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https://www.readbyqxmd.com/read/29745728/aspergillus-ochraceopetaliformis-ssp13-modulates-quorum-sensing-regulated-virulence-and-biofilm-formation-in-pseudomonas-aeruginosa-pao1
#1
Subhaswaraj Pattnaik, Tanveer Ahmed, Sampath Kumar Ranganathan, Dinakara Rao Ampasala, V Venkateswara Sarma, Siddharha Busi
Pseudomonas aeruginosa is an opportunistic nosocomial pathogen causing the majority of acute and persistent infections in human beings. The ability to form biofilm adds a new dimension to its resistance to conventional therapeutic agents. In the present study, down-regulation of quorum sensing regulated virulence and biofilm development resulting from exposure to Aspergillus ochraceopetaliformis SSP13 extract was investigated. The in vitro results inferred impairment in the production of LasA protease, LasB elastase, chitinase, pyocyanin, exopolysaccharides and rhamnolipids...
May 10, 2018: Biofouling
https://www.readbyqxmd.com/read/29735954/design-and-synthesis-of-lactams-derived-from-mucochloric-and-mucobromic-acids-as-pseudomonas-aeruginosa-quorum-sensing-inhibitors
#2
Basmah Almohaywi, Aditi Taunk, Daniel S Wenholz, Shashidhar Nizalapur, Nripendra N Biswas, Kitty K K Ho, Scott A Rice, George Iskander, David StC Black, Renate Griffith, Naresh Kumar
Bacterial infections, particularly hospital-acquired infections caused by Pseudomonas aeruginosa , have become a global threat with a high mortality rate. Gram-negative bacteria including P. aeruginosa employ N -acyl homoserine lactones (AHLs) as chemical signals to regulate the expression of pathogenic phenotypes through a mechanism called quorum sensing (QS). Recently, strategies targeting bacterial behaviour or QS have received great attention due to their ability to disarm rather than kill pathogenic bacteria, which lowers the evolutionary burden on bacteria and the risk of resistance development...
May 7, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29694695/quorum-sensing-inhibitor-potential-of-trans-anethole-aganist-pseudomonas-aeruginosa
#3
Demet Hançer Aydemir, Gülşah Çifçi, Viktorya Aviyente, Gülgün Boşgelmez-Tinaz
AIMS: Quorum sensing (QS) is a cell-cell communication system used by a broad spectrum of pathogenic bacteria to control the expression of their virulence genes. The interruption of QS systems of pathogenic bacteria has been considered as a novel way to fight bacterial diseases. In this study, trans-anethole, the main component of anise (Pimpinella anisum) oil was examined for its QS inhibitor (QSI) potential in an attempt to identify novel QSI compound effective against opportunistic pathogen P...
April 25, 2018: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/29680931/cinnamic-acid-attenuates-quorum-sensing-associated-virulence-factors-and-biofilm-formation-in-pseudomonas-aeruginosa-pao1
#4
Jobina Rajkumari, Subhomoi Borkotoky, Ayaluru Murali, Kitlangki Suchiang, Saswat Kumar Mohanty, Siddhardha Busi
OBJECTIVE: Anti-quorum sensing and anti-biofilm efficacy of Cinnamic acid against Pseudomonas aeruginosa was comparatively assessed with respect to potent quorum sensing inhibitor, Baicalein. RESULTS: At sub-lethal concentration, Cinnamic acid effectively inhibited both the production of the QS-dependent virulence factors and biofilm formation in P. aeruginosa without affecting the viability of the bacterium. The phytocompound interfered with the initial attachment of planktonic cells to the substratum thereby causing reduction in biofilm development...
April 21, 2018: Biotechnology Letters
https://www.readbyqxmd.com/read/29616198/regulation-of-nicotine-tolerance-by-quorum-sensing-and-high-efficiency-of-quorum-quenching-under-nicotine-stress-in-pseudomonas-aeruginosa-pao1
#5
Huiming Tang, Yunyun Zhang, Yifan Ma, Mengmeng Tang, Dongsheng Shen, Meizhen Wang
Quorum sensing (QS) regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ), the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT) expression and biofilm formation help Pseudomonas aeruginosa PAO1 resist nicotine stress...
2018: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/29601791/biofilm-production-by-clinical-isolates-of-pseudomonas-aeruginosa-and-structural-changes-in-lasr-protein-of-isolates-non-biofilm-producing
#6
Jailton Lobo da Costa Lima, Lilian Rodrigues Alves, Paula Regina Luna de Araújo Jacomé, João Pacífico Bezerra Neto, Maria Amélia Vieira Maciel, Marcia Maria Camargo de Morais
INTRODUCTION: Biofilm production is an important mechanism for the survival of Pseudomonas aeruginosa and its relationship with antimicrobial resistance represents a challenge for patient therapeutics. P. aeruginosa is an opportunistic pathogen frequently associated to nosocomial infections, especially in imunocompromised hosts. OBJECTIVES: Analyze the phenotypic biofilm production in P. aeruginosa isolates, describe clonal profiles, and analyze quorum sensing (QS) genes and the occurrence of mutations in the LasR protein of non-biofilm producing isolates...
March 27, 2018: Brazilian Journal of Infectious Diseases
https://www.readbyqxmd.com/read/29571725/attenuation-of-quorum-sensing-regulated-virulence-and-biofilm-development-in-pseudomonas-aeruginosa-pao1-by-diaporthe-phaseolorum-ssp12
#7
Subha Swaraj Pattnaik, SampathKumar Ranganathan, Dinakara Rao Ampasala, Asad Syed, Fuad Ameen, Siddhardha Busi
In recent years, Pseudomonas aeruginosa PAO1 emerged as the significant pathogenic microorganism in majority of the hospital-acquired infections due to its resistance to the conventional antibiotics by virtue of its highly organized quorum sensing and associated biofilm formation. In the present study, quorum sensing attenuation potential of Diaporthe phaseolorum SSP12 extract was investigated against P. aeruginosa PAO1 amply supported by molecular docking studies. D. phaseolorum SSP12 extract significantly inhibited the production of LasI/R mediated LasA protease, LasB elastase and chitinase with 66...
March 20, 2018: Microbial Pathogenesis
https://www.readbyqxmd.com/read/29535700/a-metabolic-trade-off-modulates-policing-of-social-cheaters-in-populations-of-pseudomonas-aeruginosa
#8
Huicong Yan, Meizhen Wang, Feng Sun, Ajai A Dandekar, Dongsheng Shen, Na Li
Pseudomonas aeruginosa uses quorum sensing (QS) to regulate the production of public goods such as the secreted protease elastase. P. aeruginosa requires the LasI-LasR QS circuit to induce elastase and enable growth on casein as the sole carbon and energy source. The LasI-LasR system also induces a second QS circuit, the RhlI-RhlR system. During growth on casein, LasR-mutant social cheaters emerge, and this can lead to a population collapse. In a minimal medium containing ammonium sulfate as a nitrogen source, populations do not collapse, and cheaters and cooperators reach a stable equilibrium; however, without ammonium sulfate, cheaters overtake the cooperators and populations collapse...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29526565/attenuation-of-quorum-sensing-controlled-virulence-factors-and-biofilm-formation-in-pseudomonas-aeruginosa-by-pentacyclic-triterpenes-betulin-and-betulinic-acid
#9
Jobina Rajkumari, Subhomoi Borkotoky, Ayaluru Murali, Kitlangki Suchiang, Saswat Kumar Mohanty, Siddhardha Busi
The production of virulence determinants and biofilm formation in numerous pathogens is regulated by the cell-density-dependent phenomenon, Quorum sensing (QS). The QS system in multidrug resistant opportunistic pathogen, P. aeruginosa constitutes of three main regulatory circuits namely Las, Rhl, and Pqs which are closely linked to its pathogenicity and establishment of chronic infections. In spite intensive antibiotic therapy, P. aeruginosa continue to be an important cause of nosocomial infections and also the major cause of mortality in Cystic Fibrosis patients with 80% of the adults suffering from chronic P...
March 8, 2018: Microbial Pathogenesis
https://www.readbyqxmd.com/read/29524516/exploring-the-impact-of-parthenolide-as-anti-quorum-sensing-and-anti-biofilm-agent-against-pseudomonas-aeruginosa
#10
Manmohit Kalia, Vivek Kumar Yadav, Pradeep Kumar Singh, Deepmala Sharma, Shahid Suhail Narvi, Vishnu Agarwal
AIMS: Pseudomonas aeruginosa is a well-known pathogen responsible for various infections due to its capability to develop biofilm and various virulent phenotypes that are regulated by quorum sensing. Pathogenesis of the bacteria may be halted by interfering with the signaling molecules and the quorum sensing receptors. Therefore, the present study explores the potential of parthenolide, a sesquiterpene lactone of feverfew plant, as a promising candidate against P. aeruginosa PAO1 associated virulence factors and biofilm...
April 15, 2018: Life Sciences
https://www.readbyqxmd.com/read/29482361/effect-of-reserpine-on-pseudomonas-aeruginosa-quorum-sensing-mediated-virulence-factors-and-biofilm-formation
#11
Debaprasad Parai, Malabika Banerjee, Pia Dey, Arindam Chakraborty, Ekramul Islam, Samir Kumar Mukherjee
This study aimed to evaluate the effect of reserpine, a plant-derived indole-alkaloid, against Pseudomonas aeruginosa PAO1 biofilms. The anti-biofilm activity of reserpine was evaluated by crystal violet staining, MTT assay, confocal laser scanning microscopy and scanning electron microscopy. Reserpine effects were also assessed by qRT-PCR of quorum sensing (QS)-regulated genes and biochemical quantification of the QS-mediated virulence factors pyocyanin, rhamnolipids, proteases and elastases. Reserpine reduced biofilm formation, cell motility, virulence factor production, and QS-controlled gene expression...
February 27, 2018: Biofouling
https://www.readbyqxmd.com/read/29463534/alginate-oligosaccharide-induced-modification-of-the-lasi-lasr-and-rhli-rhlr-quorum-sensing-systems-in-pseudomonas-aeruginosa
#12
Alison A Jack, Saira Khan, Lydia C Powell, Manon F Pritchard, Konrad Beck, Hina Sadh, Lucy Sutton, Alessandra Cavaliere, Hannah Florance, Philip D Rye, David W Thomas, Katja E Hill
Pseudomonas aeruginosa plays a major role in many chronic infections. Its ability to readily form biofilms contributes to its success as an opportunistic pathogen and its resistance/tolerance to antimicrobial/antibiotic therapy. A low-molecular-weight alginate oligomer (OligoG CF-5/20) derived from marine algae has previously been shown to impair motility in P. aeruginosa biofilms and disrupt pseudomonal biofilm assembly. As these bacterial phenotypes are regulated by quorum sensing (QS), we hypothesized that OligoG CF-5/20 may induce alterations in QS signaling in P...
May 2018: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/29437248/mechanism-of-agonism-and-antagonism-of-the-pseudomonas-aeruginosa-quorum-sensing-regulator-qscr-with-non-native-ligands
#13
Christina L Wysoczynski-Horita, Michelle E Boursier, Ryan Hill, Kirk Hansen, Helen E Blackwell, Mair E A Churchill
Pseudomonas aeruginosa is an opportunistic pathogen that uses the process of quorum sensing (QS) to coordinate the expression of many virulence genes. During quorum sensing, N-acyl-homoserine lactone (AHL) signaling molecules regulate the activity of three LuxR-type transcription factors, LasR, RhlR and QscR. To better understand P. aeruginosa QS signal reception, we examined the mechanism underlying the response of QscR to synthetic agonists and antagonists using biophysical and structural approaches. The structure of QscR bound to a synthetic agonist reveals a novel mode of ligand binding supporting a general mechanism for agonist activity...
May 2018: Molecular Microbiology
https://www.readbyqxmd.com/read/29407907/silver-complex-of-salicylic-acid-and-its-hydrogel-cream-in-wound-healing-chemotherapy
#14
Maria-Eleni K Stathopoulou, Christina N Banti, Nikolaos Kourkoumelis, Antonios G Hatzidimitriou, Angelos G Kalampounias, Sotiris K Hadjikakou
The known metallotherapeutic [Ag(salH)]2 (AGSAL-1) of salicylic acid (salH2 ), was used for the development of new efficient silver based material for wounds healing. AGSAL-1 was characterized by spectroscopic techniques and X-ray crystallography. The wound healing epithelialization of AGSAL-1 was investigated by the means of scratch assay against immortalized human keratinocytes (HaCaT) cells. The anti-inflammatory activity of AGSAL-1 was evaluated by monitoring the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX)...
April 2018: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/29353476/hordenine-a-novel-quorum-sensing-inhibitor-and-antibiofilm-agent-against-pseudomonas-aeruginosa
#15
Jin-Wei Zhou, Huai-Zhi Luo, Huan Jiang, Ting-Kun Jian, Zi-Qian Chen, Ai-Qun Jia
The quorum sensing (QS) inhibitory activity of hordenine from sprouting barley against foodborne pathogen Pseudomonas aeruginosa was evaluated for the first time here. At concentrations ranging from 0.5 to 1.0 mg mL-1 , hordenine inhibited the levels of acyl-homoserine lactones. The enhanced susceptibility of hordenine with netilmicin on P. aeruginosa PAO1 biofilm formation as well as their efficiency in disrupting preformed biofilms was also evaluated using scanning electron microscopy and confocal laser scanning microscopy (CLSM)...
February 21, 2018: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29348452/combination-therapy-strategy-of-quorum-quenching-enzyme-and-quorum-sensing-inhibitor-in-suppressing-multiple-quorum-sensing-pathways-of-p-aeruginosa
#16
July Fong, Chaodong Zhang, Renliang Yang, Zhao Zhi Boo, Soon Keat Tan, Thomas E Nielsen, Michael Givskov, Xue-Wei Liu, Wu Bin, Haibin Su, Liang Yang
The threat of antibiotic resistant bacteria has called for alternative antimicrobial strategies that would mitigate the increase of classical resistance mechanism. Many bacteria employ quorum sensing (QS) to govern the production of virulence factors and formation of drug-resistant biofilms. Targeting the mechanism of QS has proven to be a functional alternative to conventional antibiotic control of infections. However, the presence of multiple QS systems in individual bacterial species poses a challenge to this approach...
January 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29302024/tuning-the-dynamic-range-of-bacterial-promoters-regulated-by-ligand-inducible-transcription-factors
#17
Ye Chen, Joanne M L Ho, David L Shis, Chinmaya Gupta, James Long, Daniel S Wagner, William Ott, Krešimir Josić, Matthew R Bennett
One challenge for synthetic biologists is the predictable tuning of genetic circuit regulatory components to elicit desired outputs. Gene expression driven by ligand-inducible transcription factor systems must exhibit the correct ON and OFF characteristics: appropriate activation and leakiness in the presence and absence of inducer, respectively. However, the dynamic range of a promoter (i.e., absolute difference between ON and OFF states) is difficult to control. We report a method that tunes the dynamic range of ligand-inducible promoters to achieve desired ON and OFF characteristics...
January 4, 2018: Nature Communications
https://www.readbyqxmd.com/read/29184024/identification-of-fitness-determinants-during-energy-limited-growth-arrest-in-pseudomonas-aeruginosa
#18
David W Basta, Megan Bergkessel, Dianne K Newman
Microbial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen...
November 28, 2017: MBio
https://www.readbyqxmd.com/read/29177135/quorum-sensing-down-regulation-counteracts-the-negative-impact-of-pseudomonas-aeruginosa-on-cftr-channel-expression-function-and-rescue-in-human-airway-epithelial-cells
#19
Émilie Maillé, Manon Ruffin, Damien Adam, Hatem Messaoud, Shantelle L Lafayette, Geoffrey McKay, Dao Nguyen, Emmanuelle Brochiero
The function of cystic fibrosis transmembrane conductance regulator (CFTR) channels is crucial in human airways. However unfortunately, chronic Pseudomonas aeruginosa infection has been shown to impair CFTR proteins in non-CF airway epithelial cells (AEC) and to alter the efficiency of new treatments with CFTR modulators designed to correct the basic CFTR default in AEC from cystic fibrosis (CF) patients carrying the F508del mutation. Our aim was first to compare the effect of laboratory strains, clinical isolates, engineered and natural mutants to determine the role of the LasR quorum sensing system in CFTR impairment, and second, to test the efficiency of a quorum sensing inhibitor to counteract the deleterious impact of P...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/29135250/structure-activity-relationships-of-6-and-8-gingerol-analogs-as-anti-biofilm-agents
#20
Hyunsuk Choi, So-Young Ham, Eunji Cha, Yujin Shin, Han-Shin Kim, Jeong Kyu Bang, Sang-Hyun Son, Hee-Deung Park, Youngjoo Byun
Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation...
December 14, 2017: Journal of Medicinal Chemistry
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