Objective To comapre and analyze the differences and commonalities of expression profiles of serum exosomal microRNA between patients with thyroid nodules and healthy persons at different iodine levels,and then provide evidence for screening early diag-nostic markers of thyroid nodules at different iodine levels.Methods The peripheral blood samples from 10 patients with thyroid nod-ules and healthy volunteers at different iodine levels were collected.Their serum iodine levels were measured by the arsenic cerium cat-alytic spectrophotometry.Serum exosomal microRNA were extracted and the expression levels of microRNA were determined by the high-throughput sequencing technology.The differential target genes were predicted and further performed Gene ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.Results Compared with healthy volunteers,there were 6 downreg-ulated miRNAs in the patients with thyroid nodules at different iodine levels,namely miR-324-5p,miR-6511b-3p,miR-9903,miR-550a-3p,miR-5001-3p,and miR-3688-3p.Differentially expressed exosomal microRNA could regulate the MAPK signaling path-way,PI3K-AKT signaling pathway,VEGF signaling pathway,and NF-κB signaling pathway.Conclusion Six differentially expressed microRNAs is identified,which may serve as biological markers for the early diagnosis of thyroid nodules at different iodine levels.

Objective Genotypes(G)1,3,and 5 of the Japanese encephalitis virus(JEV)have been isolated in China,but the dominant genotype circulating in Chinese coastal areas remains unknown.We searched for G5 JEV-infected cases and attempted to elucidate which JEV genotype was most closely related to human Japanese encephalitis(JE)in the coastal provinces of China. Methods In this study,we collected serum specimens from patients with JE in three coastal provinces of China(Guangdong,Zhejiang,and Shandong)from 2018 to 2020 and conducted JEV cross-neutralization tests against G1,G3,and G5. Results Acute serum specimens from clinically reported JE cases were obtained for laboratory confirmation from hospitals in Shandong(92 patients),Zhejiang(192 patients),and Guangdong(77 patients),China,from 2018 to 2020.Seventy of the 361 serum specimens were laboratory-confirmed to be infected with JEV.Two cases were confirmed to be infected with G1 JEV,32 with G3 JEV,and two with G5 JEV. Conclusion G3 was the primary infection genotype among JE cases with a definite infection genotype,and the infection caused by G5 JEV was confirmed serologically in China.

Objective:To analyze the growth characteristics of different genotypes of Japanese encephalitis virus (JEV) in different cell lines, and to provide scientific basis for the selection of cell lines in the study of JEV.Methods:BHK-21, Vero, C6/36, PK-15, DF-1, N2a, SH-sy5y and MDCK cell lines were selected. The proliferation ability of genotype 1 (NX1889 strain), genotype 3 (P3 strain) and genotype 5 (XZ0934 strain) JEV in these cell lines was evaluated by plaque assay and RT-qPCR.Results:Significant cytopathogenic effects (CPE) were observed in BHK-21, Vero, C6/36, DF-1, N2a and PK-15 cell lines across all three JEV genotypes. However, no significant differences in CPE characteristics were observed within the same cell line. SH-sy5y and MDCK cell lines did not show significant CPE, but virus proliferation was detected in SH-sy5y cell line, while MDCK cell line were found to be insensitive to JEV. No significant difference was observed in the proliferation curves of G1, G3 and G5 JEV in BHK-21, Vero and SH-sy5y cell lines. In C6/36 and PK-15 cell lines, the titer of G1 JEV was higher than that of G3 and G5. In DF-1 cell line, G5 demonstrated a higher titer than the other two genotypes, whereas in N2a cell line, G5 showed a lower titer than the other two.Conclusions:There are differences in the proliferation of three different genotypes of JEV in different cell lines, which can provide reference for the study of JEV in different directions.

Objective:In this study, the collected mosquito samples were subjected to viral isolation to identify the species and branch characteristics of arboviruses in five regions of Shanxi Province.Methods:Eight arboviruses in mosquito samples collected from July to September 2020 were detected by real-time fluorescent quantitative PCR, and virus isolation was carried out through cell culture. Virus isolates were identified and analyzed by molecular biology and bioinformatics method.Results:We detected 1 batch of positive samples of Japanese encephalitis virus, 2 batches of positive samples of Culex flavivirus and 8 batches of positive samples of Nam Dinh virus among 121 batches of mosquito samples. Seven virus isolates were isolated, numbered: SX-YJ-Cxp-4、SX-YJ-Ars-2、SX-YJ-Cxp-1、SX-LY-Cxp-10、SX-GP-Ars-5、SX-GP-Cxp-2、SX-GP-Cxp-4, all of which were identified as Nam Dinh virus, and the whole genome sequencing was performed on one of them, and the result showed that Shanxi Nam Dinh virus isolate and Yunnan Nam Dinh virus isolate belonged to the same evolutionary branch.Conclusions:Nam Dinh virus was isolated and identified on the specimen from Shanxi province for the first time.

Objective:To determine the evaluation indexes of national standard strains of genotypes 1, 3 and 5 of Japanese encephalitis virus (JEV) and evaluate the national standard JEV strains.Methods:According to the national standard strain evaluation technical standards of pathogenic microbial bacteria (virus) species, based on the application of Japanese encephalitis virus research, and according to the morphological characteristics, biological characteristics, molecular biological characteristics and other research data to identify the characteristics of G1, G3 and G5 genotypes of JEV.Results:Spherical virus particles with a diameter of about 60 nm were visible under electron microscope of the three Japanese encephalitis virus strains. The cytopathic effect was mainly characterized by cell shrinkage and exfoliation in BHK-21 and Vero cell lines, cell fusion and exfoliation were shown after infection with C6/36 cell line; the virus titer was 10 5-10 7 PFU/ml, and the plaque size was different by genotype. The median lethal dose of intrabitoneal challenge in G1, G3 and G5 JEV in three weeks-old mice was 50.51 PFU, 6.98 PFU, and 8.13 PFU, and the median lethal dose of intracranial challenge in five weeks mice was 3 PFU, 0.3 PFU, 1.35 PFU. The whole genome length of G1, G3 and G5 JEV was 10 967 bp, 10 976 bp and 10 983 bp, respectively. Conclusions:Three genotypic national standard strains of JE V were identified and evaluated by electron microscopy, cell, animal and genome laboratory indexes, which provided reference for the identification and evaluation of other national standard strains of JEV.

Objective:To establish a rapid method for the detection of varicella-zoster virus (VZV) by recombinase-aid amplification (RAA).Methods:The whole genome sequences of VZV were downloaded from the global shared database for comparison and analysis. Specific primers and probe were designed for the four conserved genes respectively and the optimal combination was selected. The optimal reaction system was selected through the concentration gradient of primers and probes, and a fluorescence RAA detection method was established. The sensitivity of the method was evaluated with VZV positive plasmid standard and clinical samples with gradient dilution, the repeatability of the method was evaluated with the lowest detectable limit concentration of positive plasmid standard, and the specificity of other viral nucleic acid method was evaluated. At the same time, this method and quantitative real-time PCR (qPCR) were used to detect clinical samples and the result were compared.Results:The optimal combination of primer pair F2/R2 and probe P2 targeting open reading frame (ORF) 28 gene was selected. Considering the cost factor, the optimal primer concentration was set at 500 nmol/L and the optimal probe concentration was 280 nmol/L. The minimum detection limit was 10 1 copies/μL, and the minimum clinical positive samples with a Ct value of 36.027 could be detected, and the result of repeated experiments were consistent. The method has no cross-reaction with other viral nucleic acids. The detection rate of clinical positive samples was 93.33%, which was almost identical to that of qPCR. Conclusions:This method is simple to operate with high sensitivity, strong specificity, low requirements for experimental conditions, visual detection result, and can detect VZV nucleic acid in samples within 20 minutes, which is a rapid VZV detection method that can be considered for clinical use for detection.

Objective To monitor ventilator-associated event (VAE) for the first time in an intensive care unit (ICU) in China,understand the applicability,incidence,and clinical significance of VAE in China.Methods Targeted monitoring on VAE was performed among patients ≥18 years and with mechanical ventilation (MV)＞2 days in the ICU of a hospital between January 2014 and September 2015,incidence of VAE was calculated,and patients were grouped according to whether or not they had VAE,prognostic factors were analyzed statistically.Results A total of 1 004 patients were monitored,the total hospital stay was 13 795 days in patients who used ventilator,307 (30.58％) cases of VAE occurred,incidence of VAE per 1 000 ventilator-days was 22.25.Univariate analysis showed that patients with VAE had longer length of ICU stay and MV,and higher mortality rate than patients without VAE when they moved out of ICU (all P＜0.05).Multivariate logistic regression analysis showed that VAE was independent risk factor for length of ICU stay,duration of MV,as well as mortality when patients moved out of ICU(all P＜0.05).Conclusion Judgment of VAE is based on MV parameters,it is more objective and accurate.There is a high incidence of VAE among ICU patients,it may lead to poor clinical outcomes,and has good values for the targeted monitoring on ICU patients in large comprehensive hospitals of China.

Objective To understand the infection caused by multidrug-resistant organisms(MDROs)in a neurological in-tensive care unit (Neuro-ICU),and evaluate the effect of comprehensive intervention measures.Methods Targeted monito-ring on MDROs among patients who hospitalized in a Neuro-ICU for >48 hours between March and December 2011 was implemented,comprehensive intervention measures were taken,MDRO infection before and after intervention was com-pared.Results A total of 932 patients were monitored,72 (7.73%)developed MDRO healthcare-associated infection (HAI);the top five MDROs were Acinetobacter baumannii ,Klebsiella pneumoniae ,Pseudomonas aeruginosa ,Staphylo-coccus aureus ,and Escherichia coli .The main infection site of MDRO infection was lower respiratory tract,followed by urinary tract and bloodstream.Detection rates of MDROs before and after intervention were 11.70%(n=55)and 3.68%(n=17)respectively(χ2 =16.675,P <0.001).Conclusion Patients in Neuro-ICU are prone to develop MDRO infection, comprehensive intervention measures can reduce the incidence of HAI.

Objective To explore strategies and measures to improve hand hygiene (HH)compliance and correctness of health care workers (HCWs)in a large hospital.Methods The WHO multimodal hand hygiene improvement strategy was adopted by healthcare-associated infection(HAI)management department of a hospital,measures consisted of five key com-ponents,including:system change,education and training,evaluation and feedback,reminders in the workplace,and insti-tutional safety climate.HH compliance and correctness of HCWs were observed by infection control practitioners,HH compliance and correctness in January-June of 2012 (pre-intervention)and January-June of 2014 (post-intervention)were compared,effectiveness of intervention strategies were evaluated.Results HH compliance rate and correctness rate of post-intervention were both higher than pre-intervention (75.92% [8 369/11 023]vs 53.67% [5 127/9 553],P <0.001;94.11%[7 782/8 269]vs 83.88%[3 642/4 342],P <0.001).Of different occupations,HH compliance rates of doctors and nurses were significantly different before and after intervention (both P <0.001),while workers and staff of other oc-cupations before and after intervention were not significantly different(both P >0.05).Except ‘after body fluid exposure’, HH compliance rates of the other four indications for HH before and after intervention were significantly different(all P <0.001).Conclusion HH compliance and correctness of HCWs can be improved after adopting WHO multimodal hand hy-giene improvement strategy.

Objective To explore the risk factors and prognosis of hospitalized patients with bloodstream infection due to carbapenem-resistant Acinetobacter baumannii (CRAB).Methods 163 patients with CRAB bloodstream in-fection from 2010 to 2013 were conducted retrospective case-control study,68 patients with bloodstream infection due to carbapenem-susceptible Acinetobacter baumannii (CSAB)during the same period were as control group. Results The independent risk factors for CRAB bloodstream infection were stay in intensive care unit(ICU)(OR, 1 .27[95%CI ,5.55-22.89])and emergency department(OR,3.57 [95%CI ,1 .67 -7.62])before infection.Pa-tients with CRAB bloodstream infection had lower 28-day survival rate than those with CSAB bloodstream infection (66.17% vs 96.95%,χ2 =15.71 ,P <0.001 ).The independent risk factors for influencing prognosis of Acineto-bacter baumannii bloodstream infection were infection of CRAB (HR 95% CI ,3.01 -67.28),blood disease(HR 95%CI ,3.77-25.97),cardiac insufficiency(HR 95%CI ,2.10-20.41),stay in ICU(HR 95%CI ,1 .01 -5.28), and age(HR 95%CI ,1 .01 -1 .04).Conclusion The independent risk factors for CRAB bloodstream infection are stay in ICU and emergency department before infection,CRAB bloodstream infection is risk factor for influencing prognosis of patients.