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Construction of Prokaryotic Expressing Vector of Antisense Nucleic Acid of lasR and Its Effect on the virulence of Pseudomonas Aeruginosus

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2007年第4期27卷 349-353页

作者：张玲周俊立李静铭廖芳 Department of Pathogenic Biology Tongji Medical CollegeHuazhong University of Science and Technology

To construct a pUCP18/lasR^antisense plasmid carrying the reversed gene and analyze its effect on the virulence of Pseudomonas aeruginosus, LasR gene was amplified from the genome of Pseudomonas aeruginosus by PCR and reversely recombined with plasmid pUCP18. The recombinant pUCP18/lasR^antisense was verified by enzyme digestion, PCR and sequencing. The biological effects of pUCP18/lasR^antisense were examined by using RT-PCR, NAD method and the assay of pyocyanin. Our results showed that the expected full length lasR fragment （721 bp） was extended from Pseudomonas aeruginosus gene with PCR. And it is consistent with LasR gene of Pseudomonas aeruginosa in GenBank （No. NC_002516）. The recombinant plasmid was successfully constructed and transferred into Pseudomonas aeruginosus. The antisense nucleic acid of LasR gene could reduce the virulence of Pseudomonas aeruginosus and might serve as a new target site for treatment purpose.

关键词： LasR gene antisense nucleic acids bacterial transformation virulence factor

Medicinal plant activity on Helicobacter pylori related diseases

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World Journal of Gastroenterology 2014年第30期20卷 10368-10382页

作者： Yuan-Chuen Wang Department of Food Science and Biotechnology National Chung Hsing University

More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group I carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori vacA-positive strains can lead to vacuolation and apoptosis, whereas infection with cagA-positive strains might result in severe gastric inflammation and gastric cancer. Numerous medicinal plants have been reported for their anti-H. pylori activity, and the relevant active compounds including polyphenols, flavonoids, quinones, coumarins, terpenoids, and alkaloids have been studied. The anti-H. pylori action mechanisms, including inhibition of enzymatic (urease, DNA gyrase, dihydrofolate reductase, N-acetyltransferase, and myeloperoxidase) and adhesive activities, high redox potential, and hydrophilic/hydrophobic natures of compounds, have also been discussed in detail. H. pylori-induced gastric inflammation may progress to superficial gastritis, atrophic gastritis, and finally gastric cancer. Many natural products have anti-H. pylori-induced inflammation activity and the relevant mechanisms include suppression of nuclear factor-κB and mitogen-activated protein kinase pathway activation and inhibition of oxidative stress. Anti-H. pylori induced gastric inflammatory effects of plant products, including quercetin, apigenin, carotenoids-rich algae, tea product, garlic extract, apple peel polyphenol, and finger-root extract, have been documented. In conclusion, many medicinal plant products possess anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect. Those plant products have showed great potential as pharmaceutical candida

关键词： Helicobacter pylori virulence factor Medicinal plant Active compound Mechanism Inflammation Gastric cancer nuclear factor-kappa B pathway

In vitro Transcriptome Analysis of Two Chinese Isolates of Streptococcus suis Serotype 2

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Genomics, Proteomics & Bioinformatics 2014年第6期12卷 266-275页

作者： Dake Zhang Nan Du Sufang Ma Qingtao Hu Guangwen Lu Wei Chen Changqing Zeng CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of Sciences University of Chinese Academy of Sciences

The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two Chinese isolates with that of a reference strain（P1/7）. In the89 K genomic island that is specific to these Chinese isolates, a toxin–antitoxin system showed relatively high levels of transcription among the S. suis. The known virulence factors with high transcriptional activity in these two highly-pathogenic strains are mainly involved in adhesion, biofilm formation, hemolysis and the synthesis and transport of the outer membrane protein. Furthermore,our analysis of novel transcripts identified over 50 protein-coding genes with one of them encoding a toxin protein. We also predicted over 30 small RNAs（s RNAs） in each strain, and most of them are involved in riboswitches. We found that six s RNA candidates that are related to bacterial virulence, including csp A and rli38, are specific to Chinese isolates. These results provide insight into the factors responsible for the difference in virulence among the different S. suis 2 isolates.

关键词： Streptococcus suis serotype 2 Transcriptome Novel transcripts s RNA virulence factor

VICMpred: An SVM-based Method for the Prediction of Functional Proteins of Gram-negative Bacteria Using Amino Acid Patterns and Composition

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Genomics, Proteomics & Bioinformatics 2006年第1期4卷 42-47页

作者： Sudipto Saha G.P.S. Raghava Institute of Microbial Technology Chandigarh India.

In this study, an attempt has been made to predict the major functions of gramnegative bacterial proteins from their amino acid sequences. The dataset used for training and testing consists of 670 non-redundant gram-negative bacterial proteins （255 of cellular process, 60 of information molecules, 285 of metabolism, and 70 of virulence factors）. First we developed an SVM-based method using amino acid and dipeptide composition and achieved the overall accuracy of 52.39% and 47.01%, respectively. We introduced a new concept for the classification of proteins based on tetrapeptides, in which we identified the unique tetrapeptides significantly found in a class of proteins. These tetrapeptides were used as the input feature for predicting the function of a protein and achieved the overall accuracy of 68.66%. We also developed a hybrid method in which the tetrapeptide information was used with amino acid composition and achieved the overall accuracy of 70.75%. A five-fold cross validation was used to evaluate the performance of these methods. The web server VICMpred has been developed for predicting the function of gram-negative bacterial proteins （http：//***/raghava/vicmpred/）.

关键词： virulence factor cellular process information molecule tetrapeptide VICMpred gram-negative bacteria

The Group A Streptococcus Interleukin-8 Protease SpyCEP Promotes Bacterial Intracellular Survival by Evasion of Autophagy

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Infectious Microbes & Diseases 2022年第3期4卷 116-123页

作者： RenéBergmann Giuseppe Gulotta Federica Andreoni Tomoko Sumitomo Shigetada Kawabata Annelies S.Zinkernagel Gursharan S.Chhatwal Victor Nizet Manfred Rohde Satoshi Uchiyama Central Unit for Microscopy(ZEIM) Helmholtz Centre for Infection ResearchBraunschweigGermany Division of Infectious Diseases and Hospital Epidemiology University Hospital ZurichZurichSwitzerland Department of Oral and Molecular Microbiology Osaka University Graduate School of DentistrySuita-OsakaJapan Division of Host-Microbe Systems and Therapeutics Department of PediatricsUniversity of CaliforniaSan DiegoLa JollaCalifornia

Autophagy serves an innate immune function in defending the host against invading bacteria,including group A Streptococcus(GAS).Autophagy is regulated by numerous host proteins,including the endogenous negative regulator calpain,a cytosolic *** disseminated serotypeM1T1 GAS strains associated with high invasive disease potential express numerous virulence factors and resist autophagic *** in vitro infection of human epithelial cell lines with representative wild-type GAS M1T1 strain 5448(M1.5448),we observed increased calpain activation linked to a specific GAS virulence factor,the interleukin-8 protease *** activation inhibited autophagy and decreased capture of cytosolic GAS in *** contrast,the serotype M6 GAS strain JRS4(***4),which is highly susceptible to host autophagy-mediated killing,expresses low levels of SpyCEP and does not activate *** of SpyCEP in ***4 stimulated calpain activation,inhibited autophagy,and significantly decreased bacterial capture in *** paired loss-and gain-of-function studies reveal a novel role for the bacterial protease SpyCEP in enabling GAS M1 evasion of autophagy and host innate immune clearance.

关键词： group A Streptococcus SpyCEP virulence factor epithelial cells intracellular survival autophagy xenophagy calpain

Reprogramming of phytopathogen transcriptome by a non-bactericidal pesticide residue alleviates its virulence in rice

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Fundamental Research 2022年第2期2卷 198-207页

作者： Haruna Matsumoto Yuan Qian Xiaoyan Fan Sunlu Chen Yanxia Nie Kun Qiao Dandan Xiang Xinzhong Zhang Meng Li Bo Guo Peilin Shen Qiangwei Wang Yunlong Yu Tomislav Cemava Mengcen Wang State Key Laboratory of Rice Biology&Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects Institute of Pesticide and Environmental ToxicologyZhejiang UniversityHangzhou 310058China Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province College of Agriculture and BiotechnologyZhejiang UniversityHangzhou 310058China Institute of Environmental Biotechnology Graz University of TechnologyPetersgasse 128010 GrazAustria Global Education Program for AgriScience Frontiers Graduate School of AgricultureHokkaido UniversitySapporo 0608589Japan State Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural UniversityNanjing 210095China Ecology and Environmental Sciences Center South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Key laboratory of South Subtropical Fruit Biology and Genetic Resource Uilization(MOA) Instiute of Fruit Tree ResearchGuangdong Acadermy of Agricultural SciencesGuangzhou 510640China Tea Research Instiute Chinese Academy of Agriculural SciencesHangzhou 310008China Shanghai Intermnational Studies University Shanghai 200083China Xiaoshan Agricultural Comprehensive Development Zone&Management Committee Hangzhou 311200China

Bacteria equipped with virulence systems based on highly bioactive small molecules can circumvent their host's defense *** employing this strategy are currently threatening global rice *** the present study,variations in the virulence of the highly destructive Barkholderiaplantarii were observed in different rice-producing *** environment-linked variation was not attributable to any known host-related or external ***-occurrence analyses indicated a connection between reduced virulence and 5-Amino-l,3,4-thiadiazole-2-thiol(ATT),a non-bactericidal organic ***,which accumulates in rice plants during metabolization of specific agrochemicals,was found to reduce virulence factor secretion by *** up to 88.8%and inhibit pathogen virulence by hijacking an upstream signaling *** assessment of the newly discovered virulence inhibitor resulted in mechanistic insights into positive effects of ATT accumulation in plant *** of virulence alleviation were deciphered by integrating high-throughput data,gene knockout mutants,and molecular interaction ***,a histidine protein kinase in a two-component system that regulates virulence factor secretion,is likely the molecular target antagonized by *** findings provide novel insights into virulence modulation in an important plant-pathogen system that relies on the host's metabolic activity and subsequent signaling interference.

关键词： Phytopathogen virulence factor Transcriptome reprogramming Agrochemical Pesticide Rice

Structural Insight into the Substrate Gating Mechanism by Staphylococcus aureus Aldehyde Dehydrogenase

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CCS Chemistry 2020年第5期2卷 946-954页

作者： Xuan Tao Zhemin Zhang Xiao Zhang Hongyan Li Hongzhe Sun Zong-Wan Mao Wei Xia MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-sen UniversityGuangzhou510275 Department of Chemistry The University of Hong KongPokfulam RoadHong Kong

Staphylococcus aureus produces staphyloxanthin,a C30 carotenoid with golden color,as an antioxidant to promote bacterial resistance to reactive oxygen *** biosynthesis pathway of staphyloxanthin involves a series of catalytic *** dehydrogenase(AldH)is a dehydrogenase recently identified to convert 4,4’-diaponeurosporenaldehyde into 4,4’-diaponeurosporenoic acid during staphyloxanthin ***,we present the crystallographic structures of apo-and holo-forms of *** *** dimeric enzyme contains a unique C-terminal helix,which resembles a“gatekeeper”helix found in human membrane-bound fatty aldehyde dehydrogenase(FALDH).Particularly,the helix adopts“open”and“closed”conformations in apo-and holo-AldH,respectively,to control the access of the substrate *** in combination with in vitro and in vivo activity assays identifies several residues essential for *** AldH substrate recognition and enzyme catalytic *** results provide insights into substrate recognition of *** AldH toward polyunsaturated long-chain aldehydes at atomic resolution.

关键词： Staphylococcus aureus virulence factor substrate recognition aldehyde dehydrogenase protein structure

Infectious Spondylitis-Associated Staphylococcus aureus with virulence Gene pvl or tst Causes More Necrosis than Apoptosis in Human Alveolar Basal Epithelial Cell Line A549

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Advances in Microbiology 2016年第7期6卷 479-488页

作者： Tsung-Jen Huang Chi-Han Lee Meng-Huang Wu Yen-Yao Li Tsung Han Yang Chin-Chang Cheng Ching-Yu Lee Chih-Cheng Lu Chishih Chu Department of Orthopedic Surgery Chang Gung Memorial Hospital Chiayi Branch Taiwan College of Medicine Chang Gung University Taiwan Department of Orthopedic Surgery Taipei Medical University Hospital Taiwan School of Medicine Taipei Medical University Taiwan Department of Microbiology Immunology and Biopharmaceutics National Chiayi University Taiwan Department of Laboratory Medicine Chang Gung Memorial Hospital Linkou Branch Taiwan

Methicillin-sensitive and resistant Staphylococcus aureus (MSSA and MRSA, respectively) can cause non-tuberculosis infectious spondylitis. In 43 cases of bacterial infectious spondylitis, Mycobacterium tuberculosis and S. aureus were the two major causative pathogens. MRSA caused more anterior operations and thoracic infections, while MSSA caused more posterior infections and lumbar infections. Differences between six S. aureus isolates from infectious spondylitis were characterized. MLST and staphylococcal cassette chromosome mec (SCCmec) analysis identified MSSA ST959 and ST30 isolates, MRSA ST239/SCCmec IIIA isolates 2 and 3, ST59/SCCmec IIIA-like isolate 6, and ST30/SCCmec IV isolate 5. While all of the isolates were resistant to penicillin and ampicillin, the MRSA isolates were more resistant than the MSSA isolates. Carbapenem-resistant MRSA ST239/SCCmec IIIA and ST59/SCCmec IIIA-like isolates of the agr1 type were also resistant to clindamycin and erythromycin. Leukocidin genes (pvl or lukED) and hemolysin genes (hla, hld and hlg) were present in all of the isolates. All six isolates caused more necrosis than apoptosis in the human alveolar basal epithelial cell line A549;however, ST59/SCCmec IIIA-like isolate 6, ST30/ SCCmec IV isolate 5 with pvl genes, and MSSA ST30 isolates with tst caused greater than 40% cell death after the 4-h incubation. Regardless of the MRSA isolate and its SCCmec type or the MSSA isolate, the infectious spondylitis-associated S. aureus isolates differed genetically, and the pvl and tst genes may be important genes for cell necrosis.

关键词： Infectious Spondylitis Staphylococcus aureus virulence factor MLST Necrosis Apoptosis

Candidate effector proteins of the necrotrophic apple canker pathogen Valsa mali can suppress BAX-induced PCD

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Candidate effector proteins of the necrotrophic apple canker...