Fucoidan-Stabilized Gold Nanoparticle-Mediated Biofilm Inhibition, Attenuation of Virulence and Motility Properties in Pseudomonas aeruginosa PAO1

The emergence of antibiotic resistance in Pseudomonas aeruginosa due to biofilm formation has transformed this opportunistic pathogen into a life-threatening one. Biosynthesized nanoparticles are increasingly being recognized as an effective anti-biofilm strategy to counter P. aeruginosa biofilms. In the present study, gold nanoparticles (AuNPs) were biologically synthesized and stabilized using fucoidan, which is an active compound sourced from brown seaweed. Biosynthesized fucoidan-stabilized AuNPs (F-AuNPs) were subjected to characterization using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission transmission electron microscopy (FE-TEM), dynamic light scattering (DLS), and energy dispersive X-ray diffraction (EDX). The biosynthesized F-AuNPs were then evaluated for their inhibitory effects on P. aeruginosa bacterial growth, biofilm formation, virulence factor production, and bacterial motility. Overall, the activities of F-AuNPs towards P. aeruginosa were varied depending on their concentration. At minimum inhibitory concentration (MIC) (512 µg/mL) and at concentrations above MIC, F-AuNPs exerted antibacterial activity. In contrast, the sub-inhibitory concentration (sub-MIC) levels of F-AuNPs inhibited biofilm formation without affecting bacterial growth, and eradicated matured biofilm. The minimum biofilm inhibition concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were identified as 128 µg/mL. Furthermore, sub-MICs of F-AuNPs also attenuated the production of several important virulence factors and impaired bacterial swarming, swimming, and twitching motilities. Findings from the present study provide important insights into the potential of F-AuNPs as an effective new drug for controlling P. aeruginosa-biofilm-related infections.

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Effect of tannic and gallic acids alone or in combination with carbenicillin or tetracycline on Chromobacterium violaceum CV026 growth, motility, and biofilm formation

Canadian Journal of Microbiology ◽

10.1139/cjm-2015-0101 ◽

2015 ◽

Vol 61 (7) ◽

pp. 487-494 ◽

Cited By ~ 4

Author(s):

Devendra H. Dusane ◽

Che O’May ◽

Nathalie Tufenkji

Keyword(s):

Antibacterial Activity ◽

Gallic Acid ◽

Tannic Acid ◽

Bacterial Growth ◽

Biofilm Formation ◽

Opportunistic Pathogen ◽

Chromobacterium Violaceum ◽

Minimum Inhibitory Concentrations

Chromobacterium violaceum is an opportunistic pathogen that causes infections that are difficult to treat. The goal of this research was to evaluate the effect of selected tannins (tannic acid (TA) and gallic acid (GA)) on bacterial growth, motility, antibiotic (carbenicillin, tetracycline) susceptibility, and biofilm formation. Both tannins, particularly TA, impaired bacterial growth levels and swimming motilities at sub-minimum inhibitory concentrations (sub-MICs). In combination with tannins, antibiotics showed increased MICs, suggesting that tannins interfered with antibacterial activity. Sub-MICs of tetracycline or TA alone enhanced biofilm formation of C. violaceum; however, in combination, these compounds inhibited biofilm formation. In contrast, carbenicillin at sub-MICs was effective in inhibiting C. violaceum biofilm formation; however, in combination with lower concentrations of TA or GA, biofilms were enhanced. These results provide insights into the effects of tannins on C. violaceum growth and their varying interaction with antibiotics used to target C. violaceum infections.

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Enhancement of pyocyanin production by subinhibitory concentration of royal jelly in Pseudomonas aeruginosa

F1000Research ◽

10.12688/f1000research.27915.3 ◽

2021 ◽

Vol 10 ◽

pp. 14

Author(s):

Dina Auliya Amly ◽

Puspita Hajardhini ◽

Alma Linggar Jonarta ◽

Heribertus Dedy Kusuma Yulianto ◽

Heni Susilowati

Keyword(s):

Pseudomonas Aeruginosa ◽

Bacterial Growth ◽

Biofilm Formation ◽

Royal Jelly ◽

Microtiter Plate ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Antibiotic Tolerance ◽

Subinhibitory Concentration ◽

Pyocyanin Production

Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods: Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: The royal jelly concentration of 25% or higher inhibits bacterial growth; however, the subinhibitory concentration increases pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.

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PmtA Regulates Pyocyanin Expression and Biofilm Formation in Pseudomonas aeruginosa

Frontiers in Microbiology ◽

10.3389/fmicb.2021.789765 ◽

2021 ◽

Vol 12 ◽

Author(s):

Amy V. Thees ◽

Kathryn M. Pietrosimone ◽

Clare K. Melchiorre ◽

Jeremiah N. Marden ◽

Joerg Graf ◽

...

Keyword(s):

Oxidative Stress ◽

Pseudomonas Aeruginosa ◽

Metal Binding ◽

Biofilm Formation ◽

Binding Capacity ◽

Opportunistic Pathogen ◽

Small Molecular Weight ◽

Heavy Metal Binding ◽

The Impact

The opportunistic pathogen Pseudomonas aeruginosa expresses a small molecular weight, cysteine-rich protein (PmtA), identified as a metallothionein (MT) protein family member. The MT family proteins have been well-characterized in eukaryotes as essential for zinc and copper homeostasis, protection against oxidative stress, and the ability to modify a variety of immune activities. Bacterial MTs share sequence homology, antioxidant chemistry, and heavy metal-binding capacity with eukaryotic MTs, however, the impact of bacterial MTs on virulence and infection have not been well-studied. In the present study, we investigated the role of PmtA in P. aeruginosa PAO1 using a PmtA-deficient strain (ΔpmtA). Here we demonstrated the virulence factor, pyocyanin, relies on the expression of PmtA. We showed that PmtA may be protective against oxidative stress, as an alternative antioxidant, glutathione, can rescue pyocyanin expression. Furthermore, the expression of phzM, which encodes a pyocyanin precursor enzyme, was decreased in the ΔpmtA mutant during early stationary phase. Upregulated pmtA expression was previously detected in confluent biofilms, which are essential for chronic infection, and we observed that the ΔpmtA mutant was disrupted for biofilm formation. As biofilms also modulate antibiotic susceptibility, we examined the ΔpmtA mutant susceptibility to antibiotics and found that the ΔpmtA mutant is more susceptible to cefepime and ciprofloxacin than the wild-type strain. Finally, we observed that the deletion of pmtA results in decreased virulence in a waxworm model. Taken together, our results support the conclusion that PmtA is necessary for the full virulence of P. aeruginosa and may represent a potential target for therapeutic intervention.

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Antimicrobial and antibiofilm properties of essential oils from Piper marginatum Jacq.

Research Society and Development ◽

10.33448/rsd-v10i11.19967 ◽

2021 ◽

Vol 10 (11) ◽

pp. e514101119967

Author(s):

Ana Lúcia Mendes dos Santos ◽

Filipe Augusto Matos Araújo ◽

Érika da Silva Matisui ◽

Luiz Antonio Mendonça Alves da Costa ◽

Alexandre José Macêdo ◽

...

Keyword(s):

Essential Oils ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Inhibitory Concentration ◽

Folk Medicine ◽

Gram Negative Bacteria ◽

Biofilm Inhibition ◽

Future Developments ◽

Phytochemical Constituents ◽

Amazonian Region

A low shrub growing in the Amazonian region, Piper marginatum Jacq. has been related to the treatment of a disease variety in folk medicine, however, still lacking scientific support. This study aimed to describe the composition of essential oils obtained from leaves (EOL) and branches (EOB) of P. marginatum and their antimicrobial effects on six relevant pathogenic bacteria. A combination of GC-FID and GC-MS was used to identify the phytochemical constituents. As antimicrobial assays, the oils were screened at the minimum inhibitory concentration (MIC) of 3 µg/ml for planktonic and biofilm inhibition. EOL revealed the presence of trans–nerolidol, o–cymene, spathulenol, elemicin, and α–copaene, while EOB composition was mainly of myristicin, trans-caryophyllene, trans-nerolidol, caryophyllene oxide, α–copaene, γ–muurolene and spathulenol. The strongest inhibition of planktonic growth was achieved against Pseudomonas aeruginosa (EOB) and Escherichia coli (EOB). Overall, Gram negative bacteria were more sensitive to both EOB/EOL showing less ability of growth and biofilm formation. The Gram-positive strains seemed to react to the essential oils by massive adhesion. Our results corroborate the relevance of Piperaceae and indicate the possible use of P. marginatum in future developments of antimicrobials.

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Reservoirs of resistance: polymyxin resistance in veterinary-associated companion animal isolates of Pseudomonas aeruginosa

Veterinary Record ◽

10.1136/vr.105075 ◽

2019 ◽

Vol 185 (7) ◽

pp. 206-206 ◽

Cited By ~ 1

Author(s):

Andrea Scott ◽

Sian Pottenger ◽

Dorina Timofte ◽

Matthew Moore ◽

Laura Wright ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Pathogenic Bacteria ◽

Inhibitory Concentration ◽

Respiratory Infections ◽

Companion Animals ◽

Opportunistic Pathogen ◽

Polymyxin B ◽

Potential Reservoir ◽

Human Infections ◽

Animal Isolates

BackgroundPseudomonas aeruginosa is an opportunistic pathogen and a major cause of infections. Widespread resistance in human infections are increasing the use of last resort antimicrobials such as polymyxins. However, these have been used for decades in veterinary medicine. Companion animals are an understudied source of antimicrobial resistant P. aeruginosa isolates. This study evaluated the susceptibility of P. aeruginosa veterinary isolates to polymyxins to determine whether the veterinary niche represents a potential reservoir of resistance genes for pathogenic bacteria in both animals and humans.Methods and resultsClinical P. aeruginosa isolates (n=24) from UK companion animals were compared for antimicrobial susceptibility to a panel of human-associated isolates (n=37). Minimum inhibitory concentration (MIC) values for polymyxin B and colistin in the companion animals was significantly higher than in human isolates (P=0.033 and P=0.013, respectively). Genotyping revealed that the veterinary isolates were spread throughout the P. aeruginosa population, with shared array types from human infections such as keratitis and respiratory infections, suggesting the potential for zoonotic transmission. Whole genome sequencing revealed mutations in genes associated with polymyxin resistance and other antimicrobial resistance-related genes.ConclusionThe high levels of resistance to polymyxin shown here, along with genetic similarities between some human and animal isolates, together suggest a need for sustained surveillance of this veterinary niche as a potential reservoir for resistant, clinically relevant bacteria in both animals and humans.

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Interactions between Candida albicans and Enterococcus faecalis in an Organotypic Oral Epithelial Model

Microorganisms ◽

10.3390/microorganisms8111771 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1771

Author(s):

Akshaya Lakshmi Krishnamoorthy ◽

Alex A. Lemus ◽

Adline Princy Solomon ◽

Alex M. Valm ◽

Prasanna Neelakantan

Keyword(s):

Candida Albicans ◽

Enterococcus Faecalis ◽

Biofilm Formation ◽

Opportunistic Pathogen ◽

Surface Erosion ◽

Host Immune System ◽

Microbial Invasion ◽

Mucosal Surfaces ◽

Life Threatening ◽

Hyphal Formation

Candida albicans as an opportunistic pathogen exploits the host immune system and causes a variety of life-threatening infections. The polymorphic nature of this fungus gives it tremendous advantage to breach mucosal barriers and cause oral and disseminated infections. Similar to C. albicans, Enterococcus faecalis is a major opportunistic pathogen, which is of critical concern in immunocompromised patients. There is increasing evidence that E. faecalis co-exists with C. albicans in the human body in disease samples. While the interactive profiles between these two organisms have been studied on abiotic substrates and mouse models, studies on their interactions on human oral mucosal surfaces are non-existent. Here, for the first time, we comprehensively characterized the interactive profiles between laboratory and clinical isolates of C. albicans (SC5314 and BF1) and E. faecalis (OG1RF and P52S) on an organotypic oral mucosal model. Our results demonstrated that the dual species biofilms resulted in profound surface erosion and significantly increased microbial invasion into mucosal compartments, compared to either species alone. Notably, several genes of C. albicans involved in tissue adhesion, hyphal formation, fungal invasion, and biofilm formation were significantly upregulated in the presence of E. faecalis. By contrast, E. faecalis genes involved in quorum sensing, biofilm formation, virulence, and mammalian cell invasion were downregulated. This study highlights the synergistic cross-kingdom interactions between E. faecalis and C. albicans in mucosal tissue invasion.

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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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Plantain Herb Extracts significantly attenuate the quorum sensing-controlled virulence factors and inhibit biofilm formation in Pseudomonas aeruginosa PAO1

E3S Web of Conferences ◽

10.1051/e3sconf/20197801004 ◽

2019 ◽

Vol 78 ◽

pp. 01004

Author(s):

Shan Li ◽

Jiangning Yao ◽

Haoming Li

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Opportunistic Pathogen ◽

Significant Inhibition ◽

Control Group ◽

Produce Cell ◽

Group B ◽

Herb Extracts

Pseudomonas aeruginosa is a Gram-negative organism that can survive under harsh conditions, and it is also an opportunistic pathogen that can produce cell-associated extracellular virulence factors. Several of these virulence factors have been demonstrated to be regulated by quorum sensing (QS). Plantain Herb has been used as antibacterial agents for many centuries in China. In this study, we analyzed Plantain Herb Extracts (PHE) at the concentration of 16 μg/mL (Group A, MIC), 8 μg/mL (Group B, 1/2 MIC) and 4 μg/mL (Group C, 1/4 MIC) for inhibition of the virulence factors production and biofilm formation in P. aeruginosa PAO1. The virulence factors included pyocyanin, rhamnolipids, protease and alginate. PHE showed significant inhibition of virulence factors as compared to the control group without interfering its growth. Thus, PHE might be a potent QS inhibitor and anti-biofilm agent in the treatment of Pseudomonas aeruginosa infections.

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Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions

Journal of Medical Microbiology ◽

10.1099/jmm.0.004416-0 ◽

2009 ◽

Vol 58 (6) ◽

pp. 765-773 ◽

Cited By ~ 61

Author(s):

Che Y. O'May ◽

Kevin Sanderson ◽

Louise F. Roddam ◽

Sylvia M. Kirov ◽

David W. Reid

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Low Oxygen ◽

Anaerobic Conditions ◽

Chronic Infections ◽

Strain Pao1 ◽

Biofilm Inhibition ◽

Oxygen Conditions ◽

Biofilm Development ◽

Chelating Compounds

The success of Pseudomonas aeruginosa in cystic fibrosis (CF) and other chronic infections is largely attributed to its ability to grow in antibiotic-resistant biofilm communities. This study investigated the effects of limiting iron levels as a strategy for preventing/disrupting P. aeruginosa biofilms. A range of synthetic and naturally occurring iron-chelating agents were examined. Biofilm development by P. aeruginosa strain PAO1 and CF sputum isolates from chronically infected individuals was significantly decreased by iron removal under aerobic atmospheres. CF strains formed poor biofilms under anaerobic conditions. Strain PAO1 was also tested under anaerobic conditions. Biofilm formation by this model strain was almost totally prevented by several of the chelators tested. The ability of synthetic chelators to impair biofilm formation could be reversed by iron addition to cultures, providing evidence that these effective chelating compounds functioned by directly reducing availability of iron to P. aeruginosa. In contrast, the biological chelator lactoferrin demonstrated enhanced anti-biofilm effects as iron supplementation increased. Hence biofilm inhibition by lactoferrin appeared to occur through more complex mechanisms to those of the synthetic chelators. Overall, our results demonstrate the importance of iron availability to biofilms and that iron chelators have potential as adjunct therapies for preventing biofilm development, especially under low oxygen conditions such as encountered in the chronically infected CF lung.

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Pseudomonas aeruginosa Exopolysaccharide Psl Promotes Resistance to the Biofilm Inhibitor Polysorbate 80

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00373-12 ◽

2012 ◽

Vol 56 (8) ◽

pp. 4112-4122 ◽

Cited By ~ 22

Author(s):

Michael E. Zegans ◽

Daniel Wozniak ◽

Edward Griffin ◽

Christine M. Toutain-Kidd ◽

John H. Hammond ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Nonionic Surfactant ◽

Biofilm Formation ◽

Laboratory Strain ◽

Polysorbate 80 ◽

Biosynthetic Pathways ◽

Human Tissues ◽

Biofilm Inhibition ◽

Content Type ◽

Biofilm Inhibitor

ABSTRACTPolysorbate 80 (PS80) is a nonionic surfactant and detergent that inhibits biofilm formation byPseudomonas aeruginosaat concentrations as low as 0.001% and is well tolerated in human tissues. However, certain clinical and laboratory strains (PAO1) ofP. aeruginosaare able to form biofilms in the presence of PS80. To better understand this resistance, we performed transposon mutagenesis with a PS80-resistant clinical isolate, PA738. This revealed that mutation ofalgCrendered PA738 sensitive to PS80 biofilm inhibition. AlgC contributes to the biosynthesis of the exopolysaccharides Psl and alginate, as well as lipopolysaccharide and rhamnolipid. Analysis of mutations downstream of AlgC in these biosynthetic pathways established that disruption of thepsloperon was sufficient to render the PA738 and PAO1 strains sensitive to PS80-mediated biofilm inhibition. Increased levels of Psl production in the presence of arabinose in a strain with an arabinose-induciblepslpromoter were correlated with increased biofilm formation in PS80. InP. aeruginosastrains MJK8 and ZK2870, known to produce both Pel and Psl, disruption of genes in thepslbut not thepeloperon conferred susceptibility to PS80-mediated biofilm inhibition. The laboratory strain PA14 does not produce Psl and does not form biofilms in PS80. However, when PA14 was transformed with a cosmid containing thepsloperon, it formed biofilms in the presence of PS80. Taken together, these data suggest that production of the exopolysaccharide Psl byP. aeruginosapromotes resistance to the biofilm inhibitor PS80.

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