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Loree Mewborn, Jorge A Benitez, Anisia J Silva
Vibrio cholerae of serogroups O1 and O139, the causative agent of Asiatic cholera, continues to be a major global health threat. This pathogen utilizes substratum-specific pili to attach to distinct surfaces in the aquatic environment and the human small intestine and detaches when conditions become unfavorable. Both attachment and detachment are critical to bacterial environmental survival, pathogenesis and disease transmission. However, the factors that promote detachment are less understood. In this study, we examine the role of flagellar motility and hemagglutinin/protease (HapA) in vibrio detachment from a non-degradable abiotic surface and from the suckling mouse intestine...
October 13, 2017: Microbial Pathogenesis
Olga Sarenko, Gisela Klauck, Franziska M Wilke, Vanessa Pfiffer, Anja M Richter, Susanne Herbst, Volkhard Kaever, Regine Hengge
The bacterial second messenger bis-(3'-5')-cyclic diguanosine monophosphate (c-di-GMP) ubiquitously promotes bacterial biofilm formation. Intracellular pools of c-di-GMP seem to be dynamically negotiated by diguanylate cyclases (DGCs, with GGDEF domains) and specific phosphodiesterases (PDEs, with EAL or HD-GYP domains). Most bacterial species possess multiple DGCs and PDEs, often with surprisingly distinct and specific output functions. One explanation for such specificity is "local" c-di-GMP signaling, which is believed to involve direct interactions between specific DGC/PDE pairs and c-di-GMP-binding effector/target systems...
October 10, 2017: MBio
Cherisse L Hall, Vincent T Lee
Signaling pathways allow bacteria to adapt to changing environments. For pathogenic bacteria, signaling pathways allow for timely expression of virulence factors and the repression of antivirulence factors within the mammalian host. As the bacteria exit the mammalian host, signaling pathways enable the expression of factors promoting survival in the environment and/or nonmammalian hosts. One such signaling pathway uses the dinucleotide cyclic-di-GMP (c-di-GMP), and many bacterial genomes encode numerous proteins that are responsible for synthesizing and degrading c-di-GMP...
October 8, 2017: Wiley Interdisciplinary Reviews. RNA
Jacob R Chambers, Kathryn E Cherny, Karin Sauer
The biofilm lifecycle is characterized by the transition of planktonic cells exhibiting high susceptibly to antimicrobial agents to a biofilm mode of growth characterized by high tolerance to antimicrobials, followed by dispersion of cells from the biofilm back into the environment. Dispersed cells, however, are not identical to planktonic cells but have been characterized as having a unique transitionary phenotype relative to biofilm and planktonic cells, with dispersed cells attaching in a manner similar to exponential phase cells, but demonstrating gene expression patterns that are distinct from both exponential and stationary phase planktonic cells...
October 2, 2017: Antimicrobial Agents and Chemotherapy
Yuzhou Wang, Ye Li, Jianli Wang, Xiaoyuan Wang
Based on the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry, flagellin FliC and a key member of the type VI secretion system Hcp1 were found to be secreted from Pseudomonas putida KT2442 cells in the late exponential phase, but in the early exponential phase only FliC was secreted. Relevant genes fleQ and rpoN were then individually deleted in P. putida KT2442, and the expression and transcription of fliC and hcp1 in these mutant strains were analyzed. In both △fleQ and △rpoN mutant cells, Hcp1 but not FliC was secreted in the late exponential phase, and it was secreted even in the early exponential phase...
October 2, 2017: Biotechnology and Applied Biochemistry
Juping Zhao, Yicheng Sun
Yersinia pestis, the cause of plague, is transmitted by flea bite. Y. pestis forms a biofilm in the proventriculus of its flea vector to enhance transmission. Biofilm formation in Y. pestis is positively regulated by the intracellular levels of the second messenger cyclic diguanylate (c-di-GMP). The c-di-GMP in Y. pestis is synthesized by two diguanylate cyclases (DGC), HmsT and HmsD, and degraded by phosphodiesterase (PDE), HmsP. Here we summarized the regulators that modulate c-di-GMP metabolism and biofilm formation in Y...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Xuwen Xiang, Xingyu Liu, Hui Tao, Zining Cui, Lianhui Zhang
The cyclic dinucleotide c-di-GMP is known as an important second messenger in bacteria, which controls various important cellular processes, such as cell differentiation, biofilm formation and virulence factors production. It is extremely vital for the development of new antibacterial agents by virtue of blocking c-di-GMP signal conduction. Current research indicates that there are three potential targets for discovering new antibacterial agents based on c-di-GMP regulated signal pathway, which are c-di-GMP synthases, c-di-GMP degrading enzymes and c-di-GMP receptors...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Shouting Cheng, Fangfang Wang, Wei Qian
cyclic di-GMP (c-di-GMP) is a universal second messenger in bacterial cells. It regulates various biological processes such as biofilm development, pathogenicity, motility, exopolysaccharide (EPS) production and cell cycle. The second messenger exerts its function by binding to effectors, such as riboswitches and proteins. However, due to the diverse conformations of c-di-GMP, its effectors are hardly to be predicted by homology search. Identification of c-di-GMP effectors is the initial step to investigate its regulatory function in bacterial signal transduction, however, it remains to be a technically difficult task...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Xinfeng Li, Fang Chen, Jinfeng Xiao, Jin He
Cyclic diguanosine monophosphate (c-di-GMP) is a ubiquitous nucleotide second messenger present in a wide variety of bacteria. It regulates many important bacterial physiological functions such as biofilm formation, motility, adhesion, virulence and extracellular polysaccharide synthesis. It binds with many different proteins or RNA receptors, one of which is called riboswitch that is usually located at the 5'-untranslational region (5'-UTR) in some mRNA. Riboswitch usually comprises a specific ligand-binding (sensor) domain (named aptamer domain, AD), as well as a variable domain, termed expression platform (EP), to regulate expression of downstream coding sequences...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Wei Qian, Luyan Ma, Lichuan Gu, Lianhui Zhang
Biofilm is prevalent in various ecological niches, in which microbial cells interconnect with each other through extracellular polymeric substances including polysaccharides, extracellular DNA, and proteins. When living in biofilms, the microbial cells employ small signalling chemicals as their "language" to communicate mutually, and exhibit remarkable differences in physiology compared to those living in planktonic state. It has been proven that the development of biofilm is subject to the regulation of c-di-GMP, an important second messenger found in prokaryotes...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Li-Bing Zheng, Jun Wang, Yong Mao, Ruan-Ni Chen, Yong-Quan Su, Jia Chen, Qiao-Zhen Ke, Wei-Qiang Zheng
The marine white spot disease caused by protozoan ectoparasite Cryptocaryon irritans is a severe problem to the large yellow croaker farming industry. To understand the molecular immune mechanisms and improve its immune capacity are particular important. STING, one of the important second messengers in innate immune response process, plays pivotal roles in defensing against different pathogenic microorganisms. Many reports have pointed that STING could not only combine the uncovered dsDNA, ssDNA directly in the cytoplasm from the pathogens or biology itself, but it also could recognize cyclic diguanylate monophosphate (c-di-GMP), cyclic diadenylate monophosphate (c-di-AMP)...
September 23, 2017: Fish & Shellfish Immunology
Ricardo N Moreira, Clémentine Dressaire, Susana Barahona, Lisete Galego, Volkhard Kaever, Urs Jenal, Cecília M Arraiano
The bacterial second messenger cyclic dimeric GMP (c-di-GMP) is a nearly ubiquitous intracellular signaling molecule involved in the transition from the motile to the sessile/biofilm state in bacteria. C-di-GMP regulates various cellular processes, including biofilm formation, motility, and virulence. BolA is a transcription factor that promotes survival in different stresses and is also involved in biofilm formation. Both BolA and c-di-GMP participate in the regulation of motility mechanisms leading to similar phenotypes...
September 19, 2017: MBio
Sébastien Crépin, Gaëlle Porcheron, Sébastien Houle, Josée Harel, Charles M Dozois
The pst gene cluster encodes the phosphate specific transport system (Pst). Inactivation of the Pst system constitutively activates the two-component regulatory system PhoBR and attenuates virulence of pathogenic bacteria. In uropathogenic E. coli strain CFT073, attenuation by inactivation of pst is predominantly attributed to the decreased expression of type 1 fimbriae. However, the molecular mechanisms connecting the Pst system and type 1 fimbriae are unknown. To address this, a transposon library was constructed in the pst mutant, and clones were tested for a regain in type 1 fimbriae production...
September 18, 2017: Journal of Bacteriology
Annika Cimdins, Roger Simm, Fengyang Li, Petra Lüthje, Kaisa Thorell, Åsa Sjöling, Annelie Brauner, Ute Römling
Agar plate-based biofilm of enterobacteria like Escherichia coli is characterized by expression of the extracellular matrix components amyloid curli and cellulose exopolysaccharide, which can be visually enhanced upon addition of the dye Congo Red, resulting in a red, dry, and rough (rdar) colony morphology. Expression of the rdar morphotype depends on the transcriptional regulator CsgD and occurs predominantly at ambient temperature in model strains. In contrast, commensal and pathogenic isolates frequently express the csgD-dependent rdar morphotype semi-constitutively, also at human host body temperature...
October 2017: MicrobiologyOpen
Elio Rossi, Sara Motta, Alessandro Aliverti, Federica Cossu, Louise Gourlay, Pierluigi Mauri, Paolo Landini
Production of cellulose, a stress response-mediated process in enterobacteria, is modulated in Escherichia coli by the activity of the two pyrimidine nucleotide biosynthetic pathways, namely, the de novo biosynthetic pathway, and the salvage pathway, which relies on the environmental availability of pyrimidine nitrogenous bases. We had previously reported that prevalence of the salvage over the de novo pathway triggers cellulose production via synthesis of the second messenger c-di-GMP by the DgcQ (YedQ) diguanylate cyclase...
September 11, 2017: Environmental Microbiology
Livia Leoni, Sarika Vishnu Pawar, Giordano Rampioni
Pseudomonas aeruginosa infections are often difficult or impossible to treat, mainly due to its ability to form antibiotic-resistant biofilms. Since c-di-GMP signaling strongly influences P. aeruginosa biofilm development and sensitivity to antibiotics, it is considered a promising target for the development of anti-biofilm drugs and it is under intensive investigation. However, studying c-di-GMP signaling in P. aeruginosa is challenging, mainly due to (1) the multiplicity of enzymes involved in c-di-GMP metabolism, (2) the difficulty to extract and measure c-di-GMP intracellular levels by chemical methods, and (3) the lack of genetic tools specifically dedicated to this purpose...
2017: Methods in Molecular Biology
Julie Groizeleau, Jens Bo Andersen, Michael Givskov, Jens Berthelsen, Tim Tolker-Nielsen
Bacteria in the biofilm mode of growth cause numerous problematic infections due to their resistance to antimicrobials and the immune system. Because conventional antimicrobial compounds cannot efficiently eradicate biofilm infections, we urgently need new efficient anti-biofilm drugs. The secondary messenger c-di-GMP is a positive regulator of biofilm formation in many clinically relevant bacteria, and it is assumed that drugs that lower the intracellular level of c-di-GMP will force biofilm bacteria into a more treatable planktonic lifestyle...
2017: Methods in Molecular Biology
S Rinaldo, G Giardina, F Mantoni, A Paiardini, Alessio Paone, Francesca Cutruzzolà
One of the most important signals involved in controlling biofilm formation is represented by the intracellular second messenger 3',5'-cyclic diguanylic acid (c-di-GMP). Since the pathways involved in c-di-GMP biosynthesis and breakdown are found only in bacteria, targeting c-di-GMP metabolism represents an attractive strategy for the development of biofilm-disrupting drugs. Here, we present the workflow required to perform a structure-based design of inhibitors of diguanylate cyclases, the enzymes responsible for c-di-GMP biosynthesis...
2017: Methods in Molecular Biology
Clement Opoku-Temeng, Herman O Sintim
Bacteria possess several signaling molecules that regulate distinct phenotypes. Cyclic di-GMP (c-di-GMP) has emerged as a ubiquitous second messenger that regulates bacterial virulence, cell cycle, motility, and biofilm formation. The link between c-di-GMP signaling and biofilm formation affords novel strategies for treatment of biofilm-associated infections, which is a major public health problem. The complex c-di-GMP signaling pathway creates a hurdle in the development of small molecule modulators. Nonetheless, some progress has been made in this regard and inhibitors of c-di-GMP metabolizing enzymes that affect biofilm formation and motility have been documented...
2017: Methods in Molecular Biology
Bruno Y Matsuyama, Petya V Krasteva, Marcos V A S Navarro
Isothermal titration calorimetry (ITC) is a commonly used biophysical technique that enables the quantitative characterization of intermolecular interactions in solution. Based on enthalpy changes (ΔH) upon titration of the binding partner (e.g., a small-molecule ligand such as c-di-GMP) to the molecule of interest (e.g., a receptor protein), the resulting binding isotherms provide information on the equilibrium association/dissociation constants (K a, K d) and stoichiometry of binding (n), as well as on changes in the Gibbs free energy (ΔG) and entropy (ΔS) along the interaction...
2017: Methods in Molecular Biology
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