was (333.4±81.9) ～ (370.9±88.1) ng/mL, with an overall variation trend of decline and then increase(P<0.05); The subclinical vitamin A deficiency(SVAD) rate of students was 18.0% to 31.5%, which increased first and then decreased (P<0.05); and the vitamin A deficiency(VAD) rate was 0.8% to 2.0%, without significant change in 4 years(P>0.05). From 2014 to 2017, The serum retinol concentration of junior high school students was higher than that of primary school students (P<0.05), except for 2015, there was no statistically significant difference between different genders (P>0.05); and the SVAD rate of junior high school students was lower than that of primary school students (P<0.05). The minority nationality (OR=2.290) and anemia (OR=2.373) were risk factors for SVAD or VAD, the junior middle school students (OR=0.235) and daily outdoor activity time≥30 min (OR=0.554) were protective factors. Conclusion The nutritional status of vitamin A among students in the region had been improved, but the SVAD was still a striking problem, the minority nationality and pupils were at higher risk, and improve anemia and increasing outdoor activity might help reduce the risk of SVAD or VAD in students.

Abstract:Objective To summarize the differences of food allergen labeling requirements between China and other countries/regions. To investigate the occurrence of food allergy and the public awareness of food allergen labeling, and make suggestions on food allergen labeling management. Methods Laws and standards related to food allergen labeling of some countries/regions were collected and a questionnaire survey was conducted among consumers, and 5 975 survey reports were collected and analyzed. Results The current food labeling requirements of allergens in China are relatively loose, and consumers have obvious demands on the labeling of food allergen. Conclusion Mandatory labeling of allergens in food should be implemented to improve the management of labeling of allergens in food.

Abstract:Objective To study the implementation of food recalls managed by U.S. Food and Drug Administration (FDA) and explore experiences for the food recalling in Chinaour country. Methods Food recall information was collected from FDA website. The information was analyzed by EXCEL 2013. Results Information including 461 recall events and 1734 types of food were obtained from the weekly enforcement reports in 2019. Sixty percent of the recalls were class Ⅱ. About one third of recalls were class Ⅰ. Milk products were the most frequently recalled food, accounted for consisting of 17.88% of the total recalling food. Microbiology contamination was the main recall reason, resultsing in 31.45% of recall events and 37.89% of recall food types. Not notifying allergen was responsible for 35.01% of the recall events, which was the highest proportion among the reasons. The proportion of recall food types caused by not notifying allergen was only 18.40%. Inappropriate proceeding resulted in 3.47% of recall events and 24.63% of recall food types, respectively. More than 99% of the recalls were carried voluntarily by food firms except 4 mandatory recalls by FDA. Conclusion Food recall is implemented efficiently in America. FDA publishes food recall information and makes it easily obtainable to public. Manufacture process monitoring is a high efficiency food safety managing measure. Food firms have strong conscientiousness to recall defective food voluntarily. It’s important to promote the participation of the public, transfer the traditional end-product managing model, and cultivate the conscientiousness of the firms for the implementation of food recall in China.

Abstract:Follow-up evaluation of food safety standard is an important legal system determined by the Food Safety Law of the People's Republic of China. This paper discusses the situation of follow-up evaluation of food safety standard in Zhejiang Province, and analyzes the current situation and main problems of food safety standard follow-up evaluation. Countermeasures and suggestions are put forward in order to maximize the role of follow-up evaluation in food safety management.

Abstract:Objective Analyze the food safety standard management of food additives nitrate and nitrite used in meat products. Analyze the food safety standard management of food additives nitrates and nitrite used in meat products.Methods The future direction of national food safety standard management is discussed through the analysis of the standards of Codex Alimentarius, the United States of America, Canada, the European Union, Australia, New Zealand, Japan, Republic of Korea and China, combined with risk assessment results, monitoring data and food poisoning incident data. Through the analysis of the standards of Codex Alimentarius, the United States of America, Canada, the European Union, Australia, New Zealand, Japan, Republic of Korea and China, combined with risk assessment result, monitoring reports and food poisoning incident data analysis, to discuss the future direction of national food safety standard management.Results From the perspective of process control, operability of final product testing and practical detection at import-export ports, the United States of America, Canada, Australia and New Zealand set the maximum use level, while Japan and the Republic of Korea set the maximum residual level. At the same time, the European Union sets the maximum use level or residual level according to the specific food products. China sets both the maximum use level and the residual level, and the N-dimethyl nitrosamine is regulated as pollutant in the corresponding food categories. The dietary exposure result indicates that nitrate and nitrite used as food additives have a low contribution to dietary exposure, therefore they pose low food safety risks to the public. From the perspective of production and processing process control, operability of final product testing, or practical detection at import and export ports. The United States of America, Canada, Australia and New Zealand set the maximum use level, while Japan and the Republic of Korea set the maximum residual level. At the same time, the European Union set the maximum use level or residual level according to the specific food products. China set both the maximum use level and the residual level, and the N-dimethyl nitrosamine is regulated as pollutant in the corresponding food categories. The dietary exposure result indicated that nitrate and nitrite used as food additives have a low contribution to dietary exposure, therefore they pose lower food safety risks to the public.Conclusion Although maintaining the maximum use level and residual level of nitrate and nitrite in the food safety standard is in line with the process control principles and actual regulatory requirements, it is still recommended to continue to carry out research on improvement of food processing technology and alternatives of these food additives, and it is necessary to go on promoting food safety education for consumers and catering industry to prevent food poisoning caused by misuse of nitrites and nitrates. Although maintaining the maximum use level and residual level of nitrate and nitrite in the food safety standard is in line with the process control principles and actual regulatory requirements, it is still recommended to continue to carry out research on improvement of food processing technology and alternatives of these food additives, and it is necessary to go on promoting food safety education for consumers and catering industry to prevent food poisoning caused by misuse of nitrites and nitrates.

Abstract:Objective To analyze the causes and suspicious risk factors of an outbreak of foodborne diseases involving several kindergartens in Ji'nan City, so as to provide basis for strengthening the prevention and control of foodborne diseases in schools. Methods Field epidemiological method was used to investigate the cases, descriptive epidemiological method and cohort study method were used to analyze the data and factors of the outbreak. Results A total of 195 children from 11 kindergartens in four districts of Jinan City were involved. The incidence rate was 17.06%. The age range was 3~6 years old. The ratio of male to female was 1.41∶1 (114/81), no staff got sick. The result of cohort study showed that drinking XX brand pasteurized milk increased the risk of disease by 17.06% (RD=17.06,95% CI:15.01,19.11). Further statistical analysis showed that the rate difference (RD) value of drinking XX brand pasteurized milk on August 9 was 2.82%-35.44%, which was statistically significant, suggesting that drinking XX brand pasteurized milk increased the risk of disease by 2.82%-35.44%. Bacillus cereus was detected in 13 vomit samples and 8 pasteurized milk samples from kindergartens, and the count of Bacillus cereus in 8 milk samples was more than 10⁵ CFU/g, which confirmed that XX pasteurized milk was contaminated by Bacillus cereus. Conclusion The outbreak of foodborne diseases was caused by pasteurized milk contaminated by Bacillus cereus. It is necessary to further strengthen food safety supervision and foodborne disease monitoring in schools, and actively carry out health education to effectively prevent the occurrence of such events.

Abstract:Objective To understand the characteristics of foodborne pesticide poisoning incidents in China from 2002 to 2017, and provide scientific basis for relevant departments to formulate prevention strategies for foodborne pesticide poisoning. Methods The domestic literature and national monitoring data were collected and sorted out, and the repeated incidents were excludedeliminated. The poisoning factors, foods with different causes and occurrence links were analyzed descriptively, and multi-dimensional attribution analysis on this basis was analyzed. Results The main cause of pesticide poisoning was organophosphorus pesticide poisoning (361 cases, accounting for 64.23%), followed by carbamate pesticides and herbicides. The main causes of food were vegetables, grains, and fruits, accounting for 33.45% (188/562) and 14.41%(81/562), 8.36%(47/562). The triggering facter link is mainly caused by excessive pesticide residues (200 cases, accounting for 35.59%). Conclusion Organophosphorus residues in vegetable were the main cause of food-borne pesticide poisoning. The management of pesticides (especially insecticides) should be strengthened, and pesticide safety education should be popularized to the public to minimize the risk of disease.

Abstract:Objective Analyze Through the collation and analysis of the surveillance data of foodborne diseases in Guiyang City from 2015 to 2019, in order to understand the characteristics and regularity of foodborne diseases in the region. Methods The surveillance data were statistically analyzed according to the time of onset, age, occupation, place of occurrence,food packaging mode and regional distribution. Results A total of 4 335 cases of foodborne diseases were reported in Guiyang surveillance hospital from 2015 to 2019. The period from June to October is the high incidence period of foodborne diseases, which accounts for 59.22% (2 567/4 335) of the total reported cases.Infant and farmers are high-risk groups of foodborne diseases, mainly aged 0-3 years and 18-59 years old, accounting for 71.79% (3 112/4 335). The main place of occurrence was family, accounting for 67.14% (2 785/4 148), followed by catering service institutions. Most of the food processing and packaging method were home-made, accounting for 48.29% (2 006/4 154), and mixed food accounted for 34.11% (1 417/4 154). The second was fungi and their products 25.16% (1 045/4 154). The top three districts of high reported cases in Guiyang were Nanming, Huaxi and Yunyan, total accounting for 50.77% (2 201/4 335). Conclusion The season of high incidence of foodborne diseases in Guiyang was in hot seasons, and families and food service organizations were the high-risk places. Food safety supervision and health education should be further targeted to prevent and control the occurrence and prevalence of food-borne diseases.

Abstract:As the incidence of global food allergies increases year-by-year, food allergic diseases have become a growing concern in food safety and public health issue circles. In this paper, the characteristics of food allergens, allergenicity mechanism, clinical manifestations, common allergenic foods, and main exposure sources were introduced. The formulation method and the latest adjustment of food allergen threshold and reference dose were summarized, and several internationally recognized risk assessment method of food allergens were also summarized, which provides the theoretical basis for the next step of food allergy risk assessment in our country.

Abstract:A balanced and adequate diet is the key point to ensure healthy development of children's brains, physical health, and immunity in early life. Infant nutritional status is affected by many factors, among which complementary feeding is most important. In this paper, we reviewed the definition and assessment method of complementary feeding patterns, the prevalence of Chinese complementary feeding patterns and existing problems,, the research progress of the relationship between patterns of complementary feeding and nutritional status. and the limitation and future study of complementary feeding. Previous studies showed that the malnutrition status and qualified complementary feeding patterns of infants and young children in poor areas need improvement. And there is almost no research focus on introducing different types of a specific food, the number of food types and the amount of feeding. There is still a lack of research on the patterns of complementary feeding and its effect on the nutritional status of infants. Few studies focus on the causes of the complementary feeding patterns, such as the patterns of complementary feeding and its associated factors for breastfed and non-breastfed infants. The relationship between the characteristics of complementary foods and nutritional status of infants, and the overall analysis of risk factors of complementary foods.