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Quorum sensing inhibition, Pseudomonas aeruginosa

Darja Kušar, Karin Šrimpf, Petra Isaković, Lina Kalšek, Javid Hosseini, Irena Zdovc, Tina Kotnik, Modest Vengušt, Gabrijela Tavčar-Kalcher
BACKGROUND: Bacterial intercellular communication, called quorum sensing, takes place via the production and collective response to signal molecules. In Gram-negative bacteria, like Pseudomonas aeruginosa, these signaling molecules are N-acylhomoserine lactones (AHLs). P. aeruginosa is a common cause of inflammation of the ear canal (otitis externa) in dogs. It employs quorum sensing to coordinate the expression of host tissue-damaging factors, which are largely responsible for its virulence...
October 18, 2016: BMC Veterinary Research
Marina Pekmezovic, Ivana Aleksic, Aleksandra Barac, Valentina Arsic-Arsenijevic, Branka Vasiljevic, Jasmina Nikodinovic-Runic, Lidija Senerovic
Mixed microbial infections caused by Pseudomonas aeruginosa and pathogenic fungi are commonly found in patients with chronic infections and constitute a significant health care burden. The aim of this study was to address the potential polymicrobial antibiofilm activity of pompia and grapefruit essential oils (EOs). The mechanism of antimicrobial activity of EOs was analysed. EOs of pompia and grapefruit inhibited fungal growth with MIC concentrations between 50 and 250 mg L(-1), whereas no effect on P. aeruginosa growth was observed...
November 2016: Pathogens and Disease
Maira P de Carvalho, Giuseppe Gulotta, Matheus W do Amaral, Heinrich Lünsdorf, Florenz Sasse, Wolf-Rainer Abraham
Pathogens embedded in biofilms are involved in many infections and are very difficult to treat with antibiotics because of higher resistance compared to planktonic cells. Therefore, new approaches for their control are urgently needed. One way to search for biofilm dispersing compounds is to look at defense strategies of organisms exposed to wet environments, which makes them prone to biofilm infections. It is reasonable to assume that mushrooms have developed mechanisms to control biofilms on their sporocarps (fruiting bodies)...
October 3, 2016: Environmental Microbiology
Arunava Bandyopadhaya, Amy Tsurumi, Damien Maura, Kate L Jeffrey, Laurence G Rahme
The mechanisms by which pathogens evade elimination without affecting host fitness are not well understood. For the pathogen Pseudomonas aeruginosa, this evasion appears to be triggered by excretion of the quorum-sensing molecule 2-aminoacetophenone, which dampens host immune responses and modulates host metabolism, thereby enabling the bacteria to persist at a high burden level. Here, we examined how 2-aminoacetophenone trains host tissues to become tolerant to a high bacterial burden, without compromising host fitness...
October 3, 2016: Nature Microbiology
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
Xiaohui Xu, Hua Yu, Di Zhang, Junzhi Xiong, Jing Qiu, Rong Xin, Xiaomei He, Halei Sheng, Wenqiang Cai, Lu Jiang, Kebin Zhang, Xiaomei Hu
During infection, bacteria might generate adaptive responses to facilitate their survival and colonization in the host environment. The alarmone guanosine 5'-triphosphate-3'-diphosphate (ppGpp), the levels of which are regulated by the RelA and SpoT enzymes, plays a critical role in mediating bacterial adaptive responses and virulence. However, the mechanism by which ppGpp regulates virulence-associated traits in Pseudomonas aeruginosa is poorly understood. To investigate the regulatory role of ppGpp, the ppGpp-deficient strain ΔRS (relA and spoT gene double mutant) and the complemented strain ΔRS(++) (complemented with relA and spoT genes) were constructed...
November 2016: Microbiological Research
Qiao Guo, Qiaolian Wu, Dangdang Bai, Yang Liu, Lin Chen, Sheng Jin, Yuting Wu, Kangmin Duan
Dimethyl Sulfoxide (DMSO) is commonly used as a solvent to dissolve water-insoluble drugs or other test samples in both in vivo and in vitro experiments. It was observed during our experiment that DMSO at non-inhibitory concentrations could significantly inhibit pyocyanin production in human pathogen Pseudomonas aeruginosa. Pyocyanin is an important pathogenic factor whose production is controlled by cell-density dependent quorum-sensing (QS) system. Investigation of the effect of DMSO on QS shows that DMSO has significant QS antagonistic activities, and micromolar range concentrations of DMSO attenuated a battery of QS-controlled virulence factors, including rhamnolipids, elastase, LasA protease and biofilm formation...
September 19, 2016: Antimicrobial Agents and Chemotherapy
Subramaniyan S, Divyasree S, Sandhia G S
BACKGROUND: Quorum sensing or the bacterial information flow in an orchestrated manner is an essential feature of many pathogenic bacteria. Quorum quenching molecules (QQ) can inhibit the growth of such bacteria. OBJECTIVE: The purpose of this study is to evaluate the potential of plant extracts as quorum quenchers and monitor the recent patents. METHODS: Many available reports and patents are on synthetic ligand molecules or even compounds isolated from cyanobacteria (Honaucin A) and other microorganisms inhibiting quorum sensing molecules...
September 8, 2016: Recent Patents on Biotechnology
Malena E Skogman, Sonja Kanerva, Suvi Manner, Pia M Vuorela, Adyary Fallarero
Quorum sensing (QS) is the process by which bacteria produce and detect signal molecules to coordinate their collective behavior. This intercellular communication is a relevant target for anti-biofilm therapies. Here we have optimized a screening-applicable assay to search for new quorum sensing inhibitors from natural compound libraries. In this system, QS is correlated with the production of violacein, which is directly controlled by the LuxI/LuxR system in Chromobacterium violaceum ATCC 31532. The parallel use of C...
2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Michael J Kratochvil, Michael A Welsh, Uttam Manna, Benjamín J Ortiz, Helen E Blackwell, David M Lynn
Surfaces that can both prevent bacterial biofouling and inhibit the expression of virulence phenotypes in surrounding planktonic bacteria are of interest in a broad range of contexts. Here, we report new slippery-liquid infused porous surfaces (SLIPS) that resist bacterial colonization (owing to inherent "slippery" surface character) and also attenuate virulence phenotypes in non-adherent cells by gradually releasing small-molecule quorum sensing inhibitors (QSIs). QSIs active against Pseudomonas aeruginosa can be loaded into SLIPS without loss of their slippery and antifouling properties, and imbedded agents can be released into surrounding media over hours to days depending on the structures of the loaded agent...
July 8, 2016: ACS Infectious Diseases
Bernardas Morkunas, Balint Gal, Warren R J D Galloway, James T Hodgkinson, Brett M Ibbeson, Yaw Sing Tan, Martin Welch, David R Spring
Pyocyanin is a small molecule produced by Pseudomonas aeruginosa that plays a crucial role in the pathogenesis of infections by this notorious opportunistic pathogen. The inhibition of pyocyanin production has been identified as an attractive antivirulence strategy for the treatment of P. aeruginosa infections. Herein, we report the discovery of an inhibitor of pyocyanin production in cultures of wild-type P. aeruginosa which is based around a 4-alkylquinolin-2(1H)-one scaffold. To the best of our knowledge, this is the first reported example of pyocyanin inhibition by a compound based around this molecular framework...
2016: Beilstein Journal of Organic Chemistry
Boris Pejin, Ana Ciric, Jasmina Dimitric Markovic, Jasmina Glamoclija, Milos Nikolic, Marina Sokovic
Anti-biofilm activity of three anthocyanidins (pelargonidin, cyanidin and delphinidin) was evaluated for the first time at in vitro conditions. All the compounds reduced the formation of Pseudomonas aeruginosa PAO1 biofilm at low sub-MIC (0.125 MIC) with delphinidin (c 56.25 μg/mL) being the most active (43%). In comparison, ampicillin (c 93.75 μg/mL) and streptomycin (c 21.25 μg/mL) (used as positive controls) were considerably less effective at the same sub-MIC (8 and 12%, respectively). Furthermore, at 0...
August 19, 2016: Natural Product Research
Vimal B Maisuria, Yossef Lopez-de Los Santos, Nathalie Tufenkji, Eric Déziel
Bacteria have evolved multiple strategies for causing infections that include producing virulence factors, undertaking motility, developing biofilms, and invading host cells. N-acylhomoserine lactone (AHL)-mediated quorum sensing (QS) tightly regulates the expression of multiple virulence factors in the opportunistic pathogenic bacterium Pseudomonas aeruginosa. Thus, inhibiting QS could lead to health benefits. In this study, we demonstrate an anti-virulence activity of a cranberry extract rich in proanthocyanidins (cerPAC) against P...
2016: Scientific Reports
Soha El-Shaer, Mona Shaaban, Rasha Barwa, Ramadan Hassan
The spread of multiple drug resistance 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 -naphthylamide (PAN) promote the bacterial susceptibility to antimicrobial agents. The pathogenesis of P. aeruginosa is co-ordinated via quorum sensing (QS). This study aims to find out the impact of efflux pump inhibitor, PAN, on QS and virulence attributes in clinical isolates of P...
August 5, 2016: Journal of Medical Microbiology
Parul Gupta, Sanjay Chhibber, Kusum Harjai
BACKGROUND & OBJECTIVES: Biofilms formed by pseudomonas aeruginosa lead to persistent infections. Use of antibiotics for the treatment of biofilm induced infection poses a threat towards development of resistance. Therefore, the research is directed towards exploring the property of antibiotics which may alter the virulence of an organism besides altering its growth. The aim of this study was to evaluate the role of subinhibitory concentration of ciprofloxacin (CIP) in inhibiting biofilm formation and virulence of P...
May 2016: Indian Journal of Medical Research
Barış Gökalsın, Nüzhet Cenk Sesal
Cystic Fibrosis is a genetic disease and it affects the respiratory and digestive systems. Pseudomonas aeruginosa infections in Cystic Fibrosis are presented as the main cause for high mortality and morbidity rates. Pseudomonas aeruginosa populations can regulate their virulence gene expressions via the bacterial communication system: quorum sensing. Inhibition of quorum sensing by employing quorum sensing inhibitors can leave the bacteria vulnerable. Therefore, determining natural sources to obtain potential quorum sensing inhibitors is essential...
September 2016: World Journal of Microbiology & Biotechnology
Lucy D Burr, Geraint B Rogers, Alice C-H Chen, Brett R Hamilton, Gertruida F Pool, Steven L Taylor, Deon Venter, Simon D Bowler, Sally Biga, Michael A McGuckin
RATIONALE: The mechanism by which low-dose macrolide therapy reduces exacerbations in non-cystic fibrosis bronchiectasis is not known. Pseudomonas aeruginosa quorum sensing controls the expression of a range of pathogenicity traits and is inhibited by macrolide in vitro. Quorum sensing inhibition renders P. aeruginosa less pathogenic, potentially reducing its contribution to airway damage. OBJECTIVES: The aim of this study was to determine whether long-term low-dose erythromycin inhibits P...
October 2016: Annals of the American Thoracic Society
Benjamin M Hariri, Sakeena J Payne, Bei Chen, Corrine Mansfield, Laurel J Doghramji, Nithin D Adappa, James N Palmer, David W Kennedy, Masha Y Niv, Robert J Lee
BACKGROUND: T2R bitter taste receptors play a crucial role in sinonasal innate immunity by upregulating mucociliary clearance and nitric oxide (NO) production in response to bitter gram-negative quorum-sensing molecules in the airway surface liquid. Previous studies showed that phytochemical flavonoid metabolites, known as anthocyanidins, taste bitter and have antibacterial effects. Our objectives were to examine the effects of anthocyanidins on NO production by human sinonasal epithelial cells and ciliary beat frequency, and their impact on common sinonasal pathogens Pseudomonas aeruginosa and Staphylococcus aureus...
July 2016: American Journal of Rhinology & Allergy
Ketema Bacha, Yinebeb Tariku, Fisseha Gebreyesus, Shibru Zerihun, Ali Mohammed, Nancy Weiland-Bräuer, Ruth A Schmitz, Mulugeta Mulat
BACKGROUND: Traditional medicinal plants have been used as an alternative medicine in many parts of the world, including Ethiopia. There are many documented scientific reports on antimicrobial activities of the same. To our knowledge, however, there is no report on the anti-Quorum Sensing (Quorum Quenching, QQ) potential of traditional Ethiopian medicinal plants. As many of the opportunistic pathogenic bacteria depend on Quorum Sensing (QS) systems to coordinate their virulence expression, interference with QS could be a novel approach to control bacterial infections...
2016: BMC Microbiology
H M H N Bandara, M J Herpin, D Kolacny, A Harb, D Romanovicz, H D C Smyth
The challenge of eliminating Pseudomonas aeruginosa infections, such as in cystic fibrosis lungs, remains unchanged due to the rapid development of antibiotic resistance. Poor drug penetration into dense P. aeruginosa biofilms plays a vital role in ineffective clearance of the infection. Thus, the current antibiotic therapy against P. aeruginosa biofilms need to be revisited and alternative antibiofilm strategies need to be invented. Fungal quorum sensing molecule (QSM), farnesol, appears to have detrimental effects on P...
August 1, 2016: Molecular Pharmaceutics
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