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 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 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.

Objective To investigate the risk factors for multiple organ dysfunction syndrome(MODS)in elderly patients with severe stroke.Methods A total of 112 elderly severe stroke pa-tients admitted to our hospital from January 2020 to December 2022 were recruited prospectively,and then according to the results of sequential organ failure assessment(SOFA)within 14 d after admission,they were divided into MODS group(n=38)and non-MODS group(n=74).Based on their clinical outcomes,they were also assigned into survival group(n=-33)and death group(n=79).General clinical data,acute physiology,chronic health evaluationⅡ(APACHEⅡ)score,Glas-gow coma scale(GCS)score,and head computed tomography parameters were collected.Logistic regression analysis was used to analyze the risk factors of MODS.Results The MODS group had significantly larger proportions of stroke/hemorrhage,chronic obstructive pulmonary disease,cor-onary heart disease and smoking,higher NIHSS and APACHE Ⅱ scores,elevated ratios of multi-vessel disease,urinary tract infection,venous thrombosis,hemorrhage,epilepsy and myocardial in-farction,more patients using acute mechanical ventilation and osmotic therapy,and increased hos-pital mortality,but lower GCS score when compared with the non-MODS group(P＜0.05,P＜0.01).Binary logistic regression analysis showed that NIHSS score,APACHE Ⅱ score,and mul-tivessel disease were independent risk factors for MODS(OR=1.124,95％CI:1.121-1.163,P=0.015;OR=1.265,95％CI:1.296-1.426,P=0.001;OR=2.532,95％CI:1.126-5.013,P=0.026).The MODS score and APACHE Ⅱ score were significantly higher in the death group than the survival group(P＜0.05).Conclusion Elderly severe stroke patients are prone to MODS during the acute period.

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 search for valuable laboratory indexes of early diagnosis of anastomotic leakage after anterior resection for rectal carcinoma.Methods:From Sep 2017 to Jan 2019, 128 patients with colorectal cancer underwent anterior rectal resection at the Department of Colorectal & Anal Surgery, the 940 Hospital of the Joint Logistics Support Force.Results:Anastomotic leakage occurred in 16 of 128 patients (12.5%). Definite diagnosis of anastomotic leakage was made on between 2nd and 9th day, postopera tively averagign (6.13±2.00) days. Tumor location was a risk factor for anastomotic leakage with the incidence significantly lower when the distance from the lower edge of the tumor to the anal margin >7 cm than when the distance ≤7 cm ( χ 2=6.022, P=0.014). The percentage of increase in peripheral blood leukocytes, neutrophils, serum interleukin-6, C-reactive protein and procalcitonin in patients 3-5 days after surgery significantly related to the occurrence of anastomotic leakage (all P<0.05). The area under the working characteristic curve of the subjects with the percentage of C-reactive protein, procalcitonin, interleukin-6, leukocytes and neutrophils from the 3rd to the 5th day after operation was greater than 0.5. Conclusion:C-reactive protein, procalcitonin, interleukin-6, leukocyte and neutrophil percentage are risk factors predicting anastomotic leakage after anterior resection of rectal cancer.

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.

Objective:To analyze the risk factors and human papillomavirus (HPV) genotypes distribution in patients with condyloma acuminatum (CA) in two regions of Shandong province.Methods:From August 2019 to December 2020, an anonymous questionnaire survey of CA patients was conducted in three hospitals in Jinan City and Jining City, Shandong Province, and samples were collected for HPV typing. Multivariate binary logistic regression was used to analyze the risk factors of CA recurrence. HPV typing was detected by PCR-reverse dot blot hybridization.Results:A total of 653 questionnaires were collected, and the valid questionnaires accounted for 98.77% (645/653). Recurrence of the disease occurred in 174 patients, with a recurrence rate of 26.98%. Univariate analysis showed that there were statistically significant differences in the distribution of CA recurrence among residence time at current address, sexual frequency, genitalia cleaning, and knowledge of preventing HPV infection ( P<0.05). Multivariate binary logistic regression showed that knowing how to prevent HPV infection was a significant factor that influences CA recurrence. A total of 428 patients underwent HPV typing, and the positive detection rate of HPV was 98.60% (422/428). The top three positive rates were HPV6 (57.58%), HPV11 (36.49%) and HPV16 (11.37%). The main type of infection was low-risk HPV, accounting for 51.42% (217/422). Conclusions:CA patients have the phenomenon of "separation of knowledge and action" , so it is necessary to strengthen health education and behavioral intervention, guide the population to correctly treat sexual behavior, and improve self-prevention awareness and risk awareness.

Objective:To understand the infection rate of Coronavirus Disease 2019 (COVID-19) in close contacts in Shandong province and explore the risk factors of infection.Methods:All data from close contacts of 2019 novel coronavirus (2019-nCoV) infected persons in Shandong province were collected for descriptive epidemiological analysis, and risk factors were analyzed by logistic regression.Results:Up to March 6, 2020, a total of 15 702 close contacts had been reported in Shandong province, of whom 321 cases were infected with 2019-nCoV, with an infection rate of 2.04%. Among all the factors, the top five with the highest infection rate were close relatives (13.39%), frequent contact (9.58%), working/living/studying in the same room (7.54%), two or more contact cases (4.58%), and over 60 years old (3.10%). Single-factor analysis showed that exposure to two or more cases, over 60 years old, close relatives with cases, frequent contact and working/living/studying in the same room were the risk factors for infection in close contacts. Multivariate analysis showed that exposure to two or more cases ( OR=2.510, 95% CI: 1.843-3.417), 30~60 year old group ( OR=1.513, 95% CI: 1.141-2.007), frequent exposure group ( OR=20.025, 95% CI: 14.625-27.419), working/living/learning in the same room ( OR=2.406, 95% CI: 1.385-4.182) and medical institution exposure ( OR=2.366, 95% CI: 1.149-4.871) were risk factors of infection in close contacts. Conclusions:Tracking and managing close contacts was an important measure to control the COVID-19 epidemic situation, and reducing crowd concentration, keeping a proper social distance and taking effective protection were effective measures to control 2019-nCoV infection.

To investigate Streptococcus suis ( S.suis) isolated from patients in Shandong province using genomic epidemiology and pathogenologic analysis. To provide the foundation to establish reasonable and accurate prevention and control measures of human S. suis infection. Molecular typing, whole genome phylogenetic tree, virulence gene typing, antibiotic resistance profile and mobile genetic elements carrying antibiotic resistance genes of isolated S. suis strains were investigated. The pathogenicity of isolated strains was also evaluated by comparing their capacity to induce pro-inflammatory cytokine production in vitro. S. suis infections in Shandong province were predominantly due to serotype 2 and sequence type 1 strains. The major symptoms were meningitis. The studied strains could be divided into five lineages. All strains belong to highly pathogenic type in Shandong province,Strains from lineage 2 possessed higher capacity to stimulate pro-inflammatory cytokine production than other strains did, even though other strains belong to highly pathogenic strains. In addition, multiple antibiotic resistance genes and corresponding mobile genetic elements werewidespread in S. suis strains from Shandong province, except strains from lineage 3. High diversities in genome, evolutionary path and pathogenicity of S. suis strains from Shandong province were revealed. It was necessary to surveillant the S. suis strain in genomic level.