Objective:To analyze the epidemiological characteristics and infection sources of cholera in China from 2005 to 2024.Methods:A total of 2 066 cholera cases were included in the study, which were obtained from the China Disease Control and Prevention Information System (CDPCIS) of China CDC. The information on cholera clusters was downloaded from the National Public Health Emergency Event Surveillance System (PHEESS) of China CDC. A total of 128 cholera clusters were included and analyzed in this study. The epidemiological characteristics and infection sources of cholera were analyzed. The Jointpoint model was applied to analyze the incidence trend, and annual percentage change (APC) was also quantified.Results:From 2005 to 2024, a total of 2 066 cholera cases were reported, with an average of 103 cases reported annually. Specifically, the incidence showed a marked downward trend from 2004 to 2015 ( APC=-26.78%, P=0.006). During 2015-2024, the disease remained at low endemic levels, with an average of 18 reported cases annually ( APC=-2.68%, P=0.807). Cholera peak season was from May to October. A total of 24 provinces reported cholera cases, which were mainly distributed in Zhejiang, Fujian, Beijing, Jiangsu, Anhui, Guangdong, and Hainan provinces, accounting for 78.03% of the total cases. Pathogen surveillance indicated an alternating prevalence of Vibrio cholerae serogroups O1 and O139 among laboratory-confirmed cases between 2005 and 2024. There was a disparity in the dominant serogroup of Vibrio cholerae by region. The results from 128 cholera clusters indicated that cholera outbreaks frequently occurred in rural banquets (64.84%), followed by regular restaurants (13.28%). Among these, 63 clusters (49.22%) with identified infection sources indicated that foodborne transmission (95.24%) was the primary mode of cholera transmission, which mainly through seafood and aquatic products, such as soft-shelled turtles, shrimp and shellfish. The characteristics of cholera clusters caused by Vibrio cholerae serogroups O1 and O139 showed statistically significant differences in scale, attack rate, place of residence, setting, and infection source ( P<0.05). Conclusion:Cholera incidence has remained consistently low since 2015 in China, mainly in sporadic cases. Rural gatherings (e.g., wedding banquets) are the main settings for cholera clusters. The main infection sources are predominantly caused by cross-contamination due to improper processing practices of aquatic products, such as soft-shelled turtles.

In order to establish a serological method for the detection of bovine parainfluenza virus type 3(BPIV3),the prokaryotic expression and purification of BPIV3 HN,NP,F,and P proteins were carried out,and the optimal protein-coated antigen was screened,and an indirect ELISA de-tection method was established.The results showed that the four recombinant proteins of BPIV3,rHN,rNP,rF,and rP were expressed,and the checkerboard titration results showed that rHN pro-tein had the highest P/N value as the coating protein,so it was used for the subsequent method es-tablishment.The optimal reaction conditions for indirect ELISA were found to be:the mass con-centration of the antigen coating was 0.5 mg/L,37 ℃ 1.5 h,5％skim milk,overnight blocking at 4 ℃,serum dilution at 1∶50,incubation at 37 ℃ 1 h,secondary antibody dilution at 1∶10 000 and incubation at 37℃ 0.5 h,substrate reaction conditions were 37℃ for 12 min.The results of speci-ficity experiments showed that the established method could specifically identify BPIV3 antibody-positive serum with a sensitivity of 1∶800,and the coefficient of variation in the detection of intra-and inter-assay repeatability was less than 10％,and the overall coincidence rate of the same batch of samples detected with the SVANOVIR kit was 92.22％.This method was used to detect 192 se-rum samples in Hebei Province,and the positive rate of BPIV3 antibody in serum was 66.15％.The indirect ELISA detection method of BP1V3 antibody constructed in this study is suitable for large-scale clinical serological investigations,and provides valuable data support for the research and de-velopment of BPIV3 antigen and antibody detection kits in China.

Objective To explore the correlations of spatial distribution frequency map of posterior reversible encephalopathy syndrome(PRES)and cerebral microvascular density map,cerebral blood flow(CBF)map,standard template of cerebral metabolic imaging and the spatial gene transcription map of human brain based on normative analysis strategy,and to analyze the pathophysiological mechanisms of PRES.Methods Cerebral MRI data of 184 patients with PRES were retrospectively analyzed.ROI of the lesions were delineated on T1WI,then registered to Montreal Neurological Institute(MNI)standard space.The spatial distribution frequency map of PRES lesions were obtained with superposition.Spatial correlation analysis were performed to observe correlations of spatial distribution frequency map of PRES and the cerebral microvascular density map,CBF map and standard template of cerebral metabolic imaging based on large sample.The potential related gene expressions were decoded based on gene expression data of Allen human brain atlas,and the correlations of spatial parts of PRES and those expressions were observed.Results No significant correlation was found between spatial distribution frequency map of PRES and cerebral microvascular density,CBF nor distribution of neurotransmitters(all P＞0.05).PLS1 weighted genes,VEGF-A gene,AQP-4 gene and RGS2 gene were all correlated with spatial distribution of PRES(r=-0.363-0.653,all P＜0.05),among which KCNAB3 gene had the highest weight(Z=17.288).Conclusion The spatial patterns of PRES risk or protective genes in brain regions were correlated with regional distribution of PRES lesions,which was consistent with arginine vasopressin(AVP)theory of the occurrence and development of PRES.

In order to establish a serological method for the detection of bovine respiratory syncytial virus,the prokaryotic expression of four proteins of BRSV,G,F,P,and M was carried out,and the most suitable coating antigen was screened to establish an indirect ELISA detection method.The results showed that the four recombinant proteins of BRSV,rG,rF,rP and rM were successfully expressed.The results of checkerboard screening showed that the P/N value of rG protein was the largest,which was determined to be the best coating antigen established by indirect ELISA meth-od.The optimal reaction conditions for indirect ELISA were as follows:the mass concentration of rG protein coating was 1 mg/L,37℃ for 2 h;3％BSA 37℃ block for 1 h;Serum was diluted 1∶50 and incubated at 37℃ for 1h;Secondary antibody 1∶5 000 dilution,37℃ for 30min;The color development conditions of the substrate were 37℃ for 15 min;Thirty negative sera were selected,and the cut-off value was determined to be 0.63 by the established indirect ELISA method.The re-sults of the specificity test showed that the indirect ELISA method established in this test only recognized BRSV-positive serum,and did not react with IBRV,BCoV,and BPIV3-positive serum.The results of repeatability test showed that the method had good repeatability,and the coefficient of variation within and between batches was less than 10％.The results of the sensitivity test showed that the BRSV-positive serum was still positive when diluted to 1∶8 192.The indirect ELISA method established in this experiment was used to detect 100 clinical serum samples at the same time,and the total coincidence rate of the two reached 90.48％,the positive coincidence rate was 93.42％,and the negative coincidence rate was 82.75％.The indirect ELISA established in this test can be used for the detection of bovine respiratory syncytial virus in clinical practice.

In order to investigate the role of sRNA OxyS in the pathogenicity of Salmonella typhi-murium infection,the OxyS gene deletion strain ATCC25241 △OxyS and the back-complemented strain ATCC25241 △OxyS/OxyS of Salmonella typhimurium ATCC25241 were constructed by using λRed homologous recombination technique.We investigated the effect of OxyS deletion on the biological characteristics and pathogenicity of Salmonella typhimurium ATCC25241.The re-sults showed that the deletion of OxyS did not affect the growth rate,the ability of biofilm forma-tion,and the ability of adhesion,invasion and intracellular survival of Salmonella typhimurium,but significantly reduced the motility of Salmonella typhimurium as well as its ability to survive in alkaline and oxidative environments.The results of mouse infection test showed that OxyS dele-tion caused a significant decrease in the virulence of Salmonella typhimurium in mice,and toxicity is reduced obviously.The qPCR results also showed that OxyS deletion could lead to changes in the transcript levels of a number of virulence-related genes of Salmonella typhimurium such as pipB,orf245,csgA,invH,tatA,sipA,sipB,and so on.The above results indicate that OxyS gene affects the biological characteristics and pathogenicity of Salmonella typhimurium and is an important virulence regulator of Salmonella typhimurium.

Objective:To analyze the epidemiological characteristics and infection sources of cholera in China from 2005 to 2024.Methods:A total of 2 066 cholera cases were included in the study, which were obtained from the China Disease Control and Prevention Information System (CDPCIS) of China CDC. The information on cholera clusters was downloaded from the National Public Health Emergency Event Surveillance System (PHEESS) of China CDC. A total of 128 cholera clusters were included and analyzed in this study. The epidemiological characteristics and infection sources of cholera were analyzed. The Jointpoint model was applied to analyze the incidence trend, and annual percentage change (APC) was also quantified.Results:From 2005 to 2024, a total of 2 066 cholera cases were reported, with an average of 103 cases reported annually. Specifically, the incidence showed a marked downward trend from 2004 to 2015 ( APC=-26.78%, P=0.006). During 2015-2024, the disease remained at low endemic levels, with an average of 18 reported cases annually ( APC=-2.68%, P=0.807). Cholera peak season was from May to October. A total of 24 provinces reported cholera cases, which were mainly distributed in Zhejiang, Fujian, Beijing, Jiangsu, Anhui, Guangdong, and Hainan provinces, accounting for 78.03% of the total cases. Pathogen surveillance indicated an alternating prevalence of Vibrio cholerae serogroups O1 and O139 among laboratory-confirmed cases between 2005 and 2024. There was a disparity in the dominant serogroup of Vibrio cholerae by region. The results from 128 cholera clusters indicated that cholera outbreaks frequently occurred in rural banquets (64.84%), followed by regular restaurants (13.28%). Among these, 63 clusters (49.22%) with identified infection sources indicated that foodborne transmission (95.24%) was the primary mode of cholera transmission, which mainly through seafood and aquatic products, such as soft-shelled turtles, shrimp and shellfish. The characteristics of cholera clusters caused by Vibrio cholerae serogroups O1 and O139 showed statistically significant differences in scale, attack rate, place of residence, setting, and infection source ( P<0.05). Conclusion:Cholera incidence has remained consistently low since 2015 in China, mainly in sporadic cases. Rural gatherings (e.g., wedding banquets) are the main settings for cholera clusters. The main infection sources are predominantly caused by cross-contamination due to improper processing practices of aquatic products, such as soft-shelled turtles.

In order to investigate the role of sRNA OxyS in the pathogenicity of Salmonella typhi-murium infection,the OxyS gene deletion strain ATCC25241 △OxyS and the back-complemented strain ATCC25241 △OxyS/OxyS of Salmonella typhimurium ATCC25241 were constructed by using λRed homologous recombination technique.We investigated the effect of OxyS deletion on the biological characteristics and pathogenicity of Salmonella typhimurium ATCC25241.The re-sults showed that the deletion of OxyS did not affect the growth rate,the ability of biofilm forma-tion,and the ability of adhesion,invasion and intracellular survival of Salmonella typhimurium,but significantly reduced the motility of Salmonella typhimurium as well as its ability to survive in alkaline and oxidative environments.The results of mouse infection test showed that OxyS dele-tion caused a significant decrease in the virulence of Salmonella typhimurium in mice,and toxicity is reduced obviously.The qPCR results also showed that OxyS deletion could lead to changes in the transcript levels of a number of virulence-related genes of Salmonella typhimurium such as pipB,orf245,csgA,invH,tatA,sipA,sipB,and so on.The above results indicate that OxyS gene affects the biological characteristics and pathogenicity of Salmonella typhimurium and is an important virulence regulator of Salmonella typhimurium.

Objective To explore the correlations of spatial distribution frequency map of posterior reversible encephalopathy syndrome(PRES)and cerebral microvascular density map,cerebral blood flow(CBF)map,standard template of cerebral metabolic imaging and the spatial gene transcription map of human brain based on normative analysis strategy,and to analyze the pathophysiological mechanisms of PRES.Methods Cerebral MRI data of 184 patients with PRES were retrospectively analyzed.ROI of the lesions were delineated on T1WI,then registered to Montreal Neurological Institute(MNI)standard space.The spatial distribution frequency map of PRES lesions were obtained with superposition.Spatial correlation analysis were performed to observe correlations of spatial distribution frequency map of PRES and the cerebral microvascular density map,CBF map and standard template of cerebral metabolic imaging based on large sample.The potential related gene expressions were decoded based on gene expression data of Allen human brain atlas,and the correlations of spatial parts of PRES and those expressions were observed.Results No significant correlation was found between spatial distribution frequency map of PRES and cerebral microvascular density,CBF nor distribution of neurotransmitters(all P＞0.05).PLS1 weighted genes,VEGF-A gene,AQP-4 gene and RGS2 gene were all correlated with spatial distribution of PRES(r=-0.363-0.653,all P＜0.05),among which KCNAB3 gene had the highest weight(Z=17.288).Conclusion The spatial patterns of PRES risk or protective genes in brain regions were correlated with regional distribution of PRES lesions,which was consistent with arginine vasopressin(AVP)theory of the occurrence and development of PRES.

In order to establish a serological method for the detection of bovine respiratory syncytial virus,the prokaryotic expression of four proteins of BRSV,G,F,P,and M was carried out,and the most suitable coating antigen was screened to establish an indirect ELISA detection method.The results showed that the four recombinant proteins of BRSV,rG,rF,rP and rM were successfully expressed.The results of checkerboard screening showed that the P/N value of rG protein was the largest,which was determined to be the best coating antigen established by indirect ELISA meth-od.The optimal reaction conditions for indirect ELISA were as follows:the mass concentration of rG protein coating was 1 mg/L,37℃ for 2 h;3％BSA 37℃ block for 1 h;Serum was diluted 1∶50 and incubated at 37℃ for 1h;Secondary antibody 1∶5 000 dilution,37℃ for 30min;The color development conditions of the substrate were 37℃ for 15 min;Thirty negative sera were selected,and the cut-off value was determined to be 0.63 by the established indirect ELISA method.The re-sults of the specificity test showed that the indirect ELISA method established in this test only recognized BRSV-positive serum,and did not react with IBRV,BCoV,and BPIV3-positive serum.The results of repeatability test showed that the method had good repeatability,and the coefficient of variation within and between batches was less than 10％.The results of the sensitivity test showed that the BRSV-positive serum was still positive when diluted to 1∶8 192.The indirect ELISA method established in this experiment was used to detect 100 clinical serum samples at the same time,and the total coincidence rate of the two reached 90.48％,the positive coincidence rate was 93.42％,and the negative coincidence rate was 82.75％.The indirect ELISA established in this test can be used for the detection of bovine respiratory syncytial virus in clinical practice.

In order to establish a serological method for the detection of bovine parainfluenza virus type 3(BPIV3),the prokaryotic expression and purification of BPIV3 HN,NP,F,and P proteins were carried out,and the optimal protein-coated antigen was screened,and an indirect ELISA de-tection method was established.The results showed that the four recombinant proteins of BPIV3,rHN,rNP,rF,and rP were expressed,and the checkerboard titration results showed that rHN pro-tein had the highest P/N value as the coating protein,so it was used for the subsequent method es-tablishment.The optimal reaction conditions for indirect ELISA were found to be:the mass con-centration of the antigen coating was 0.5 mg/L,37 ℃ 1.5 h,5％skim milk,overnight blocking at 4 ℃,serum dilution at 1∶50,incubation at 37 ℃ 1 h,secondary antibody dilution at 1∶10 000 and incubation at 37℃ 0.5 h,substrate reaction conditions were 37℃ for 12 min.The results of speci-ficity experiments showed that the established method could specifically identify BPIV3 antibody-positive serum with a sensitivity of 1∶800,and the coefficient of variation in the detection of intra-and inter-assay repeatability was less than 10％,and the overall coincidence rate of the same batch of samples detected with the SVANOVIR kit was 92.22％.This method was used to detect 192 se-rum samples in Hebei Province,and the positive rate of BPIV3 antibody in serum was 66.15％.The indirect ELISA detection method of BP1V3 antibody constructed in this study is suitable for large-scale clinical serological investigations,and provides valuable data support for the research and de-velopment of BPIV3 antigen and antibody detection kits in China.