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quorum sensing and resistence gene

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https://www.readbyqxmd.com/read/27915294/insightful-directed-evolution-of-escherichia-coli-quorum-sensing-promoter-region-of-the-lsracdbfg-operon-a-tool-for-synthetic-biology-systems-and-protein-expression
#1
Pricila Hauk, Kristina Stephens, Ryan Mckay, Chelsea Ryan Virgile, Hana Ueda, Marc Ostermeier, Kyoung-Seok Ryu, Herman O Sintim, William E Bentley
Quorum sensing (QS) regulates many natural phenotypes (e.q. virulence, biofilm formation, antibiotic resistance), and its components, when incorporated into synthetic genetic circuits, enable user-directed phenotypes. We created a library of Escherichia coli lsr operon promoters using error-prone PCR (ePCR) and selected for promoters that provided E. coli with higher tetracycline resistance over the native promoter when placed upstream of the tet(C) gene. Among the fourteen clones identified, we found several mutations in the binding sites of QS repressor, LsrR...
December 1, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27907154/pheromone-recognition-and-selectivity-by-comr-proteins-among-streptococcus-species
#2
Erin Shanker, Donald A Morrison, Antoine Talagas, Sylvie Nessler, Michael J Federle, Gerd Prehna
Natural transformation, or competence, is an ability inherent to bacteria for the uptake of extracellular DNA. This process is central to bacterial evolution and allows for the rapid acquirement of new traits, such as antibiotic resistance in pathogenic microorganisms. For the Gram-positive bacteria genus Streptococcus, genes required for competence are under the regulation of quorum sensing (QS) mediated by peptide pheromones. One such system, ComRS, consists of a peptide (ComS) that is processed (XIP), secreted, and later imported into the cytoplasm, where it binds and activates the transcription factor ComR...
December 2016: PLoS Pathogens
https://www.readbyqxmd.com/read/27902410/inhibition-of-quorum-sensing-controlled-virulence-factors-of-pseudomonas-aeruginosa-by-murraya-koenigii-essential-oil-a-study-in-a-caenorhabditis-elegans-infectious-model
#3
P Sankar Ganesh, Ravishankar Vittal Rai
The global emergence of antibiotic resistant strains of Pseudomonas aeruginosa poses a major threat in hospital environments as well as in the community. P. aeruginosa is an opportunistic human pathogen and it also infects a wide range of model organisms including the nematode Caenorhabditis elegans. Quorum sensing (QS) mediates cell-to-cell communication in bacteria and has an important role in regulating virulence genes, antibiotic resistance and biofilm formation which are crucial for establishment of the infection...
November 3, 2016: Journal of Medical Microbiology
https://www.readbyqxmd.com/read/27892495/quorum-regulated-resistance-of-vibrio-cholerae-against-environmental-bacteriophages
#4
M Mozammel Hoque, Iftekhar Bin Naser, S M Nayeemul Bari, Jun Zhu, John J Mekalanos, Shah M Faruque
Predation by bacteriophages can significantly influence the population structure of bacterial communities. Vibrio cholerae the causative agent of cholera epidemics interacts with numerous phages in the aquatic ecosystem, and in the intestine of cholera patients. Seasonal epidemics of cholera reportedly collapse due to predation of the pathogen by phages. However, it is not clear how sufficient number of the bacteria survive to seed the environment in the subsequent epidemic season. We found that bacterial cell density-dependent gene expression termed "quorum sensing" which is regulated by signal molecules called autoinducers (AIs) can protect V...
November 28, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27864804/activity-of-norspermidine-on-bacterial-biofilms-of-multidrug-resistant-clinical-isolates-associated-with-persistent-extremity-wound-infections
#5
Anthony P Cardile, Ronald L Woodbury, Carlos J Sanchez, Sandra C Becerra, Rebecca A Garcia, Katrin Mende, Joseph C Wenke, Kevin S Akers
Biofilm formation is a major virulence factor for numerous pathogenic bacteria and is cited as a central event in the pathogenesis of chronic human infections, which is in large part due to excessive extracellular matrix secretion and metabolic changes that occur within the biofilm rendering them highly tolerant to antimicrobial treatments. Polyamines, including norspermidine, play central roles in bacterial biofilm development, but have also recently been shown to inhibit biofilm formation in select strains of various pathogenic bacteria...
November 19, 2016: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/27849583/quorum-sensing-controls-the-pseudomonas-aeruginosa-crispr-cas-adaptive-immune-system
#6
Nina M Høyland-Kroghsbo, Jon Paczkowski, Sampriti Mukherjee, Jenny Broniewski, Edze Westra, Joseph Bondy-Denomy, Bonnie L Bassler
CRISPR-Cas are prokaryotic adaptive immune systems that provide protection against bacteriophage (phage) and other parasites. Little is known about how CRISPR-Cas systems are regulated, preventing prediction of phage dynamics in nature and manipulation of phage resistance in clinical settings. Here, we show that the bacterium Pseudomonas aeruginosa PA14 uses the cell-cell communication process, called quorum sensing, to activate cas gene expression, to increase CRISPR-Cas targeting of foreign DNA, and to promote CRISPR adaptation, all at high cell density...
November 14, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27815466/fluorinated-beta-diketo-phosphorus-ylides-are-novel-efflux-pump-inhibitors-in-bacteria
#7
Annamária Kincses, Ágnes Míra Szabó, Ryosuke Saijo, Genki Watanabe, Masami Kawase, Joseph Molnár, Gabriella Spengler
BACKGROUND: One of the most important resistance mechanisms in bacteria is the increased expression of multidrug efflux pumps. To combat efflux-related resistance, the development of new efflux pump inhibitors is essential. MATERIALS AND METHODS: Ten phosphorus ylides were compared based on their MDR-reverting activity in multidrug efflux pump system consisting of the subunits acridine-resistance proteins A and B (AcrA and AcrB) and the multidrug efflux pump outer membrane factor TolC (TolC) of Escherichia coli K-12 AG100 strain and its AcrAB-TolC-deleted strain...
November 2016: In Vivo
https://www.readbyqxmd.com/read/27806930/rnd-efflux-pump-and-its-interrelationship-with-quorum-sensing-system
#8
Liang Zhibin, Chen Yumei, Chen Yufan, Cheng Yingying, Zhang Lianhui
Antibiotic resistance has become a serious concern in treatment of bacterial infections. Overexpression of efflux pump is one of the important mechanisms in antibiotic resistance. In Gram negative bacteria, RND (Resistance-nodulation-cell division) superfamily efflux pump plays a vital important role in antibiotics resistance. Recent research progress unveils an intriguing interrelationship between RND efflux pump and the bacterial quorum sensing system, whose regulation is dependent on small signal molecules...
October 20, 2016: Yi Chuan, Hereditas
https://www.readbyqxmd.com/read/27803696/new-weapons-to-fight-old-enemies-novel-strategies-for-the-bio-control-of-bacterial-biofilms-in-the-food-industry
#9
REVIEW
Laura M Coughlan, Paul D Cotter, Colin Hill, Avelino Alvarez-Ordóñez
Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27756112/a-thiadiazole-reduces-the-virulence-of-xanthomonas-oryzae-pv-oryzae-by-inhibiting-the-histidine-utilization-pathway-and-quorum-sensing
#10
Xiao Yu Liang, Xiaoyue Yu, Xiayan Pan, Jian Wu, Yabing Duan, Jianxin Wang, Mingguo Zhou
Thiazole, isothiazole, thiadiazole, and their derivatives are widely thought to induce host defenses against plant pathogens. However, this article reports that bismerthiazol, a thiadiazole molecule, reduces disease by inhibiting the histidine utilization (Hut) pathway and quorum sensing (QS). Bismerthiazol provides excellent control of bacterial rice leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) but does not greatly inhibit Xoo growth in vitro. According to RNA-seq analysis, transcription of Hut pathway genes of Xoo ZJ173 was inhibited after 4...
October 18, 2016: Molecular Plant Pathology
https://www.readbyqxmd.com/read/27756102/exogenous-n-acyl-homoserine-lactones-enhance-the-expression-of-flagella-of-pseudomonas-syringae-and-activate-defence-responses-in-plants
#11
Feifei Cheng, Anzhou Ma, Guoqiang Zhuang, Rupert G Fray
In order to cope with pathogens, plants have evolved sophisticated mechanisms to sense pathogenic attacks and to induce defence responses. The N-acyl-homoserine lactone (AHL)-mediated quorum sensing in bacteria regulates diverse physiological processes including those involved in pathogenicity. In this work, we study the interactions between AHL-producing transgenic tobacco plants and Pseudomonas syringae pv. tabaci 11528 (P. syringae 11528). Both a reduced incidence of disease and decrease in the growth of P...
October 18, 2016: Molecular Plant Pathology
https://www.readbyqxmd.com/read/27734907/in-silico-evaluation-of-the-impacts-of-quorum-sensing-inhibition-qsi-on-strain-competition-and-development-of-qsi-resistance
#12
Guopeng Wei, Chieh Lo, Connor Walsh, N Luisa Hiller, Radu Marculescu
As understanding of bacterial regulatory systems and pathogenesis continues to increase, QSI has been a major focus of research. However, recent studies have shown that mechanisms of resistance to quorum sensing (QS) inhibitors (QSIs) exist, calling into question their clinical value. We propose a computational framework that considers bacteria genotypes relative to QS genes and QS-regulated products including private, quasi-public, and public goods according to their impacts on bacterial fitness. Our results show (1) QSI resistance spreads when QS positively regulates the expression of private or quasi-public goods...
October 13, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27718524/antisense-locked-nucleic-acids-targeting-agra-inhibit-quorum-sensing-and-pathogenesis-of-community-associated-methicillin-resistant-staphylococcus-aureus
#13
Fei Da, Lin Yao, Zhijie Su, Zhen Hou, Zhi Li, Xiaoyan Xue, Jingru Meng, Xiaoxing Luo
AIM: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is commonly associated with non-nosocomial skin and soft tissue infections (SSTIs) due to its virulence, which is mainly controlled by the accessory gene regulator (agr) quorum sensing (QS) system. In this study (KFF)3 K peptide-conjugated Locked Nucleic Acids (PLNAs) targeting agrA mRNA were developed to inhibit agr activity and arrest the pathogenicity of CA-MRSA. METHODS AND RESULTS: Two PLNAs were designed, and synthesized, after predicting the secondary structure of agrA mRNA...
October 8, 2016: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/27683577/is-quorum-sensing-interference-a-viable-alternative-to-treat-pseudomonas-aeruginosa-infections
#14
Rodolfo García-Contreras
Quorum sensing (QS) coordinates the expression of multiple virulence factors in Pseudomonas aeruginosa; hence its inhibition has been postulated as a new alternative to treat its infections. In particular, QS interference approaches claim that they attenuate bacterial virulence without directly decreasing bacterial growth and suggest that in vivo the immune system would control the infections. Moreover, since in vitro experiments performed in rich medium demonstrate that interfering with QS decreases the production of virulence factors without affecting bacterial growth it was assumed than in vivo therapies will minimize the selection of resistant strains...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27650657/the-genetics-of-the-bitter-taste-receptor-t2r38-in-upper-airway-innate-immunity-and-implications-for-chronic-rhinosinusitis
#15
Noam A Cohen
OBJECTIVE: Chronic rhinosinusitis (CRS) refractory to therapeutic intervention may involve a particularly resistant infection known as a bacterial biofilm. Critical to biofilm formation is the microbial process of quorum sensing whereby microbes secrete factors that regulate the expression of microbial genes involved in biofilm formation, persistence, and virulence. Here, we review recent work demonstrating that the bitter taste receptor T2R38, expressed on the apical surface of the sinonasal epithelium, serves a sentinel role in eavesdropping on microbial quorum-sensing communications and regulates localized innate biocidal defenses...
September 21, 2016: Laryngoscope
https://www.readbyqxmd.com/read/27637885/pseudomonas-brassicacearum-strain-df41-kills-caenorhabditis-elegans-through-biofilm-dependent-and-biofilm-independent-mechanisms
#16
Munmun Nandi, Chrystal Berry, Ann Karen C Brassinga, Mark F Belmonte, W G Dilantha Fernando, Peter C Loewen, Teresa R de Kievit
: Pseudomonas brassicacearum DF41 is a biocontrol agent that suppresses disease caused by the fungal pathogen Sclerotinia sclerotiorum A number of exometabolites are produced by DF41 including the lipopeptide sclerosin, hydrogen cyanide (HCN) and degradative enzymes. Production of these compounds is controlled at both the transcriptional and posttranscriptional level by quorum sensing (QS) and the Gac-two component regulatory system. In order to be successful, a biocontrol agent must persist in the environment at levels sufficient for pathogen control...
September 16, 2016: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/27635055/complete-genome-sequence-of-the-mrsa-isolate-hc1335-from-st239-lineage-displaying-a-truncated-agrc-histidine-kinase-receptor
#17
Ana M N Botelho, Maiana O C Costa, Cristiana O Beltrame, Fabienne A Ferreira, Nicholas C B Lima, Bruno S S Costa, Guilherme L de Morais, Rangel C Souza, Luiz G P Almeida, Ana T R Vasconcelos, Marisa F Nicolás, Agnes M S Figueiredo
Methicillin-resistant Staphylococcus aureus (MRSA) is still one of the most important hospital pathogen globally. The multiresistant isolates of the ST239-SCCmecIII lineage are spread over large geographic regions, colonizing and infecting hospital patients in virtually all continents. The balance between fitness (adaptability) and virulence potential is likely to represent an important issue in the clonal shift dynamics leading the success of some specific MRSA clones over another. The accessory gene regulator (agr) is the master quorum sensing system of staphylococci playing a role in the global regulation of key virulence factors...
September 15, 2016: Genome Biology and Evolution
https://www.readbyqxmd.com/read/27623343/engineering-soluble-human-paraoxonase-2-for-quorum-quenching
#18
Xin Cathy Li, Christopher Wang, Ashok Mulchandani, Xin Ge
Many pathogenic bacteria utilize quorum sensing (QS) systems to regulate the expression of their virulence genes and promote the formation of biofilm, which renders pathogens with extreme resistance to conventional antibiotic treatments. As a novel approach for attenuating antibiotic resistance and in turn fighting chronic infections, enzymatic inactivation of QS signaling molecules, such as N-acyl homoserine lactones (AHLs), holds great promises. Instead of using bacterial lactonases that can evoke immune response when administered, we focus on the human paraoxonase 2 (huPON2)...
September 30, 2016: ACS Chemical Biology
https://www.readbyqxmd.com/read/27542729/methicillin-resistant-food-related-staphylococcus-aureus-a-review-of-current-knowledge-and-biofilm-formation-for-future-studies-and-applications
#19
Agapi I Doulgeraki, Pierluigi Di Ciccio, Adriana Ianieri, George-John E Nychas
There is increasing concern about the public health impact of methicillin-resistant Staphylococcus aureus. Food and animal are vectors of transmission, but the contribution of a contaminated environment is not well characterized. With regard to this, staphylococcal biofilms serve as a virulence factor, allowing MRSA strains to adhere to surfaces and other materials used in the food industry. Methicillin resistance and biofilm-forming capacity may contribute to the success of S. aureus as a human pathogen in both health care and community settings and the food production chain...
August 17, 2016: Research in Microbiology
https://www.readbyqxmd.com/read/27498852/control-of-quorum-sensing-and-virulence-factors-of-pseudomonas-aeruginosa-using-phenylalanine-arginyl-%C3%AE-naphthylamide
#20
Soha El-Shaer, Mona Shaaban, Rasha Barwa, Ramadan Hassan
The spread of multidrug-resistant Pseudomonas aeruginosa isolates constitutes a serious clinical challenge. Bacterial efflux machinery is a crucial mechanism of resistance among P. aeruginosa. Efflux inhibitors such as phenylalanine arginyl β-naphthylamide (PAβN) promote the bacterial susceptibility to antimicrobial agents. The pathogenesis of P. aeruginosa is coordinated via quorum sensing (QS). This study aims to find out the impact of efflux pump inhibitor, PAβN, on QS and virulence attributes in clinical isolates of P...
October 2016: Journal of Medical Microbiology
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