Objective:To characterize the complete genome sequence and elucidate the structural features of norovirus (NoV) isolate SD20200267.Methods:The viral nucleic acid was extracted from patient samples, followed by amplification and sequencing for genotyping based on the nucleotide sequences. The metagenomic sequencing technology was utilized for whole genome sequencing, and subsequent analysis was performed on the acquired nucleotide sequences.Results:The complete genome sequence of the SD20200267 strain, spanning a total length of 7 465 nucleotides, was successfully obtained. The SD20200267 strain belongs to the GⅡ.12 and GⅡ.P16 genotypes in the VP1 and RdRp regions, respectively. The nucleotide sequence identity of SD20200267 strain with other GⅡ.12[P16] strains ranged from 96.0% to 97.3%, exhibiting 15 amino acid variations. The strain displayed evidence of recombination, with the recombination site located in the overlapping region of ORF1 and ORF2.Conclusions:SD20200267 is classified as a GⅡ.12[P16] strain, and recombination was observed in the overlapping region of ORF1 and ORF2.

Objective:To investigate the effects of human umbilical cord mesenchymal stem cell (hUCMSC) exosomes in the treatment of full-thickness skin defect wounds in mice through local wound application, subcutaneous injection at the wound margin, and tail vein injection, and to explore the optimal administration route of hUCMSC exosomes for wound treatment.Methods:This study was an experimental study. hUCMSC exosomes were extracted from the discarded umbilical cord tissue of three normal delivery women aged 25-35 years in the Department of Obstetrics and Gynecology of Baogang Hospital of Inner Mongolia and successfully identified. Totally 120 male BALB/c mice aged 6-8 weeks were selected, and full-thickness skin defect wounds were prepared on the back of them. According to the random number table, the injured mice were divided into control group (without drug administration), local wound application group, wound margin subcutaneous injection group, and tail vein injection group (with 30 mice in each group). Mice in the latter three groups were given 0.2 mL phosphate buffer solution containing 200 μg hUCMSC exosomes by local wound application, subcutaneous injection at the wound margin, and tail vein injection, respectively. On post injury day (PID) 7, 14, and 21, the general condition of the wound was observed, and the wound healing rate was calculated; the wound tissue was collected, the pathological changes and collagen fibers were observed respectively by hematoxylin-eosin staining and Masson staining, the number of new microvessels was observed by CD31 immunohistochemical staining, and the content of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) was detected by enzyme-linked immunosorbent assay. The sample number was 10 in each group at each time point.Results:On PID 7, 14, and 21, the wounds of mice in the 4 groups all healed gradually, and the wound healing of the mice in wound margin subcutaneous injection group was the best; the wound healing rates of mice in the three administration groups were significantly higher than those in control group ( P<0.05), the wound healing rates of mice in wound margin subcutaneous injection group and tail vein injection group were significantly higher than those in local wound application group ( P<0.05), and the wound healing rates of mice in wound margin subcutaneous injection group were significantly higher than those in tail vein injection group ( P<0.05). On PID 7, 14, and 21, the growth and epithelialization speed of the wound tissue of mice in the three administration groups were significantly accelerated, and the collagen fibers in the wounds of mice in the three administration groups were larger in number and more neatly arranged in comparison with the control group. On PID 7, 14, and 21, under every 200-fold visual field, the number of new microvessels in the wound tissue of mice in local wound application group was 24.1±2.5, 50.7±4.1, and 44.2±2.3, respectively, the number of new microvessels in the wound tissue of mice in wound margin subcutaneous injection group was 32.2±2.9, 67.5±4.9, and 53.6±3.7, respectively, and the number of new microvessels in the wound tissue of mice in tail vein injection group was 27.8±2.4, 59.1±3.7, and 49.6±2.6, respectively, which was significantly more than 20.6±1.7, 46.7±3.4, and 40.9±2.8 in control group ( P<0.05); the number of new microvessels in the wound tissue of mice in wound margin subcutaneous injection group and tail vein injection group was significantly more than that in local wound application group ( P<0.05); the number of new microvessels in the wound tissue of mice in wound margin subcutaneous injection group was significantly more than that in tail vein injection group ( P<0.05). On PID 7, 14, and 21, the content of TNF-α and IL-6 in the wound tissue of mice in the three administration groups was significantly less than that in control group ( P<0.05), the content of TNF-α and IL-6 in the wound tissue of mice in wound margin subcutaneous injection group and tail vein injection group was significantly less than that in local wound application group ( P<0.05), and the content of TNF-α and IL-6 in the wound tissue of mice in wound margin subcutaneous injection group was significantly less than that in tail vein injection group ( P<0.05). Conclusions:Local wound application, subcutaneous injection at the wound margin, and tail vein injection of hUCMSC exosomes can all promote the wound healing of full-thickness skin defects in mice through alleviating excessive inflammatory response and promoting angiogenesis. Among them, subcutaneous injection at the wound margin has a better therapeutic effect, indicating subcutaneous injection at the wound margin is the optimal administration route for hUCMSC exosomes in wound treatment.

Objective:To investigate the drug-resistant gene characteristics and core genome characteristics of carbapenem-resistant Enterobacter cloacae (CR-ECL) in rural residents of Weifang City, Shandong Province. Methods:Fecal samples were collected from rural community residents in Weifang City, Shandong Province in 2017. Drug-resistant strains were screened using a carbapenem-resistant enterobacter chromogenic medium. CR-ECL positive strains were acquired via Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry(MALDI-TOFMS) analysis. The antibiotic resistance phenotype of CR-ECL was determined using a microbroth dilution assay. Whole genome sequencing (WGS) and analysis were conducted, along with an examination of the immediate vicinity of the blaNDM gene and phylogenetic analysis of the strains. Results:A total of 628 fecal samples were collected and tested, of which 6 were CR-ECL positive (detection rate 0.96%), all exhibiting multiple drug resistance (MDR) phenotypes. Six CR-ECL strains had four MLST genotypes (ST), all of which carried multiple drug resistance genes ( blaNDM-1, blaNDM-5, etc.) and virulence genes ( acrA, acrB, entB, fepC, etc.). There were mobile genetic elements ISAba125, TN3-IS3000, TN3 and IS5 in the genetic environment surrounding the blaNDM gene. The phylogenetic tree showed that the multi-locus sequence typing of the core genome (cgMLST) was consistent with the single nucleotide polymorphism (SNPs) results. The cgMLST results showed that the allele differences between strains 2BC0101B and 2BC0251B, 2BG0561B and 2BI0221B were 2 and 1, respectively. The SNPs results showed that the above two pairs of bacteria also clustered together. It was found that the strains of chicken fecal samples in the National Center for Biotechnology Information (NCBI) database were located in the center of the evolutionary tree, and the local sequences could be traced back to American human sequences. Conclusion:Multidrug-resistant CR-ECL is detected in rural community residents in Weifang City, Shandong Province.

BACKGROUND:It is known that N6-methyladenosine(m6A)plays a role in the pathogenesis of various diseases and studies have suggested its involvement in the pathologic changes of steroid-induced femoral head necrosis(SNFH).However,research on m6A methylation modifications in steroid-induced femoral head necrosis is limited. OBJECTIVE:Using bioinformatics methods to identify the differential expression of m6A-related genes in steroid-induced femoral head necrosis and to predict miRNAs associated with these genes to further elucidate the role and mechanism of m6A methylation in steroid-induced femoral head necrosis. METHODS:Differential gene expression between steroid-induced femoral head necrosis and control groups was analyzed using GSE123568 gene expression data and identified using the"limma"package in R.Functional enrichment analysis was performed on the differentially expressed genes.Differential analysis of the related genes was carried out using the"ggstatsplot"package in R.The differential genes were cross-validated using the GSE74089 dataset.An mRNA-miRNA regulatory network was constructed,and co-expression analysis was performed on the module genes followed by enrichment analysis.Differences in immune cell infiltration between steroid-induced femoral head necrosis and control groups were quantified using the ssGSEA method. RESULTS AND CONCLUSION:Correlation analysis revealed 13 m6A-related genes,and further analysis through the protein-protein interaction network identification and receiver operating characteristic curve analysis showed that YTHDF2 was expected to be a core differential gene as a potential early biomarker.Enrichment analysis indicated that differentially expressed genes were mainly involved in inflammation and immune response and were closely related to osteoclasts.Cross-validation analysis showed that differential gene expression results between the two datasets were consistent.mRNA-miRNA regulatory network analysis revealed that YTHDF2 was negatively correlated with miRNA-27a.Immune infiltration analysis revealed an increase in immune cell infiltration in steroid-induced femoral head necrosis,and YTHDF2 was positively correlated with the infiltration of CD4+T cells.To conclude,m6A-related gene YTHDF2 can serve as a potential biomarker of steroid-induced femoral head necrosis and is valuable for the early clinical diagnosis and treatment of steroid-induced femoral head necrosis.The negative correlation between YTHDF2 and mir-27a and the positive correlation between YTHDF2 and CD4+T cell infiltration provide new insights into the early diagnosis and treatment of steroid-induced femoral head necrosis and shed light on the mechanism of m6A in steroid-induced femoral head necrosis.

Objective:To investigate the drug resistance status and genomic characterization of Proteus mirabilis (PM) isolated from outpatient cases with diarrhea in Tai′an City and Laizhou City, Shandong Province. Methods:A total of 510 fecal samples were collected from 510 patients with acute diarrhea admitted to 43 sentinel hospitals in Tai′an City and Laizhou City, Shandong Province, between January 2021 and December 2022. The samples were cultured and isolated to identify Proteus spp. by direct inoculation, the drug susceptibility testing was performed by microbroth dilution method, and resistance genes and virulence genes were obtained by whole genome sequencing and bioinformatic analysis, thereby revealing the genetic environment surrounding the blaOXA-1 and blaCTX-M-65 genes. Single nucleotide polymorphism (SNP) analysis and core genome multilocus sequence typing (cgMLST) were conducted on the current strains and 100 PM isolates downloaded from the National Center for Biotechnology Information (NCBI) database via customizable methods utilizing RidomSeqSphere+ software, with the objective of exploring the phylogenetic relationships among the strains. Results:A total of 35 strains of Proteus were isolated from 510 fecal samples, including 31 strains of PM with a detection rate of 6.08% (31/510) and four strains of Proteus vulgaris.The multidrug resistance rate of PM was 100.00% (31/31).The 35 isolates carried a total of 43 resistance genotypes.Thirteen strains of PM carried blaOXA-1, six strains carried both blaOXA-1 and blaCTX-M-65, and 15 PM strains carried at least 15 antibiotic resistance genes (ARGs). The virulence genes included ureA, mrpA, ZapA, hpmA and so on. blaOXA-1 and blaCTX-M-65 genes were surrounded by mobile elements such as Tn3, ISL3 and IS6. cgMLST showed consistency with the SNP clustering results. Isolate 2022LZ41 from Laizhou City clustered with isolates 2022TA018, 2022TA017 and 2022TA019 from Tai′an City, with the number of allelic differences ranging from zero to two, and the Laizhou City isolate 2022LZ40 was highly genetically related to strain CRK0056 (human, USA, 2015). Conclusions:PM isolated from patients with diarrhea is multidrug-resistant, carrying many resistance and virulence genes.The presence of mobile genetic elements can lead to horizontal transfer of resistance genes.

Objective:To characterize and analyze the genetic variation of hemagglutinin (HA) of influenza A (H1N1) pdm09 subtype virus in Shandong Province, and explore the genetic variation patterns for providing reference for influenza monitoring, epidemic prevention and control, and vaccine strain selection.Methods:HA gene sequences of the recommended strains of influenza vaccine from 2009 to 2024 and the representative strains of each branch were downloaded from the GISAID Influenza Data Platform, and were phylogenetically analyzed and characterized in terms of amino acid site variation with the HA gene sequences of 298 influenza A (H1N1) virus strains isolated from Shandong Province. A phylogenetic tree was constructed using the maximum likelihood (ML) method of the IQ-TREE online tool, and the amino acid site variants were viewed using MegAlign software. The potential glycosylation sites of the HA gene were predicted using the NetNGlyc 1.0 online software.Results:The HA gene homology of the 298 influenza A (H1N1) viruses isolated in Shandong Province ranged from 91.2% to 100.0%. The evolutionary branches were gradually distantly related over time, but the direction of evolution was roughly the same as that in other provinces. Amino acid mutations in the HA occurred every year and most were found in the antigenic determinants.Conclusions:The HA genes of influenza viruses isolated in Shandong Province from 2009 to 2024 are still in the process of continuous evolution, and continuous monitoring of the epidemiological trends and the evolutionary directions of influenza viruses is essential for early warning of influenza virus pandemics.

OBJECTIVE To explore the role of Yes-associated protein(YAP)in epidermal stem cell(EPSC)differentiation after ionizing radiation(IR).METHODS ① A punch was used to induce skin injuries on the back of mice.The IR group received localized irradiation with 60 Co γ-rays,while the normal control group did not.Samples were collected at 0,1,3,6,9,and 12 d for RNA and protein extraction.Western blotting was used to detect changes in YAP protein expressions during wound healing.Real-time quantitative polymerase chain reaction(RT-qPCR)was performed to assess the mRNA levels of Yap and its downstream target genes,connective tissue growth factor(Ctgf),and cysteine-rich protein 61(Cyr61).② EPSCs were exposed to 60 Co γ at a dose of 4 or 8 Gy,while the control group was not irradiated.Cells were collected to detect the levels of YAP protein via Western blotting.Cells were collected at 4,12,24,and 36 h post-IR to assess the levels of YAP mRNA by RT-qPCR.③ Short hairpin RNA(shRNA)was used to establish stable YAP knockdown cell lines,and the knockdown efficiency of sh YAP was verified by Western blotting.RT-qPCR was then performed to detect the impact of YAP knockdown on mRNA levels of K1 and K10 after IR.RESULTS① Compared with the control group,the YAP protein level in the IR group during wound healing was significantly reduced(P<0.05,P<0.01),so were the mRNA levels of Yap and its downstream target genes Ctgf and Cyr61(P<0.05,P<0.01).② Compared to the cell control group,the mRNA and protein levels of YAP in the IR group cells were significantly reduced(P<0.01).③ In the sh YAP cells,the YAP protein level was significantly reduced(P<0.01).Furthermore,the mRNA levels of K1 and K10 were significantly decreased after IR in sh YAP cells(P<0.01).CONCLUSION YAP can regulate EPSC differentiation in wound healing after IR.

Objective:To study the infection of human rhinovirus, respiratory syncytial virus and human adenovirus in Jinan from April 2018 to March 2019, and analyze epidemiological characteristics of human adenovirus.Methods:All of 1969 nasopharyngeal swabs were collected from hospitalized patients with acute respiratory tract infections in The Fourth People’s Hospital of Jinan, Qilu Children′s Hospital of Shandong University, Peoples Hospital of Zhangqiu District from April 2018 to March 2019, fluorescence quantitative PCR was used to detect the positive rate of human rhinovirus, respiratory syncytial virus and human adenovirus. Seven adenovirus positive samples were isolated and examined by sequencing, then we determined adenovirus type, constructed gene phylogenetic trees for analysis.Results:Of the 1969 samples, 242 were positive, the total positive rate was 12.30% (242/1969), the positive rate was 3.00% (59/1969) for rhinovirus, 6.30% (124/1969) for respiratory syncytial virus (RSV), and 3.86% (76/1969) for adenovirus. There was no significant difference in the detective rate of rhinovirus in different age groups (Fisher′s exact test value =8.376, P=0.720), the positive rates of RSV and adenovirus in different age groups was statistically significant ( χ2=19.28, 12.16; P=0.001, 0.016). There was a statistically significant difference in the positive rate of adenovirus between different sexes ( χ2=14.33, P<0.001), and there was no statistically significant difference in the positive rate of rhinovirus and RSV between males and females ( χ2=0.30, 2.90, P=0.862, 0.089). Comparing the positive rates of viral nucleic acid in different months, we found that the positive rate of rhinovirus, RSV and adenovirus separately reached the highest in October, December and November (8.61%, 26.50% and 8.84%). We constructed a gene phylogenetic tree after seven positive samples of adenoviruses were sequenced, by the molecular typing method we detected that seven adenovirus-positive samples were all HAdV-2 type. Conclusions:By comparing the epidemiological trends of human rhinovirus, RSV and human adenovirus in Jinan from April 2018 to March 2019 in different ages, genders, and months, providing reference basis for the early prevention and clinical treatment of acute respiratory tract infection.

Enterotoxigenic Escherichia coli（ETEC）infection can induce watery diarrhea，leading to dehydration，electrolyte disturbance，and even death in severe cases. Recombinant B subunit/inactivated whole-cell cholera（rBS/WC）vaccine is effective in preventing ETEC infectious diarrhea. On the basis of the latest evidence on etiology and epidemiology of ETEC，as well as the effectiveness，safety，and health economics of rBS/WC vaccine，National Clinical Research Center for Child Health（The Children’s Hospital，Zhejiang University School of Medicine）and Zhejiang Provincial Center for Disease Control and Prevention invited experts to develop expert consensus on rBS/WC vaccine in prevention of ETEC infectious diarrhea. It aims to provide the clinicians and vaccination professionals with guidelines on using rBS/WC vaccine to reduce the incidence of ETEC infectious diarrhea.