Abstract:All substances that may migrate from food contact materials (FCM) into foods need to be evaluated, including intentionally added substance (IAS), such as monomers, starting materials and additives, as well as non-intentionally added substances (NIAS), such as impurities, by-products and degradants produced during production process. The safety assessment of FCM can be mainly divided into pre-market safety evaluation and post-market monitoring evaluation. At present, there are mainly two approaches to do the pre-market safety evaluation, that is, the United States approach and the European Union approach. The two method have their own advantages and disadvantages. China has no basic parameters to do pre-market safety evaluation of FCM. Establishment of China FCM safety assessment system is an important project determined by National Expert Committee on Food Safety Risk Assessment. This paper describes the frame of FCM safety assessment system, its expected goals and the challenges of FCM risk assessment.

Abstract:Objective This study was to understand the whole genomic characteristics of a foodborne pathogen Burkholderia gladioli pv.cocovenenans strain Co14, and also to predict and analyze the biosynthesis genes of its virulence factors bongkrekic acid (BA) and toxoflavin (TF). Methods The whole genome sequencing of Co14 was sequenced by the third generation high-throughput sequencing technology (PacBio).The biosynthesis genes of BA and TF were predicted by BLAST in the whole genome sequences. Results Two independent closed circle chromosomes were found in the whole genome sequence of Co14. The lengths of the two chromosomes were 4.1 and 4.0 Mb and their GC contents were 67.82% and 68.32%, respectively. A 146 kb completed plasmid was found in the genome, which GC content was 63.25% and it encoded 149 genes. In the sequence of chromosomes 1, BA biosynthesis related gene cluster bonR1R2LJKFGABDEHIM and TF biosynthesis related gene cluster toxRABCDE were found. Conclusion The whole genome sequence of Co14 laid a genetic foundation for further study of the pathogenicity and virulence factor biosynthesis mechanisms of foodborne pathogen Burkholderia gladioli pv.cocovenenans.

Abstract:Objective Based on the sequence-related amplification polymorphism (SRAP) technology and the sequence similarity of internal transcribed space(ITS),β-tubulin and combined with morphological identification method, the phylogenetic relationships of different species of Monascus were inferred and a reliable method for rapid and accurate identification of Monascus was developed. Methods Using the Monascus genome as template, ITS and partial β-tubulin gene sequence were amplified and sequenced.Phylogenetic tree was constructed by using the maximum likelihood method with Mega 7.0 software. SRAP specific binding sequences were also amplified and the phylogenetic tree was built by using unweighted pair-group method with arithmetic means(UPGMA) algorithm with FigTree software in R phangorn package. A rapid and reliable identification method was built by analyzing the phylogenetic relationships of different species of Monascus. Results Combined with phenotypic analysis and two molecular identification method,16 strains of Monascus was identified as Monascus anka, Monascus aurantiacus and Monascus purpureus. Conclusion SRAP identification method had more detailed classification basis and could identify Monascus species quickly and accurately when combined with phenotypic analysis.

Abstract:Objective To summarize and analyze the molecular typing and drug resistance trends of Salmonella Derby(S.Derby)in Sichuan Province during the past 10 years from 2007 to 2016, so as to understand the contamination status of S.Derby in Sichuan, and provide reference data for outbreak warning, traceability investigation and antibiotic use strategy. Methods Using pulse field gel electrophoresis(PFGE)and micro broth dilution to test the molecular typing and susceptibility of 14 antibiotics for 106 strains of S.Derby from Sichuan Province from 2007 to 2016, which were isolated from clinical patients, food practitioners, food poisoning outbreaks, breeding animal and retail food. Results Result showed that 106 strains of S.Derby had different levels of resistance to 14 kinds of antibiotics. The resistance rates of human and animal source strains to tetracycline, nalidixic acid, chloramphenicol and compound sulfonamide were all above 20%. The resistance rates of human source strains to cefotaxime, ciprofloxacin, ampicillin, ampicillin/sulbactam and cefazolin were higher than those of animal source. The resistance rates of animal source strains to tetracycline, nalidixic acid and chloramphenicol was higher than that of human source. A total of 106 strains of S.Derby were divided into 67 PFGE patterns by digestion with Xba I. The clinical patients food practitioners and retail raw pork isolates from different years had the same PFGE pattern. Conclusion The situation of drug resistance of S.Derby isolates in Sichuan was rather serious with an increasing trend. PFGE types were diverse. The clinical patients food practitioners and retail raw pork isolates from different years had the same PFGE pattern.

Abstract:Objective To understand the prevalence of antibiotic susceptibility, virulence and antibiotic resistance associated genes of 4 kinds of bacteria in a pig farm in Shaanxi Province. Methods Eighty five Escherichia coli, 93 Enterococcus, 33 Salmonella and 7 Staphylococcus aureus isolates that recovered from a pig farm in Fufeng County, Shaanxi Province, from 2015 to 2016, were tested for their susceptibility to 14 antibiotics by disk diffusion method. Some antibiotic resistance associated genes in Enterococcus and Salmonella, and some virulence genes in Enterococcus and S.aureus were detected by polymerase chain reaction (PCR). Results All S.aureus isolates were susceptible to gentamicin, amikacin, amoxicillin/clavulanic acid, cefoperazone and ceficidin. The rate (100.00%,7/7) of nalidixic acid resistant for S.aureus isolates was significantly (χ²=54.77,P<0.05) higher than that of other antibiotics tested for. All Salmonella isolates were sensitive to amoxicillin/clavulanic acid, cefoperazone and cefoxitin. The rates of trimethoprim/sulfamethoxazole (100.00%,33/33) and tetracycline (96.97%,32/33) resistant Salmonella isolates were significantly (χ²=5.83,P<0.05) higher than those of the remaining 9 antibiotics tested for. Seventy-four E.coli isolates resisted to tetracycline, and the rate (87.06%,74/85) of tetracycline resistant was significantly (χ²=4.68,P<0.05) higher than that of other 13 antibiotics screened for. The rates of amoxicillin/clavulanic acid and cefoxitin resistant E.coli isolates were lower than other antibiotics. The rate (97.85%, 91/93) of trimethoprim/sulfamethoxazole resistant Enterococcus isolates was the highest.The detection rate(47.13%,41/87)of aph(3′)-Ⅲ gene in Enterococcus isolates was the highest. The detection rates of aadA1 and aadA2 in Salmonella isolates were the highest, both were 84.85% (28/33). The detection rate(50.57%, 44/87)of Enterococci isolates virulence gene asal was the highest. The detection rates of sea, see and seb genes in S.aureus isolates were 42.86%(3/7), 42.86%(3/7) and 14.29%(1/7), respectively. Conclusion Antibiotic resistance situation of the 4 kinds of bacteria in the pig farm in Shaanxi Province was quite serious, and the majority of the isolates carried antibiotic resistance associated genes and virulence genes. The antibiotic application and monitoring should be strengthened to ensure the safety of pork from the source.

Abstract:Objective To study the etiological characteristics of Yersinia enterocolitica (Ye)isolated from diarrheal patients and household refrigerators, and to provide basis for scientific prevention and control of Ye. Methods Stool samples were collected from diarrhea patients from two outpatients in two hospitals in Shunyi District, Beijing in 2017.Smear samples were collected from 83 household refrigerators in Shunyi District.Ye was isolated and cultured, and the isolated stains of Ye were tested for toxin genes,pulsed field gel electrophoresis (PFGE) molecular typing and drug resistance tests. Results The positive rate of Ye was 0.27% (1/372) in stool samples of diarrhea patients and 6.02% (5/83) in household refrigerators. The strains isolated from refrigerators only carried the ystB gene and the strains isolated from diarrhea patients carried ail,ystA, virF and yadA genes. Six Ye strains showed 4 PFGE patterns with a low similarity.All Ye strains were resistant to ampicillin, amoxicillin/ clavulanic acid and cefazolin,and the Ye strain isolated from diarrhea patient was resistant to nalidixic acid. Conclusion The prevalence of Ye was not high in the patients of diarrhea in Shunyi District of Beijing.Ye contaminationin household refrigerators was more serious.Ye pathogenic characteristics in environment and diarrhea patient were different.

Abstract:Objective To establish a rapid identification method of Vibrio alginolyticus using matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). Methods The effect of different sample pretreat method (direct smear method and formic acid extraction method), laser intensity and times of subculture on the quality of spectrum was investigate using the reference strain CICC 10889. The impact of database on identification result was evaluate by comparing the identification result (species and Logscore) of 36 isolated strains before and after adding the main spectra product (MSP) of CICC 10889 to the database. Results The formic acid extraction method was better than the direct smear method. Spectra of ethanol/formic acid treatment got more characteristic peak of protein with smooth baseline,less noise and higher signal-noise ratio. Laser intensity could affect spectra. High quality spectra could be obtained when the laser intensity was appropriate. Database was the most important impact factor. The Logscore of identification result was improved greatly by adding the in-house database, score of isolated strains were all above 2.300. Times of subculture had no effect on spectra. Conclusion MALDI-TOF MS could accurately identify Vibrio alginolyticus to the species level. The established MALDI-TOF MS method was accurate and constant and could be used to identify Vibrio alginolyticus rapidly.

Abstract:Objective To develop a method for Vibrio vulnificus(V.vulnificus)detection from aquatic products for the contamination monitoring. Methods The selective medium specific for V.vulnificus detection was optimized by inoculating 18 V.vulnificus strains and common competing flora in aquatic products into 8 selective enrichment broth and 4 selective plates. Then the method was established and validated which was combined polymerase chain reaction(PCR) method with enrichment culture method for detecting V.vulnificus through comparing the performance of these two method. And the method was applied to V.vulnificus detection from Beijing commercial aquatic products for the contamination monitoring. Results The modified selective enrichment broth was applied to V.vulnificus detection. The isolation rate in Beijing retail aquatic products was 15.7%(18/115).Isolation rate in shellfish products was 23.4%(15/64). Isolation rate in crab products was 8.3%(1/12). Isolation rate in fish products was 5.3%(1/19). Isolation rate in shrimp products was 5.0%(1/20). Conclusion The method that combined PCR with traditional enrichment culture method exhibited a better isolation rate. A higher contamination rate of V.vulnificus in shellfish products was found which should be paid attention to.

Abstract:Objective To develop a real-time reverse transcription polymerase chain reaction (RT-PCR) method for detection of Norovirus GⅡ (NoV GⅡ) in water. To survey NoV GⅡ in 10 water samples. MethodsNitrocellulose membrane and PEG precipitation were used to enrich virus in bottle water, river and sewage samples, and real-time RT-PCR method was developed. The recoveries from MS2 spiked samples were used to evaluate the effect of the established method. Results The average recoveries of bottle water, river and sewage samples were (60.1±8.0)%, (22.0±6.5)% and (35.7±8.1)% respectively. Three in 10 submitted water samples were positive for NoV GⅡ. Conclusion A real-time PCR method for detection of NoV GⅡ in water sources was developed in this study. NoV G Ⅱ was one of the reasons of the poisoning incidents.

Abstract:Objective To establish a reliable pretreatment method for olaquindox and its metabolite methyl-3-quinoxaline-2-carboxylic acid (MQCA) in milk with ultra performance liquid chromatography-tandem mass spectrometry. Methods The sample was hydrolyzed by hydrochloric acid and extracted by ethyl acetate-acetonitrile (1∶1, V/V), then the concentration was analyzed directly or after PAX and PEP cartridge purification. The objective compounds were separated using Inertsil ODS-3 column (2.1 mm×100 mm, 3 μm) with acetonitrile-water (0.05% ammonia) as mobile phase and analyzed by mass spectrometry in the positive electrospray ionization under multiple reaction monitoring mode(MRM). Results The result showed that direct concentration had good recovery. The detection limit of olaquindox was 0.06 μg/kg, limit of quantitation was 0.20 μg/kg, the average recoveries or spiked levels of 0.20,1.00,5.00 μg/kg were 69.8%,111% and 97.4%. The detection limit of MQCA was 0.02 μg/kg, the limit of quantitation was 0.10 μg/kg,the average recoveries for spiked levels of 0.10,1.00,3.00 μg/kg were 75.8%, 112%, 117%. Conclusion The method was suitable for the detection of olaquindox residual in milk.

Abstract:Microorganisms are widely used in food industry during the production process of food and food additives.The safety of the strains are directly related to food safety and public health. Pathogenicity is one of the important evaluation indicators for the safety of the strains. It is also required in the application of novel food and new food additives related to microorganisms in China, but there is no standard method for safety evaluation so far.This paper reviews the regulations in pathogenicity evaluation of strains from international organizations and other countries in food, feed, etc. which will provide useful informations for the development of appropriate safety evaluation method in China.

Abstract:Objective To understand the contamination of 4 alternaria toxins in wheat flour sold in Henan Province in 2016-2017. Methods Totally 182 wheat flour samples were collected from 9 cities in the main grain producing areas of Henan Province from 2016 to 2017.The samples were detected with national handbook for monitoring food contamination and hazardous factors.The data were analyzed by chi-square test and correlation analysis. Results Among the 182 samples of wheat flour in 9 regions, 4 kinds of alternaria toxins were all detected.The detection rate of alternariol (AOH) was 10.4%(19/182)with concentration range from 0.50 to 14.21 μg/kg; the detection rate of alternariol methyl ether (AME) was 42.9%(78/182) with concentration range from 0.05 to 38.73 μg/kg; the detection rate of tenuazonic acid (TeA) was 91.2%(166/182) with concentration range from 0.50 to 134.23 μg/kg and the detection rate of tentoxin (TEN) was 45.6%(83/182) with concentration range from 0.05 to 17.42 μg/kg. Conclusion The contamination of the alternaria toxins of wheat flour in the circulation link (farm trade market and store) was exit in Henan Province, but the level of contaminationwas lower than reported in the literature.

Abstract:Objective A quality control assessment was conducted to assess the Salmonella qualitative detection capability of responsible unit in inspection institutions of food safety risk monitoring system in China, and to fully understand Salmonella serotyping ability of monitoring laboratories at different level, in order to guarantee reliable detection data and isolates, and enhance the monitoring quality. Methods Bacterial samples including 6 different common Salmonella serovars and negative control were prepared with substrate samples, and distributed to 435 participates after stability test. The result were evaluated with point-score system and ratios were analyzed with Pearson χ² test. Results A total of 431 reports were received from the participate laboratories, 72.6% (313/431) of which were all correct, and the overall satisfaction rate was 92.6% (399/431). The main category for the dissatisfaction was the false positive of the negative samples(7.4%,32/431). The satisfaction rate of county participates(80.0%,52/65)was lower than provincial(100.0%,32/32)and prefecture level(94.3%,315/334). The correct rate of serotyping section was 80.7% (348/431). There was no significant difference in the correct rate of serogroups between different levels (P>0.05), but the correct rate of serotypes in prefecture-level laboratories was lower than that of provincial or even county level participates. Conclusion This assessment indicates that ability of Salmonella qualitative detection at all levels of task-undertaking units in inspection institutions can basically meet the requirements, however, some laboratories need to improve quality control in order to strengthen ability of Salmonella detection. A continuing need for improvement on serotype identification still existed among laboratories below provincial level. This quality control assessment could play a role in providing a data basis for training in inspection institutions.

Abstract:Objective To investigate the natural occurrence of hexadepsipeptides mycotoxins, including beauvercin (BEA), enniatins (ENNs)of enniatin A (ENA), enniatin A₁ (ENA₁), enniatin B (ENB), and enniatin B1 (ENB₁) in corn and corn-based samples collected from Shandong Province in 2017. Methods One hundred and fifty-eight corn and corn-based samples were collected from the east, west, south, and central district of Shandong in 2017. The samples were extracted with acetonitrile-water(85∶15, V/V), cleaned up with solid phase extraction column, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) detection of the concentrations of 5 mycotoxins. Results BEA was the predominant mycotoxin in 158 samples, and the positive rate and the average level of BEA were 82.3% (130/158) and 65.26 μg/kg. The positive rates and the average levels of 4 ENNs were 55.1% (87/158) and 0.28 μg/kg for ENA, 8.2% (13/158) and 0.62 μg/kg for ENA₁,3.8% (6/158) and 1.19 μg/kg for ENB, 56.3% (89/158) and 0.13 μg/kg for ENB₁. The average levels of the 5 mycotoxins in corn kernels, corn flour and corn flakes were 46.96,6.45 and 0.17 μg/kg for BEA, 0.13,0.35 and 0.06 μg/kg for ENA, 0.14,0.76 and 0.00 μg/kg for ENA₁,0.23,2.15 and 0.00 μg/kg for ENB, 0.21,0.15 and 0.08 μg/kg for ENB₁. BEA was the most predominant mycotoxin in samples collected from east district, and the positive rate and the average level for those samples were 87.0% (87/100) and 95.75 μg/kg. The positive rates of 4 ENNs in the east, west and central districts were lower than those of BEA, but not for the positive rates of ENA and ENB₁ in south (both of 91.3%, 21/23). The average levels of 4 ENNs in the 4 districts were lower than BEA. Conclusion Corn and corn-based products collected from Shandong were contaminated by 5 hexadepsipeptides mycotoxins, especially for BEA, and there were mycotoxin kinds and geographic distribution differences for mycotoxin contamination. It wa necessary to conduct a wide range of monitoring especially for BEA in corn and corn-based samples collected from eastern seaboard of Shandong.

Abstract:Objective To study the etiologies and causes food of foodborne disease outbreaks in China in 2014. Methods The foodborne disease data collected by the National Foodborne Disease Surveillance Network in 2014 were analyzed. Results There were 1 480 outbreaks of foodborne disease reported from 31 provinces in 2014, resulting in 17 651 illnesses and 111 deaths. Among outbreaks of which suspected etiologic agents were identified,microbial pathogens cased the largest percentage of outbreaks(38.0%, 437/1 151)and the largest percentage of cases(58.1%, 8 181/14 093),poisonous mushroom cased the largest percentage of deaths(56.5%, 61/108). Among outbreaks of which suspected food were identified,the most common food categories causing outbreaks(in addition to poisonous mushroom)were meat products with the largest percentage of outbreaks(14.7%,186/1 265),followed by vegetables with the percentage of outbreaks(13.5%, 171/1 265). The most common location of outbreaks were food and beverage service places with the largest percentage of outbreaks of 37.1%(549/1 480)and cases 51.0%(9 008/17 651).Among outbreaks for which suspected pollution link were identified,the most contributing factors of outbreaks were eating poisonous and improper processing food which caused the largest percentage of outbreaks of 31.1%(348/1 118) and 27.3%(305/1 118). Conclusion Microbial foodborne disease was an important food safety problem that could not be ignored.The misuse of eating poisonous mushrooms was the main factor causing deaths occurred in the family.Improper food processing in location of catering services which restaurants and workplace cafeteria were the common cause of the outbreak,the misuse of eating poisonous food was the highest risk factor causing foodborne disease outbreaks.

Abstract:Objective To compare the risk of Bacillus cereus contamination in powdered infant formula (PIF) in China under ten different limit levels. Methods The quantitative retail stage monitoring data of Bacillus cereus in PIF in China was used. Based on the microbial risk exposure assessment model of Bacillus cereus in PIF, and the criteria set by Australia, New Zealand and Canada, the other 8 limit levels were assumed. The risk of Bacillus cereus contamination in PIF in China was calculated under the ten limit levels. Results The risks were different under ten limit levels of Bacillus cereus in PIF when the period from preparation to feeding lasts for 2,3 and 4 hours. If the limits adopted in Australia and New Zealand [n=5, c=0, m=100 CFU/g] was applied to China, the total risk was 0 under 2 and 3 hours. Under 4 hours, compare with the other nine limit levels,the standard had the lowest residual risk, which was reduced by more than 36%, and the failure rate was 11.28% (1 128/10 000). Based on the sacrifice of 11.28% of the market milk powder, the risk was better controlled. Conclusion This study screened the limit levels that might be applied to the management of Bacillus cereus in PIF in China through the comparison of risks.

Abstract:Objective This study aimed to assess the potential risk and influence factors of the dietary exposure of nitrite to the health of Yantai residents. Methods The content of nitrite in cooked meat products and demographic data were filtered based on Monte Carlo, and the cooked meat products consumption of residents derived from the China Health and Nutrition Survey household food inventory of Shandong collected in 2009. The hazard quotient (HQ) was used to estimate dietary exposure that was exposure daily intake (EDI) divided by the acceptable daily intake (ADI) established by the Joint FAO/WHO Expert Committee on Food Additives. Results The residue content of nitrite in cooked meat products in Yantai market was between not detected (ND) to 130.00 mg/kg and the mean was 5.48 mg/kg with a Logistic distribution. The mean exposure daily intake of sodium nitrite in cooked meat products for 2-6,7-12,3-17,8-59 and ≥60 years old groups were 0.004 27,0.004 02,0.003 31,0.002 48,0.002 08 mg/kg BW, and the possibilities of HQ higher than 1 were 0.80%, 0.43%, 0.59%, 0.12%, 0.02%, respectively. The content of nitrite in cooker meat products was the most sensitive factor for HQ value with the contribution of 91.1%, and the contribution of consumption by body weight was 8.9%. The contributions of the nitrite content and the consumption by body weight were different between each group. The content of nitrite in cooked meat products was the main sensitive factor of the dietary exposure risk. Conclusion The nitrite dietary exposure of cooked meat products of Yantai population could lead chronic toxicity to health for 0.05% of all residents. Not only the residue content of sodium nitrite in cooked meat products, but also the daily intake was the main influence factors of the dietary exposure risk.

Abstract:Objective To analyze the arsenic level in main foods, and assess the risk of dietary exposure of inhabitants in Jilin Province. Methods Arsenic concentration data were obtained from the national food contamination program during 2012-2017. Food samples (n=4 532) were collected from 11 food categories in Jilin Province. Consumption data were derived from Jilin provincial nutrition and health survey in 2012. The provisional tolerable weekly intake (PTWI) and margin of exposure (MOE) were used to estimate dietary arsenic exposure of inhabitants in Jilin Province. Results The average concentration of arsenic in 11 categories of food was 0.030 mg/kg. Cereals, vegetables and aquatic products were the main source of dietary arsenic exposure. The contribution rate of the three was 76.59%, of which cereal contributed 54.44%.Dietary arsenic exposure of different age-gender population groups was in the range of 0.73-1.31 μg/kg BW. The MOE of mean dietary arsenic exposure was above 1. Conclusion The status of arsenic exposure of the inhabitants in Jilin Province was safe.

Abstract:Objective To analyze the feedback from National Food Safety Standard follow-up evaluation in 2017; to figure out the valuable suggestions regarding the standards with high concern. To provide advice to improve the mechanism of National Food Safety Standard follow-up evaluation. Methods According to the suggestions collected from January to December in 2017, through national food safety standard follow-up evaluation and feedback platform, descriptive analysis was conducted and the high frequency words were selected from the suggestions. The suggestions regarding the top 10 key standards were classified into valuable or non-valuable group and the rates of valuable suggestions were calculated. Results In 2017, totally 5 057 suggestions covering 298 standards were collected. The suggestions reflected that the food classification,detection method, items and limit levels, food label, scope and definition were highly concerned. Among the suggestions regarding the top 10 key standards, 43.5%(1 279/2 937) of the suggestions were valuable. Conclusion Some suggestions collected through the platform were valuable and worthy to be taken into consideration during the revision of the standards. In order to improve the efficiency of the standard follow-up evaluation and ensure the quality of National Food Safety Standards, it is necessary to expand the concept of ‘national food safety standard follow-up evaluation’, and establish related expert group.

Abstract:The development procedure is an important guarantee for ensuring the contents of the food safety standards are authoritative, fair, scientific and reasonable, which to some extent affects the correct understanding and implementation of the standards. In this paper, the food safety standards development procedure between the United States of America and China are compared and analyzed, and the differences and reasons are discussed in order to provide new ideas and suggestions for the management of national food safety standards in China.

Abstract:Objective To identify the pathogen in the food and the source of infection that might be responsible for a food poisoning outbreak for the banquet in the countryside, and provide evidence for control measures. Methods Case survey, descriptive epidemiological analysis and case study were conducted. A case-control study on 108 people was conducted to identify the foods that might be responsible for this event. Clinical sample from the cases and food processing staff, food and water samples were collected for laboratory detection. Results The attack rate of this event was 21.6% (138/640), and the main clinical symptoms were diarrhea, abdominal pain and fever. 94.4%(51/54) of the cases and 66.7%(36/54) of the controls ate the dishes of cold dish-mixed, the risk of eaten cold dish-mixed was increased (OR=8.50,5%CI: 2.32-31.02). Data from the crossover analysis result showed that the risk of outbreak increased if more than two ingredient of the cold dish-mixed were eaten (OR=9.25,5%CI:2.46-34.82). Four cases were detected Salmonella in serum type B group from their anus swabs and the same bacteria type was also detected in the guan du ingredient of the cold dish-mixed. The result of pulsed field gel electrophoresis for the 5 strains of Salmonella were highly homologous which indicated that the strains was from the same source of exposure. Conclusion Salmonella in serum type B group was responsible for this outbreak which contaminated the cold dish-mixed during food processing. The risk of foodborne disease outbreak was high in rural area, and the supervision in this situation should be strengthened.

Abstract:As a class A pathogen in powdered infant formula, Cronobacter could cause meningitis, necrotizing enterocolitis and bacteremia to neonates and the mortality rate is 40%-80%, which has caused public concern. This article was based on domestic and abroad reports of Cornobacter, summerized the epidemiological characteristics, serotyping characteristics, environmental resistance characteristics, virulence genes and dominant clones related to pathogenicity.It is suggested that the clinical survelliance system should be strengthened to catch the incidence and high-risk foods of Cronobacter in China, so as to develop prevention and control strategies.

Abstract:Microbial food cultures (MFC) plays an important role in food production, processing, or consumers’ health. With the deepening research on the strains used for fermentation and non-fermented food production, the microbial-related food is increasing rapidly. Whereas the safety of MFC used in food production has become the focus of attention of enterprises, consumers and government officials. In order to ensure the safety of microbial-related foods, especially those for infant and young children’s consumption, and to standardize the supervision of food produced with microorganisms, many countries have formulated guidelines and taken measures to manage the strains. The definition, classification, procedure of safety evaluation, application and approval management of MFC, mainly probiotics by international organizations and related countries were systematically reviewed.