scholarly journals Dual bioresponsive antibiotic and quorum sensing inhibitor combination nanoparticles for treatment of Pseudomonas aeruginosa biofilms in vitro and ex vivo

2019 ◽  
Vol 7 (10) ◽  
pp. 4099-4111 ◽  
Author(s):  
Nishant Singh ◽  
Manuel Romero ◽  
Alessandra Travanut ◽  
Patricia F. Monteiro ◽  
Elena Jordana-Lluch ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Ex Vivo ◽  
Biofilm Growth ◽  
Quorum Sensing Inhibitor ◽  
Quorum Sensing Inhibitors ◽  
Inhibitor Combination

Nanoparticles combining Quorum Sensing Inhibitors and anti-bacterials can eradicate biofilm growth in vitro and ex vivo.

scholarly journals Effect of host-mimicking medium and biofilm growth on the ability of colistin to kill Pseudomonas aeruginosa

Microbiology ◽  
2020 ◽  
Vol 166 (12) ◽  
pp. 1171-1180 ◽  
Author(s):  
Esther Sweeney ◽  
Akshay Sabnis ◽  
Andrew M. Edwards ◽  
Freya Harrison
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ex Vivo ◽  
Clinical Success ◽  
Biofilm Growth ◽  
Content Type ◽  
The Matrix ◽  
Model Versus ◽  
High Doses

In vivo biofilms cause recalcitrant infections with extensive and unpredictable antibiotic tolerance. Here, we demonstrate increased tolerance of colistin by Pseudomonas aeruginosa when grown in medium that mimics cystic fibrosis (CF) sputum versus standard medium in in vitro biofilm assays, and drastically increased tolerance when grown in an ex vivo CF model versus the in vitro assay. We used colistin conjugated to the fluorescent dye BODIPY to assess the penetration of the antibiotic into ex vivo biofilms and showed that poor penetration partly explains the high doses of drug necessary to kill bacteria in these biofilms. The ability of antibiotics to penetrate the biofilm matrix is key to their clinical success, but hard to measure. Our results demonstrate both the importance of reduced entry into the matrix in in vivo-like biofilm, and the tractability of using a fluorescent tag and benchtop fluorimeter to assess antibiotic entry into biofilms. This method could be a relatively quick, cheap and useful addition to diagnostic and drug development pipelines, allowing the assessment of drug entry into biofilms, in in vivo-like conditions, prior to more detailed tests of biofilm killing.

scholarly journals Effect of host-mimicking medium and biofilm growth on the ability of colistin to kill Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Esther Sweeney ◽  
Akshay Sabnis ◽  
Andrew M. Edwards ◽  
Freya Harrison
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ex Vivo ◽  
Clinical Success ◽  
Biofilm Growth ◽  
The Matrix ◽  
Model Versus ◽  
High Doses ◽  
Fluorescent Tag

AbstractIn vivo biofilms cause recalcitrant infections with extensive and unpredictable antibiotic tolerance. Here, we demonstrate increased tolerance of colistin by Pseudomonas aeruginosa when grown in cystic fibrosis-mimicking medium versus standard medium in in vitro biofilm assays, and drastically increased tolerance when grown in an ex vivo CF model versus the in vitro assay. We used colistin conjugated to the fluorescent dye BODIPY to assess the penetration of the antibiotic into ex vivo biofilms and showed that poor penetration partly explains the high doses of drug necessary to kill bacteria in these biofilms. The ability of antibiotics to penetrate the biofilm matrix is key to their clinical success, but hard to measure. Our results demonstrate both the importance of reduced entry into the matrix in in vivo-like biofilm, and the tractability of using a fluorescent tag and benchtop fluorimeter to assess antibiotic entry into biofilms. This method could be a relatively quick, cheap and useful addition to diagnostic and R&D pipelines, allowing the assessment of drug entry into biofilms, in in vivo-like conditions, prior to more detailed tests of biofilm killing.

scholarly journals EnhancedIn VitroFormation and Antibiotic Resistance of Nonattached Pseudomonas aeruginosa Aggregates through Incorporation of Neutrophil Products

2014 ◽  
Vol 58 (11) ◽  
pp. 6851-6860 ◽  
Author(s):  
Silvia M. Caceres ◽  
Kenneth C. Malcolm ◽  
Jennifer L. Taylor-Cousar ◽  
David P. Nichols ◽  
Milene T. Saavedra ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Acquired Resistance ◽  
Biofilm Growth ◽  
Content Type ◽  
Viable Bacteria ◽  
And Function ◽  
Small Clusters

ABSTRACTPseudomonas aeruginosais a major pathogen in cystic fibrosis (CF) lung disease. Children with CF are routinely exposed toP. aeruginosafrom the natural environment, and by adulthood, 80% of patients are chronically infected.P. aeruginosain the CF airway exhibits a unique biofilm-like structure, where it grows in small clusters or aggregates of bacteria in association with abundant polymers of neutrophil-derived components F-actin and DNA, among other components. These aggregates differ substantially in size and appearance compared to surface-attachedin vitrobiofilm models classically utilized for studies but are believed to share properties of surface-attached biofilms, including antibiotic resistance. However, little is known about the formation and function of surface-independent modes of biofilm growth, how they might be eradicated, and quorum sensing communication. To address these issues, we developed a novelin vitromodel ofP. aeruginosaaggregates incorporating human neutrophil-derived products. Aggregates grownin vitroand those found in CF patients' sputum samples were morphologically similar; viable bacteria were distributed in small pockets throughout the aggregate. ThelasAquorum sensing gene was differentially expressed in the presence of neutrophil products. Importantly, aggregates formed in the presence of neutrophils acquired resistance to tobramycin, which was lost when the aggregates were dispersed with DNase, and antagonism of tobramycin and azithromycin was observed. This novel yet simplein vitrosystem advances our ability to model infection of the CF airway and will be an important tool to study virulence and test alternative eradication strategies againstP. aeruginosa.

scholarly journals An In Vitro Coumarin-Antibiotic Combination Treatment of Pseudomonas aeruginosa Biofilms

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Combination Treatment ◽  
Crude Extract ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Biofilm Growth ◽  
Antibiotic Combination

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.

scholarly journals A Novel Infection Protocol in Zebrafish Embryo to Assess Pseudomonas aeruginosa Virulence and Validate Efficacy of a Quorum Sensing Inhibitor In Vivo

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 401
Author(s):  
Pauline Nogaret ◽  
Fatima El El Garah ◽  
Anne-Béatrice Blanc-Potard
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Animal Model ◽  
Quorum Sensing ◽  
Drug Testing ◽  
Drug Efficacy ◽  
Embryo Viability ◽  
Immersion Method ◽  
Opportunistic Human Pathogen

The opportunistic human pathogen Pseudomonas aeruginosa is responsible for a variety of acute infections and is a major cause of mortality in chronically infected cystic fibrosis patients. Due to increased resistance to antibiotics, new therapeutic strategies against P. aeruginosa are urgently needed. In this context, we aimed to develop a simple vertebrate animal model to rapidly assess in vivo drug efficacy against P. aeruginosa. Zebrafish are increasingly considered for modeling human infections caused by bacterial pathogens, which are commonly microinjected in embryos. In the present study, we established a novel protocol for zebrafish infection by P. aeruginosa based on bath immersion in 96-well plates of tail-injured embryos. The immersion method, followed by a 48-hour survey of embryo viability, was first validated to assess the virulence of P. aeruginosa wild-type PAO1 and a known attenuated mutant. We then validated its relevance for antipseudomonal drug testing by first using a clinically used antibiotic, ciprofloxacin. Secondly, we used a novel quorum sensing (QS) inhibitory molecule, N-(2-pyrimidyl)butanamide (C11), the activity of which had been validated in vitro but not previously tested in any animal model. A significant protective effect of C11 was observed on infected embryos, supporting the ability of C11 to attenuate in vivo P. aeruginosa pathogenicity. In conclusion, we present here a new and reliable method to compare the virulence of P. aeruginosa strains in vivo and to rapidly assess the efficacy of clinically relevant drugs against P. aeruginosa, including new antivirulence compounds.

scholarly journals Antibiotic Resistance Evolution Is Contingent on the Quorum-Sensing Response in Pseudomonas aeruginosa

2019 ◽  
Vol 36 (10) ◽  
pp. 2238-2251 ◽  
Author(s):  
Sara Hernando-Amado ◽  
Fernando Sanz-García ◽  
José Luis Martínez
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Wild Type ◽  
Resistance Mutations ◽  
Epistatic Interactions ◽  
Adaptive Mutations ◽  
Resistance Evolution ◽  
Evolutionary Trajectories

Abstract Different works have explored independently the evolution toward antibiotic resistance and the role of eco-adaptive mutations in the adaptation to a new habitat (as the infected host) of bacterial pathogens. However, knowledge about the connection between both processes is still limited. We address this issue by comparing the evolutionary trajectories toward antibiotic resistance of a Pseudomonas aeruginosa lasR defective mutant and its parental wild-type strain, when growing in presence of two ribosome-targeting antibiotics. Quorum-sensing lasR defective mutants are selected in P. aeruginosa populations causing chronic infections. Further, we observed they are also selected in vitro as a first adaptation for growing in culture medium. By using experimental evolution and whole-genome sequencing, we found that the evolutionary trajectories of P. aeruginosa in presence of these antibiotics are different in lasR defective and in wild-type backgrounds, both at the phenotypic and the genotypic levels. Recreation of a set of mutants in both genomic backgrounds (either wild type or lasR defective) allowed us to determine the existence of negative epistatic interactions between lasR and antibiotic resistance determinants. These epistatic interactions could lead to mutual contingency in the evolution of antibiotic resistance when P. aeruginosa colonizes a new habitat in presence of antibiotics. If lasR mutants are selected first, this would constraint antibiotic resistance evolution. Conversely, when resistance mutations (at least those studied in the present work) are selected, lasR mutants may not be selected in presence of antibiotics. These results underlie the importance of contingency and epistatic interactions in modulating antibiotic resistance evolution.

scholarly journals Adaptive resistance of Pseudomonas aeruginosa induced by aminoglycosides and killing kinetics in a rabbit endocarditis model.

1997 ◽  
Vol 41 (4) ◽  
pp. 823-826 ◽  
Author(s):  
Y Q Xiong ◽  
J Caillon ◽  
M F Kergueris ◽  
H Drugeon ◽  
D Baron ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Single Dose ◽  
Ex Vivo ◽  
Day Treatment ◽  
Total Daily Dose ◽  
Once Daily ◽  
Adaptive Resistance ◽  
Dosing Regimens

Adaptive resistance following the first exposure to aminoglycosides is a recently described in vitro phenomenon in Pseudomonas aeruginosa and other aerobic gram-negative bacilli. We investigated the in vivo relevance of adaptive resistance in P. aeruginosa following a single dose of amikacin in the experimental rabbit endocarditis model. Rabbits with P. aeruginosa endocarditis received either no therapy (control) or a single intravenous (i.v.) dose of amikacin (80 mg/kg of body weight) at 24 h postinfection, after which they were sacrificed at 5, 8, 12, 16, or 24 h postdose. Excised aortic vegetations were subsequently exposed ex vivo to amikacin at 2.5, 5, 10 or 20 times the MIC for 90 min. In vivo adaptive resistance was identified when amikacin-induced pseudomonal killing within excised aortic vegetations was less in animals receiving single-dose amikacin in vivo than in vegetations from control animals not receiving amikacin in vivo. Maximal adaptive resistance occurred between 8 and 16 h after the in vivo amikacin dose, with complete refractoriness to ex vivo killing by amikacin seen at 12 h postdose. By 24 h postdose, bacteria within excised vegetations had partially recovered their initial amikacin susceptibility. In a parallel treatment study, we demonstrated that amikacin given once daily (but not twice daily) at a total dose of 80 mg/kg i.v. for 1-day treatment significantly reduced pseudomonal densities within aortic vegetations versus those in untreated controls. When therapy was continued for 3 days with the same total daily dose (80 mg/kg/day), amikacin given once or twice daily significantly reduced intravegetation pseudomonal densities versus those in controls. However, amikacin given once daily was still more effective than the twice-daily regimen. These data confirm the induction of aminoglycoside adaptive resistance in vivo and further support the advantages of once-daily aminoglycoside dosing regimens in the treatment of serious pseudomonal infections.

scholarly journals Calpurnia aurea (Aiton) Benth Extracts Reduce Quorum Sensing Controlled Virulence Factors in Pseudomonas aeruginosa

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2283
Author(s):  
Sekelwa Cosa ◽  
Jostina R. Rakoma ◽  
Abdullahi A. Yusuf ◽  
Thilivhali E. Tshikalange
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Molecular Docking ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Promising Alternative ◽  
The Individual

Pseudomonas aeruginosa is the causative agent of several life-threatening human infections. Like many other pathogens, P. aeruginosa exhibits quorum sensing (QS) controlled virulence factors such as biofilm during disease progression, complicating treatment with conventional antibiotics. Thus, impeding the pathogen’s QS circuit appears as a promising alternative strategy to overcome pseudomonas infections. In the present study, Calpurnia aurea were evaluated for their antibacterial (minimum inhibitory concentrations (MIC)), anti-quorum sensing/antivirulence (AQS), and antibiofilm potential against P. aeruginosa. AQS and antivirulence (biofilm formation, swimming, and swarming motility) activities of plant extracts were evaluated against Chromobacterium violaceum and P. aeruginosa, respectively. The in vitro AQS potential of the individual compounds were validated using in silico molecular docking. Acetone and ethanolic extracts of C. aurea showed MIC at 1.56 mg/mL. The quantitative violacein inhibition (AQS) assay showed ethyl acetate extracts as the most potent at a concentration of 1 mg/mL. GCMS analysis of C. aurea revealed 17 compounds; four (pentadecanol, dimethyl terephthalate, terephthalic acid, and methyl mannose) showed potential AQS through molecular docking against the CviR protein of C. violaceum. Biofilm of P. aeruginosa was significantly inhibited by ≥60% using 1-mg/mL extract of C. aurea. Confocal laser scanning microscopy correlated the findings of crystal violet assay with the extracts significantly altering the swimming motility. C. aurea extracts reduced the virulence of pseudomonas, albeit in a strain- and extract-specific manner, showing their suitability for the identification of lead compounds with QS inhibitory potential for the control of P. aeruginosa infections.

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