Objective: To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China. Methods: A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. Results: All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Conclusion Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

Objective Glucagon-like peptide-1 (GLP-1) has been reported to be effective in the treatment of nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanism of GLP-1 on NAFLD is remained unclear. The present study was to detect whether the effect of GLP-1 on triglyceride (TG) content in hepatocytes is dependent on Foxos. Methods HepG2 cells were treated with palmitic/oleic acid for 24 h. The knockdown of Foxo1, Foxo3 was conducted through small interfering RNA (siRNA). Real time PCT (RT-PCR) was used to detect the changes of the SREBP1c and Acox2 genes in HepG2 cells after Foxo1/3 knockdown. Results As expected, palmitic/oleic acid increased TG concentration in HepG2 cells [(12.65 ± 1.32) μg/mg vs. (4.32 ± 0.54) μg/mg, P<0.05]. Addition of GLP-1 dose (10, 50, 100nmol/L) dependently lowered the TG content and reached plateau at 100 nmol/L of GLP-1 [TG(8.38±1.47) μg/mg]. The GLP-1 effect on TG remained after knocking down either Foxo1 [(9.09±1.34)μg/mg] or Foxo3 [(8.90± 1.60) μg/mg] alone, but not when knocking down Foxo1 and Foxo3 (Foxo1/3) together [(14.66±1.77)μg/mg]. Moreover, knocking down Foxo1/3 also abolished GLP-1 effect on SREBP1c and Acox2 expression. Conclusion GLP-1 can inhibit the synthesis of TG in hepatocytes depending on Foxo1 and Foxo3. Further studies are needed to explore the specific mechanisms.

Objective To observe the effects of warm water bath active rewarming and passive rewarming on lung pathological injury and arterial blood gas of SD rats with hypothermia induced by prolonged seawater immersion.Methods One hundred male Sprague-Dawley rats were randomly divided into the normal control group (without any treatment) and the hypothermia group (seawater immersion at 20 ℃ for 24 h),The animals in the passive rewarming groups 1,2,3 and 4,each consisting of 10,had seawater immersion at 20 ℃for 24 h and received passive rewarming,and then they were respectively executed at 0,3,6 and 12 hours after rewarming,The animals in the active rewarming groups 1,2,3 and 4,each consisting of 10,underwent seawater immersion at 20 ℃ for 24 h and received active rewarming,and then they were sacrificed at 0,3,6and 12 hours after rewarming,Changes in lung pathology,arterial blood gas and other indicators were detected in all the animal groups.Results Both warm water bath active rewarming and passive rewarming all could help to restore lung injury and blood gas abnormality in rats with hypothermia induced by prolonged seawater immersion.Compared with that of the passive rewarming group [6 h:(7.6 ± 2.2) scores,12 h:(5.3 _± 1.3)scores],the recovery of lung pathological injury in warm water bath rewarming group was obviously better at 6 h(5.8 ± 1.2) scores and 12 h(3.8 ± 1.4) scores after rewarming,with statistical significance (P ＜ 0.05),and actual bicarbonate recovery was even better at 6 h after rewarming,also with statistical significance (P ＜0.05).Conclusions Compared with passive rewarming,warm water bath rewarming could significantly alleviate lung injury and arterial blood gas abnormality in hypothermic rats induced by prolonged seawater immersion,and it might produce even better effect on the prevention of rewarming-related acute respiratory distress syndrome.

Objective To investigate the dynamic changes in the nature of the pleural effusion via Light criteria in hypothermic rats induced by seawater immersion and analyze possible mechanism involved.Methods One hundred male Sprague-Dawley rats were randomly divided into the normal control group (without any treatment) and hypothermia group exposed to 20 ℃ seawater for 24 hours.Then,the hypothermia group was sub-divided into the passive rewarming groups 1,2,3 and 4 and warm water bath active rewarming groups 1,2,3 and 4,each consisting of 10 animals.The passive rewarming groups had passive rewarming after exposure to 20 ℃ seawater for 24 hours,while the active rewarming groups had warm water bath rewarming following exposure to 20 ℃ seawater for 24 hours.Then,all the animals in the sub-groups were executed 0,3,6 and 12 hours after rewarming.Serum,pleural effusion,total protein (TP) in pleural effusion,concentrations of lung homogenate lactate dehydrogenase (LDH) were measured,and Light criteria were calculated.Results There was no significant pleural effusion in the normal rats.LDH level in hypothermia-induced pleural effusion was higher than that in normal serum LDH,pleural effusion/total serum protein ratio (TPR) was lower than 0.5,and lactate dehydrogenase ratio (LDHR) was lower than 0.6.After rewarming,the amount of hypothermia-induced pleural effusion decreased gradually,while the levels of TPR and LDHR increased gradually.However,changes of LDH in pleural effusion were different with those in serum and lung homogenate.The warm water bath rewarming in the absorption of hypothermic pleural effusion was faster than passive rewarming,Warm water bath rewarming seemed to promote absorption of hypothermia-induced pleural effusion,but without statistical significance.Conclusions The 3 values of the pleural effusion criteria in hypothermic rats continuously increased following rewarming and reached the standards of effusion fluid,which did not necessarily reflect the seriousness of inflammatory pleural damage.The possible mechanism involved might be associated with the decrease of pleural effusion after rewarming,and water absorption by the body might be greater than protein absorption.

Objective To establish hypothermia SD rat model induced by prolonged seawater immersion and to observe pathological damage to vital organs as well as certain important hematological parameters .Methods Twenty male adult Sprague-Dawley rats were randomly and equally divided into the normal control group and the hypothermia experimental group ( or simply the hypothermia group ) , each consisting of 10 rats.The control group was left there without any treatment , while the hypothermia group was immersed in artificial seawater at 20 ℃ for 24 hours to observe changes in vital signs of the rats during cold seawater immersion .At the end of the experiment , body temperature , general hematological parameters and pathological changes of vital organs were detected for further study .Results During the course of cold seawater immersion, the vital signs of the rats in the hypothermia group gradually worsened [( Heart rate before immersion (369 ±25.1) beats/min] vs (126.5 ±8.6) beats/min after immersion] (P<0.05).Respiratory rate before immersion was (92.8 ±7.2) times/min vs (43.9 ±3.8) times/min after immersion (P<0.05). Rectal temperature before immersion was (37.3 ±0.3) ℃vs (21.9 ±0.8) ℃ after immersion (P<0.05). After immersion, the blood routine detection indicated that hemoglobin level of the normal control group was (145.4 ±11.5) g/L, while that of the hypothermia group was (129.5 ±12.1) g/L ( P<0.05); neutrophil percentage of the normal control group was (18.3 ±3.5) ％, while that of the hypothermia group was (34.9 ± 6.1) ％(P<0.05).Prothrombin time (PT) of the normal control group was (11.42 ±2.36) s, while that of the hypothermia group was (17.86 ±2.41) s (P<0.05); APTT of the normal control group was (12.97 ± 2.41) s while that of the hypothermia group was (17.28 ±2.33) s (P <0.05).As for biochemical parameters, alanine aminotransferase (ALT) of the normal control group was (70.40 ±15.48) U/L, while that of the hypothermia group was (183.00 ±61.62) U/L (P<0.05); aspartate transaminase (AST) of the normal control group was (115.1 ±14.8) U/L, while that of the hypothermia group was (722.3 ±248.2) U/L (P<0.05);blood urea nitrogen (BUN) of the normal control group was (9.08 ±2.44) mmol/L, while that of the hypothermia group was (21.45 ±3.43) mmol/L (P<0.05);creatinine of the normal control group was (24.71 ±6.27) μmol/L, while that of the hypothermia group was (28.08 ±5.19) μmol/L (P<0.05);CK-MB of the normal control group was (451.00 ±266.53) U/L, while that of the hypothermia group was (2854.4 ±1089.6) U/L, with significant differences (P<0.05).Pathological detection indicated that there were lesions to various extents in all the vital organs , with the lesions to the lungs and stomach being most serious, and pleural effusion induced by hypothermia was also present .Conclusion The SD rat model of hypothermia induced by prolonged seawater immersion was successfully established for subsequent studies .Our present study showed that lungs and stomach were important target organs involved in prolonged seawater immersion.

Objective To observe changes in blood biochemistry and coagulation function before and after warm water bath rewarming in SD rats with hypothermia induced by prolonged seawater immersion . Methods One hundred male Sprague-Dawley rats were randomly divided into the normal control group ( the NC group, without any treatment ) and the hypothermia group ( the HT group, exposed to seawater immersion at 20 ℃for 24 hours).The passive rewarming sub-groups (the pR group 1, 2, 3 and 4, n=10) (exposed to seawater immersion at 20 ℃for 24 hours +passive rewarming ) were respectively executed after rewarming at hour 0, hour 3, hour 6, and hour 12).The warm-water bath rewarming sub-groups (the wR group 1, 2, 3 and 4, n=10 ) ( exposed to seawater immersion at 20 ℃ for 24 hours +warm-water bath rewarming ) were respectively executed after rewarming at hour 0, hour 3, hour 6, and hour 12).Blood samples were taken from abdominal aorta for biochemical and coagulation detection .Results Zero to 3 hours after warm water bath rewarming , important parameters of hepatic and renal functions , as well as myocardial enzymes in the SD rats with hypothermia induced by prolonged seawater immersion remained at high levels or even increased to some extent.Only after 6 hours after rewarming , the above-mentioned parameters dropped considerably .However, coagulation indicators began to decline immediately after rewarming , and as compared with the passive rewarming , warm water bath rewarming could produce obviously better effects on the alleviation of abnormal hepatic and renal functions, as well as myocardial enzyme parameters (P<0.05).Conclusion Warm water bath rewarming could produce better effects on the recovery of serum biochemical parameters in rats with hypothermia induced by prolonged seawater immersion when compared with those of passive rewarming .

Objective To observe the effects of warm water bath active rewarming and passive rewarming on lung pathological injury and arterial blood gas of SD rats with hypothermia induced by prolonged seawater immersion.Methods One hundred male Sprague-Dawley rats were randomly divided into the normal control group (without any treatment) and the hypothermia group (seawater immersion at 20 ℃ for 24 h),The animals in the passive rewarming groups 1,2,3 and 4,each consisting of 10,had seawater immersion at 20 ℃for 24 h and received passive rewarming,and then they were respectively executed at 0,3,6 and 12 hours after rewarming,The animals in the active rewarming groups 1,2,3 and 4,each consisting of 10,underwent seawater immersion at 20 ℃ for 24 h and received active rewarming,and then they were sacrificed at 0,3,6and 12 hours after rewarming,Changes in lung pathology,arterial blood gas and other indicators were detected in all the animal groups.Results Both warm water bath active rewarming and passive rewarming all could help to restore lung injury and blood gas abnormality in rats with hypothermia induced by prolonged seawater immersion.Compared with that of the passive rewarming group [6 h:(7.6 ± 2.2) scores,12 h:(5.3 _± 1.3)scores],the recovery of lung pathological injury in warm water bath rewarming group was obviously better at 6 h(5.8 ± 1.2) scores and 12 h(3.8 ± 1.4) scores after rewarming,with statistical significance (P ＜ 0.05),and actual bicarbonate recovery was even better at 6 h after rewarming,also with statistical significance (P ＜0.05).Conclusions Compared with passive rewarming,warm water bath rewarming could significantly alleviate lung injury and arterial blood gas abnormality in hypothermic rats induced by prolonged seawater immersion,and it might produce even better effect on the prevention of rewarming-related acute respiratory distress syndrome.

Objective To investigate the dynamic changes in the nature of the pleural effusion via Light criteria in hypothermic rats induced by seawater immersion and analyze possible mechanism involved.Methods One hundred male Sprague-Dawley rats were randomly divided into the normal control group (without any treatment) and hypothermia group exposed to 20 ℃ seawater for 24 hours.Then,the hypothermia group was sub-divided into the passive rewarming groups 1,2,3 and 4 and warm water bath active rewarming groups 1,2,3 and 4,each consisting of 10 animals.The passive rewarming groups had passive rewarming after exposure to 20 ℃ seawater for 24 hours,while the active rewarming groups had warm water bath rewarming following exposure to 20 ℃ seawater for 24 hours.Then,all the animals in the sub-groups were executed 0,3,6 and 12 hours after rewarming.Serum,pleural effusion,total protein (TP) in pleural effusion,concentrations of lung homogenate lactate dehydrogenase (LDH) were measured,and Light criteria were calculated.Results There was no significant pleural effusion in the normal rats.LDH level in hypothermia-induced pleural effusion was higher than that in normal serum LDH,pleural effusion/total serum protein ratio (TPR) was lower than 0.5,and lactate dehydrogenase ratio (LDHR) was lower than 0.6.After rewarming,the amount of hypothermia-induced pleural effusion decreased gradually,while the levels of TPR and LDHR increased gradually.However,changes of LDH in pleural effusion were different with those in serum and lung homogenate.The warm water bath rewarming in the absorption of hypothermic pleural effusion was faster than passive rewarming,Warm water bath rewarming seemed to promote absorption of hypothermia-induced pleural effusion,but without statistical significance.Conclusions The 3 values of the pleural effusion criteria in hypothermic rats continuously increased following rewarming and reached the standards of effusion fluid,which did not necessarily reflect the seriousness of inflammatory pleural damage.The possible mechanism involved might be associated with the decrease of pleural effusion after rewarming,and water absorption by the body might be greater than protein absorption.

Objective To establish hypothermia SD rat model induced by prolonged seawater immersion and to observe pathological damage to vital organs as well as certain important hematological parameters .Methods Twenty male adult Sprague-Dawley rats were randomly and equally divided into the normal control group and the hypothermia experimental group ( or simply the hypothermia group ) , each consisting of 10 rats.The control group was left there without any treatment , while the hypothermia group was immersed in artificial seawater at 20 ℃ for 24 hours to observe changes in vital signs of the rats during cold seawater immersion .At the end of the experiment , body temperature , general hematological parameters and pathological changes of vital organs were detected for further study .Results During the course of cold seawater immersion, the vital signs of the rats in the hypothermia group gradually worsened [( Heart rate before immersion (369 ±25.1) beats/min] vs (126.5 ±8.6) beats/min after immersion] (P<0.05).Respiratory rate before immersion was (92.8 ±7.2) times/min vs (43.9 ±3.8) times/min after immersion (P<0.05). Rectal temperature before immersion was (37.3 ±0.3) ℃vs (21.9 ±0.8) ℃ after immersion (P<0.05). After immersion, the blood routine detection indicated that hemoglobin level of the normal control group was (145.4 ±11.5) g/L, while that of the hypothermia group was (129.5 ±12.1) g/L ( P<0.05); neutrophil percentage of the normal control group was (18.3 ±3.5) ％, while that of the hypothermia group was (34.9 ± 6.1) ％(P<0.05).Prothrombin time (PT) of the normal control group was (11.42 ±2.36) s, while that of the hypothermia group was (17.86 ±2.41) s (P<0.05); APTT of the normal control group was (12.97 ± 2.41) s while that of the hypothermia group was (17.28 ±2.33) s (P <0.05).As for biochemical parameters, alanine aminotransferase (ALT) of the normal control group was (70.40 ±15.48) U/L, while that of the hypothermia group was (183.00 ±61.62) U/L (P<0.05); aspartate transaminase (AST) of the normal control group was (115.1 ±14.8) U/L, while that of the hypothermia group was (722.3 ±248.2) U/L (P<0.05);blood urea nitrogen (BUN) of the normal control group was (9.08 ±2.44) mmol/L, while that of the hypothermia group was (21.45 ±3.43) mmol/L (P<0.05);creatinine of the normal control group was (24.71 ±6.27) μmol/L, while that of the hypothermia group was (28.08 ±5.19) μmol/L (P<0.05);CK-MB of the normal control group was (451.00 ±266.53) U/L, while that of the hypothermia group was (2854.4 ±1089.6) U/L, with significant differences (P<0.05).Pathological detection indicated that there were lesions to various extents in all the vital organs , with the lesions to the lungs and stomach being most serious, and pleural effusion induced by hypothermia was also present .Conclusion The SD rat model of hypothermia induced by prolonged seawater immersion was successfully established for subsequent studies .Our present study showed that lungs and stomach were important target organs involved in prolonged seawater immersion.

Objective To observe changes in blood biochemistry and coagulation function before and after warm water bath rewarming in SD rats with hypothermia induced by prolonged seawater immersion . Methods One hundred male Sprague-Dawley rats were randomly divided into the normal control group ( the NC group, without any treatment ) and the hypothermia group ( the HT group, exposed to seawater immersion at 20 ℃for 24 hours).The passive rewarming sub-groups (the pR group 1, 2, 3 and 4, n=10) (exposed to seawater immersion at 20 ℃for 24 hours +passive rewarming ) were respectively executed after rewarming at hour 0, hour 3, hour 6, and hour 12).The warm-water bath rewarming sub-groups (the wR group 1, 2, 3 and 4, n=10 ) ( exposed to seawater immersion at 20 ℃ for 24 hours +warm-water bath rewarming ) were respectively executed after rewarming at hour 0, hour 3, hour 6, and hour 12).Blood samples were taken from abdominal aorta for biochemical and coagulation detection .Results Zero to 3 hours after warm water bath rewarming , important parameters of hepatic and renal functions , as well as myocardial enzymes in the SD rats with hypothermia induced by prolonged seawater immersion remained at high levels or even increased to some extent.Only after 6 hours after rewarming , the above-mentioned parameters dropped considerably .However, coagulation indicators began to decline immediately after rewarming , and as compared with the passive rewarming , warm water bath rewarming could produce obviously better effects on the alleviation of abnormal hepatic and renal functions, as well as myocardial enzyme parameters (P<0.05).Conclusion Warm water bath rewarming could produce better effects on the recovery of serum biochemical parameters in rats with hypothermia induced by prolonged seawater immersion when compared with those of passive rewarming .