B lymphocyte response patterns vary in different infection scenarios, such as acute or chronic infections. This study aimed to construct recombinant Armstrong and Clone13 strains of lymphocytic choriomeningitis virus (LCMV) to induce the immune response of KL25HL B cells carrying the transgenic B cell receptor (BCR) specific to the glycoprotein (GP) of the WE strain, thereby establishing a model for comparing host B cell immune response differences between acute and chronic infection processes. Firstly, by co-transfecting cells with plasmids to transcribe LCMV genome fragments and express viral proteins, recombinant LCMV-Armstrong (rARM) and recombinant LCMV-Clone13 (rCL13) were successfully rescued. Sequencing analysis results indicated that the GP sequences of these two recombinant viruses were accurately replaced with the GP sequence of the LCMV-WE strain, and they were confirmed to have plaque-forming ability after infecting cells. For further characterizing the properties of rARM and rCL13, they were used to infect C57BL/6J mice. The results suggested that these two recombinant viruses retained the acute or chronic infection properties of wild type LCMV-Armstrong (wtARM) or wild type LCMV-Clone13 (wtCL13) strains. Specifically, after establishing infection, rARM would be rapidly cleared by the host immune system within a week, while rCL13 would persist in the host for more than two months. Finally, wild-type mice adoptively transferred with KL25HL B cells were infected with different LCMV strains to study the immune response. The results showed that, compared with wtARM or wtCL13, infection with rARM or rCL13 could significantly induce the activation and proliferation of KL25HL B cells. The rARM and rCL13 constructed in this study, after infecting mice that were adoptively transferred with KL25HL B cells, could serve as a powerful tool for comparative research on B lymphocyte response patterns in acute and chronic infections, which is of great significance for deepening understanding of humoral immune response mechanisms.

The purpose of the current study is to analyze the identification and antimicrobial susceptibility characteristics of Herbaspirillum huttiense (H. huttiense) which was isolated from a lung adenocarcinoma patient with bloodstream infection, and review the literature in search of any similar cases of this rare condition to provide guidance for clinical treatment. The positive blood culture samples from a patient with lung adenocarcinoma after radiotherapy was smeared, gram stained and examined under microscope. At the same time, VITEK MS automatic microbial mass spectrometry system, VITEK 2 Compact automatic microbial analysis system and molecular sequencing technology were used to identify and analyze the isolate. And the antimicrobial susceptibility was determined by the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for non-fermented Gram-negative bacilli. The results demonstrated that the strain was Gram-negative rods. And the colonies on the blood plate were milky, gelatinous, raised and without hemolytic. The strain was identified as H. huttiense by VITEK MS mass spectrometer and molecular sequencing technology, but identified as Burkholderia cepacia by VITEK 2 Compact. The results of antimicrobial susceptibility showed that the strain was intermediate to aztreonam, and sensitive to imipenem, meropenem, cefoperazone/sulbactam sodium, ceftazidime, cefepime, piperacillin/tazobactam and levofloxacin. This study describes the biological characteristics and the approach to diagnosis and treatment of H. huttiense, which emphasizes the importance of multiple diagnostic techniques in the identification of rare bacteria.

In order to explore the ability of routine laboratory identification methods to identify clinical isolates of Herbaspirillum huttiense (H. huttiense), the source of infection of H. huttiense in the blood of this patient was analyzed. Automated biochemical identification system, matrix-assisted laser desorption ionization-time of flight mass spectrometer (MALDI-TOF MS), 16S rRNA gene sequencing and rpoB gene sequencing were used to identify H. huttiense, and the specimens from multiple parts of the patient were detected. The results showed that the automatic biochemical identification system misidentified H. huttiense as Burkholderia cepacia. MALDI-TOF MS and 16S rRNA gene sequencing were not able to distinguish H. huttiense from Herbaspirillum aquaticum and Herbaspirillum camelliae, while rpoB gene sequencing could accurately identify H. huttiense. In addition to the blood, only a small amount of H. huttiense was detected in the patient’s feces. The results of enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) showed the same DNA band patterns of H. huttiense from blood and feces. MALDI-TOF MS main spectra projection(MSP)cluster analysis showed that they were located at the same node, and the distance level was under 50, with the same resistance phenotype. The blood and fecal origins of H. huttiense were highly homologous. This study demonstrated the performance of automated biochemical identification system, MALDI-TOF MS, 16S rRNA gene sequencing and rpoB gene sequencing for identification of H. huttiense, which confirmed that H. huttiense could infect gastrointestinal tract through contaminated food and cause sepsis in patients with postoperative chemotherapy for rectal adenocarcinoma.

Objective To analyze the clinical drug-sensitivity results, types of drug resistance Staphylococcus aureus  (S.aureus)  isolated from the patients of nosocomial infection and risk factors for nosocomial infection over two years, and to explore its reference value in clinical control of the occurrence of drug-resistant S. aureus, hospital infection and rational application of antimicrobial drugs.  Methods  The clinical characteristics and drug resistance of drug-resistant S. aureus isolated in 2020-2021 were analyzed, and independent risk factors of nosocomial infection caused by drug-resistant S. aureus were explored using univariate and logistic regression.  Results  Multi-drug resistant S. aureus accounted for 49.7% (69/139), MRSA (methicillin-resistant Staphylococcus aureus) strains accounted for 41.0% (57/139), β-lactamase-producing strains accounted for 72.7% (101/139), and clindamycin-induced resistant strains accounted for 15.1% (21/139). S. aureus was mainly isolated from respiratory and wound infection sites (36.0% and 48.9%), and it had a high rate of resistance to a variety of antimicrobial drugs, with 100% sensitivity to vancomycin and tigecycline, the sensitivity rate to linezolid and chloramphenicol was 99.28% and 93.85%. Regression analysis showed an OR of 3.184 for invasive manipulation, with a P value < 0.05.  Conclusion   S. aureus was mainly isolated from wound site specimens, with a high occupancy of clinical multi-drug resistant bacteria, mostly MRSA and β-lactamase-producing strains, and a high prevalence of common antibiotic resistance. Invasive manipulation was an independent risk factor for drug-resistant S. aureus infection.

The single-cell study of hepatitis B virus (HBV) in liver tissue is of paramount significance. However, the associated research technology is still in an advanced stage and represents an unmet clinical need. Based on ddPCR (digital droplet polymerase chain reaction), this study has pioneered a single-cell ddPCR (sc-ddPCR) method for the precise quantification of HBV DNA and RNA at the single-cell level. To ascertain the linearity and lower detection limit of HBV DNA, a series of experiments were conducted by simulating a chronic HBV infection in the liver through the mixing of various proportions of HBV-positive and negative cells. The study focused on the detection of episome-derived RNA (eRNA), developing a tailored protocol for its analysis. By capitalizing on the structural disparities in HBV transcripts, the study had formulated a specific primer and probe system for eRNA, the specificity of which was rigorously confirmed in HBV liver cancer cell lines. The linearity and lower detection limit of eRNA were scrutinized through the utilization of gradient-diluted standard cell lines. The results unequivocally demonstrated the establishment of an advanced single-cell detection method for HBV DNA and RNA based on ddPCR, characterized by exceptional linearity (HBV DNA: R²＝0.998 7; eRNA: R²＝0.942 5). Moreover, the method exhibited a remarkable sensitivity, as it consistently detected positive signals in gradient-diluted standard cell lines, with a lower detection limit of 0.16% for HBV DNA and 0.2% for eRNA. The sc-ddPCR method developed in this study is versatile, enabling simultaneous detection of DNA and RNA, and it serves as a robust technical foundation for further exploration of HBV virology activities within liver tissue. It is also invaluable for optimizing and advancing HBV treatment strategies, presenting promising prospects for broad applications.

The purpose of this study is to evaluate the effect of online teaching of medical microbiology course in Dalian Medical University, find and summarize the problems in online teaching in time, and provide a basis for teaching curriculum reform. The examination paper of 641 students who participated in the online teaching and examination of medical microbiology course in 2021 was analyzed by using the network question bank and examination evaluation system of Dalian Medical University, including the accuracy rate of each chapter of the paper, difficulty coefficient, reliability and discrimination. The results showed that the score of this exam was normal distribution, the accuracy of each chapter was between 70% and 90%, the average score of the exam was 72.28, the pass rate was 85%, and the excellent rate was 4%. The overall quality of the examination paper was good.The difficulty of the examination paper was slightly easier, and the difficulty coefficient was 0.72. The discrimination was 0.29, the reliability was 0.9. There was no significant difference in the final exam scores between online teaching students in 2021 and offline teaching students in 2019 (P>0.05). This study confirms that the overall quality of the online examination paper is good, which can objectively reflect the teaching quality and students’ academic level. The online teaching effect is basically satisfied. This study also compares the difficulty coefficient and differentiation of each question type in the test paper to provide the basis and reference for the development of scientific and reasonable online examination papers in the future.

To understand the prevalence of rabies, Toxoplasma gondii and influenza A virus in stray cats in Qingpu, Shanghai. Serum samples from 153 stray cats collected from 40 residential community between June 2022 and August 2010 were tested for antibodies to rabies, Toxoplasma gondii and influenza A viruses by ELISA. The H3, H5, H7 and H9 serotypes of influenza A antibody positive samples were identified by HI test. Real-time PCR was used for the detection of Toxoplasma gondii RNA in whole blood samples and influenza virus RNA in throat and anal swab samples. The results showed that the positive rates of rabies, Toxoplasma gondii and influenza A were 14.38% (22/153) , 11.76% (18/153) and 3.92% (6/153) respectively. The difference of positive rate of Toxoplasma gondii antibody between spring (March-May) and summer (June-August) was very significant. The positive rate of H3 was 0.65% (1/153) . No H5, H7 and H9 antibody was detected. The results showed no Toxoplasma gondii antigen was detected in the whole blood samples ,and no influenza antigen was detected in throat swab samples and anal swab samples. The results suggest that the rabies antibody level of stray cats in Qingpu District was low, which was not enough to block the Rabies transmission. Toxoplasma gondii infection exists in stray cats, especially in summer. The presence of influenza A infection in stray cats suggests that stray cats can act as a "Mixer" for human and animal influenza viruses, posing a risk of zoonosis transmission. Therefore, it is necessary to continuously monitor the infection of rabies, Toxoplasma gondii and influenza A virus in stray cats to provide basis for scientific prevention and control.

Microneedles, as an efficient transdermal immunization modality, can penetrate the stratum corneum and deliver antigens to the immune cell-rich dermis without damaging the neurovascular system. Among them, dissolving microneedles (dMNs) have attracted much attention due to many advantages such as simple preparation, convenient operation, high drug capacity, and less tip waste. In this review, we mainly summarized the immune effect of dMNs vaccines and the current progress of clinical trials, discussed the issues that exist during the use of dMNs and looked forward to the future research, so as to provide a reference for the research of dMNs vaccination and promote its application.

Sever fever with thrombocytopenia syndrome virus (SFTSV) is a novel virus discovered in recent years. Sever fever with thrombocytopenia syndrome (SFTS) is caused by SFTSV infection, characterized by high fever, thrombocytopenia, leukopenia and multiple organ function damage, with a mortality rate from 5% to 30%. There is no proven effective antiviral drugs and vaccine available now. SFTSV infection can cause immune dysfunction in patients, and B lymphocytes are one of the important target cells for SFTSV infection, but the impact of SFTSV infection on B lymphocyte function is still unclear. This article reviews research on the abnormalities and underlying mechanism of B lymphocyte functions caused by SFTSV infection, so as to promote the research progress of the immunopathological mechanism of SFTSV infection, providing a basis for a deeper understanding of the impact of SFTSV infection on B lymphocytes and the development of related diagnostic and therapeutic technologies.

To analyze the clinical characteristics, pathogens and drug sensitivity of children urinary tract infection (UTI), so as to help pediatricians better manage UTI in children, clinical data of 591 hospitalized children with UTI from January, 2014 to February, 2021 were collected and analyzed. The results showed that the incidence of male and female, clinical manifestations and co-exist diseases were statistically significant in different age groups (P<0.05). The common pathogens were mainly E. coli and Enterococcus faecium. The proportion of pathogens in 2014-2017 and 2018-2021 was statistically significant (P<0.05). The enzyme-producing rate of E. coli decreased during 2018 and 2021, and the enzyme-producing strains showed higher drug resistance rate than the non-enzyme-producing strains, and the resistance rate of some antimicrobials decreased in recent years. The drug resistance rate of Enterococcus faecium to gentamycin and levofloxacin was higher than 50%, and the sensitivity rate to daptomycin and macrodantin was higher than 60%. It was concluded that the incidence, clinical manifestations and co-exist diseases in children with UTI varied with ages. In recent years, the proportion of gram-negative bacteria show an upward trend, while the proportion of gram-positive bacteria show a downward trend, and β lactamase-producing E．coli and Enterococcus faecium are resistant to many commonly used antibiotics.

Acinetobacter baumannii is a multi-drug resistant opportunistic pathogen. Its pathogenic mechanism is complex and diverse, which has posed a major threat to human health. Therefore, it is imperative to investigate its pathogenic mechanism. Bacterial motility not only plays a role in the migration of bacteria, but is also closely related to virulence, drug resistance, adhesion, chemotaxis and biofilm formation. The lack of flagella caused Acinetobacter baumannii to be thought non-motile for a long time, but further research had revealed that it could move across the wet surface by twitching and surface-associated motility. The factors affecting motility mainly include type IV pili, quorum sensing, efflux pumps, chemotaxis and blue light. This article discussed the motility, influencing factors and biological effects of motility of Acinetobacter baumannii, and provided a reference for its treatment and prevention.

This paper reported the first case of thoracic infection caused by Neisseria elongata in China. MALDI-TOF Vitek MS system, VITEK 2 Compact automatic microbial analysis system and molecular sequencing technology were used to identify and analyze the isolated strains. Drug susceptible test of the isolated strains was performed by K-B method and E-Test method, and the break point interpretation was carried out according to the reference of Clinical and Laboratory Standards Institute (CLSI) for Neisseria meningitidis. The biological characteristics and diagnosis and treatment process of Neisseria elongata were analyzed to improve the attention of microbiological staff to rare pathogens, and to provide experimental evidences for clinical diagnosis and treatment.

Viral encephalitis/meningitis is a severe inflammatory disease of the central nervous system that poses a significant threat to public health. Despite the crucial role played by medical history, symptoms, routine tests and imaging in its diagnosis, and continuous improvements in molecular diagnostic techniques, limitations including technical limitations, assay variability, sample types, and detection time windows still constrain its diagnosis. Moreover, the selection of appropriate diagnostic techniques depends on different clinical features, leaving 40% to 60% of patients with an unclear etiology. Timely and accurate diagnosis is fundamental for initiating targeted and appropriate treatment. Sixty to eighty percent of patients with viral encephalitis initially seek medical attention at primary healthcare institutions. However, due to technical constraints, the diagnostic rate in these institutions is below 20%. Therefore, establishing a standardized diagnostic pathway based on etiology and implementing a tiered diagnostic strategy are particularly necessary. In situations where resources are limited at primary healthcare institutions, the preliminary diagnosis can be established by detailed inquiry into medical history, comprehensive physical examination, and basic laboratory tests. Based on the suspected etiology, routine molecular biology techniques such as polymerase chain reaction (PCR) can be employed for initial pathogen screening. In cases whose PCR results are negative or not feasible, non-targeted broad-coverage techniques like metagenomic next-generation sequencing (mNGS) should be considered. The establishment of a multidisciplinary team for diagnosis and treatment, along with the creation of clinical diagnostic and treatment networks, are essential to enhance the diagnostic rate and improve clinical outcomes. With advancements in diagnostic technologies and the application of artificial intelligence, the diagnosis of viral encephalitis is expected to become more precise.

The human vaginal microbiota (VMB), which plays a vital role in maintaining health and homeostasis, exhibits low diversity compared to the microbiomes of other organs. Cervical cancer (CC) is a common malignancy in women and has been shown to be highly associated with persistent infection with high-risk human papillomavirus (HPV). VMB is associated with human papillomavirus infection and cervical lesions, and may play a positive role in the progression of HPV infection and cervical intraepithelial neoplasia (CIN). On the one hand, lactobacillus can reduce the permeability of cervical cells, and reduce inflammatory response, inhibit the growth of cervical cancer cells, but the bacterias enhancing the diversity of VMB can express virulence and attachment genes, which cause damage to cervix and epithelial cells, causing HPV infection and high-grade disease states; On the other hand, HPV-associated E7 oncoprotein can reduce the secretion of defense peptides which are conducive to the growth of lactobacillus through NF-β-κB and Wnt/β-catenin signaling pathways, resulting in an increase in vaginal pH, which further facilitates the growth of vaginal pathogenic bacteria, and ultimately leads to structural changes of VMB. This review focuses on the relationship between the vaginal microbiome, persistent HPV infection and cervical dysplasia and the factors that mediate these relationships, which will help to find new targets for VMB-related diseases.

Abstract：Objective To investigate the risk factors and clinical characteristics of lung abscess patients with high virulence Klebsiella pneumoniae infection to provide more reference for early identification of high virulence infection high-risk groups. Methods 35 lung abscess patients with Klebsiella pneumoniae infection were retrospectively chosen in the period from January 2019 to January 2022 and grouped according to the types of Klebsiella pneumoniae infection into high virulence group (23 cases) and classical group (12 cases). The clinical characteristics, imaging data, drug resistance and clinical characteristics of 2 groups were compared. The independent risk factors of highly virulent Klebsiella pneumoniae infection in lung abscess were evaluated by Logistic regression model multivariate method. Results The proportion of high virulence combination with diabetes mellitus, extrapulmonary abscess, multiple infections, respiratory tract infection as the first symptom and multiple abscess as indicated by imaging were significantly higher than classical group（P<0.05）. The proportion of indignant catheters and invasive procedures before infection in the high virulence group were significantly lower than classical group（P<0.05）. Multivariate analysis of Logistic regression model showed that combined diabetes were independent risk factors of highly virulent Klebsiella pneumoniae infection in lung abscess（P<0.05）. The drug resistance rates of cefuroxime, ceftriaxone, ceftazidime, cefepime, amoxicillin/clavulanate, piperacillin/tazobactam, cefoperazone/sulbactam and levofloxacin in high virulence group were significantly lower than classic group（P<0.05）. The proportions of virulence genotype aero and rmpA+aero in high virulence group were significantly higher than classic group（P<0.05）. Conclusion High virulence Klebsiella pneumoniae infection in lung abscess was closely related to diabetes mellitus. Meanwhile, the main virulence genotype of this infection was aero.

Nucleic acid vaccines play a pivotal role in the development of advancing vaccine technologies against infectious diseases. Despite their potential, the clinical application of nucleic acid vaccines still faces hurdles including limited transfection efficacy and suboptimal biocompatibility. Addressing these challenges, this study introduced a novel strategy utilizing the self-assembly of poly(β-amino ester) (PBAE) with nucleic acids to form PBAE nanoparticles (PBAE-NPs). PBAE-NPs were further modified with poly(glutamic acid) (PGA) to produce PGA modified PBAE nanoparticles (PPs) as potential nucleic acid delivery carriers. Comprehensive synthesis, structural characterization, and biological evaluation of PPs were performed. The characterization results demonstrated that PPs exhibited favorable biological characteristics, such as well-controlled particle size, low zeta potential, and exceptional serum stability. The lysosomal escape experiment results showed that PPs had good lysosomal escape ability endowed with PGA. Flow cytometry results indicated that PPs exhibited significantly enhanced nucleic acid transfection efficiency compared to PBAE-NPs. The CCK-8 results showed that PPs had good biocompatibility. Collectively, these results suggest that PPs could significantly improve nucleic acid transfection efficiency, thereby providing insight into the formulations design for nucleic acid vaccines.

Chronic hepatitis B (CHB) is a major risk factor for liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Despite the use of interferons and nucleoside analogues as treatment options, a complete cure remains elusive, making the exploration of HBV infection's immunological mechanisms, especially the role of host genetic background, crucial for developing new therapeutic strategies. This study utilized the AAV8-rcccDNA mouse model to investigate the differences in immune response to HBV infection between mice of two genetic backgrounds, FVB/N×C57BL/6 and DBA/2×C57BL/6. The results showed that FVB/N×C57BL/6 mice exhibited an immune-tolerant state, characterized by persistent HBsAg expression and low levels of HBsAb. In contrast, DBA/2×C57BL/6 mice simulated the recovery phase of acute infection, specifically showing HBsAg seroclearance, HBsAb positivity, and mid-to-low levels of viral replication. This study underscores the necessity of considering the host genetic background in HBV infection treatment and research and highlights the potential of adaptive immune system regulation in achieving HBV cure. The improvement of the AAV8-rcccDNA mouse model provides an effective tool for simulating the human immune state during HBV infection, facilitating the optimization and development of HBV treatment strategies.

Global public health is facing great challenges due to the infection caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) and its mutated strains. Although we have entered the post-pandemic era, a new crisis is the long-term effects of SARS-CoV-2 infection, which can involve multiple organs, mainly manifested by pulmonary, neuropsychiatric, cardiovascular and gastrointestinal symptoms. In some coronavirus disease 2019 (COVID-19) patients, symptoms including complications can last for months or even years, which is called long COVID-19. In the future, long COVID may significantly affect patients’ quality of life and social healthcare costs as the number of recovering patients increases dramatically, further placing a huge burden on families and society. Therefore, it is very important to study the long-term health status and dynamic changes of COVID-19 patients during the recovery period.

Fecal microbiota transplantation (FMT) is an innovative method to reconstruct the intestinal microecological balance by transplanting the fecal microbiota of healthy donors into patients, which provides help for the treatment of diseases. It has a good effect on the treatment of recurrent Clostridioides difficile infection (rCDI), and its therapeutic potential is not only limited to gastrointestinal diseases, but also can be continuously explored in other microbial-related diseases. In the exploration of factors for the success of FMT in the treatment of diseases, in addition to the recovery of intestinal bacteria, the regulation of intestinal phages is also involved. Intestinal phages, an important part of the gut microbiota, play an important role in the complex dynamics of bacteria; their transfer may be related to the curative effect of FMT. This review analyzed the biological characteristics of intestinal phage and the main bioinformatics analysis strategies, summarized the clinical research on the role of intestinal phage in FMT, explored the changes in the intestinal phage community in FMT and the possible mechanisms of action, and discussed the relationship between intestinal phage and the efficacy of FMT, as well as the existing safety issues. It can not only improve the understanding of the role of intestinal phages in FMT, but also promote the clinical application of FMT.

With the continuous improvement of people’s living standards, simply creating a comfortable air environment with suitable temperature and humidity can no longer meet the needs of people’s lives. Healthy and clean air quality has begun to become a focus of public concern. In recent years, SARS-CoV-2 has been raging around the world, and aerosol transmission as one of the infection routes deserves sufficient attention. Air purification and disinfection technology is of great significance in preventing the spread of pathogens such as bacteria and viruses. This article mainly introduces a variety of physical and chemical air purification and disinfection technologies in detail, points out the problems existing in the research and application of these technologies, and finally proposes the characteristics that ideal air purification and disinfection technologies in the future should have.

Hepatitis B virus (HBV) is a non-cytopathic virus, and the liver damage caused by its continuous infection gradually causes liver inflammation, which leads to liver fibrosis, cirrhosis, and eventually causes 80% of hepatocellular carcinoma (HCC). Liver is an important organ of metabolism in the body. The abnormal activation of oncogenes and the inactivation of tumor suppressor genes will cause changes in the level and mode of cell metabolism, which is called metabolism reprogramming. Metabolic reprogramming is a key step in the transformation from liver inflammation to cancer. In this study, the expressions of key genes of lipid metabolism in HBV-positive cells (or tissues) and control cells (or tissues) were detected by reverse transcription-polymerase chain reaction (RT-PCR), enzyme linked immunosorbent assay (ELISA) and multiple fluorescence immuno histochemistry, and on this basis, the relationship between their functions and lipid metabolism was analyzed. The results showed that in HepG2.2.15 cells with stable HBV expression and Hep3B cells with stable HBsAg expression, the mRNA expressions of lipid metabolism-related genes HMGCR, SREBP-2 and PSCK9 were significantly up-regulated, and the corresponding protein expression levels were also increased synchronously in the clinicopathological results of hepatocellular carcinoma patients. It is suggested that HBV infection leads to the high expression of corresponding metabolic genes, and HBsAg is the key protein regulating the disorder of lipid metabolism enzyme genes. By analyzing the pathological data of 365 large samples of liver cancer patients, it was found that the high expression of lipid metabolism-related genes in liver cancer tissues has a trend of poor prognosis, suggesting that the disorder of lipid metabolism may be a risk factor affecting the overall survival of liver cancer patients.

Abstract: The purpose of this study is to understand the molecular characteristics of Salmonella, reveal the genetic relationship among the strains, and provide a certain basis for the origin of Salmonella outbreak. Virulence and drug resistance genes of 105 Salmonella strains isolated from Changchun in recent years had been screened, by whole genome sequencing and bioinformatics methods. The wgSNP, MLST and cgMLST genotyping were performed for 105 Salmonella. 144 virulence genes were analyzed on this study. The results showed that the gene of Salmonella Pathogenicity Island 1 (SPI) was relatively stable.The carrying rate of the virulence factors outside the secretion varied greatly with serotype.69 drug resistance genes of Classes were screened, with high carrying rate of Aminoglycosides (100%) , β-lactams(73.33%) , Sulfonamides (72.38%), and low carrying rate of Macrolides (6.67%) and Lincosamides (0.95%) . The cgST and MLST types of 105 strains of salmonella were identical and divided into 13 species. The major prevalent strains, Salmonella enteritidis (ST11) and Salmonella I 4, [5] , 12: I:-(ST34) , were essentially in the same branch as the international prevalent strains. This study confirmed that Salmonella carries stable virulence genes and multi-drug resistance genes in Changchun. The major prevalent strains were distributed in different time and source. The molecular characteristics of the two strains were consistent with those of the foreign prevalent strains. The serotypes were closely related to ST and cgST types.

Colorectal cancer (CRC) is a common digestive malignant tumor in China. A large number of studies have confirmed that intestinal flora disorders can promote the occurrence and development of CRC through a variety of mechanisms, and regulating intestinal flora can exert certain auxiliary therapeutic effects on CRC. But the treatment still has certain limitations and side effects. Studies have shown that the clinical treatment of CRC by engineered and edited intestinal bacteria through gene editing may have potential application values. In this paper, the current research progress on gene-editing for modifying intestinal bacteria in the treatment of CRC is reviewed, aiming to explore the possibility of gene-edited intestinal bacteria in the treatment of CRC in the future.

This study aims to investigate the virulence, antibiotic resistance gene profiles, and molecular types of Staphylococcus aureus small colony variants (SASCVs) in periprosthetic joint infections (PJIs) to provide fundamental data for understanding their pathogenic mechanisms. A total of 19 SASCV strains isolated from synovial fluid samples of PJI patients were collected, and whole genome sequencing, bioinformatics analysis, and database comparison were performed to determine the presence of virulence and antibiotic resistance genes. Multilocus sequence typing (MLST) was employed to classify strain types and a phylogenetic tree was constructed by MEGA software. The results demonstrated that among the 19 SASCV strains, eight were found to coexist with Staphylococcus aureus with a normal phenotype. All 27 strains underwent whole genome sequencing, with genome lengths ranging from 2 696 437 bp to 3 011 803 bp and G＋C content of (32.8±0.05)%. A total of 23 virulence-related genes were detected: 14 adhesin-related genes had detection rates between 21.1% and 100.0%; four immune evasion-related genes had detection rates ranging from 36.8% to 68.4%; and five hemolytic and leukocidin genes were also identified. Twelve resistance genes were detected: blaZ was detected in 78.9% (15/19) of the samples; mecA was detected in 31.6% (6/19) of the samples; resistance genes for macrolide and aminoglycoside antibiotics were detected with varying rates; and methicillin-resistant Staphylococcus aureus (MRSA) had a higher number of detected resistance genes compared to methicillin-sensitive Staphylococcus aureus (MSSA). MLST analysis revealed 10 different sequence types (STs) among the 19 SASCV strains. There were eight groups of phenotypically mixed strains. In two groups SCVs and their normal phenotype (NP) counterparts belonged to different geno-types, with significant differences in virulence and antibiotic resistance genes, while in the remaining six groups SCVs and NP strains belonged to the same genotype. This study revealed that in PJIs, the detection rate of biofilm-related adhesion genes in SASCVs is high, and the prevalence of mecA is relatively elevated. Among the MLST genotypes, ST59 is the most common, followed by ST398 and ST25. When SCVs coexist with normal phenotype strains, they may belong to different genotypes.

To provide reference for rational use of antibiotics in clinic, this study investigated the distribution and antimicrobial resistance of pathogens causing bloodstream infection. The main pathogenic bacteria isolated from positive blood culture specimens and their antimicrobial resistance in Shanghai East Hospital from 2014 to 2021 were statistically analyzed. After eliminating the duplicate strains, a total of 1 396 strains of pathogenic bacteria were detected in blood culture samples during the past eight years. The gram-negative bacteria, gram-positive bacteria and fungi account for 56.3%, 38.4% and 5.3%, respectively. The top eight strains were Escherichia coli (21.5%), Coagulase negative Staphylococcus (CNS) (17.4%), Klebsiella pneumoniae (14.9%), Staphylococcus aureus (7.2%), Acinetobacter baumannii (5.4%), Enterococcus faecalis (4.2%), Enterococcus faecium (3.7%) and Pseudomonas aeruginosa (3.5%). The resistance rate of Escherichia coli to third-generation cephalosporins exceeded 50%, and the resistance rate to carbapenems was as low as 1%; The resistance rate of Klebsiella pneumoniae to carbapenems was 46.3%; The cumulative resistance rate of Acinetobacter baumannii to cephalosporins, aminoglycosides and carbapenems was more than 45%; The cumulative rates of methicillin resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococci (MRCNS) were 44.6% and 74.5%, respectively.

This study explored the risk factors, clinical characteristics, and drug resistance of Elizabethkingia meningoseptica (EM) infection in elderly patients to provide the reference for scientific and effective clinical treatment. Analysis of 27 strains isolated from EM infected patients aged over 60 years of Shaoxing People’s Hospital from January 2018 to January 2023 was carried out using VITEK-2 automatic microbial identification and drug sensitivity analyzer for bacterial identification and drug sensitivity tests, and analyzed the clinical characteristics and drug resistance of the bacteria.EM mainly infected the patients with long hospitalization stays (hospital days ≥4 weeks), accounting for 66.7%; And patients with serious underlying diseases, including respiratory system diseases account for 44.4%, and malignant tumors 22.2%; Elderly patients who have used broad-spectrum antibacterial drugs for a long time and have undergone invasive procedures. The main type of specimen was sputum 85.2%, followed by urine of 11.1%. The patients mainly came from the department of critical care (74.1%), followed by the department of radiotherapy (7.4%). EM exhibited high resistance to a variety of broad-spectrum antibacterial drugs, but was 100% sensitive to doxycycline. Resistance to cefoperazone/tazobactam, piperacillin/tazobactam, compound sulfamethoxazole and levofloxacin was under 30%. The presence of serious underlying diseases and prolonged hospitalization, combined use of broad-spectrum antibiotics, and multiple invasive diagnoses and treatments are risk factors for elderly patients with EM infection. The phenomenon of multiple drug resistance in EM is serious. So, rational use of antibiotics, active treatment of primary diseases, minimizing invasive procedures, reducing hospital stay, and strengthening medical environmental management are conducive to the treatment and prevention of EM.

The purpose of the current study is to study the effect of in-hospital three-color zoning management mode in SARS-CoV-2 nucleic acid sample collection during the epidemic. Patients and staff involved in nucleic acid sample collection in our hospital during April 1 st to 15th April, 2022 were selected as the control group, and the original nucleic acid sample collection mode was adopted. Patients and staff involved in nucleic acid sample collection During April16th to 30th April, 2022 in our hospital were regarded as observation group which adopted the three-color zoning management mode. Compared with the control group, the whole time of nucleic acid sampling-transport-testing in the red zone (all P<0.05), the detection time (P＝0.024) and detection time (P<0.001) and the tracing time of patients with nucleic acid abnormalities (P<0.001) were significantly shortened in the observation group. Conditions of unqualified samples were significantly reduced (P＝0.001), including sample leakage (P＝0.018), lack of internal parameters (P＝0.012), and information errors (P＝0.014). Patient (P<0.001) and staff (P<0.001) satisfaction increased significantly. The three-color zoning management model can effectively shorten the time consumption of sampling-transporting-testing of nucleic acid sample collection and of the tracing of patients with nucleic acid abnormalities. This mode improved work efficiency, and the quality of nucleic acid samples, and satisfaction of patients and staff.

A case of bloodstream infection caused by Campylobacter jejuni was reported, and its biological characteristics and possible drug resistance genes was studied to provide scientific laboratory basis for effective clinical treatment of related diseases. The strain isolated from the blood of an elderly female was identified by conventional methods, matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOFMS), sequencing and polymerase chain reaction(PCR). Results show that the isolated strain was Campylobacter jejuni, and it was resistant to ciprofloxacin and tetracycline and sensitive to erythromycin. Three drug resistance genes gyrA, gyrB and tex(O) in Campylobacter jejuni were detected by PCR, which may be related to the results of drug sensitivity test.

Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B virus (HBV) infection undergoes two phases in sequence, termed non-aggressive hepatitis (NAH) and aggressive hepatitis (AH), respectively. But there is still a lack of perfect standard for defining HBeAg-positive NAH and AH. In this study, based on a long-term follow-up cohort of 179 patients, the functional cutoffs for alanine transaminase (ALT), hepatitis B surface antigen (HBsAg) and HBV DNA in identifying HBeAg-positive NAH were designated using Kaplan-Meier survival analysis with spontaneous HBeAg seroconversion as the endpoint event; On this basis, the performance of ALT in tandem with HBsAg and in tandem with HBV DNA in identifying HBeAg-positive NAH was evaluated. The results showed that, ALT≤60 IU/L, HBsAg >4.602 log10 IU/mL and HBV DNA >7.477 log10 IU/mL were the functional cutoffs in identifying HBeAg-positive NAH. Based on the functional cutoffs, among patients with ALT in tandem with HBsAg, the proportion of patients with pathological grade≤G1 and “grade≤G1 and stage≤S2” were both 100%, and with pathological stage≤S1 and “grade≤G2 and stage≤S1” were both 68.2%; among patients with ALT in tandem with HBV DNA, the proportion of patients with pathological grade≤G1 and “grade≤G1 and stage≤S2” were both 86.2%, and with pathological stage≤S1 and “grade≤G2 and stage≤S1” were both 69.0%; the positive likelihood ratios of ALT in tandem with HBsAg in identifying pathological grade≤G1 and “grade≤G1 and stage≤S2” were both ＋∞， and in identifying pathological stage≤S1 and “grade≤G2 and stage≤S1” were both 2.034; the positive likelihood ratios of ALT in tandem with HBV DNA in identifying pathological grade≤G1 and “grade≤G1 and stage≤S2” were 3.000 and 3.068, respectively, and in identifying pathological stage≤S1 and “grade≤G2 and stage≤S1” were both 2.106. The results suggested that, both ALT in tandem with HBsAg and in tandem with HBV DNA can effectively identify HBeAg-positive NAH. The performance of ALT in tandem with HBsAg in identifying HBeAg-positive NAH is better than that of ALT in tandem with HBV DNA.

This review aims to provide a comprehensive overview of the advancements in Nipah virus animal models, enhancing the understanding of Nipah virus infection pathways, pathogenic mechanisms, and the targeted development and evaluation of vaccines and antibodies. Nipah virus is a zoonotic paramyxovirus with a high fatality rate and is classified as a Biosafety Level 4 pathogen. Since its first outbreak in Malaysia in 1998, it has continued to cause epidemics in Southeast and South Asia, leading to severe respiratory diseases and encephalitis in humans and animals, with no approved vaccines or therapeutic drugs currently on the market. The World Health Organization has prioritized Nipah virus disease for research and development. This review summarizes the construction and development of Nipah virus infection animal models, with multiple species having been utilized in the development of Nipah virus infection models, such as golden hamsters, ferrets, pigs, African green monkeys, and guinea pigs, which reflect the symptoms and pathological characteristics of Nipah virus infection to varying degrees, as well as the advantages and limitations of the models. The review also discusses the establishment and application of pseudovirus animal infection models and looks forward to the future direction of Nipah virus animal model research.

The aim of the study is to analyze the clinic characteristics and the risk factors of long COVID in patients infected with severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2). A total of 1 209 patients infected with SARS-Cov-2 before August 31, 2023 were enrolled in this study. Demographic data, symptoms of long COVID and laboratory examination of these patients were collected. Simple and multiple logistic regression analyses were used to identify the risk factors associated with long COVID. 146 of 1 209 patients (12.08%) self-reported long COIVD. The symptoms of long COVID were mainly characterized by fatigue, cough, memory loss and so on. There was no significant difference in laboratory examination between patients with long COVID and patients without long COVID. Multiple logistic regression analysis showed that the risk factors for long COVID were female (aOR＝1.69, P＝0.007), ≥3 comorbidities (aOR＝4.07, P<0.001) and reinfection (aOR＝1.94, P＝0.002). After the new measures to optimize COVID-19 response were conducted, the incidence of long COVID was lower in patients infected with Omicron strain than previous strains, and female, ≥3 comorbidities, and reinfection were risk factors for long COVID.

To explore the clinical features and pathogenic characterization of the obviously increasing paediatric cases caused by nontyphoidal Salmonella (NTS) in recent years, the present study retrospectively analyzed the clinical features, distribution of serovars, and antimicrobial resistance of NTS in the infected children in Jinshan Hospital of Fudan University between January 2018 and December 2021. The difference in these features between before and after the Corona Virus Disease 2019 (COVID-19) epidemic was also analyzed. The average isolation rate of NTS in paediatric diarrhea cases was 18.1% (110/609), with the rate significantly higher in 2020-2021 (after the beginning of COVID-19) (21.3%，57/268) than in 2018-2019 (15.5%, 53/341, P＝ 0.04). NTS-infected cases were more frequent in the age group of 6 months to 3 years old (80.0%, 88/110), peaking from May to October (84.5%, 93/110). The common clinical symptoms included fever (70.9%) and blood-in-stool (22.7%). The children with NTS infections were administrated with the third-generation cephalosporins, and the therapy mostly lasted for five to seven days. All the cases recovered. The NTS isolates represented 21 serovars, with monophasic variant of S. Typhimurium the commonest (29.1%, 32/110), followed by S. Typhimurium (26.4%, 29/110). Antimicrobial susceptibility testing showed that the resistance rate of NTS isolates to ceftriaxone was 21.8%, while the resistance rates to azithromycin and ciprofloxacin were both very low (8.2% and 6.4%, respectively). 29.1% of the NTS isolates were multidrug-resistant, while 2.7% were resistant to all the tested antibiotics. NTS has become an important pathogen responsible for bacterial inflammatory diarrhea in the children residing in and around Jinshan District of Shanghai. The prevalence of NTS infections is increasing, which is probably associated with the increase of infections caused by S. Typhimurium and its monophasic variant. These NTS isolates show a high resistance rate to the third-generation cephalosporins which are often used in the clinical practice. Therefore, it is necessary to warrant continual surveillance on the changes of epidemiological features and antimicrobial resistance of NTS.

Sepsis is a systemic inflammatory response syndrome caused by bacterial, viral and fungal infections. This inflammatory response induced by pathogenic microorganisms can lead to the failure of multiple organ systems, resulting in serious consequences. Studies have shown that the expression of some non-coding RNAs such as long noncoding RNA (lncRNA), microRNA (miRNA) and circular RNA (circRNA) changes during sepsis. These transcripts can participate in multiple organ system failure through different mechanisms. Correct understanding of the role of non-coding RNA in the pathogenesis of sepsis is of great significance for the early detection, diagnosis and treatment of sepsis in clinical practice. This review mainly describe the role of these three classes of non-coding RNAs in sepsis and its related complications.

A case of mycoplasma encephalitis in newborn was reported. Sick children was admitted to hospital due to “yellow skin for 3 days”. Fever was observed during the course of illness, and the fever sustained for 22 days with the highest temperature of 39 ℃ after admission to the hospital. The examination of cerebrospinal fluid showed that the white blood cell count and the protein quatification level were obviously increased, and yet the glucose level was obviously decreased. Because of the poor effect from neonatal bacterial meningitis treatment, cerebrospinal fluid was taken for high-throughput gene detection of infectious pathogens, and Ureaplasma urealyticum was detected. Therefore, the patient was diagnosed as U. urealyticum infection. U. urealyticum is the main pathogen of neonatal mycoplasma infection, and the infection was mainly from the vertical transmission of intrauterine infection. The clinical manifestations and spinal fluid changes of mycoplasma encephalitis are pretty similar to those of neonatal bacterial meningitis. The Clinicians should pay attention to the etiological diagnosis, and macrolides can be selected for treatment.

Nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 6 (NLRP 6) is one of the important intracellular pattern recognition receptors of host innate immunity and is involved in the regulation of infection, inflammation, tumor and metabolic diseases. By sensing pathogenic organisms such as bacteria, viruses, fungi, parasites and their products, such as lipoteichoic acid (LTA) of Gram-positive bacterium and viral double-stranded RNA, it can regulate the anti-infection immune effect of the body, weaken or enhance the host resistance and affect the outcome of infection. This article reviews the structure and function of NLRP 6 and its role in host immunity against bacterial infection.

Herpes simplex virus type 1 (HSV-1) can cause fatal herpes simplex virus encephalitis (HSE), and some patients may experience severe neurological sequelae even with antiviral therapy. Effective suppression and clearance of HSV-1 infection rely on both innate and adaptive immune responses of the host, with T-cell activation and regulation playing a major role in adaptive immunity, while innate immunity also plays a crucial role in inhibiting virus replication and spread. This article summarized the immune response characteristics and mechanisms in HSE, outlined the protective and damaging effects of the immune system on the body, thereby providing insights for new mechanistic studies and the development of novel immunotherapies.

The aim of this study is to simulate the transportation/temporary storage, frozen storage, and reuse scenarios of infectious specimens in public health biological sample banks. By adding Escherichia coli to rabbit serum and drinking water to simulate infectious human serum samples and environmental water samples, the effects of different transportation temperatures, freezing temperatures, and freeze-thaw cycles on bacterial activity in samples, especially in deep low-temperature environments, were evaluated. The results showed that under transportation conditions of 4 ℃ for infectious serum and drinking water, the number of Escherichia coli in the samples gradually decreased over time. Under dry ice transportation conditions, the number of Escherichia coli in the drinking water samples decreased to an extremely low level after 12 h. Under the conditions of －20 ℃， －80 ℃， and liquid nitrogen, there was no statistical difference between the results of Escherichia coli count after 1 to 3 times freeze-thaws of serum and the reference value. This study suggests that key data affecting sample quality at each stage should be recorded throughout the entire process, and pre-analysis information such as transportation temperature, time limit, and total number of freeze-thaw cycles should be recorded in the biological sample library information system. Although they are not biological sample operation information, the accuracy of the results can be directly affected.

Alphaviruses mainly include old-world alphaviruses that cause arthritis and new-world alphaviruses that cause fatal encephalitis, which can lead to serious diseases in humans. In order to establish a safe and convenient tool to study the entry mechanism of alphaviruses, this study established pseudovirus particle system-based on murine leukemia virus (MLV) and virus replicon particle (VRP) system-based on Sindbis viurs (SINV). Using these pseudoviruses and VRPs, the effects of knockout of heparan sulfate biosynthesis related gene B3 gat3 (beta-1, 3-glucuronyltransferase 3) and arthritogenic alphavirus related entry receptor gene Mxra8 (matrix remodeling associated 8) on cell entry of different alphavirus members were verified. Therefore, the MLV-based pseudovirus and SINV-based VRP systems in this study provide a safe and reliable experimental tool for the research on the entry mechanism of alphavirus members and the development of antiviral strategy.

Actinomyces turicensis is a single-cell prokaryotic microorganism, which is the main oral flora of healthy people. If it enters other parts to cause infection, it may cause actinomycosis. This article introduced a case of tunnel infection of peritoneal dialysis catheter caused by Actinomyces turicensis. The patient was treated with meropenem and cefotaxime, and the disease was improved and the patient was discharged. By introducing the clinical characteristics, laboratory detection and treatment methods of Actinomyces turicensis infection, this study helps clinicians to become more familiar with the diagnosis and treatment of this kind of disease, and emphasizes that the clinical and laboratory should maintain timely and effective clinical communication to achieve early diagnosis and treatment.

RNA-fluorescence in situ hybridization (RNA-FISH) is widely utilized to detect the specific RNA sequences and its contribution in cells or tissues through the complementary hybridization with the fluorescence-labeled nucleotide probes. Given the weak signal, RNA-FISH would be combined with the specific signal amplification technique to improve the signal-to-background ratio. However, due to the low resolution, the traditional signal amplification technology is difficult to eliminate the high background and can not quantify RNA accurately. It is an obvious obstacle to the application of RNA-FISH. Based on the third generation hybridization chain reaction (HCR v3.0) technology, the half split probes were designed to eliminate the non-specific hybridization background and trigger fluorescence signal amplification. Here, we established the sensitive and specific RNA-FISH based on HCR v3.0 to detect the viral RNA of enterovirus A71 (EV-A71). Furthermore, combining RNA-FISH with immunofluorescence staining technology (IF) and high-resolution confocal laser imaging, we successfully detected and quantified the viral RNA and 3D polymerase of EV-A71 during the viral infection in a single-cell level. We observed that the viral RNA decreased whereas 3D polymerase increased significantly in the late stage of EV-A71 infection. It was apparently different from the traditional quantification by reverse tran-scriptase quantitative polymerase chain reaction(RT-qPCR) and western blot, which were based on the total cells during viral infection. It demonstrates that the new generation of RNA-FISH technology based on hybridization chain reaction can overcome the shortcoming of masking the change of virus composition by the increase or decrease of population cell number, so as to truly reflect the change of virus in a single cell.