15 results on '"Chen, Xiabing"'
Search Results
2. Genome analysis provides insight into hyper-virulence of Streptococcus suis LSM178, a human strain with a novel sequence type 1005
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Hu, Yong, Fu, Shiming, Zou, Geng, Kerdsin, Anusak, Chen, Xiabing, Dong, Xingxing, Teng, Lin, and Li, Jinquan
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- 2021
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3. Avian Influenza A (H7N9) Virus in a Wild Land Bird in Central China, Late 2015
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Yao, Yanfeng, Zhang, Tao, Yang, Wenhai, Shao, Zhiyong, He, Bin, Chen, Xiabing, Wu, Lijun, Jin, Erguang, Liu, Haizhou, Chen, Jianjun, and Chen, Jie
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- 2018
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4. The Feed Additive Potassium Diformate Prevents Salmonella enterica Serovar Pullorum Infection and Affects Intestinal Flora in Chickens.
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Sun, Yufan, Yu, Panyuan, Cheng, Yiluo, Liu, Jiahui, Chen, Xiabing, Zhang, Tengfei, Gao, Ting, Zhou, Rui, and Li, Lu
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SALMONELLA enterica ,FEED additives ,INTESTINAL infections ,BOTANY ,CHICKENS - Abstract
Extensive studies have shown that potassium diformate (KDF), an antibiotic substitute used as a feed additive, improves animal growth performance, although there is less direct evidence of its preventive effect on bacterial infections and its influence on the intestinal flora of animals. In this study, the inhibition effect of KDF on Salmonella enterica serovar Pullorum, an important enteric pathogen causing pullorum disease, was investigated in vitro and on a chicken infection model. The effect of KDF on the diversities and structures of chicken duodenal and cecum flora were also investigated using 16S rRNA gene sequencing. The results showed that addition of 0.5% KDF in feed or 0.1% KDF in drinking water significantly reduced the bacterial loads and the degree of pathological changes in the cecum, improved digestion and reduced the pH of the gastrointestinal tract of chickens infected with S. pullorum. KDF also significantly modified the diversity and abundance of intestinal microflorae in chickens. In particular, it promoted the colonization of several probiotics, such as Bacteroides, Blautia, Ruminococcus_torques_group and Faecalibacteriumm, which are involved in maintenance of the intestinal barrier, modulation of inflammation, energy supply for intestinal cells and pathogen resistance. These results enrich the theoretical basis for the clinical application of KDF in chickens. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Comparative genomic characterization of Actinobacillus pleuropneumoniae
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Xu, Zhuofei, Chen, Xiabing, Li, Lu, Li, Tingting, Wang, Shengyue, Chen, Huanchun, and Zhou, Rui
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Genomes -- Identification and classification ,Actinobacillus -- Genetic aspects ,Bacterial genetics -- Research ,Biological sciences - Abstract
The Gram-negative bacterium Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumoniae, a lethal respiratory infectious disease causing great economic losses in the swine industry worldwide. In order to better interpret the genetic background of serotypic diversity, nine genomes of A. pleuropneumoniae reference strains of serovars 1, 2, 4, 6, 9, 10, 11, 12, and 13 were sequenced by using rapid high-throughput approach. Based on 12 genomes of corresponding serovar reference strains including three publicly available complete genomes (serovars 3, 5b, and 7) of this bacterium, we performed a comprehensive analysis of comparative genomics and first reported a global genomic characterization for this pathogen. Clustering of 26,012 predicted protein-coding genes showed that the pan genome of A. pleuropneumoniae consists of 3,303 gene clusters, which contain 1,709 core genome genes, 822 distributed genes, and 772 strain-specific genes. The genome components involved in the biogenesis of capsular polysaccharide and lipopolysaccharide O antigen relative to serovar diversity were compared, and their genetic diversity was depicted. Our findings shed more light on genomic features associated with serovar diversity of A. pleuropneumoniae and provide broader insight into both pathogenesis research and clinical/epidemiological application against the severe disease caused by this swine pathogen. doi: 10.1128/JB.00535-10
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- 2010
6. Anti‐inflammatory activity of arctigenin against PCV2 infection in a mouse model.
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Wu, Lijun, Chen, Jie, Zhou, Danna, Chen, Runshan, Chen, Xiabing, Shao, Zhiyong, Yang, Wenhai, and He, Bin
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LUNGS ,LABORATORY mice ,ANTI-inflammatory agents ,CHINESE medicine ,ANIMAL disease models ,WESTERN immunoblotting ,CYTOPLASM - Abstract
Arctigenin (ACT) is a novel anti‐inflammatory lignan extracted from Arctium lappa L, a herb commonly used in traditional Chinese herbal medicine. In this study, we investigated the molecular mechanism whereby ACT inhibits PCV2 infection‐induced proinflammatory cytokine production in vitro and in vivo. We observed that in PCV2 infection+ACT treated PK‐15 cells, proinflammatory cytokine production was significantly reduced, compared to the PCV2‐infected cells. The transfection and luciferase reporter assay confirmed that ACT suppressed NF‐κB signalling pathway activation following PCV2 infection in PK‐15 cells. Furthermore, western blotting demonstrated that ACT suppressed the NF‐κB signal pathway in PCV2 infection‐stimulated PK‐15 cells by inhibiting the translocation of p65 from the cytoplasm to the nucleus and IκBα phosphorylation. BALB/c mice were used as a model to evaluate the anti‐inflammatory effect of ACT in vivo. We found that the BALB/c mice inoculated with PCV2 infection + ACT treated showed a significant reduction of proinflammatory cytokine production in serum, lung and spleen tissue, compared to the PCV2‐infected mice. Western blotting confirmed that ACT suppressed the NF‐κB signal pathway in PCV2‐infected mice by inhibiting the translocation of p65 from the cytoplasm to the nucleus and IκBα phosphorylation in lung tissue. Our studies first demonstrate that ACT inhibits PCV2 infection‐induced proinflammatory cytokine production by suppressing the phosphorylation and nuclear translocation of NF‐κB in vitro and in vivo. These results will help further develop ACT as a Traditional Chinese herbal medicine remedy in the treatment of porcine circovirus‐associated diseases. This study investigates the molecular mechanism of ACT inhibits PCV2 infection‐induced proinflammatory cytokine production in vitro and in vivo. The results demonstrate that ACT could inhibit PCV2 infection‐induced proinflammatory cytokine production by suppressing the phosphorylation and nuclear translocation of NF‐κB. This study will help further develop ACT as a Traditional Chinese herbal medicine remedy in the treatment of PCVADs. [ABSTRACT FROM AUTHOR]
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- 2022
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7. HylS’, a fragment of truncated hyaluronidase of <italic>streptococcus suis</italic>, contributes to immune evasion by interaction with host complement factor C3b.
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Xu, Jiajia, Chen, Long, Pang, Siqi, Zhang, Qiuhong, Deng, Simin, Zhu, Jiaqi, Chen, Xiabing, Langford, Paul R, Huang, Qi, Zhou, Rui, and Li, Lu
- Abstract
Pathogenic bacteria have evolved many strategies to evade surveillance and attack by complements.
Streptococcus suis is an important zoonotic pathogen that infects humans and pigs. Hyaluronidase (HylA) has been reported to be a potential virulence factor ofS. suis . However, in this study, it was discovered that the genomic region encoding HylA of the virulentS. suis strain SC19 and other ST1 strains was truncated into four fragments when aligned with a strain containing intact HylA and possessing hyaluronidase activity. As a result, SC19 had no hyaluronidase activity, but one truncated HylA fragment, designated as HylS,’ directly interacted with complement C3b, as confirmed by western ligand blotting, pull-down, and ELISA assays. The deposition of C3b and membrane attack complex (MAC) formation on the surface of a HylS’-deleted mutant (ΔhylS’ ) was significantly increased compared to wild-type SC19. In human sera and whole blood, ΔhylS’ survival was significantly reduced compared to that in SC19. The resistance of ΔhylS’ to macrophages and human polymorphonuclear neutrophil PMNs also decreased. In a mouse infection model, ΔhylS’ showed reduced lethality and lower bacterial load in the organs compared to that of SC19. We conclude that the truncated hyaluronidase HylS’ fragment contributes to complement evasion and the pathogenesis ofS. suis . [ABSTRACT FROM AUTHOR]- Published
- 2024
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8. Genome-wide identification of genes critical for in vivo fitness of multi-drug resistant porcine extraintestinal pathogenic Escherichia coli by transposon-directed insertion site sequencing using a mouse infection model.
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Yin F, Hu Y, Bu Z, Liu Y, Zhang H, Hu Y, Xue Y, Li S, Tan C, Chen X, Li L, Zhou R, and Huang Q
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- Animals, Swine, Mutagenesis, Virulence genetics, DNA Transposable Elements, Extraintestinal Pathogenic Escherichia coli genetics, Escherichia coli Infections veterinary
- Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) is an important zoonotic pathogen. Recently, ExPEC has been reported to be an emerging problem in pig farming. However, the mechanism of pathogenicity of porcine ExPEC remains to be revealed. In this study, we constructed a transposon (Tn) mutagenesis library covering Tn insertion in over 72% of the chromosome-encoded genes of a virulent and multi-drug resistant porcine ExPEC strain PCN033. By using a mouse infection model, a transposon-directed insertion site sequencing (TraDIS) assay was performed to identify in vivo fitness factors. By comparing the Tn insertion frequencies between the input Tn library and the recovered library from different organs, 64 genes were identified to be involved in fitness during systemic infection. 15 genes were selected and individual gene deletion mutants were constructed. The in vivo fitness was evaluated by using a competitive infection assay. Among them, Δ fimG was significantly outcompeted by the WT strain in vivo and showed defective adhesion to host cells. rfa which was involved in lipopolysaccharide biosynthesis was shown to be critical for in vivo fitness which may have resulted from its role in the resistance to serum killing. In addition, several metabolic genes including fepB , sdhC , fepG , gltS , dcuA , ccmH , ddpD , narU , glpD , malM , and yabL and two regulatory genes metJ and baeS were shown as important determinants of in vivo fitness of porcine ExPEC. Collectively, this study performed a genome-wide screening for in vivo fitness factors which will be important for understanding the pathogenicity of porcine ExPEC.
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- 2023
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9. The Metabolic Adaptation in Response to Nitrate Is Critical for Actinobacillus pleuropneumoniae Growth and Pathogenicity under the Regulation of NarQ/P.
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Zhang Q, Tang H, Yan C, Han W, Peng L, Xu J, Chen X, Langford PR, Bei W, Huang Q, Zhou R, and Li L
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- Animals, Bacterial Proteins genetics, Bacterial Proteins metabolism, Gene Expression Regulation, Bacterial, Mannose metabolism, Mice, Nitrate Reductases genetics, Nitrate Reductases metabolism, Nitrates metabolism, Pentoses metabolism, Swine, Virulence, Actinobacillus Infections, Actinobacillus pleuropneumoniae genetics, Actinobacillus pleuropneumoniae metabolism
- Abstract
Nitrate metabolism is an adaptation mechanism used by many bacteria for survival in anaerobic environments. As a by-product of inflammation, nitrate is used by the intestinal bacterial pathogens to enable gut infection. However, the responses of bacterial respiratory pathogens to nitrate are less well understood. Actinobacillus pleuropneumoniae is an important bacterial respiratory pathogen of swine. Previous studies have suggested that adaptation of A. pleuropneumoniae to anaerobiosis is important for infection. In this work, A. pleuropneumoniae growth and pathogenesis in response to the nitrate were investigated. Nitrate significantly promoted A. pleuropneumoniae growth under anaerobic conditions in vitro and lethality in mice. By using narQ and narP deletion mutants and single-residue-mutated complementary strains of Δ narQ , the two-component system NarQ/P was confirmed to be critical for nitrate-induced growth, with Arg50 in NarQ as an essential functional residue. Transcriptome analysis showed that nitrate upregulated multiple energy-generating pathways, including nitrate metabolism, mannose and pentose metabolism, and glycerolipid metabolism via the regulation of NarQ/P. Furthermore, narQ , narP , and its target gene encoding the nitrate reductase Nap contributed to the pathogenicity of A. pleuropneumoniae. The Nap inhibitor tungstate significantly reduced the survival of A. pleuropneumoniae in vivo , suggesting that Nap is a potential drug target. These results give new insights into how the respiratory pathogen A. pleuropneumoniae utilizes the alternative electron acceptor nitrate to overcome the hypoxia microenvironment, which can occur in the inflammatory or necrotic infected tissues.
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- 2022
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10. Involvement of the Actinobacillus pleuropneumoniae ompW Gene in Confrontation of Environmental Pressure.
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Chen X, Shao Z, Wu L, He B, Yang W, Chen J, Jin E, Huang Q, Lei L, Xu J, Li H, Zhang H, Wan Y, Liu W, and Zhou R
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Actinobacillus pleuropneumoniae causes porcine pleuropneumonia. The function of the outer membrane protein W gene ( ompW ) of A. pleuropneumoniae has not been evaluated. Thus a deletion mutant of ompW , Δ ompW , was constructed to explore the effect of ompW gene deletion on bacterial growth, biofilm formation, bacterial morphology, oxidative tolerance, susceptibility to antibiotics, and the expression of ribosome synthesis and ABC transporter related genes. Results showed that the ompW gene deletion did not affect biofilm formation and the growth of A. pleuropneumoniae but did affect bacterial morphology during steady growth, oxidative tolerance, and bacterial susceptibility to polymyxin B, kanamycin, and penicillin. The ompW gene deletion also affected the expression of ribosome synthesis and ABC transporter related genes. These results suggested that ompW may regulate the biological phenotype of A. pleuropneumoniae ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chen, Shao, Wu, He, Yang, Chen, Jin, Huang, Lei, Xu, Li, Zhang, Wan, Liu and Zhou.)
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- 2022
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11. The Rcs System Contributes to the Motility Defects of the Twin-Arginine Translocation System Mutant of Extraintestinal Pathogenic Escherichia coli.
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Liu T, Liu Y, Bu Z, Yin F, Zhang Y, Liu J, Li S, Tan C, Chen X, Li L, Zhou R, and Huang Q
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- Arginine metabolism, Flagella metabolism, Protein Transport, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism, Extraintestinal Pathogenic Escherichia coli genetics, Extraintestinal Pathogenic Escherichia coli metabolism, Twin-Arginine-Translocation System genetics, Twin-Arginine-Translocation System metabolism
- Abstract
Flagellum-mediated bacterial motility is important for bacteria to take up nutrients, adapt to environmental changes, and establish infection. The twin-arginine translocation system (Tat) is an important protein export system, playing a critical role in bacterial physiology and pathogenesis. It has been observed for a long time that the Tat system is critical for bacterial motility. However, the underlying mechanism remains unrevealed. In this study, a comparative transcriptomics analysis was performed with extraintestinal pathogenic Escherichia coli (ExPEC), which identified a considerable number of genes differentially expressed when the Tat system was disrupted. Among them, a large proportion of flagellar biosynthesis genes showed downregulation, indicating that transcription regulation plays an important role in mediating the motility defects. We further identified three Tat substrate proteins, MdoD, AmiA, and AmiC, that were responsible for the nonmotile phenotype. The Rcs system was deleted in the Δ tat , the Δ mdoD , and the Δ amiA Δ amiC strains, which restored the motility of Δ mdoD and partially restored the motility of Δ tat and Δ amiA Δ amiC . The flagella were also observed in all of the Δ tat Δ rcsDB , Δ mdoD Δ rcsDB , and Δ amiA Δ amiC Δ rcsDB strains, but not in the Δ tat , Δ mdoD , and Δ amiA Δ amiC strains, by using transmission electron microscopy. Quantitative reverse transcription-PCR data revealed that the regulons of the Rcs system displayed differential expression in the tat mutant, indicating that the Rcs signaling was activated. Our results suggest that the Rcs system plays an important role in mediating the motility defects of the tat mutant of ExPEC. IMPORTANCE The Tat system is an important protein export system critical for bacterial physiology and pathogenesis. It has been observed for a long time that the Tat system is critical for bacterial motility. However, the underlying mechanism remains unrevealed. In this study, we combine transcriptomics analysis and bacterial genetics, which reveal that transcription regulation plays an important role in mediating the motility defects of the tat mutant of extraintestinal pathogenic Escherichia coli. The Tat substrate proteins responsible for the motility defects are identified. We further show that the Rcs system contributes to the motility suppression. We for the first time reveal the link between the Tat system and bacterial motility, which is important for understanding the physiological functions of the Tat system.
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- 2022
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12. An Engineered Outer Membrane-Defective Escherichia coli Secreting Protective Antigens against Streptococcus suis via the Twin-Arginine Translocation Pathway as a Vaccine.
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Li W, Yin F, Bu Z, Liu Y, Zhang Y, Chen X, Li S, Li L, Zhou R, and Huang Q
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- Animals, Arginine, Escherichia coli genetics, Escherichia coli metabolism, Membrane Transport Proteins genetics, Membrane Transport Proteins metabolism, Mice, Protein Sorting Signals genetics, Protein Transport, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism, Streptococcus suis genetics, Streptococcus suis metabolism, Vaccines
- Abstract
Live bacterial vector vaccines are one of the most promising vaccine types and have the advantages of low cost, flexibility, and good safety. Meanwhile, protein secretion systems have been reported as useful tools to facilitate the release of heterologous antigen proteins from bacterial vectors. The twin-arginine translocation (Tat) system is an important protein export system that transports fully folded proteins in a signal peptide-dependent manner. In this study, we constructed a live vector vaccine using an engineered commensal Escherichia coli strain in which amiA and amiC genes were deleted, resulting in a leaky outer membrane that allows the release of periplasmic proteins to the extracellular environment. The protective antigen proteins SLY, enolase, and Sbp against Streptococcus suis were targeted to the Tat pathway by fusing a Tat signal peptide. Our results showed that by exploiting the Tat pathway and the outer membrane-defective E. coli strain, the antigen proteins were successfully secreted. The strains secreting the antigen proteins were used to vaccinate mice. After S. suis challenge, the vaccinated group showed significantly higher survival and milder clinical symptoms compared with the vector group. Further analysis showed that the mice in the vaccinated group had lower burdens of bacteria load and slighter pathological changes. Our study reports a novel live bacterial vector vaccine that uses the Tat system and provides a new alternative for developing S. suis vaccine.
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- 2022
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13. A survey of Prototheca bovis infection in dairy farms of the Hubei province, China.
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Li J, Chen X, Jin E, Wang G, Wu L, Shao Z, Wan P, Hu C, Li J, Chen J, and Ding M
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- Animals, Cattle, Farms, Female, Mice, Milk, Cattle Diseases epidemiology, Mastitis veterinary, Mastitis, Bovine epidemiology, Prototheca
- Abstract
Bovine mastitis, caused by Prototheca bovis, has received much attention worldwide. To investigate the status of P. bovis infection in dairy farms of Hubei, we collected 1,158 milk samples and 90 environmental samples from 14 dairy farms of Hubei, China. The isolates were identified with traditional biological methods and molecular biological techniques, and their pathogenicity was tested through mice infection experiments. Isolates from 57 milk and 20 environmental samples were identified as P. bovis. The mice infection tests proved that the isolated P. bovis could cause mastitis in mice, manifesting as severe red swelling of the mammary glands. Histopathological analysis of tissue sections showed necrosis and nodules lesions formed in the infected mice mammary tissue, accompanied by macrophage and neutrophil infiltration. These results suggested the existence of pathogenic P. bovis in dairy farms of the Hubei province, China, with brewer's grains and fresh feces possibly playing important roles in the spread of this disease.
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- 2021
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14. Tea polyphenols suppress growth and virulence-related factors of Haemophilus parasuis.
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Guo L, Guo J, Liu H, Zhang J, Chen X, Qiu Y, and Fu S
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- Animals, Haemophilus Infections drug therapy, Swine, Virulence, Virulence Factors, Haemophilus Infections veterinary, Haemophilus parasuis growth & development, Haemophilus parasuis pathogenicity, Polyphenols pharmacology, Swine Diseases drug therapy, Tea chemistry
- Abstract
The bacterium Haemophilus parasuis (H. parasuis) is the primary cause of Glässer's disease. Currently, there are no effective vaccines that can confer protection against all H. parasuis serovars. Therefore, the present study aimed to investigate the effect of tea polyphenols on growth, expression of virulence-related factors, and biofilm formation of H. parasuis, as well as to evaluate their protective effects against H. parasuis challenge. Our findings demonstrated that tea polyphenols can inhibit H. parasuis growth in a dose-dependent manner and attenuate the biofilm formation of H. parasuis. In addition, tea polyphenols exerted inhibitory effects on the expression of H. parasuis virulence-related factors. Moreover, tea polyphenols could confer protection against a lethal dose of H. parasuis and can reduce pathological tissue damage induced by H. parasuis. In summary, our findings demonstrated the promising use of tea polyphenols as a novel treatment for H. parasuis infection in pigs.
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- 2018
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15. Complete Genome Sequences of an H5N1 Highly Pathogenic Avian Influenza Virus Isolated from Pigeon in China in 2012.
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Yao Y, Fu S, He B, Chen X, Shao Z, Yang W, and Chen J
- Abstract
An avian influenza virus strain, A/pigeon/Hubei/RP25/2012 (H5N1), was isolated from pigeons in Hubei province, China. Phylogenetic analysis indicates that the HA gene belongs to clade 2.3.4 and the other internal genes present different recombination events. Information about the strain provides basic research data for epidemiological evidences for revealing influenza evolution., (Copyright © 2015 Yao et al.)
- Published
- 2015
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