Autoinducer-2 regulates Pseudomonas aeruginosa PAO1 biofilm formation and virulence production in a dose-dependent manner

Abstract Background Biofilms are a main pathogenicity feature of Pseudomonas aeruginosa and has a significant role in antibiotic resistance and persistent infections in humans. We investigated the in vitro activities of antibiotic ceftazidime and enzyme cellulase, either alone or in combination against biofilms of P. aeruginosa. Results Both ceftazidime and cellulase significantly decreased biofilm formation in all strains in a dose-dependent manner. Combination of enzyme at concentrations of 1.25, 2.5, 5, and 10 U/mL tested with 1/16× MIC of antibiotic led to a significant reduction in biofilm biomass. Cellulase showed a significant detachment effect on biofilms at three concentrations of 10 U/mL, 5 U/mL, and 2.5 U/mL. The MIC, MBC, and MBEC values of ceftazidime were 2 to 4 µg/mL, 4 to 8 µg/mL, and 2048 to 8192 µg/mL. When combined with cellulase, the MBECs of antibiotic showed a significant decrease from 32- to 128-fold. Conclusions Combination of the ceftazidime and the cellulase had significant anti-biofilm effects, including inhibition of biofilm formation and biofilm eradication in P. aeruginosa. These data suggest that glycoside hydrolase therapy as a novel strategy has the potential to enhance the efficacy of antibiotics and helps to resolve biofilm-associated wound infections caused by this pathogen.

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Growth inhibition of adherent Pseudomonas aeruginosa by an N-butanoyl-l-homoserine lactone analog

Canadian Journal of Microbiology ◽

10.1139/w10-013 ◽

2010 ◽

Vol 56 (4) ◽

pp. 317-325 ◽

Cited By ~ 14

Author(s):

Pouneh Khalilzadeh ◽

Barbora Lajoie ◽

Salomé El Hage ◽

Aurélie Furiga ◽

Geneviève Baziard ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Communication Systems ◽

Homoserine Lactone ◽

Adherent Cells ◽

Dependent Manner ◽

Structure Activity ◽

Opportunistic Human Pathogen ◽

Dose Dependent ◽

Related Compounds

The discovery of quorum sensing (QS) communication systems regulating bacterial virulence has afforded a novel opportunity for controlling infectious bacteria by interfering with QS. Pseudomonas aeruginosa is an example of an opportunistic human pathogen for which N-acyl homoserine lactone (AHL)-related compounds have been described as potent inhibitors of biofilm formation and virulence factors, given their similarity to the natural QS autoinducers (AHLs). Our purpose was to design potent analogs of N-butanoyl-l-homoserine lactone (C4-HSL) and to screen them for biological activity. Eleven original compounds characterized by the modification of the lactone moiety were screened for their ability to impair biofilm formation. Among them, compound 11 was able to modify the growth kinetics and to restrict the number of adherent cells when added from the early stages of biofilm formation (i.e., adhesion and microcolony formation) in a dose-dependent manner. To demonstrate antagonism with C4-HSL, we showed that the inhibition of biofilm formation by compound 11 was impaired when C4-HSL was added. Structure–activity relationships are discussed with respect to the results obtained.

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Comparative Study of Inhibitory Potential of Dietary Phytochemicals Against Quorum Sensing Activity of and Biofilm Formation by Chromobacterium violaceum 12472, and Swimming and Swarming Behaviour of Pseudomonas aeruginosa PAO1

Food Technology and Biotechnology ◽

10.17113/ftb.57.02.19.5823 ◽

2019 ◽

Vol 57 (2) ◽

pp. 212-221 ◽

Cited By ~ 2

Author(s):

Elif Burcu Bali ◽

Kübra Erkan Türkmen ◽

Demet Erdönmez ◽

Necdet Sağlam

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Gallic Acid ◽

Biofilm Formation ◽

Chromobacterium Violaceum ◽

Dependent Manner ◽

Pseudomonas Aeruginosa Pao1 ◽

Biosensor System ◽

Dietary Phytochemicals ◽

Inhibitory Potential

Quorum sensing (QS) and biofilm formation are important mechanisms related to antibiotic resistance of many pathogens. Alternative treatments are needed to prevent recurrent or chronic infections caused by multi-resistant pathogens. Therefore, the aim of this study is to investigate and compare the inhibitory potential of the dietary phytochemicals: curcumin, quercetin, apigenin, pyrogallol, gallic acid and luteolin against QS of and biofilm formation by Chromobacterium violaceum ATCC 12472 and the swimming and swarming abilities of Pseudomonas aeruginosa PAO1. Anti-QS potential of the phytochemicals was evaluated qualitatively and quantitatively using C. violaceum via the disk diffusion assay based on violacein pigment inhibition at the subminimal inhibitory concentrations ranging from 46.87 to 750 µg/mL. The results of anti-QS and antibiofilm activities on C. violaceum demonstrated that all the phytochemicals except pyrogallol and gallic acid inhibited violacein production (from (11.0±0.1) to (88.2±0.1) %) in a concentration-dependent manner. In addition, the biofilm formation was also significantly inhibited (p<0.05) in the presence of all the phytochemicals ((1.38±0.08)–(84.2±0.2) %). In the present study, the results revealed that quercetin, curcumin, apigenin and luteolin could be promising QS and biofilm inhibitory agents against the C. violaceum 12472 biosensor system. Our findings also suggest that all the phytochemicals, especially curcumin, quercetin and pyrogallol, might be anti-pathogenic agents against P. aeruginosa PAO1 infections due to the ability to control QS. However, more comprehensive studies at the molecular level, explaining their anti-QS mechanisms, need to be conducted to confirm these results and identify the genes involved.

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Synergistic Effect of Biogenics Derived from Potential Probiotics Together with Zingerone Against Biofilm Formation by Pseudomonas aeruginosa PAO1

Probiotics and Antimicrobial Proteins ◽

10.1007/s12602-021-09763-x ◽

2021 ◽

Author(s):

Swati Chandla ◽

Kusum Harjai ◽

Geeta Shukla

Keyword(s):

Pseudomonas Aeruginosa ◽

Synergistic Effect ◽

Biofilm Formation ◽

Pseudomonas Aeruginosa Pao1

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Oligoribonuclease is the primary degradative enzyme for pGpG inPseudomonas aeruginosathat is required for cyclic-di-GMP turnover

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1507245112 ◽

2015 ◽

Vol 112 (36) ◽

pp. E5048-E5057 ◽

Cited By ~ 75

Author(s):

Mona W. Orr ◽

Gregory P. Donaldson ◽

Geoffrey B. Severin ◽

Jingxin Wang ◽

Herman O. Sintim ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Active Site ◽

Half Life ◽

Biofilm Formation ◽

Degradation Pathway ◽

Dependent Manner ◽

Capillary Action ◽

Diguanylate Cyclases ◽

Active Site Mutants ◽

Degradative Enzyme

The bacterial second messenger cyclic di-GMP (c-di-GMP) controls biofilm formation and other phenotypes relevant to pathogenesis. Cyclic-di-GMP is synthesized by diguanylate cyclases (DGCs). Phosphodiesterases (PDE-As) end signaling by linearizing c-di-GMP to 5ʹ-phosphoguanylyl-(3ʹ,5ʹ)-guanosine (pGpG), which is then hydrolyzed to two GMP molecules by yet unidentified enzymes termed PDE-Bs. We show that pGpG inhibits a PDE-A fromPseudomonas aeruginosa. In a dual DGC and PDE-A reaction, excess pGpG extends the half-life of c-di-GMP, indicating that removal of pGpG is critical for c-di-GMP homeostasis. Thus, we sought to identify the PDE-B enzyme(s) responsible for pGpG degradation. A differential radial capillary action of ligand assay-based screen for pGpG binding proteins identified oligoribonuclease (Orn), an exoribonuclease that hydrolyzes two- to five-nucleotide-long RNAs. Purified Orn rapidly converts pGpG into GMP. To determine whether Orn is the primary enzyme responsible for degrading pGpG, we assayed cell lysates of WT and ∆ornstrains ofP. aeruginosaPA14 for pGpG stability. The lysates from ∆ornshowed 25-fold decrease in pGpG hydrolysis. Complementation with WT, but not active site mutants, restored hydrolysis. Accumulation of pGpG in the ∆ornstrain could inhibit PDE-As, increasing c-di-GMP concentration. In support, we observed increased transcription from the c-di-GMP–regulatedpelpromoter. Additionally, the c-di-GMP–governed auto-aggregation and biofilm phenotypes were elevated in the ∆ornstrain in apel-dependent manner. Finally, we directly detect elevated pGpG and c-di-GMP in the ∆ornstrain. Thus, we identified that Orn serves as the primary PDE-B enzyme that removes pGpG, which is necessary to complete the final step in the c-di-GMP degradation pathway.

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Bicarbonate Evokes Reciprocal Changes in Intracellular Cyclic di-GMP and Cyclic AMP Levels in Pseudomonas aeruginosa

Biology ◽

10.3390/biology10060519 ◽

2021 ◽

Vol 10 (6) ◽

pp. 519

Author(s):

Kasidid Ruksakiet ◽

Balázs Stercz ◽

Gergő Tóth ◽

Pongsiri Jaikumpun ◽

Ilona Gróf ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Cyclic Amp ◽

Biofilm Formation ◽

Second Messengers ◽

Brain Heart Infusion ◽

Ambient Air ◽

Dependent Manner ◽

Environmental Signals ◽

Common Causes ◽

Camp Levels

The formation of Pseudomonas aeruginosa biofilms in cystic fibrosis (CF) is one of the most common causes of morbidity and mortality in CF patients. Cyclic di-GMP and cyclic AMP are second messengers regulating the bacterial lifestyle transition in response to environmental signals. We aimed to investigate the effects of extracellular pH and bicarbonate on intracellular c-di-GMP and cAMP levels, and on biofilm formation. P. aeruginosa was inoculated in a brain–heart infusion medium supplemented with 25 and 50 mM NaCl in ambient air (pH adjusted to 7.4 and 7.7 respectively), or with 25 and 50 mM NaHCO3 in 5% CO2 (pH 7.4 and 7.7). After 16 h incubation, c-di-GMP and cAMP were extracted and their concentrations determined. Biofilm formation was investigated using an xCelligence real-time cell analyzer and by crystal violet assay. Our results show that HCO3− exposure decreased c-di-GMP and increased cAMP levels in a dose-dependent manner. Biofilm formation was also reduced after 48 h exposure to HCO3−. The reciprocal changes in second messenger concentrations were not influenced by changes in medium pH or osmolality. These findings indicate that HCO3− per se modulates the levels of c-di-GMP and cAMP, thereby inhibiting biofilm formation and promoting the planktonic lifestyle of the bacteria.

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

BioMed Research International ◽

10.1155/2019/5313918 ◽

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.

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Efficacy of Synthetic Furanones on Listeria monocytogenes Biofilm Formation

Foods ◽

10.3390/foods8120647 ◽

2019 ◽

Vol 8 (12) ◽

pp. 647 ◽

Cited By ~ 1

Author(s):

Pedro Rodríguez-López ◽

Andrea Emparanza Barrenengoa ◽

Sergio Pascual-Sáez ◽

Marta López Cabo

Keyword(s):

Listeria Monocytogenes ◽

Biofilm Formation ◽

Epifluorescence Microscopy ◽

Dependent Manner ◽

Antifouling Activity ◽

Aisi 316 ◽

Novel Strategy ◽

And Control ◽

Acylated Homoserine Lactones ◽

Dose Dependent

Furanones are analogues of acylated homoserine lactones with proven antifouling activity in both Gram-positive and Gram-negative bacteria though the interference of various quorum sensing pathways. In an attempt to find new strategies to prevent and control Listeria monocytogenes biofilm formation on stainless steel (SS) surfaces, different concentrations of six synthetic furanones were applied on biofilms formed by strains isolated from food, environmental, and clinical sources grown onto AISI 316 SS coupons. Among the furanones tested, (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone and 3,4-Dichloro-2(5H)-furanone significantly (p < 0.05) reduced the adhesion capacity (>1 log CFU cm−2) in 24 h treated biofilms. Moreover, individually conducted experiments demonstrated that (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone was able to not only significantly (p < 0.05) prevent L. monocytogenes adhesion but also to reduce the growth rate of planktonic cells up to 48 h in a dose-dependent manner. LIVE/DEAD staining followed by epifluorescence microscopy visualisation confirmed these results show an alteration of the structure of the biofilm in furanone-treated samples. Additionally, it was demonstrated that 20 µmol L−1 of 3,4-Dichloro-2(5H)-furanone dosed at 0, 24 and 96 h was able to maintain a lower level of adhered cells (>1 log CFU cm−2; p < 0.05). Since furanones do not pose a selective pressure on bacteria, these results represent an appealing novel strategy for the prevention of L. monocytogenes biofilm grown onto SS.

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