Abstract:With the development of the socio-economy and changes in lifestyle， the nutrition and health conditions of residents in Guangdong Province have improved， and nutrition deficiency diseases have decreased significantly. However， issues such as an unbalanced dietary pattern and uneven nutrient intake are becoming increasingly apparent， and the rapid growth of chronic diseases related to nutrition and lifestyle behaviors is not being effectively controlled. This article reviews and summarizes the current state of dietary nutrition and disease prevention and control among residents in Guangdong Province， as well as domestic， international， and provincial policy measures addressing nutrition and related diseases. It will also propose recommendations and outlooks on the existing problems to further promote the progress of nutrition prevention and control work in Guangdong Province.

Abstract:Objective To monitor the molecular epidemiology and antimicrobial resistance pattern of Salmonella isolates recovered from the clinical and the food sources in Shaoxing City， the genomic characterization of some clinical strains were analyzed.Methods Slide agglutination method was used to determine the serovars. PFGE method was applied to study molecular classification. Broth microdilution method was performed to carry out drug resistance testing. Whole genome data were sequenced. Whole genome single nucleotide polymorphism （wgSNP） classification was performed by BioNumerics V7.6 software. The sequence types （ST）， drug resistant genes and virulence genes were predicted with Pubmlst， ResFinder 4.1 and VFDB software， respectively.Results Twenty-four serotypes， 109 different PFGE fingerprints， 80 resistant patterns were detected in 135 clinical and the 10 food isolates of Salmonella. The predominant serovars were Salmonella typhimurium， Salmonella enteritidis and Salmonella london. The main serotypes in food were Salmonella london and Salmonella paratyphi B. Salmonella had high resistance to ampicillin， tetracycline and streptomycin. The multiple drug resistance rate reached 73.79% （107/145）. The main drug resistance in food were ampicillin， cefazolin， tetracycline and nalidixic acid. A total of 11 diverse ST types were identified from the 30 clinical strains. Phylogenetic wgSNP comparisons demonstrated that four Salmonella enteritidis from ST11 types were genetically similar and clustered together. A total of 31 different antimicrobial resistance genes among these isolates were identified. The most common antimicrobial resistance genes were the aminoglycosides resistance gene aac（6'）-Iaa （100%， 30/30）， the β-lactams resistance gene blaTEM-1B （70%， 21/30） and so on. A total of 224 virulence genes were also identified， and 107 of these existed among all isolates.Conclusion Salmonella in Shaoxing had a variety of serotypes and PFGE fingerprints， a complex resistant patterns， a high proportion of multiple drug resistance. The findings showed that selected raw poultry was not a direct source of local Salmonella infection. Part of the clinical strains had a high carrying rate of antimicrobial resistance genes and virulence genes.

Abstract:Objective To study the effects of Pseudognaphalium affine D.Don Anderberg（PADA）on reproductive hormone levels and immune function in rats.Methods PADA was extracted and concentrated according to the traditional eating habit， and given orally to SD rats for 30 consecutive days. Six sex hormones， immune organs， carbon clearance assay， ConA-induced splenic lymphocyte transformation test， determination of serum hemolysin and determination of antibody producing cell were measured.Results The prolactin levels was elevated （P<0.05） in female rats of all dose groups after exposure to PADA. Spleen weight in the male 100 g/kg.bw dose group， antibody product in the male 50 g/kg·bw dose group and thymus weight and thymus-body ratio in the female 100 g/kg·bw dose group were increased （P<0.05）. While no significant adverse changes were observed in the phagocytic index-a， the OD difference value of lymphocyte transformation test， Hemolytic plaques， WBC， globulin， the albumin/globulin ratio， and immune organs.Conclusion Prolactin levels can be increased in females at doses above 25 g/kg·bw. No significant impairment of immune function was observed. Spleen weight， thymus weigh， and thymus-body ratio were increased， suggesting a certain immune enhancement effect.

Abstract:Objective To provide scientific basis for the prevention and control of foodborne diseases and clinical treatment， the serological， drug resistance and molecular typing characteristics of Salmonella isolated from patients with foodborne diarrhea in Wenzhou City was investigated.Methods A total of 567 Salmonella strains isolated from foodborne diarrhea cases in Wenzhou City from 2017 to 2021 were sorted out and serotyped. The susceptibility tests to 15 antimicrobial agents were performed using the broth microdilution method. Pulsed field gel electrophoresis （PFGE） was used for molecular typing.Results Among the 567 patients of Salmonella， 326 were male and 241 were female， accounting for 57.5% and 42.5%， respectively. Most of them were children under 6 years old， and 119 strains were isolated， accounting for 21.0%. Next was the elderly over 60 years old， 111 strains of Salmonella were isolated， accounting for 19.6%. The 567 isolates of Salmonella were divided into 50 serotypes， among which the top two serotypes were Salmonella typhimurium （33.5%， 190/567） and Salmonella enteritidis （23.6%， 134/567）. The results showed that the resistance rate to ampicillin was the highest （73.5%， 417/567）. It was followed by tetracycline （63.3%， 359/567）. Salmonella typhimurium had the highest resistance to tetracycline （84.2%， 160/190）， and Salmonella enteritidis had the highest resistance to nalidixic acid （95.5%， 128/134） among 15 antibiotics. Among 567 strains of Salmonella， 178 kinds of drug resistance spectrum were found， the rate of multiple drug resistance was 62.6%and the highest proportion was AMP-AMS-CFZ-CT-NAL. The 201 strains of Salmonella typhimurium and the monophasic varieties of Salmonella typhimurium produced 70 band types. The band types varied greatly and the similarity was between 1.5% and 100%. One hundred and twenty-seven strains of Salmonella enteritidis obtained a total of 32 band types with the similarity between 35.8% and 100%. Fifty strains of Salmonella london obtained a total of 24 band types by PFGE， and the similarity was between 40.0% and 100%.Conclusion Foodborne Salmonella strains isolated in Wenzhou displayed diverse serotypes， varying degrees of drug resistance， and multi-drug resistance. To effectively prevent and control foodborne diseases caused by Salmonella， enhancing monitoring of Salmonella among foodborne diarrhea patients was essential. Timely understanding of Salmonella serotype distribution trends and drug resistance patterns in the region， followed by appropriate measures， was imperative.

Abstract:Objective To provide scientific basis for the prevention and control， early warning， tracing and clinical treatment of diarrheal diseases caused by Salmonella， the serotype distribution， drug resistance and molecular typing characteristics of Salmonella isolates from infectious diarrhea patients in Huzhou City were analyzed.Methods A total of 126 isolates of Salmonella were collected from 6 sentinel hospitals in Huzhou City from 2021 to 2022. The isolates were characterized by serovar determination， antimicrobial susceptibility tests， and pulsed-field gel electrophoresis （PFGE） typing.Results The 126 strains of Salmonella could be divided into 28 serotypes. The dominant serotypes were Salmonella typhimurium monophasic variant （32.5%， 41/126）， Salmonella enteritidis （24.6%， 31/126） and Salmonella typhimurium （15.1%， 19/126）. Salmonella typhimurium had different resistance characteristics to 15 antibiotics. The resistance rate of Salmonella typhimurium monophasic variant to tetracycline was 73.3% （44/60）， ampicillin and sulfamethoxazole were all 56.7% （34/60）. The resistance rate of Salmonella typhimurium to tetracycline and sulfamethoxazole was higher with 68.4% （13/19） and 52.6% （10/19）， respectively. The highest resistance rate of Salmonella enteritidis to ampicillin/sulbactam was 54.8% （17/31） and that of other Salmonella to tetracycline was the highest wih 51.4%（18/35）. The overall multidrug resistance rate was 62.7% （79/126）， showing 20 multidrug resistance spectra. The PFGE fingerprints of Salmonella typhimurium and Salmonella enteritidis were obtained 46 and 15 kinds types after digested by Xba Ⅰ enzyme.Conclusion The predominant serotypes of Salmonella infection in Huzhou City are Salmonella typhimurium and Salmonella enteritidis. The multi-drug resistance of Salmonella bacteria is serious. PFGE zone types are both diverse and dominant.

Abstract:Objective To provide scientific value for effective prevention of Salmonella infection and treatment， the drug resistance spectrum and drug resistance characteristics of Salmonella enteritidis in Lanzhou was exploreed and a database of some genotypes of Salmonella was established.Methods A total of 94 strains of Salmonella were isolated from foodborne active surveillance in Lanzhou from 2019 to 2021 by serotyping and biochemical analysis. The drug resistance of 41 strains of Salmonella enteritidis was detected by drug susceptibility testing and pulsed field gel electrophoresis. BioNumerics （Version 7.6） software was used to cluster the PFGE profiles of 41 strains of Salmonella enteritidis.Results A total of 94 strains of Salmonella could be classified into 20 serotypes， with Salmonella enteritidis as the dominant serogroup， accounting for 43.62% （41/94）. 41 strains of Salmonella enteritidis were generally resistant to quinolone nalidixic acid bacteria （100.00%）， followed by up to 80.49%（33/41） resistance to penicillin ampicillin， the resistance rate to cefazolin was 39.02%（16/41）， and the resistance rates to ampicillin/sulbactam and tetracycline were 31.71%（13/41）. But the drug resistance rates were all 0.00% to imipenem and cefoxitin. Twenty-six （63.41%） of the strains showed multi-drug resistance， resulting in eighteen multi-drug resistance profiles. Lastly， A total of 19 bands were obtained by Xba Ⅰ digestion of 41 strains of Salmonella enteritidis， and the similarity between the bands was 74.20%~100.00%. The number of strains contained in each band type was different， and the homology between strains of the same year was highly and they have 100.00% identical bands.Conclusion Salmonella serotypes in Lanzhou are diverse and PFGE band types are complex， and its dominant serogroup Salmonella enteritidis is highly resistant and multi-drug resistant seriously.

Abstract:Objective To explore the effect of sous-vide on the thermal inactivation rules of Listeria monocytogenes in different matrix， the thermal inactivation of Listeria monocytogenes in different substrates at different temperatures was studied.Methods Five lyophiliZed L. monocytogenes strains were inoculated into saline， MH broth， vacuum packed lean pork and streaky pork. The survival rates were evaluated at 55， 60， and 63 ℃. The decimal reduction time （D-value） and temperature dependence （Z-value） were determined for each strain in each matrix.Results The D value and Z value of Listeria monocytogenes in pork were higher than those in normal saline and MH broth， the difference was statistically significant （P<0.01）， and the D value in pork belly was higher than that in lean meat， the difference was statistically significant （P<0.01）.At 55 ℃， the time required for artificially contaminated Listeria monocytogenes to decrease 6lg in sous-vide packed lean pork and streaky pork matrix was about 3~4 h， while the time was 30-40 and 10-20 min at 60 and 63 ℃， respectively.Conclusion Under the conditions of sous-vide， food matrix and genetic basis of strains have significant effects on the killing effect of Listeria monocytogenes. When cooking at below 60 ℃， the cooking time should be extended to ensure the microbial safety of cooked food.

Abstract:Objective To isolate and identify a bacteriophage of Enterococcus faecalis and to analyze its biological characteristics.Methods The host bacteria was isolated from the process of yak slaughtering and identified by 16S rRNA sequencing. The bacteriophage was isolated from the environmental sewage and was purified. The titer of bacteriophages was determined using the double-layer plate method. The morphology of bacteriophage was observed by transmission electron microscopy； the bacteriophage lysis profiles， optimal infection complex， and one-step growth curve were determined； the effects of pH， UV irradiation， temperature， and organic solvents on bacteriophages have been studied. Furthermore， the lytic activity of the bacteriophage against the host bacteria was determined.Results The host bacteria were identified as E. faecalis by 16S rRNA sequencing. A bacteriophage named P45 was isolated from sewage to lyse E. faecalis. Electron microscopy showed that the bacteriophage was a tadpole-shaped long-tailed bacteriophage， which has a hexahedral head and its length is （200±5） nm. The bacteriophage had obvious lysis effect on four strains of E. faecalis. Bacteriophage’s optimal multiplicity of infection was 0.1. The results of one-step growth curve showed that the incubation period was 50 min， the lysis period was 190 min， and the burst size was 1 PFU/cell. This bacteriophage survived at pH=2 to 3，which titers were 1.05×10² PFU/mL and 1.85×10³ PFU/mL. At 75 ℃， this bacteriophage was completely inactivated. Bacteriophage’s titer was decreased by UV irradiation， and it was not sensitive to organic solvents.Conclusion This bacteriophage has a good lysis effect and has potential application on the prevention or control of E. faecalis contamination.

Abstract:Objective Osmophilic yeast in honey at home and abroad was identified ， and the contamination levels of honey was understood.Methods A total of 916 batches of domestic and imported honey were selected， and osmophilic yeast was counted according to GB 14963—2011 “National Standard Food Safety -Honey” and GB 4789.2—2022 “National Standard Food Safety -Determination of the total number of colonies for microbial Inspection”， and the detection rate of osmophilic yeast was calculated. The species of isolated strains were identyfied by 26S rDNA PCR. The ability of some yeast strains to tolerate high sugar and produce alcohol were tested by absorbance and potassium bichromate colorimetry.Results In 916 batches of honey， 36 batches of osmophilic yeast were detected， the detection rate was 3.93%， and the over-standard rate was 3.49%. Among 786 batches of domestic honey， 33 batches of osmophilic yeast were detected， the detection rate was 4.20%， with osmophilic yeast from 2.5×10² to 7×10⁴ CFU/g. Three osmophilic yeasts were detected in 130 batches of imported honey， the detection rate was 2.31%， with osmophilic yeasts from 1×10¹ to 7×10¹ CFU/g. Five osmophilic yeast strains were isolated， one was Moesziomyces aphidis/Pseudozyma sp.， and three were Zygosaccharomyces mellis. One was Candida magnoliae， and all of the tested strains were well tolerant to high glucose concentrations and had some capacity to produce alcohol.Conclusion Honey may be contaminated by osmophilic yeast， so it is necessary to strengthen its control and management. Honey can be used as a source for screening osmolal-resistant strains， and the selection of osmophilic yeast is helpful to the development of honey food fermentation industry and the research and development of excellent products.

Abstract:Objective To provide a reference basis for the early warning of food safety risks and the formulation of trade policies on imported fruits in our country， the pesticide residues in imported fruits in Beijing was investigated.Methods A total of 60 batches of fruit samples that label claims to be imported from 13 countries/regions such as Australia， the Philippines and so on were studied， and 725 pesticide residues were screened by GC/LC-Q-TOF/MS.Results Among 60 batches of samples， 58 batches were qualified， and the qualified rate was 96.67%. Seventy-four kinds of pesticide residues were detected among 725 screening items， most of which were low-toxic， and the detection rates were 6.70% （25/373） for pyraclostrobin， 5.90% （22/373） for spirotetramat， 4.82% （18/373） for trifloxystrobin and 4.29% （16/373） for fluazolamide.Conclusion The detection rate of pesticide residues in imported fruits in Beijing was good. The results indicate that the overall pesticide residues in imported fruits are at safe levels， but the potential health risks need to be concerned.

Abstract:Objective The application of population genetics model was explored to determine the main sources leading to sporadic cases of human Campylobacter infection.Methods MLST data from PubMLST public database was analyzed to assign Campylobacter sporadic cases to various sources by using the population genetics asymmetric island model （AIM）.Results As a result of sporadic cases of Campylobacter infection， chickens （50.49%） accounted for the highest percentage， followed by ducks and geese， cattle， pigs （22.56%， 18.36% and 4.52%， respectively）， whereas the environment and wild birds accounted for a lower percentage （0.78% and 0.66%， respectively）.Conclusion Based on microbial molecular typing data and statistical modeling， this study quantitatively assessed the contribution of different sources to sporadic cases of Campylobacter infections in China， using the AIM for source attribution practice. It provided directions and ideas for the next stage of source attribution for foodborne diseases.

Abstract:Objective To investigate the levels of seven organophosphorus esters （OPEs） and six indicator polychlorinated biphenyls （PCBs） in pig liver from Hubei Province， the risk of exposure to OPEs and PCBs in Hubei residents through dietary intake of pig liver were assessed.Methods A total of 51 pig liver samples were collected from Hubei Province in 2022. By isotope dilution method， OPEs and PCBs in pig liver samples were determined by ultra-high performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS） and high resolution gas chromatography high resolution magnetic mass spectrometry （HRGC-HRMS）， respectively. The source of pollution was explored by analyzing the fingerprint characteristics. Based on the estimation dietary intake （EDI） and hazard index （HI） of Hubei residents， the risk of exposure to OPEs and PCBs through dietary intake of pig liver was assessed.Results The levels of seven OPEs （∑₇OPEs） in pig liver ranged from 15.6 to 262 ng/g， with an average of 89.7 ng/g （P₅₀=88.4 ng/g）. The levels of six PCBs （∑₆PCBs） ranged from 3.67 to 19.5 pg/g， with an average of 9.02 pg/g （P₅₀=8.21 pg/g）. Tris （1，3-Dichloro-2-Propyl） Phosphate （TDCPP） and PCB 52 was the main characteristic pollutant of OPEs and PCBs in pig liver， respectively. Some OPEs were positively correlated with each other （r=0.278-0.841， P<0.05）， and all PCBs were positively correlated with each other （r=0.367-0.942， P<0.01）. The average EDI values of ∑₇OPEs and ∑₆PCBs from dietary intake of pig liver was 2.76 ng/kg·BW/d （P₉₅=5.83 ng/kg·BW/d） and 0.28 pg/kg·BW/d （P₉₅=0.58 pg/kg·BW/d）， respectively. And compared with the reference dose （RfD）， the HI values were far less than 1.Conclusion Although OPEs and PCBs are generally detected in pig liver， the pollution level is low. The dietary exposure risk of Hubei residents is relatively low.

Abstract:Objective To provide references for the formulation and revision of corresponding food standards and further improvement of China’s national food safety standard system， the implementation of national food safety standards for oils and fats was understood， and the suggestions and opinions in the implementation of food safety standards was collected.Methods The standard follow-up evaluation was carried out by means of enterprise background investigation， questionnaire survey， on-site investigation and expert consultation. Food production and marketing enterprises， supervision institutes， inspection and testing institutions， industry associations， and relevant scientific research institutes from Shanghai， Guangdong， Hebei， Jiangxi， Guangxi and Ningxia were selected as the subjects for questionnaire and on-site investigation. Collect the problems encountered in the implementation of product standards， specification， examination method standards， and general standards， as well as suggestions on the revision of standards and system construction.Results From 2019 to 2021， a total of 3 097 special follow-up evaluation questionnaires were issued， 1 348 valid questionnaires were recovered， the recovery rate was 43.53%. 183 enterprises were surveyed on the spot， and 72 valid opinions and suggestions were collected. Generally speaking， the respondents have a high degree of recognition of the national food safety standards for oils and fats， and the suggestions mainly focus on “improving food classification and definition” and “increasing or improving technical indicators”.Conclusion The implementation of national food safety standards for oils and fats is satisfactory， but it is necessary to improve the terminology definitions and technical requirements of relevant standards.

Abstract:Objective To provide reliable basis for the coordinated development of health levels among Chinese residents， understand， the dietary structure and characteristics of Chinese residents was evaluated and analyzed through the dietary mineral intake status of adult men in China.Methods According to the average daily intake of 12 types of dietary mineral elements per adult male in 20 provinces （autonomous regions， municipalities） of China， which was publicly released in the Fifth China Total Diet Study， the entropy weight method and TOPSIS comprehensive evaluation method were used to evaluate and analyze them.Results The intake of dietary calcium and dietary zinc was significantly low， and the intake in various regions was below the recommended level. The average intake of dietary potassium， magnesium， and molybdenum basically met the recommended or appropriate intake level， while the intake of other mineral elements was generally high. Overall， the food sources of mineral elements in various regions of China were basically similar， with grains， vegetables， meat and beans as the main sources. The weight of the 12 mineral element indicators ranged from 0.048 to 0.127， with the highest degree of variation in dietary manganese indicators and the lowest degree of variation in dietary magnesium indicators. Overall， the comprehensive evaluation of dietary mineral intake levels in Hebei Province， Shanghai City and other regions was good， while the comprehensive evaluation of Jilin Province， Liaoning Province and other regions was poor.Conclusion There are significant differences in the intake levels of dietary mineral elements among different regions， which are closely related to the dietary structure of local residents. Continuously adjusting the dietary structure of residents through diversified diets can help improve problems such as insufficient or excessive dietary mineral intake， and further enhance the health level of Chinese residents.

Abstract:Deoxynivalenol （DON） is a toxic secondary metabolite produced by Fusarium， which mainly infects wheat， corn and other grains. It not only causes huge economic losses to the agricultural industry， but also has a potential threat to human and animal health. Therefore， how to efficiently remove DON from grains has always been an urgent problem. Currently， there is good development space in terms of cost and large-scale promotion of the use of microorganisms and their metabolites for biological detoxification of DON. This article makes a detailed description of the harm and detection technology of DON， as well as the research and application of the detoxification mechanism of DON by lactic acid bacteria in recent years， which provides a reference for the biological pest control of DON in grains and feedstuffs by lactic acid bacteria and its large-scale industrial application.

Abstract:Objective Evidence-based review of epidemiological change trends of Salmonella serotype infections in the United States in recent 50 years.Methods To collect and analyze 30 dominant Salmonella serotypes（including enteral and parenteral dominant serotypes） infected in humans and the ecologically dominant Salmonella serotypes in farmed animals （animal disease and non-animal disease groups） in the United States from 1968 to 2011， and analyze the big Salmonella serotypes data of National Enteric Salmonella Surveillance in the United States from 2006 to 2016. To correlate the Salmonella serotypes based on the outbreaks of Multistate foodborne and pet-borne disease in the United States from 2006 to 2017.Results The United States has caused the formation of colonization and pathogenic ecological characteristics between some Salmonella serotypes and cultured animals based on the more and more developed breeding industry in the past 50 years. There is an exposure response relationship between the dominant Salmonella serotypes of colonized animals and the human infected. The long-term interaction between human and animal makes the dominant Salmonella serotypes highly match. In the past 50 years， the baseline of Salmonella infection in the population in the United States has been gradually increasing， The patients are most common in children and the elderly， the highest incidence in children under 1 year old， and more cases in the south and Midwest. In 2008， enteritis replaced typhimurium as the first human infection of Salmonella in the United States. The foods attributed to Salmonella multistate foodborne outbreaks have the consumption characteristics of transition from traditional meat， eggs， and milk to vegetables， ready-to-eat foods， fruits， etc. The Salmonella multistate pet-borne outbreaks， which have gradually increased since 2006 and are related to live animals such as domesticated reptiles， belong to behavioral ecotype infectious diseases， with longer duration， more dispersed cases and higher concealability than foodborne outbreaks.Conclusion To summarizes the disease ecological characteristics of Salmonella in the United States， which can provide reference for the comprehensive prevention and control of salmonellosis between veterinarians and humans in China.