Tackling Virulence of Pseudomonas aeruginosa by the Natural Furanone Sotolon

The bacterial resistance development due to the incessant administration of antibiotics has led to difficulty in their treatment. Natural adjuvant compounds can be co-administered to hinder the pathogenesis of resistant bacteria. Sotolon is the prevailing aromatic compound that gives fenugreek its typical smell. In the current work, the anti-virulence activities of sotolon on Pseudomonas aeruginosa have been evaluated. P. aeruginosa has been treated with sotolon at sub-minimum inhibitory concentration (MIC), and production of biofilm and other virulence factors were assessed. Moreover, the anti-quorum sensing (QS) activity of sotolon was in-silico evaluated by evaluating the affinity of sotolon to bind to QS receptors, and the expression of QS genes was measured in the presence of sotolon sub-MIC. Furthermore, the sotolon in-vivo capability to protect mice against P. aeruginosa was assessed. Significantly, sotolon decreased the production of bacterial biofilm and virulence factors, the expression of QS genes, and protected mice from P. aeruginosa. Conclusively, the plant natural substance sotolon attenuated the pathogenicity of P. aeruginosa, locating it as a plausible potential therapeutic agent for the treatment of its infections. Sotolon can be used in the treatment of bacterial infections as an alternative or adjuvant to antibiotics to combat their high resistance to antibiotics.

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Detection of Quorum-Sensing Molecules for Pathogenic Molecules Using Cell-Based and Cell-Free Biosensors

Antibiotics ◽

10.3390/antibiotics9050259 ◽

2020 ◽

Vol 9 (5) ◽

pp. 259 ◽

Cited By ~ 1

Author(s):

Craig Miller ◽

Jordon Gilmore

Keyword(s):

Quorum Sensing ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Genetic Material ◽

Treatment Strategies ◽

Signaling Molecules ◽

Resistant Bacteria ◽

Acute Infections

Since the discovery and subsequent use of penicillin, antibiotics have been used to treat most bacterial infections in the U.S. Over time, the repeated prescription of many antibiotics has given rise to many antibiotic-resistant microbes. A bacterial strain becomes resistant by horizontal gene transfer, where surviving microbes acquire genetic material or DNA fragments from adjacent bacteria that encode for resistance. In order to avoid significant bacterial resistance, novel and target therapeutics are needed. Further advancement of diagnostic technologies could be used to develop novel treatment strategies. The use of biosensors to detect quorum-sensing signaling molecules has the potential to provide timely diagnostic information toward mitigating the multidrug-resistant bacteria epidemic. Resistance and pathogenesis are controlled by quorum-sensing (QS) circuits. QS systems secrete or passively release signaling molecules when the bacterial concentration reaches a certain threshold. Signaling molecules give an early indication of virulence. Detection of these compounds in vitro or in vivo can be used to identify the onset of infection. Whole-cell and cell-free biosensors have been developed to detect quorum-sensing signaling molecules. This review will give an overview of quorum networks in the most common pathogens found in chronic and acute infections. Additionally, the current state of research surrounding the detection of quorum-sensing molecules will be reviewed. Followed by a discussion of future works toward the advancement of technologies to quantify quorum signaling molecules in chronic and acute infections.

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Multiple Mechanisms of the Synthesized Antimicrobial Peptide TS against Gram-Negative Bacteria for High Efficacy Antibacterial Action In Vivo

Molecules ◽

10.3390/molecules26010060 ◽

2020 ◽

Vol 26 (1) ◽

pp. 60

Author(s):

Rui Zhang ◽

Xiaobo Fan ◽

Xinglu Jiang ◽

Mingyuan Zou ◽

Han Xiao ◽

...

Keyword(s):

Antimicrobial Peptide ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Divalent Cations ◽

Resistant Bacteria ◽

Antibacterial Drug ◽

Gram Negative Bacteria ◽

Gram Negative

The emergence of drug-resistant bacteria emphasizes the urgent need for novel antibiotics. The antimicrobial peptide TS shows extensive antibacterial activity in vitro and in vivo, especially in gram-negative bacteria; however, its antibacterial mechanism is unclear. Here, we find that TS without hemolytic activity disrupts the integrity of the outer bacterial cell membrane by displacing divalent cations and competitively binding lipopolysaccharides. In addition, the antimicrobial peptide TS can inhibit and kill E. coli by disintegrating the bacteria from within by interacting with bacterial DNA. Thus, antimicrobial peptide TS’s multiple antibacterial mechanisms may not easily induce bacterial resistance, suggesting use as an antibacterial drug to be for combating bacterial infections in the future.

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Synergistic antibacterial activity of monoterpenes in combination with conventional antimicrobials against Gram-positive and Gram-negative bacteria

Revista de Ciências Médicas e Biológicas ◽

10.9771/cmbio.v19i2.33665 ◽

2020 ◽

Vol 19 (2) ◽

pp. 258

Author(s):

Maria Helena Pereira de Lira ◽

Gustavo Fernandes Queiroga Moraes ◽

Girlene Macena Santos ◽

Francisco Patrício de Andrade Júnior ◽

Fillipe De Oliveira Pereira ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Staphylococcus Epidermidis ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Inhibitory Concentration ◽

Synergistic Effects ◽

Public Health Problem ◽

New Drugs ◽

Gram Negative Bacteria ◽

Microdilution Method

Introduction: bacterial infections are a public health problem. Besides, the emergence of strains resistant to antimicrobials has contributed to the search for new alternatives, such for the terpenes with antimicrobial potential. Objectives: the objective of this study was to determine the possible interaction of isolated monoterpenes (-)-Carveol, Geraniol, Citronellol, α-terpineol, R-(-) Carvone, (-)-Menthol, Linalool, D-Dihydrocarvone, and (-)-Terpine-4-ol with conventional antimicrobials (Chloramphenicol, Minocycline, Amoxicillin and Ciprofloxacin) when they are evaluated on Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa strains. Methodology: the minimum inhibitory concentrations of these test drugs were determined using the microdilution method. The Checkerboard method was used to assess the interactions, by determining the fractional inhibitory concentration index (FIC index). Results: aamong the monoterpenes, only Carveol, Citronellol, and Geraniol presented antimicrobial activity (MIC < 1024 μg/mL). They presented synergistic effects against Pseudomonas aeruginosa ATCC-9027 (FIC index ≤ 0.5) when in combination with Minocycline. Conclusion: this study contributes to the development of new approaches to control bacterial resistance and to the possibility of discovering new drugs.

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On-demand pH-sensitive surface charge-switchable polymeric micelles for targeting Pseudomonas aeruginosa biofilms development

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00845-0 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Xiangjun Chen ◽

Rong Guo ◽

Changrong Wang ◽

Keke Li ◽

Xinyu Jiang ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Surface Charge ◽

Bacterial Resistance ◽

Polymeric Micelles ◽

Effective Means ◽

Ph Sensitive ◽

Bacterial Biofilm ◽

Mice Model ◽

On Demand

AbstractBacterial biofilm is the complicated clinical issues, which usually results in bacterial resistance and reduce the therapeutic efficacy of antibiotics. Although micelles have been drawn attention in treatment of the biofilms, the micelles effectively permeate and retain in biofilms still facing a big challenge. In this study, we fabricated on-demand pH-sensitive surface charge-switchable azithromycin (AZM)-encapsulated micelles (denoted as AZM-SCSMs), aiming to act as therapeutic agent for treating Pseudomonas aeruginosa (P. aeruginosa) biofilms. The AZM-SCSMs was composed of poly(l-lactide)-polyetherimide-hyd-methoxy polyethylene glycol (PLA-PEI-hyd-mPEG). It was noteworthy that the pH-sensitive acylhydrazone bond could be cleaved in acidic biofilm microenvironment, releasing the secondary AZM-loaded cationic micelles based on PLA-PEI (AZM-SCMs) without destroying the micellar integrity, which could tailor drug-bacterium interaction using micelles through electrostatic attraction. The results proved that positively charged AZM-SCMs could facilitate the enhanced penetration and retention inside biofilms, improved binding affinity with bacterial membrane, and added drug internalization, thus characterized as potential anti-biofilm agent. The excellent in vivo therapeutic performance of AZM-SCSMs was confirmed by the targeting delivery to the infected tissue and reduced bacterial burden in the abscess-bearing mice model. This study not only developed a novel method for construction non-depolymerized pH-sensitive SCSMs, but also provided an effective means for the treatment of biofilm-related infections.

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Treating Bacterial Infections with Bacteriophage-Based Enzybiotics: In Vitro, In Vivo, and Clinical Application

Antibiotics ◽

10.3390/antibiotics10121497 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1497

Author(s):

Katarzyna M. Danis-Wlodarczyk ◽

Daniel J. Wozniak ◽

Stephen T. Abedon

Keyword(s):

Bacterial Infections ◽

Bacterial Resistance ◽

High Efficiency ◽

Cross Resistance ◽

Resistant Bacteria ◽

Drug Classes ◽

Peptidoglycan Hydrolases ◽

Bacterial Peptidoglycan

Over the past few decades, we have witnessed a surge around the world in the emergence of antibiotic-resistant bacteria. This global health threat arose mainly due to the overuse and misuse of antibiotics as well as a relative lack of new drug classes in development pipelines. Innovative antibacterial therapeutics and strategies are, therefore, in grave need. For the last twenty years, antimicrobial enzymes encoded by bacteriophages, viruses that can lyse and kill bacteria, have gained tremendous interest. There are two classes of these phage-derived enzymes, referred to also as enzybiotics: peptidoglycan hydrolases (lysins), which degrade the bacterial peptidoglycan layer, and polysaccharide depolymerases, which target extracellular or surface polysaccharides, i.e., bacterial capsules, slime layers, biofilm matrix, or lipopolysaccharides. Their features include distinctive modes of action, high efficiency, pathogen specificity, diversity in structure and activity, low possibility of bacterial resistance development, and no observed cross-resistance with currently used antibiotics. Additionally, and unlike antibiotics, enzybiotics can target metabolically inactive persister cells. These phage-derived enzymes have been tested in various animal models to combat both Gram-positive and Gram-negative bacteria, and in recent years peptidoglycan hydrolases have entered clinical trials. Here, we review the testing and clinical use of these enzymes.

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Paeonol Attenuates Quorum-Sensing Regulated Virulence and Biofilm Formation in Pseudomonas aeruginosa

Frontiers in Microbiology ◽

10.3389/fmicb.2021.692474 ◽

2021 ◽

Vol 12 ◽

Author(s):

Dan Yang ◽

Suqi Hao ◽

Ling Zhao ◽

Fei Shi ◽

Gang Ye ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Resistant Bacteria ◽

Infection Model ◽

Dependent Manner ◽

Gram Negative ◽

C Elegans

With the prevalence of multidrug-resistant bacteria and clinical -acquired pathogenic infections, the development of quorum-sensing (QS) interfering agents is one of the most potential strategies to combat bacterial infections and antibiotic resistance. Chinese herbal medicines constitute a valuable bank of resources for the identification of QS inhibitors. Accordingly, in this research, some compounds were tested for QS inhibition using indicator strains. Paeonol is a phenolic compound, which can effectively reduce the production of violacein without affecting its growth in Chromobacterium violaceum ATCC 12472, indicating its excellent anti-QS activity. This study assessed the anti-biofilm activity of paeonol against Gram-negative pathogens and investigated the effect of paeonol on QS-regulated virulence factors in Pseudomonas aeruginosa. A Caenorhabditis elegans infection model was used to explore the anti-infection ability of paeonol in vivo. Paeonol exhibited an effective anti-biofilm activity against Gram-negative bacteria. The ability of paeonol to interfere with the AHL-mediated quorum sensing systems of P. aeruginosa was determined, found that it could attenuate biofilm formation, and synthesis of pyocyanin, protease, elastase, motility, and AHL signaling molecule in a concentration- and time-dependent manner. Moreover, paeonol could significantly downregulate the transcription level of the QS-related genes of P. aeruginosa including lasI/R, rhlI/R, pqs/mvfR, as well as mediated its virulence factors, lasA, lasB, rhlA, rhlC, phzA, phzM, phzH, and phzS. In vivo studies revealed that paeonol could reduce the pathogenicity of P. aeruginosa and enhance the survival rate of C. elegans, showing a moderate protective effect on C. elegans. Collectively, these findings suggest that paeonol attenuates bacterial virulence and infection of P. aeruginosa and that further research elucidating the anti-QS mechanism of this compound in vivo is warranted.

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Ethanol Extract Of Centella Asiatica (L.) Urban Leaves Effectively Inhibit Streptococcus pyogenes and Pseudomonas aeruginosa by Invitro Test

Tropical Health and Medical Research ◽

10.35916/thmr.v0i0.23 ◽

2020 ◽

Vol 2 (2) ◽

pp. 69-76

Author(s):

Dini Aulia Azmi ◽

Nurlailah Nurlailah ◽

Ratih Dewi Dwiyanti

Keyword(s):

Pseudomonas Aeruginosa ◽

Streptococcus Pyogenes ◽

Bacterial Infections ◽

Herbal Medicines ◽

Centella Asiatica ◽

Ethanol Extract ◽

Dilution Method ◽

Initial Stage ◽

Independent Variable

Streptococcus pyogenes and Pseudomonas aeruginosa are some of the causes of infectious diseases. Centella asiatica (L.) Urban has many benefits for humans, including overcoming fever, anti-bacterial, and anti-inflammatory. This study aims to determine the inhibition of Centella asiatica (L.) Urban leaves ethanol extract on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. This research is the initial stage of the development of herbal medicines to treat Streptococcus pyogenes and Pseudomonas aeruginosa infections. The independent variable was the concentration of ethanol extract of Centella asiatica (L.) Urban leaves and the dependent variable was the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. The anti-bacterial activity test was carried out by the liquid dilution method. The concentrations used are 20%, 40%, 60%, 80%. 100% The results showed that the minimum inhibitory concentration (MIC) against Streptococcus pyogenes: 40% and Pseudomonas aeruginosa: 40%. Minimum bactericidal concentration (MBC) results for Streptococcus pyogenes: 60% and Pseudomonas aeruginosa: 60%. So it can be concluded that there is inhibition of the ethanol extract of Centella asiatica (L.) Urban leaves on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. Centella Asiatica (L.) Urban extract has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.

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Baicalin Represses Type Three Secretion System of Pseudomonas aeruginosa through PQS System

Molecules ◽

10.3390/molecules26061497 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1497

Author(s):

Pansong Zhang ◽

Qiao Guo ◽

Zhihua Wei ◽

Qin Yang ◽

Zisheng Guo ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Virulence Factors ◽

Mammalian Cells ◽

Secretion System ◽

Chinese Herbs ◽

Infection Model ◽

Lung Pathology ◽

Promising Alternative ◽

The Impact

Therapeutics that target the virulence of pathogens rather than their viability offer a promising alternative for treating infectious diseases and circumventing antibiotic resistance. In this study, we searched for anti-virulence compounds against Pseudomonas aeruginosa from Chinese herbs and investigated baicalin from Scutellariae radix as such an active anti-virulence compound. The effect of baicalin on a range of important virulence factors in P. aeruginosa was assessed using luxCDABE-based reporters and by phenotypical assays. The molecular mechanism of the virulence inhibition by baicalin was investigated using genetic approaches. The impact of baicalin on P. aeruginosa pathogenicity was evaluated by both in vitro assays and in vivo animal models. The results show that baicalin diminished a plenty of important virulence factors in P. aeruginosa, including the Type III secretion system (T3SS). Baicalin treatment reduced the cellular toxicity of P. aeruginosa on the mammalian cells and attenuated in vivo pathogenicity in a Drosophila melanogaster infection model. In a rat pulmonary infection model, baicalin significantly reduced the severity of lung pathology and accelerated lung bacterial clearance. The PqsR of the Pseudomonas quinolone signal (PQS) system was found to be required for baicalin’s impact on T3SS. These findings indicate that baicalin is a promising therapeutic candidate for treating P. aeruginosa infections.

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Pseudomonas aeruginosa PAO 1 In Vitro Time–Kill Kinetics Using Single Phages and Phage Formulations—Modulating Death, Adaptation, and Resistance

Antibiotics ◽

10.3390/antibiotics10070877 ◽

2021 ◽

Vol 10 (7) ◽

pp. 877

Author(s):

Ana Mafalda Pinto ◽

Alberta Faustino ◽

Lorenzo M. Pastrana ◽

Manuel Bañobre-López ◽

Sanna Sillankorva

Keyword(s):

Pseudomonas Aeruginosa ◽

Phage Therapy ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Chronic Infections ◽

Swarming Motility ◽

Resistance Development ◽

Healthcare Settings ◽

Time Kill

Pseudomonas aeruginosa is responsible for nosocomial and chronic infections in healthcare settings. The major challenge in treating P. aeruginosa-related diseases is its remarkable capacity for antibiotic resistance development. Bacteriophage (phage) therapy is regarded as a possible alternative that has, for years, attracted attention for fighting multidrug-resistant infections. In this work, we characterized five phages showing different lytic spectrums towards clinical isolates. Two of these phages were isolated from the Russian Microgen Sextaphage formulation and belong to the Phikmvviruses, while three Pbunaviruses were isolated from sewage. Different phage formulations for the treatment of P. aeruginosa PAO1 resulted in diversified time–kill outcomes. The best result was obtained with a formulation with all phages, prompting a lower frequency of resistant variants and considerable alterations in cell motility, resulting in a loss of 73.7% in swimming motility and a 79% change in swarming motility. These alterations diminished the virulence of the phage-resisting phenotypes but promoted their growth since most became insensitive to a single or even all phages. However, not all combinations drove to enhanced cell killings due to the competition and loss of receptors. This study highlights that more caution is needed when developing cocktail formulations to maximize phage therapy efficacy. Selecting phages for formulations should consider the emergence of phage-resistant bacteria and whether the formulations are intended for short-term or extended antibacterial application.

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