Objective To conduct a quantitative risk assessment of Listeria monocytogenes(LM)in prepackaged,non-vacuum sealed,short shelf-life,ready-to-eat meat products in Chengdu using the@Risk software.Methods Based on monitoring data of LM contamination in pre-packaged,non-vacuum sealed,refrigerated ready-to-eat meat products in Chengdu obtained from a previous study,a risk assessment model was established.The risk of LM infection caused by consuming cooked meat products in different groups of people was quantitatively assessed.In addition,the growth of LM in cooked meat products,from retail to consumption,was also taken into consideration in the assessment.Results In Chengdu,the numbers of potential cases of listeriosis caused by consumption of prepackaged,non-vacuum sealed,refrigerated ready-to-eat meat products were 0.01(95％confidence interval[CI]:0-1.71 × 10-2)per year per million in healthy individuals aged 5-＜65 years old,0.22(95％CI:0-2.67 × 10-1)in healthy individuals aged 65 and above,and 2.88(95％CI:3.85 × 10-8-4.35)in pregnant women.According to the results of the sensitivity analysis,the initial pollution level of LM in the retail stage was the most important factor affecting the prevalence(R=0.25),followed by retail temperature(R=0.08),retail time(R=0.07),and amount of consumption per meal(R=0.07).Conclusions For pre-packaged,non-vacuum sealed,cooked meat products,the most important measure to reduce the prevalence of listeriosis is to control the initial contamination level,which requires food processing plants to regularly clean and strictly disinfect the processing environment and equipment to minimize LM contamination at the source.Retail delicatessens should strictly maintain a storage temperature below 5.0℃ and strictly adhere to product shelf-life recommendations.As for consumers,they should consume these meat products as soon as possible after purchase or store them under refrigerated conditions and shorten the storage time.Pregnant women should thoroughly heat the meat products before eating to reduce the risk of listeriosis.

Objective:To analyze the contamination characteristics and pathogenic potential of Listeria monocytogenes (LM) in pre-packaged and refrigerated ready-to-eat cooked meat products in Chengdu City. Methods:From September 2022 to May 2023, pre-packaged and refrigerated ready-to-eat cooked meat products were collected from six districts and counties in Chengdu City. Qualitative and quantitative determination of LM was performed on these samples. Whole genome sequencing was carried out on the isolated strains. Different ST strains were selected for cell adhesion and invasion experiments. The results were expressed as adhesion rate and invasion rate. One-way ANOVA was used for comparison between groups, and the Dunnett t-test was used for pairwise comparison. Results:A total of 145 samples were collected, and LM was detected and isolated in 29 samples. The total detection rate was 20.00%, and the detection rate of braised pork was the highest (68.18%). The contamination level of LM in 9 samples (31.03%) was greater than 100.00 MPN/g. The 29 strains of Listeria monocytogenes belonged to 7 STs, including ST 3 (27.59%), ST 8 (17.24%) and ST 87 (13.79%). The strain of ST 87 carried Listeria pathogenicity islands 4 (LIPI-4), which was a highly virulent strain. The medium and high virulence strains accounted for 79.31%. Some moderately virulent and highly virulent strains of ST 8 and ST 87 were closely related to clinical patient strains. Some LM isolates of the same ST type had little SNP differences (1-6) in the same manufacturer at different stages. In vitro cell experiments showed that the highly virulent strain ST 87 had the strongest adhesion and invasion ability towards Caco-2 cells. Conclusion:The pre-packaged and refrigerated cooked meat products have a high contamination rate. Some samples have high contamination levels and carry medium and high virulence strains, posing potential health risks to human beings. LM residues continue to persist in some manufacturers′ production and processing stages.

Objective:To analyze the contamination characteristics and pathogenic potential of Listeria monocytogenes (LM) in pre-packaged and refrigerated ready-to-eat cooked meat products in Chengdu City. Methods:From September 2022 to May 2023, pre-packaged and refrigerated ready-to-eat cooked meat products were collected from six districts and counties in Chengdu City. Qualitative and quantitative determination of LM was performed on these samples. Whole genome sequencing was carried out on the isolated strains. Different ST strains were selected for cell adhesion and invasion experiments. The results were expressed as adhesion rate and invasion rate. One-way ANOVA was used for comparison between groups, and the Dunnett t-test was used for pairwise comparison. Results:A total of 145 samples were collected, and LM was detected and isolated in 29 samples. The total detection rate was 20.00%, and the detection rate of braised pork was the highest (68.18%). The contamination level of LM in 9 samples (31.03%) was greater than 100.00 MPN/g. The 29 strains of Listeria monocytogenes belonged to 7 STs, including ST 3 (27.59%), ST 8 (17.24%) and ST 87 (13.79%). The strain of ST 87 carried Listeria pathogenicity islands 4 (LIPI-4), which was a highly virulent strain. The medium and high virulence strains accounted for 79.31%. Some moderately virulent and highly virulent strains of ST 8 and ST 87 were closely related to clinical patient strains. Some LM isolates of the same ST type had little SNP differences (1-6) in the same manufacturer at different stages. In vitro cell experiments showed that the highly virulent strain ST 87 had the strongest adhesion and invasion ability towards Caco-2 cells. Conclusion:The pre-packaged and refrigerated cooked meat products have a high contamination rate. Some samples have high contamination levels and carry medium and high virulence strains, posing potential health risks to human beings. LM residues continue to persist in some manufacturers′ production and processing stages.

OBJECTIVETo investigate the impact of premature birth on long term cardio-cerebral vascular events of puerpera.

METHODSAmbispective cohort study method was used and 3 659 pregnant women giving birth during October 1976 to December 2008 at Kailuan medical group were included and divided into premature birth (PTB) group (n = 226) and non-PTB (NPTB) group (n = 3 433) by the history of PTB. Incidence of cardio-cerebral vascular events (myocardial infarction, cerebral infarction and cerebral hemorrhage) was obtained during follow-up. Multivariable Cox proportional hazards regression models was used to assess the relative risk of cardio-cerebral vascular events.

RESULTS(1) The childbearing age, proportion of pregnancy-induced hypertension, systolic blood pressure and diastolic blood pressure before delivery were significantly higher while weight and height of newborn were significantly less in PTB group than in NPTB group (P < 0.05 or 0.01). (2) There were 71 cardio-cerebral vascular events during the follow-up of (15.19 ± 7.75) years. In PTB group, the incidence of cardio-cerebral vascular events and myocardial infarction was 3.23/1 000 person-years and 2.05/1 000 person-years, respectively, while the corresponding incidence was 1.15/1 000 person-years and 0.42/1 000 person-years, respectively in NPTB group (all P < 0.05). After adjustment for other traditional cardiovascular risk factors, the risk of total cardio-cerebral vascular events, myocardial infarction in PTB group was 2.03 fold (95% CI: 1.02-4.04, P = 0.002) and 3.11 fold (95% CI: 1.18-8.18, P < 0.001) higher than in NPTB group.

CONCLUSIONPTB is an independent risk factor for total cardio-cerebral vascular events, especially myocardial infarction of puerpera.

Blood Pressure ; Cardiovascular Diseases ; epidemiology ; Cohort Studies ; Female ; Humans ; Hypertension, Pregnancy-Induced ; Incidence ; Myocardial Infarction ; epidemiology ; Pregnancy ; Premature Birth ; Proportional Hazards Models ; Risk Factors ; Stroke

Objective To investigate the impact of premature birth on long term cardio-cerebral vascular events of puerpera.Methods Ambispective cohort study method was used and 3 659 pregnant women giving birth during October 1976 to December 2008 at Kailuan medical group were included and divided into premature birth(PTB) group (n=226) and non-PTB(NPTB) group (n=3 433) by the history of PTB.Incidence of cardio-cerebral vascular events ( myocardial infarction , cerebral infarction and cerebral hemorrhage ) was obtained during follow-up.Multivariable Cox proportional hazards regression models was used to assess the relative risk of cardio-cerebral vascular events.Results ( 1 ) The childbearing age , proportion of pregnancy-induced hypertension , systolic blood pressure and diastolic blood pressure before delivery were significantly higher while weight and height of newborn were significantly less in PTB group than in NPTB group ( P<0.05 or 0.01 ).( 2 ) There were 71 cardio-cerebral vascular events during the follow-up of (15.19 ±7.75) years.In PTB group, the incidence of cardio-cerebral vascular events and myocardial infarction was 3.23/1 000 person-years and 2.05/1 000 person-years, respectively, while the corresponding incidence was 1.15/1 000 person-years and 0.42/1 000 person-years, respectively in NPTB group( all P <0.05 ).After adjustment for other traditional cardiovascular risk factors , the risk of total cardio-cerebral vascular events, myocardial infarction in PTB group was 2.03 fold(95%CI:1.02-4.04, P=0.002) and 3.11 fold ( 95%CI: 1.18 -8.18, P <0.001 ) higher than in NPTB group.Conclusion PTB is an independent risk factor for total cardio-cerebral vascular events , especially myocardial infarction of puerpera.