Efficacy of Synthetic Furanones on Listeria monocytogenes Biofilm Formation

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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In vitro activities of cellulase and ceftazidime, alone and in combination against Pseudomonas aeruginosa biofilms

BMC Microbiology ◽

10.1186/s12866-021-02411-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Esmat Kamali ◽

Ailar Jamali ◽

Ahdieh Izanloo ◽

Abdollah Ardebili

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Resistance ◽

Biofilm Formation ◽

Glycoside Hydrolase ◽

Dependent Manner ◽

Wound Infections ◽

Persistent Infections ◽

Novel Strategy ◽

Dose Dependent

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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Inhibition of Biofilm Formation and Related Gene Expression of Listeria monocytogenes in Response to Four Natural Antimicrobial Compounds and Sodium Hypochlorite

Frontiers in Microbiology ◽

10.3389/fmicb.2020.617473 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yunge Liu ◽

Lina Wu ◽

Jina Han ◽

Pengcheng Dong ◽

Xin Luo ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Quorum Sensing ◽

Sodium Hypochlorite ◽

Biofilm Formation ◽

Natural Compounds ◽

Antimicrobial Compounds ◽

Natural Antimicrobial ◽

Low Degree ◽

Chemical Disinfectant ◽

Dose Dependent

The aim of this study was to assess the efficacy of four natural antimicrobial compounds (cinnamaldehyde, eugenol, resveratrol and thymoquinone) plus a control chemical disinfectant (sodium hypochlorite) in inhibiting biofilm formation by Listeria monocytogenes CMCC54004 (Lm 54004) at a minimum inhibitory concentration (MIC) and sub-MICs. Crystal violet staining assay and microscopic examination were employed to investigate anti-biofilm effects of the evaluated compounds, and a real-time PCR assay was used to investigate the expression of critical genes by Lm 54004 biofilm. The results showed that five antimicrobial compounds inhibited Lm 54004 biofilm formation in a dose dependent way. Specifically, cinnamaldehyde and resveratrol showed better anti-biofilm effects at 1/4 × MIC, while sodium hypochlorite exhibited the lowest inhibitory rates. A swimming assay confirmed that natural compounds at sub-MICs suppressed Lm 54004 motility to a low degree. Supporting these findings, expression analysis showed that all four natural compounds at 1/4 × MIC significantly down-regulated quorum sensing genes (agrA, agrC, and agrD) rather than suppressing the motility- and flagella-associated genes (degU, motB, and flaA). This study revealed that sub-MICs of natural antimicrobial compounds reduced biofilm formation by suppressing the quorum sensing system rather than by inhibiting flagella formation.

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Microtiter Plate Assay for Assessment of Listeria monocytogenes Biofilm Formation

Applied and Environmental Microbiology ◽

10.1128/aem.68.6.2950-2958.2002 ◽

2002 ◽

Vol 68 (6) ◽

pp. 2950-2958 ◽

Cited By ~ 529

Author(s):

D. Djordjevic ◽

M. Wiedmann ◽

L. A. McLandsborough

Keyword(s):

Listeria Monocytogenes ◽

Crystal Violet ◽

Biofilm Formation ◽

Microtiter Plate ◽

Cellular Growth ◽

Epifluorescence Microscopy ◽

Simple Method ◽

Microtiter Plate Assay ◽

Plate Assay ◽

Biofilm Production

ABSTRACT Listeria monocytogenes has the ability to form biofilms on food-processing surfaces, potentially leading to food product contamination. The objective of this research was to standardize a polyvinyl chloride (PVC) microtiter plate assay to compare the ability of L. monocytogenes strains to form biofilms. A total of 31 coded L. monocytogenes strains were grown in defined medium (modified Welshimer's broth) at 32°C for 20 and 40 h in PVC microtiter plate wells. Biofilm formation was indirectly assessed by staining with 1% crystal violet and measuring crystal violet absorbance, using destaining solution. Cellular growth rates and final cell densities did not correlate with biofilm formation, indicating that differences in biofilm formation under the same environmental conditions were not due to growth rate differences. The mean biofilm production of lineage I strains was significantly greater than that observed for lineage II and lineage III strains. The results from the standardized microtiter plate biofilm assay were also compared to biofilm formation on PVC and stainless steel as assayed by quantitative epifluorescence microscopy. Results showed similar trends for the microscopic and microtiter plate assays, indicating that the PVC microtiter plate assay can be used as a rapid, simple method to screen for differences in biofilm production between strains or growth conditions prior to performing labor-intensive microscopic analyses.

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Endothelium-dependent relaxation and experimental atherosclerosis in the rabbit aorta

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y86-246 ◽

1986 ◽

Vol 64 (11) ◽

pp. 1451-1453 ◽

Cited By ~ 71

Author(s):

N. Sreeharan ◽

R. L. Jayakody ◽

M. P. J. Senaratne ◽

A. B. R. Thomson ◽

C. T. Kappagoda

Keyword(s):

Rabbit Aorta ◽

Experimental Atherosclerosis ◽

Isometric Tension ◽

Dependent Manner ◽

Bicarbonate Buffer ◽

New Zealand White Rabbits ◽

Set Up ◽

And Control ◽

Dose Dependent ◽

Endothelium Dependent Relaxation

This study was undertaken to determine whether the production or release of the endothelium-dependent relaxatory factor is impaired in atherosclerotic New Zealand White rabbits. Atherosclerosis was induced by feeding a diet containing 2% cholesterol for 6 weeks. The production or release of endothelium-dependent relaxatory factor was assayed as follows. A 5-cm length of aorta donor was perfused with Krebs–bicarbonate buffer and the perfusate drained over a deendothelialized ring of recipient aorta set up for recording isometric tension. The recipient was precontracted with norepinephrine (0.2 μmol/L) in the perfusate. When acetylcholine was added to the perfusate, the recipient relaxed in a dose-dependent manner. This assay was used to compare the relaxatory responses produced in recipient rings by adding acetylcholine to donors from atherosclerotic and control rabbits. The relaxation produced by atherosclerotic donors were smaller than those generated by control donors (16.5 ± 4.9 vs. 32.7 ± 5.3%; n = 10, p < 0.05). It is suggested that in atherosclerotic rabbits the ability of aortic endothelium to produce or release endothelium-dependent relaxatory factor is impaired.

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Dimethyl itaconate inhibits TNF-α induced NF-κB signaling pathway in human epithelial cells

10.21203/rs.2.17569/v2 ◽

2020 ◽

Author(s):

Yalei Zhang ◽

Xiaobing Deng ◽

Hao Liang ◽

Annan Guo ◽

Kenan Li ◽

...

Keyword(s):

Inflammatory Responses ◽

Inflammatory Diseases ◽

Cysteine Residue ◽

Luciferase Assay ◽

Dependent Manner ◽

Nuclear Entry ◽

Tnf Α ◽

Novel Strategy ◽

Dose Dependent ◽

Dimethyl Itaconate

Abstract Background: Dimethyl itaconate (DMI), a membrane-permeable derivative of itaconate, was found to moderate IL-17-IκBζ-induced skin pathology including psoriasis in mouse experiments . TNF-α induced NF-κB pathway, which controls a variety of immune and inflammatory responses, was also proven to play a crucial role as mediator in psoriasis. However, whether DMI interacts with the TNF-α induced NF-κB pathway remains unclear. Results: Here we show that DMI inhibits TNF-α induced NF-κB transcriptional activities in dose-dependent manner in several human cell lines using dual luciferase assay and blocks the NF-κB nuclear entry. Moreover, DMI potently inhibits IKKβ dependent phosphorylation and degradation of IκBα in TNF-α induced activation of NF-κB pathway. We also demonstrate that DMI covalently binds to cysteine residue in IKKβ, a key regulator in NF-κB pathway, to suppress IKKβ activation and inhibit the canonical NF-κB pathway. Conclusion Our study presents a new mechanism for DMI as an anti-inflammatory agent that may have therapeutic potentials in treating NF-κB related human inflammatory diseases. Our results also suggest that itaconate produced by endogenous IRG1 may regulate NF-κB at post translation modification level, and the IRG1-itaconate-NF-κB axis could be targeted as a novel strategy for the treatment of IRG1-NF-κB mediated diseases.

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Induction of Metalloproteinases by Glomerular Mesangial Cells Stimulated by Proteins of the Extracellular Matrix

Journal of the American Society of Nephrology ◽

10.1681/asn.v12188 ◽

2001 ◽

Vol 12 (1) ◽

pp. 88-96

Author(s):

JOHN MARTIN ◽

LISA EYNSTONE ◽

MALCOLM DAVIES ◽

ROBERT STEADMAN

Keyword(s):

Mesangial Cells ◽

Dynamic Equilibrium ◽

Matrix Proteins ◽

Dependent Manner ◽

Glomerular Mesangial Cells ◽

Matrix Components ◽

Membrane Type ◽

And Control ◽

Dose Dependent ◽

Synthesis And Degradation

Abstract. Human glomerular mesangial cells (HMC) are embedded in the mesangial matrix (MM) and control its turnover through a dynamic equilibrium between synthesis and degradation. Degradation is controlled by matrix metalloproteinases (MMP), whose activity has been causally implicated in the progression of glomerular disease. In other systems, MMP secretion may be directly affected by exposure to specific matrix proteins. The present study, therefore, investigated the effect of different matrix components on the adherence of HMC and on their secretion and activation of the gelatinases MMP2 and MMP9. HMC adhered strongly (quantified using crystal violet staining) to collagen IV and collagen I (P < 0.01, relative to binding to control, bovine serum albumin (BSA)-coated wells) and to a lesser extent to gelatin IV and fibronectin (P < 0.05). Binding to vitronectin and laminin was not statistically different to control wells. After the addition of these matrix proteins (0.1 μg/ml to 100 μg/ml) to growth-arrested HMC for 72 h, zymography of the conditioned medium established that only fibronectin and collagens I and IV dose-dependently increased latent (72 kD) MMP2 secretion and activation. Fibronectin, however, also induced the secretion of MMP9. Membranes from HMC that had been co-cultured with fibronectin for 72 h were prepared to investigate whether the activation of MMP2 in this system was due to the action of membrane-type (MT)-MMP. When incubated with latent MMP2 for times up to 24 h, these membranes activated the enzyme in a time- and dose-dependent manner. The results demonstrate that specific matrix components increased the secretion of MMP2 and MMP9 from HMC. In addition, MT-MMP activity, selectively induced by fibronectin, was implicated in the activation of the secreted proteinases.

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Effects of topical corticosteroids on the sciatic nerve: an experimental study to adduce the safety in treating carpal tunnel syndrome

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193410390760 ◽

2011 ◽

Vol 36 (3) ◽

pp. 236-243 ◽

Cited By ~ 18

Author(s):

P.-H. Wang ◽

C.-L. Tsai ◽

J.-S. Lee ◽

K.-C. Wu ◽

K.-I. Cheng ◽

...

Keyword(s):

Sciatic Nerve ◽

Evoked Potentials ◽

Carpal Tunnel ◽

Somatosensory Evoked Potentials ◽

Corticosteroid Injection ◽

Dependent Manner ◽

Tunnel Syndrome ◽

And Control ◽

Dose Dependent ◽

Mixed Nerve

Despite known detrimental effects on the blood flow and histology of nerves after intraneural corticosteroid injection, the neurotoxic effect of corticosteroids remains unclear. We investigated the effect of topical dexamethasone on nerve function. Two sponge strips soaked with dexamethasone at doses of 0.8, 1.6, and 3.2 mg were placed under and over the left sciatic nerve of adult Wistar rats for 30 minutes. Mixed-nerve-elicited somatosensory evoked potentials and dermatomal somatosensory evoked potentials were evaluated immediately and repeated together with functional tests and histology 2 weeks later. Evoked potential amplitude was dose-dependently lower and latency was prolonged in dexamethasone-treated sciatic nerves compared to controls. The suppression persisted with incomplete recovery for at least 4 hours, but differences between treated and control nerves were not significant after 2 weeks. Topical dexamethasone adversely affected neural conduction in a dose-dependent manner. Our results suggest that caution is required when using large doses of corticosteroid for injection of the carpal tunnel.

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Platelet-derived CD154 enables T-cell priming and protection against Listeria monocytogenes challenge

Blood ◽

10.1182/blood-2007-05-091728 ◽

2008 ◽

Vol 111 (7) ◽

pp. 3684-3691 ◽

Cited By ~ 53

Author(s):

Bennett D. Elzey ◽

Nathan W. Schmidt ◽

Scott A. Crist ◽

Timothy P. Kresowik ◽

John T. Harty ◽

...

Keyword(s):

Listeria Monocytogenes ◽

T Cell ◽

Low Dose ◽

Cytotoxic T Lymphocyte ◽

Dependent Manner ◽

Cell Immunity ◽

Report Data ◽

Membrane Bound ◽

Dose Dependent ◽

Ctl Activity

AbstractCollagen exposure in tissue activates platelets, initiates wound healing, and modulates adaptive immunity. In this report, data are presented to demonstrate a requirement for platelet-derived CD154 for both collagen-induced augmentation of T-cell immunity and induction of pro-tective immunity to Listeria challenge. Specifically, we demonstrate that Ad5 encoding the membrane-bound form of ovalbumin (Ad5-mOVA) delivered in collagen induces higher ovalbumin-specific cytotoxic T lymphocyte (CTL) activity in a dose-dependent manner compared with Ad5-mOVA delivered in PBS. Increased CTL activity was dependent on the ability of platelets to respond to collagen and to express CD154. Furthermore, mice immunized with low-dose Ad5-mOVA in collagen were able to control a challenge of Listeria monocytogenes recombinant for ovalbumin expression (Lm-OVA), whereas mice immunized with low-dose Ad5-mOVA in PBS were not. These data indicate that in a physiologic setting that mimics wounding, platelets perform a sentinel function when antigen dose is too low to provoke an efficient immune response, and can enhance the generation of antigen-specific CD8 T cells that are functionally relevant to the host.

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Trypsinization of bovine parathyroid cells abolishes Ca2+-regulated parathyroid hormone secretion

Journal of Endocrinology ◽

10.1677/joe.0.1220213 ◽

1989 ◽

Vol 122 (1) ◽

pp. 213-218 ◽

Cited By ~ 2

Author(s):

R. Muff ◽

J. A. Fischer

Keyword(s):

Protein Kinase C ◽

Parathyroid Hormone ◽

Protein Kinase ◽

Adrenergic Receptors ◽

Hormone Secretion ◽

Dependent Manner ◽

Kinase C ◽

And Control ◽

Β Adrenergic Receptors ◽

Dose Dependent

ABSTRACT The secretion of parathyroid hormone (PTH) is inversely related to the extracellular Ca2+ concentration (Cae2+). To test the hypothesis that a Ca2+ sensor on the surface of parathyroid cells is involved in Ca2+-regulated PTH secretion, limited trypsinization of bovine parathyroid cells was carried out. Treatment with trypsin (1·1–10 mg/ml) inhibited, in a dose-dependent manner, PTH secretion stimulated by lowering Cae2+ from 2·0 to 0·5 mmol/l. In control cells, activation of protein kinase C with 12-O-tetradecanoylphorbol-13-acetate (TPA) enhanced PTH secretion at 2·0 mmol Cae2+/1 but not at 0·5 mmol Cae2+/1. In trypsinized cells, however, TPA enhanced PTH secretion at both 0·5 and 2·0 mmol Cae2+/1. Isoproterenol-stimulated PTH secretion was maintained in trypsinized cells, but reduced cyclic AMP production revealed that some β-adrenergic receptors were destroyed. The cytosolic free Ca2+ concentration (Cai2+), as measured with fura-2, was raised within seconds in response to increasing Cae2+ from 0·5 to 2·0 mmol/l and was then lowered within 1 min to a sustained plateau; the changes were the same in trypsinized and control cells. In conclusion, trypsinization of parathyroid cells abolished Ca2+-regulated PTH secretion without affecting Cai2+. Journal of Endocrinology (1989) 122, 213–218

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Genistein Inhibits the Pathogenesis of Aeromonas hydrophila by Disrupting Quorum Sensing Mediated Biofilm Formation and Aerolysin Production

Frontiers in Pharmacology ◽

10.3389/fphar.2021.753581 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jing Dong ◽

Defu Zhang ◽

Jianrong Li ◽

Yongtao Liu ◽

Shun Zhou ◽

...

Keyword(s):

Quorum Sensing ◽

Aeromonas Hydrophila ◽

Biofilm Formation ◽

Cell Injury ◽

Foodborne Pathogen ◽

Opportunistic Pathogen ◽

Dependent Manner ◽

Novel Drugs ◽

Encoding Gene ◽

Dose Dependent

Aeromonas hydrophila is an opportunistic pathogen that is responsible for a variety of infectious diseases both in human and animals, particularly aquatic animals. Moreover, the pathogen has become a foodborne pathogen by transmitting from seafood to human. The abuse of antibiotics in aquaculture results in the emergence of antibiotic resistance and treatment failure. Therefore, novel approaches are urgently needed for managing resistant A. hydrophila associated infections. Aerolysin, an essential virulence factor of pathogenic A. hydrophila strain, has been identified as target developing novel drugs against pathogenesis of A. hydrophila. In the present study, genistein, without anti-A. hydrophila activity, was identified that could decrease the production of aerolysin and biofilm formation at a dose-dependent manner. Transcription of aerolysin encoding gene aerA and quorum sensing related genes ahyI and ahyR was significantly down-regulated when co-cultured with genistein. Cell viability studies demonstrated that genistein could significantly improve aerolysin mediated A549 cell injury. Furthermore, genistein could provide a remarkable protection to channel catfish infected with A. hydrophila. These findings indicate that targeting quorum sensing and virulence can be a useful approach developing drugs against A. hydrophila infections in aquaculture. Moreover, genistein can be chosen as a promising candidate in developing drugs against A. hydrophila.

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