Objective:To study the distribution of drug resistance genes and virulence genes in multidrug-resistant Salmonella typhimurium strains.Methods:A total of 96 strains of Salmonella typhimurium were collected，and drug sensitivity tests were performed to evaluate the drug resistance and multidrug-resistance of Salmonella typhimurium.Multidrug-resistant Salmonella typhimurium strains were selected to conducted whole genome sequencing，and the distribution of drug resistance genes and virulence genes in the strain were analyzed.Results:Salmonella typhimurium strains had the highest resistance rates to ampicillin and ampicillin/sulbactam，with 89.58% and 76.04%，respectively.Followed by trimethoprim/sulfamethoxazole，ceftriaxone，and aztreonam，with 47.92%，38.54% and 33.33%，respectively，and low resistance rates to ciprofloxacin and levofloxacin，with 8.33% and 4.17%，respectively.Ninety-six strains were all sensitive to carbapenem antibiotics and piperacillin/tazobactam.Fifty-seven strains（59.38%）of Salmonella typhimurium showed multidrug-resistance.Resistance genes were detected in all 57 multidrug-resistant Salmonella typhimurium strains,with higher carrier rates of 98.25%,77.19%,and 59.65% for aac(6')-Iaa,aadA22,and blaTEM-1B,respectively.The multidrug-resistant Salmonella typhimurium strains had the highest carrier rates for invA，sipA，sseL，and sopB.Conclusion:Multidrug-resistant Salmonella typhimurium strains have a high incidence and a high carrier rate for multiple drug resistance genes and virulence genes.The monitoring and prevention of Salmonella typhimurium should be strengthened in the clinic in order to reduce the spreading epidemic of multidrug-resistant strains.

OBJECTIVE The abnormal amyloid-β(Aβ)and oxidative stress assiociated with the progression of Alzheimer disease(AD).Quercetin has been reported to possess antioxidant and anti-inflammatory properties in neurodegenerative disorders.In this present study,we designed to characterize the mechanisms by which quer-cetin exerts neuroprotective effects in murine neuroblas-toma N2a cells stably expressing human Swedish mutant amyloid precursor protein(N2a/APP).METHODS N2a/APP cells were treated with quercetin at concentrations of 10,20 and 50 μ mol·L-1 for 24 h.Cell viability was examined with CCK-8 assays.The protein levels of ERK1/2 and Akt were detected by Western blotting.Intra-cellular reactive oxygen species(ROS)was detected by a fluorescent probe 2,7-dichlorofluorescein diacetate(DCFH-DA).The mitochondrial membrane potential(Δψ m)in N2a/APP cells was detected by using JC-1 staining method.Immunofluorescence was used to detect the generation of 8-hydroxy-2′-deoxyguanosine(8-OHdG)and 4-hydroxynonenal(4-HNE).RESULTS Quercetin attenuated the enhancement of p-ERK1/2,reductions of p-Akt,and decreased levels of APP expression.More-over,quercetin alleviated loss of mitochondria membrane potential(MMP)since it attenuates these oxidative stress,as reflected in the levels of ROS,4-HNE and 8-OHdG,was elevated in N2a/APP cells and these effects were again ameliorated by quercetin.CONCLUSION Neuroprotection by quercetin in N2a/APP cells involves normalizing the impaired mitochondrial function and reducing oxidative stress via inactivation of the ERK1/2 and activation of the Akt pathways.

Abstract: Cell death is a fundamental biological phenomenon that is essential for the survival and development of organisms. Cell death can be either a spontaneous programmed process by the host or an accidentally triggered process. According to the different signaling pathway activated by various stimulates, programmed cell death exhibits the lytic or non-lytic morphology. For example, apoptosis, a typical non-lytic form of cell death, exhibits cell shrinkage and induces the formation of apoptotic bodies. Pyroptosis mediated by cysteine-containing aspartate-specific protease-1/11 (caspase-1/11) and necroptosis can induce inflammatory reactions and promote cell lysis to release inflammatory cytokines via triggering the pore-forming mechanism of the cell membrane, representing a typical modes of lytic cell death. In addition, the release of reactive oxygen species caused by the damaged mitochondria may further trigger ferroptosis during the pathogen infection. Programmed cell death can play an immune defensive role by eliminating infected cells and intracellular pathogens and stimulating the innate immune response through the resulting cell corpses. Here, we discuss the molecular mechanisms of five programmed cell death pathways: apoptosis, pyroptosis, ferroptosis, necroptosis and PANoptosis. We describe their roles in the innate immune defense against bacterial infections and give a brief statement of the interactions between the different programmed cell death, hoping to provide new insights for in-depth study of the pathogenic mechanisms of infectious diseases.

Objective:To investigate the changes of intestinal microecology in the early stage of sepsis rat model by 16S rDNA sequencing.Methods:Sixty male Sprague-Dawley (SD) rats were randomly divided into cecal ligation and puncture (CLP) group and sham operation group (Sham group), with 30 rats in each group. In the CLP group, sepsis rat model was reproduced by CLP method; the rats in the Sham group only underwent laparotomy without CLP. At 24 hours after the operation, the intestinal feces and serum samples of 8 rats in each group were collected. The survival rate of the rest rats was observed until the 7th day. The level of serum tumor necrosis factor-α (TNF-α) was detected by enzyme-linked immunosorbent assay (ELISA). Intestinal feces were sequenced by 16S rDNA sequencing technology. The operational taxonomic unit (OTU) data obtained after sequence comparison and clustering was used for α diversity and β diversity analysis, principal coordinate analysis and linear discriminant analysis effect size analysis (LEfSe) to observe the changes of intestinal microecology in early sepsis rats and excavate the marker flora.Results:At 24 hours after the reproduction of the model, the rats in the CLP group showed shortness of breath, scattered hair and other manifestations, and the level of serum TNF-α increased significantly as compared with that in the Sham group (ng/L: 43.95±9.05 vs. 11.08±3.27, P < 0.01). On the 7th day after modeling, the cumulative survival rate of the Sham group was 100%, while that of the CLP group was 31.82%. Diversity analysis showed that there was no significant difference in α diversity parameter between the Sham group and the CLP group (number of species: 520.00±52.15 vs. 492.25±86.61, Chao1 richness estimator: 707.25±65.69 vs. 668.93±96.50, Shannon index: 5.74±0.42 vs. 5.79±0.91, Simpson index: 0.93±0.03 vs. 0.94±0.05, all P > 0.05). However, the β diversity analysis showed that the difference between groups was greater than that within groups whether weighted according to OTU or not (abundance weighted matrix: R = 0.23, P = 0.04; abundance unweighted matrix: R = 0.32, P = 0.01). At the phylum level, the abundance of Proteobacteria and Candidatus_sacchari in the CLP group increased significantly as compared with the Sham group [18.100% (15.271%, 26.665%) vs. 6.974% (2.854%, 9.764%), 0.125% (0.027%, 0.159%)% vs. 0.018% (0.008%, 0.021%), both P < 0.05]. At the genus level, the abundance of opportunistic pathogen including Helicobacter, Ruthenium, Streptococcus, Clostridium ⅩⅧ in the CLP group was significantly higher than that in the Sham group [5.090% (1.812%, 6.598%) vs. 0.083% (0.034%, 0.198%), 0.244% (0.116%, 0.330%) vs. 0.016% (0.008%, 0.029%), 0.006% (0.003%, 0.010%) vs. 0.001% (0%, 0.003%), 0.094% (0.035%, 0.430%) vs. 0.007% (0.003%, 0.030%), all P < 0.05], and the abundance of probiotics such as Alloprevotella and Romboustia was significantly lower than that in the Sham group [7.345% (3.662%, 11.546%) vs. 22.504% (14.403%, 26.928%), 0.113% (0.047%, 0.196%) vs. 1.229% (0.809%, 2.29%), both P < 0.01]. LEfSe analysis showed that the probiotics belonging to Firmicutes were significantly enriched in the Sham group, and Romboustia was the most significantly enriched species. Opportunistic pathogens such as Helicobacter, Streptococcus and Clostridium ⅩⅧ were significantly enriched in the CLP group, Helicobacter_NGSU_ 2015 was the most significantly enriched species. Conclusion:In the early stage of sepsis, the intestinal microbiota structure of rats is significantly changed, which mainly shows that the abundance of Alloprevotella and other probiotics is significantly reduced, while that of Helicobacter and other opportunistic pathogens is significantly increased.

Accurate identification of cell types from single-cell RNA sequencing (scRNA-seq) data plays a critical role in a variety of scRNA-seq analysis studies.This task corresponds to solving an unsupervised clustering problem,in which the similarity measurement between cells affects the result significantly.Although many approaches for cell type identification have been proposed,the accuracy still needs to be improved.In this study,we proposed a novel single-cell clustering framework based on similarity learning,called SSRE.SSRE models the relationships between cells based on subspace assumption,and generates a sparse representation of the cell-to-cell similarity.The sparse representation retains the most similar neighbors for each cell.Besides,three classical pairwise similarities are incorporated with a gene selection and enhancement strategy to further improve the effectiveness of SSRE.Tested on ten real scRNA-seq datasets and five simulated data-sets,SSRE achieved the superior performance in most cases compared to several state-of-the-art single-cell clustering methods.In addition,SSRE can be extended to visualization of scRNA-seq data and identification of differentially expressed genes.The matlab and python implementations of SSRE are available at https://github.com/CSUBioGroup/SSRE.

Objective To translate Chinese version of the Family Impact of Childhood Bronchial Asthma-Revised(IFABI-R), and to evaluate its reliability and validity in family caregivers for children with asthma. Methods The English version of IFABI-R was translated into Chinese by means of translation, back translation, expert consultation and cultural debugging to form a Chinese version of the questionnaire. A total of 158 parents of the children with asthma treated in the First Affiliated Hospital of Zhengzhou University from January to June 2016 were investigated by the Chinese version IFABI-R. The reliability and validity was tested. Results The Chinese version of IFABI-R has 14 entries. The content validity (I-CVI) of the items ranged from 0.80 to 1.0, and the content validity (S-CVI) of the total scale was 0.98. Exploratory factor analysis extracted 3 factors, the cumulative contribution rate is 68.362%. The Cronbach's alpha coefficient of the scale was 0.843, and the Guttman split half coefficient was 0.842, with the test-retest reliability 0.796. Conclusions The Chinese version of IFABI-R has good cultural applicability, with good reliability and validity. It can be used to assess the quality of life of parents with asthma in children.

High mobility group protein box 1 (HMGB1) is a highly conserved DNA binding protein, which is found in the nucleus of a variety of cells in the body, regulating the transcription of cell genes.It plays a role of nuclear binding protein in physiological state.Once released into the cell gap, it performances the role of inflammatory mediators.Recent studies showed that pathogenesis of HMGB1 not only involved in sepsis, autoimmune diseases, chronic liver disease, malignant tumor, but also involved in cell injury repair,which plays important role in a variety of diseases, organ damage, repair process.

The innate immune system is critical for clearing infection, and is tightly regulated to avert excessive tissue damage. Nod1/2-Rip2 signaling, which is essential for initiating the innate immune response to bacterial infection and ER stress, is subject to many regulatory mechanisms. In this study, we found that LRRK2, encoded by a gene implicated in Crohn's disease, leprosy and familial Parkinson's disease, modulates the strength of Nod1/2-Rip2 signaling by enhancing Rip2 phosphorylation. LRRK2 deficiency markedly reduces cytokine production in macrophages upon Nod2 activation by muramyl dipeptide (MDP), Nod1 activation by D-gamma-Glu-meso-diaminopimelic acid (iE-DAP) or ER stress. Our biochemical study shows that the presence of LRRK2 is necessary for optimal phosphorylation of Rip2 upon Nod2 activation. Therefore, this study reveals that LRRK2 is a new positive regulator of Rip2 and promotes inflammatory cytokine induction through the Nod1/2-Rip2 pathway.
Animals ; Cytokines ; genetics ; immunology ; HEK293 Cells ; Humans ; Immunity, Innate ; genetics ; Inflammation ; genetics ; immunology ; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 ; genetics ; immunology ; Mice ; Mice, Knockout ; Nod1 Signaling Adaptor Protein ; genetics ; immunology ; Nod2 Signaling Adaptor Protein ; genetics ; immunology ; Phosphorylation ; genetics ; immunology ; Receptor-Interacting Protein Serine-Threonine Kinase 2 ; genetics ; immunology ; Receptor-Interacting Protein Serine-Threonine Kinases ; genetics ; immunology ; Signal Transduction ; genetics ; immunology

Objective:To examine the oncogenic mutations involved in melanoma in Southern China and to provide a theoretical basis for the development of melanoma molecular targeted therapy strategy. Methods:The Sequenom platform (OncoCarta Panel v1.0 and MassARRAY System) was used to determine the prevalence of oncogene mutations in 28 acral melanoma samples, 28 mucosal mel-anoma samples, and 30 non-chronic sun-induced-damage (no-CSD) melanoma samples from Southern China. Results:At least one mu-tation was detected in 33 of the 86 melanomas (38.4%) with mutations observed in BRAF (16.3%), NRAS (10.5%), KIT (5.8%), EGFR (4.7%), HRAS (2.3%), KRAS (2.3%), MET (2.3%), and PIK3CA (1.2%). In BRAF, the age of patients with mutations was significantly lower than those without BRAF mutation (45.7±15.3 vs. 55.9±12.7, P=0.01). Patients with mutations in NRAS were more likely to have ulceration compared with patients without NRAS mutations (88.9%vs. 48.1%, P=0.049). Conclusions:This study represents a compre-hensive and concurrent analysis of the major recurrent oncogenic mutations involved in melanoma cases from Southern China areas. The data have implications for both clinical trial designs and therapeutic strategies.