scholarly journals Peptide Mix from Olivancillaria hiatula Interferes with Cell-to-Cell Communication in Pseudomonas aeruginosa

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Edward Ntim Gasu ◽  
Hubert Senanu Ahor ◽  
Lawrence Sheringham Borquaye
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Cell Communication ◽  
Microtiter Plate ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Biofilm Inhibition ◽  
Swarming Motility

Bacteria in biofilms are encased in an extracellular polymeric matrix that limits exposure of microbial cells to lethal doses of antimicrobial agents, leading to resistance. In Pseudomonas aeruginosa, biofilm formation is regulated by cell-to-cell communication, called quorum sensing. Quorum sensing facilitates a variety of bacterial physiological functions such as swarming motility and protease, pyoverdine, and pyocyanin productions. Peptide mix from the marine mollusc, Olivancillaria hiatula, has been studied for its antibiofilm activity against Pseudomonas aeruginosa. Microscopy and microtiter plate-based assays were used to evaluate biofilm inhibitory activities. Effect of the peptide mix on quorum sensing-mediated processes was also evaluated. Peptide mix proved to be a good antibiofilm agent, requiring less than 39 μg/mL to inhibit 50% biofilm formation. Micrographs obtained confirmed biofilm inhibition at 1/2 MIC whereas 2.5 mg/mL was required to degrade preformed biofilm. There was a marked attenuation in quorum sensing-mediated phenotypes as well. At 1/2 MIC of peptide, the expression of pyocyanin, pyoverdine, and protease was inhibited by 60%, 72%, and 54%, respectively. Additionally, swarming motility was repressed by peptide in a dose-dependent manner. These results suggest that the peptide mix from Olivancillaria hiatula probably inhibits biofilm formation by interfering with cell-to-cell communication in Pseudomonas aeruginosa.

scholarly journals Antibiofilm activity of aminopropanol derivatives against Pseudomonas aeruginosa

2018 ◽  
pp. 93-100
Author(s):  
D. M. Dudikova ◽  
Z. S. Suvorova ◽  
V. V. Nedashkivska ◽  
A. O. Sharova ◽  
M. L. Dronova ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Biofilm ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Inhibition Activity ◽  
Chronic Infections ◽  
High Concentration ◽  
Biofilm Inhibition

Bacterial biofilm, particularly formed by Pseudomonas aeruginosa, are a cause of severe chronic infectious diseases. Bacteria within a biofilm are phenotypically more resistant to antibiotics and the macroorganism immune system, making it an important virulence factor for many microbes. The aminopropanol derivatives with adamantyl (KVM-97) and N-alkylaryl radicals (KVM-194, KVM-204, KVM-261, and KVM-262) were used as study object. The aim of this study was to investigate the antibiofilm activity of compounds on biofilm formation and on mature biofilm of P. aeruginosa. The effects of the aminopropanol derivatives on the biofilm mass were evaluated by using crystal violet assay. Ciprofloxacin, meropenem, ceftazidime, gentamicin were used as reference substances. Reported results demonstrate that all compounds displayed antibiofilm activity at the tested concentrations. Remarkable reduction in biofilm formation of P. aeruginosa was found after treatment with KVM-97, KVM-261 and KVM-262 in high concentration (5× MIC), biofilm inhibition activity were 84.3%, 90.5% and 83.3% respectively. After a treatment with KVM-204 at 250 μg/ml (5× MIC) 76.6% of the preformed 24-hr biofilms were destroyed. Furthermore, compounds KVM-97, KVM-194, and KVM-261 in both concentrations showed potent antibiofilm activity against the P. aeruginosa, inhibition activity values being between 56.7 and 65.7%. All tested compounds in dose-dependent manner exhibited pronounced inhibition activity against mature 5-days P. аeruginosa biofilm. It was also observed that tested compounds show high antibiofilm activity in comparison to reference antimicrobials. The aminopropanol derivatives may provide templates for a new group of antimicrobial agents and potential future therapeutics for treating chronic infections.

scholarly journals Mechanisms and Impact of Biofilms and Targeting of Biofilms Using Bioactive Compounds—A Review

Medicina ◽  
2021 ◽  
Vol 57 (8) ◽  
pp. 839
Author(s):  
Antony V Samrot ◽  
Amira Abubakar Mohamed ◽  
Etel Faradjeva ◽  
Lee Si Jie ◽  
Chin Hooi Sze ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Bioactive Compounds ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Cell Communication ◽  
Vital Role ◽  
Control Measures ◽  
Biofilm Inhibition ◽  
Antibiofilm Agents ◽  
And Control

Biofilms comprising aggregates of microorganisms or multicellular communities have been a major issue as they cause resistance against antimicrobial agents and biofouling. To date, numerous biofilm-forming microorganisms have been identified, which have been shown to result in major effects including biofouling and biofilm-related infections. Quorum sensing (which describes the cell communication within biofilms) plays a vital role in the regulation of biofilm formation and its virulence. As such, elucidating the various mechanisms responsible for biofilm resistance (including quorum sensing) will assist in developing strategies to inhibit and control the formation of biofilms in nature. Employing biological control measures (such as the use of bioactive compounds) in targeting biofilms is of great interest since they naturally possess antimicrobial activity among other favorable attributes and can also possibly act as potent antibiofilm agents. As an effort to re-establish the current notion and understanding of biofilms, the present review discuss the stages involved in biofilm formation, the factors contributing to its development, the effects of biofilms in various industries, and the use of various bioactive compounds and their strategies in biofilm inhibition.

scholarly journals Natural and Enantiopure Alkylglycerols as Antibiofilms Against Clinical Bacterial Isolates and Quorum Sensing Inhibitors of Chromobacterium violaceum ATCC 12472

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 430
Author(s):  
Klauss E. Chaverra Daza ◽  
Edelberto Silva Gómez ◽  
Bárbara D. Moreno Murillo ◽  
Humberto Mayorga Wandurraga
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Resistance Mechanisms ◽  
Chromobacterium Violaceum ◽  
Dependent Manner ◽  
Bacterial Isolates ◽  
Concentration Dependent Manner ◽  
Biofilm Inhibition ◽  
Microtiter Plate Assay

Resistance mechanisms occur in almost all clinical bacterial isolates and represent one of the most worrisome health problems worldwide. Bacteria can form biofilms and communicate through quorum sensing (QS), which allow them to develop resistance against conventional antibiotics. Thus, new therapeutic candidates are sought. We focus on alkylglycerols (AKGs) because of their recently discovered quorum sensing inhibition (QSI) ability and antibiofilm potential. Fifteen natural enantiopure AKGs were tested to determine their effect on the biofilm formation of other clinical bacterial isolates, two reference strains and their QSI was determined using Chromobacterium violaceum ATCC 12472. The highest biofilm inhibition rates (%) and minimum QS inhibitory concentration were determined by a microtiter plate assay and ciprofloxacin was used as the standard antibiotic. At subinhibitory concentrations, each AKG reduced biofilm formation in a concentration-dependent manner against seven bacterial isolates, with values up to 97.2%. Each AKG displayed QSI at different levels of ability without affecting the growth of C. violaceum. AKG (2S)-3-O-(cis-13’-docosenyl)-1,2-propanediol was the best QS inhibitor (20 μM), while (2S)-3-O-(cis-9’-hexadecenyl)-1,2-propanediol was the least effective (795 μM). The results showed for the first time the QSI activity of this natural AKG series and suggest that AKGs could be promising candidates for further studies on preventing antimicrobial resistance.

scholarly journals Effect of Titanium Dioxide Nanoparticles on the Expression of Efflux Pump and Quorum-Sensing Genes in MDR Pseudomonas aeruginosa Isolates

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Fatma Y. Ahmed ◽  
Usama Farghaly Aly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Nancy G. F. M. Waly
Keyword(s):  
Titanium Dioxide ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Efflux Pumps ◽  
Antibiofilm Activity ◽  
The Impact

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.

scholarly journals Effect of Silver Nanoparticles on Biofilm Formation and EPS Production of Multidrug-Resistant Klebsiella pneumoniae

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Hussnain Siddique ◽  
Bilal Aslam ◽  
Muhammad Imran ◽  
Asma Ashraf ◽  
Habibullah Nadeem ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Microtiter Plate ◽  
Cellular Protein ◽  
Antibiofilm Activity ◽  
Biofilm Inhibition ◽  
Microtiter Plate Assay ◽  
Protein Leakage ◽  
Hela Cell Lines

Antibiotic resistance against present antibiotics is rising at an alarming rate with need for discovery of advanced methods to treat infections caused by resistant pathogens. Silver nanoparticles are known to exhibit satisfactory antibacterial and antibiofilm activity against different pathogens. In the present study, the AgNPs were synthesized chemically and characterized by UV-Visible spectroscopy, scanning electron microscopy, and X-ray diffraction. Antibacterial activity against MDR K. pneumoniae strains was evaluated by agar diffusion and broth microdilution assay. Cellular protein leakage was determined by the Bradford assay. The effect of AgNPs on production on extracellular polymeric substances was evaluated. Biofilm formation was assessed by tube method qualitatively and quantitatively by the microtiter plate assay. The cytotoxic potential of AgNPs on HeLa cell lines was also determined. AgNPs exhibited an MIC of 62.5 and 125 μg/ml, while their MBC is 250 and 500 μg/ml. The production of extracellular polymeric substance decreased after AgNP treatment while cellular protein leakage increased due to higher rates of cellular membrane disruption by AgNPs. The percentage biofilm inhibition was evaluated to be 64% for K. pneumoniae strain MF953600 and 86% for MF953599 at AgNP concentration of 100 μg/ml. AgNPs were evaluated to be minimally cytotoxic and safe at concentrations of 15-120 μg/ml. The data evaluated by this study provided evidence of AgNPs being safe antibacterial and antibiofilm compounds against MDR K. pneumoniae.

scholarly journals The impact of quorum sensing and swarming motility on Pseudomonas aeruginosa biofilm formation is nutritionally conditional

2006 ◽  
Vol 62 (5) ◽  
pp. 1264-1277 ◽  
Author(s):  
Joshua D. Shrout ◽  
David L. Chopp ◽  
Collin L. Just ◽  
Morten Hentzer ◽  
Michael Givskov ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Swarming Motility ◽  
The Impact

The SagS sensory protein modulates biofilm formation and c-di-GMP levels by Pseudomonas aeruginosa in response to glucose-6-phosphate.

2020 ◽  
Author(s):  
Soyoung Park ◽  
Jozef Dingemans ◽  
Madison Gowett ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genetic Analysis ◽  
Signaling Pathway ◽  
Biofilm Formation ◽  
Phosphate Concentration ◽  
Dependent Manner ◽  
Diguanylate Cyclase ◽  
Swarming Motility ◽  
Two Component ◽  
Insight Into

<p>In <em>Pseudomonas aeruginosa</em>, the orphan two-component sensor SagS contributes to both, the transition to biofilm formation and to biofilm cells gaining their heightened tolerance to antimicrobials. However, little is known about the identity of the signals or conditions sensed by SagS to induce the switch to the sessile, drug tolerant mode of growth. Using a modified Biolog phenotype assay to screen for compounds that modulate attachment in a SagS-dependent manner, we identified glucose-6-phosphate to enhance attachment in a manner dependent on the glucose-6-phosphate concentration and SagS. The stimulatory effect was not limited to the attachment as glucose-6-phosphate likewise enhanced biofilm formation. We show that exposure to glucose-6-phosphate results in decreased swarming motility but increased cellular c-di-GMP levels in biofilms. Genetic analysis indicated that the diguanylate cyclase NicD is an activator of biofilm formation and is not only required for enhanced biofilm formation in response to glucose-6-phosphate but also interacts with SagS. Our findings indicate glucose-6-phosphate to likely mimic a signal or conditions sensed by SagS to activate its motile-sessile switch function. Additionally, our findings provide new insight into the interfaces between the ligand-mediated TCS signaling pathway and c-di-GMP levels.</p>

Anti-Pseudomonas aeruginosa Activity of Metal Schiff Base Complex and Probiotics Against Planktonic- and Biofilm-Growing Cells

2020 ◽  
Vol 18 ◽  
Author(s):  
Sepideh Hassanzadeh ◽  
Sudabeh Ebrahimi ◽  
Sara Ganjloo ◽  
Saeid Amel Jamehdar ◽  
Samaneh Dolatabadi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Schiff Base ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Schiff Base Complex ◽  
Diffusion Method ◽  
Antibiofilm Activity ◽  
Planktonic Cells ◽  
Biochemical Tests ◽  
Base Complex

Introduction: The biofilm formation by Pseudomonas aeruginosa seems to protect the bacteria from antibiotics since these entities are highly resistant to such antimicrobial agents. The aim of this study was to investigate the role of Lactobacillus salivarus, Lactobacillus plantarum supernatants and CuII Schiff base complex in eliminating planktonic cells and biofilm of P. aeruginosa. Methods: : One hundred specimens of blood, urine, cerebrospinal fluid, respiratory samples, and wound swabs were collected from patients attending three hospitals in Mashhad. All specimens were identified by biochemical tests. The susceptibility of the isolates to the conventional antibiotics were assessed using disk diffusion method. The biofilm formation ability of P. aeruginosa isolates was evaluated by crystal violet assay and confirmed using PCR. The anti-planktonic and anti-biofilm ability of L. salivarus, L. plantarum supernatants and CuII Schiff base complex was evaluated separately in P. aeruginosa isolates. Results and Conclusion: The highest and lowest resistance rates was detected in Cefazoline (95%) and cefepime (23%), respectively. The thickest biofilm was produced by 8% of P. aeruginosa isolates, 9% and 83% of the isolates were considered as moderate and weak biofilm producers, respectively. The rhlR and lasR genes was reported in 100% of the isolates, but algD gene was existence in 92% of them. Particularly, the CuII Schiff base complex could affect both planktonic and biofilm cells by the lowest concentration in comparison of probiotic supernatants. L. plantarum supernatant inhibited planktonic cells at a lower concentration than L. salivarius. Also, L. salivarius showed better antibiofilm activity than another probiotic in lower doses of supernatant. Unlike that these compounds have not completely eliminated biofilm cells, but only reduced the biofilm formation.Metal Schiff base complex and Lactobacillus supernatants is a potent antimicrobial agent against Pseudomonas aeruginosa biofilm cells.

scholarly journals Antibiofilm Activity of Methanol Extract of Rumex dentatus Against Pseudomonas aeruginosa

2020 ◽  
Vol 1 (1) ◽  
pp. 25-32
Author(s):  
Maryam Pezeshki Najafabadi ◽  
Maryam Mohammadi-Sichani ◽  
Mohammad Javad Kazemi ◽  
Mohammad Sadegh Shirsalimian ◽  
Majid Tavakoli
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Microtiter Plate ◽  
Extracellular Polysaccharides ◽  
Antibiofilm Activity ◽  
Plate Method ◽  
Hospital Acquired Infections ◽  
Hospital Acquired

Biofilm formation of Pseudomonas aeruginosa makes up a sizeable proportion of hospital-acquired infections, because bacteria in biofilms can resist antibiotic treatment. The extracellular polymeric substance of P. aeruginosa biofilm is an imprecise collection of extracellular polysaccharides, proteins and microbial cells. Rumex dentatus belongs to polygonaceae family. This family can be found in Middle East. The aim of this present study was to assess the effect of various concentrations of methanol extract of Rumex dentatus on biofilm formation of Pseudomonas aeruginosa after 48 h and 72 h. In this experimental study we collected Rumex dentatus from Khoramabad, Iran. The working extracts were 250, 125, 62.5, 31.25, 15.62, 7.81, 3.9, 1.95, 0.97 and 0.48 mg/ml. We used microtiter plate method to grow P. aeruginosa biofilm and assess the antibiofilm activity of plant extract. The composition of methanol extract obtained from Rumex dentatus was studied by gas chromatography. The minimum biofilm inhibitory concentration (MBIC) for P. aeruginosa found to be 250 mg/ml. GC-MS  analyses indicated that these fractions contained a variety of compounds including Bicyclo (3.1.1) heptan- 3 -one, 2, 6, 6- trimethyl,  Bicyclo (3.1.1) heptan, 6, 6- dimethyl and Eucalyptol. There were consequential correlations between antibiofilm activity and the concentration of extracts after 48 and 72 h.

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