Regulation of Enterococcus faecalis Biofilm Formation and Quorum Sensing Related Virulence Factors with Ultra-low Dose Reactive Species Produced by Plasma Activated Water

2018 ◽  
Vol 39 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Yinglong Li ◽  
Jie Pan ◽  
Dan Wu ◽  
Ying Tian ◽  
Jue Zhang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Enterococcus Faecalis ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Low Dose ◽  
Reactive Species ◽  
Plasma Activated Water

Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

2020 ◽  
Vol 26 ◽  
Author(s):  
Madison Tonkin ◽  
Shama Khan ◽  
Mohmmad Younus Wani ◽  
Aijaz Ahmad
Keyword(s):  
Drug Resistance ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Cell Communication ◽  
Natural Compounds ◽  
Quorum Sensing Inhibitors ◽  
Communication Technique ◽  
Multicellular Organisms ◽  
Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

scholarly journals Anti-quorum Sensing Potential of Ageratum Conyzoides L. (Asteraceae) Extracts

2021 ◽  
Author(s):  
Eli COMPAORE ◽  
Moussa COMPAORE ◽  
Vincent OUEDRAOGO ◽  
Ablassé ROUAMBA ◽  
Martin KIENDREBEOGO
Keyword(s):  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Methanolic Extract ◽  
Negative Impact ◽  
Significant Inhibition ◽  
High Morbidity ◽  
Ageratum Conyzoides ◽  
Phytochemical Content

Abstract Background: Pseudomonas aeruginosa causes infections in human particularly immunocompromised patients with cystic fibrosis, severe burns and HIV, resulting in high morbidity and mortality. The pathogenic bacteria P aeruginosa produces virulence factors regulated by the mechanism called quorum sensing system. Objective: The aim of this study was to assess the anti-quorum sensing activity of Ageratum conyzoides extracts Method: Chromobacterium violaceum reporter strain CV026 was used to highlight any interference with bacterium QS and strains derived from P. aeruginosa PAO1 were used to reveal any interference with the expression of quorum sensing genes, and to assess any impact of extract on the kinetics of the production of pyocyanin, elastases and biofilm formation. Results: Hydro-methanolic extract at the sub-inhibitory concentration of 100 μg/mL reduced quorum sensing virulence factors production such as, pyocyanin, elastases, rhamnolipids and biofilm formation in P. aeruginosa PAO1 after 18 hours monitoring. Extract showed significant inhibition in HSL-mediated violacein production on C. violaceum CV026 after 48 hours monitoring. Biofilm formation was inhibited up to 32%. It affected QS gene expression in PAO1. The regulatory genes lasR / rhlR and the lasI synthases were most affected. At 8hours, hydro-methanolic extract reduced both QS gene to more than 30% (lasI/lasR and rhlI/R respectively 33.8% /30.2% and 36% /33.2%). RhlA and lasB genes have been relatively affected (13.4% and 28.9%). After 18 h, this extract reduced significantly the expression of regulatory 30 genes lasR (31%) and rhlR (39.6%) although synthases genes seemed to be less affected (lasI/21.2% and rhlI/11.6%). A limited impact was observed on the downstream genes (lasB /20.0% and rhlA /15.3%). No negative impact was observed on CV026 and PAO1 growth and cell viability. Our study also showed that A. conyzoides having ample amount of phenolics, flavonoids and triterpenoids. This phytochemical content could be one of the factors for showing anti quorum potential. Conclusion: Results indicate that hydro methanol 80 % extract from A. conyzoides could be a source of potential QS inhibition compounds.

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

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.

scholarly journals Drosophila Host Model Reveals New Enterococcus faecalis Quorum-Sensing Associated Virulence Factors

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e64740 ◽  
Author(s):  
Neuza Teixeira ◽  
Sriram Varahan ◽  
Matthew J. Gorman ◽  
Kelli L. Palmer ◽  
Anna Zaidman-Remy ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Enterococcus Faecalis ◽  
Virulence Factors

scholarly journals Inhibition of Quorum Sensing in Pseudomonas aeruginosa by N-Acyl Cyclopentylamides

2007 ◽  
Vol 73 (10) ◽  
pp. 3183-3188 ◽  
Author(s):  
Takenori Ishida ◽  
Tsukasa Ikeda ◽  
Noboru Takiguchi ◽  
Akio Kuroda ◽  
Hisao Ohtake ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Ring Structure ◽  
Response Regulators ◽  
Maximal Inhibition ◽  
Sensing Systems ◽  
Reporter Assays

ABSTRACT N-Octanoyl cyclopentylamide (C8-CPA) was found to moderately inhibit quorum sensing in Pseudomonas aeruginosa PAO1. To obtain more powerful inhibitors, a series of structural analogs of C8-CPA were synthesized and examined for their ability to inhibit quorum sensing in P. aeruginosa PAO1. The lasB-lacZ and rhlA-lacZ reporter assays revealed that the chain length and the ring structure were critical for C8-CPA analogs to inhibit quorum sensing. N-Decanoyl cyclopentylamide (C10-CPA) was found to be the strongest inhibitor, and its concentrations required for half-maximal inhibition for lasB-lacZ and rhlA-lacZ expression were 80 and 90 μM, respectively. C10-CPA also inhibited production of virulence factors, including elastase, pyocyanin, and rhamnolipid, and biofilm formation without affecting growth of P. aeruginosa PAO1. C10-CPA inhibited induction of both lasI-lacZ by N-(3-oxododecanoyl)-l-homoserine lactone (PAI1) and rhlA-lacZ by N-butanoyl-l-homoserine lactone (PAI2) in the lasI rhlI mutant of P. aeruginosa PAO1, indicating that C10-CPA interferes with the las and rhl quorum-sensing systems via inhibiting interaction between their response regulators (LasR and RhlR) and autoinducers.

scholarly journals AHL-Lactonase Producing Psychrobacter sp. From Palk Bay Sediment Mitigates Quorum Sensing-Mediated Virulence Production in Gram Negative Bacterial Pathogens

2021 ◽  
Vol 12 ◽  
Author(s):  
Issac Abraham Sybiya Vasantha Packiavathy ◽  
Arunachalam Kannappan ◽  
Sivaprakasam Thiyagarajan ◽  
Ramanathan Srinivasan ◽  
Danaraj Jeyapragash ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Virulence Factors ◽  
Marine Sediment ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Proteinase K ◽  
Ring Cleavage ◽  
Heat Inactivation ◽  
Sediment Bacteria ◽  
Palk Bay

Quorum sensing (QS) is a signaling mechanism governed by bacteria used to converse at inter- and intra-species levels through small self-produced chemicals called N-acylhomoserine lactones (AHLs). Through QS, bacteria regulate and organize the virulence factors’ production, including biofilm formation. AHLs can be degraded by an action called quorum quenching (QQ) and hence QQ strategy can effectively be employed to combat biofilm-associated bacterial pathogenesis. The present study aimed to identify novel bacterial species with QQ potential. Screening of Palk Bay marine sediment bacteria for QQ activity ended up with the identification of marine bacterial isolate 28 (MSB-28), which exhibited a profound QQ activity against QS biomarker strain Chromobacterium violaceum ATCC 12472. The isolate MSB-28 was identified as Psychrobacter sp. through 16S-rRNA sequencing. Psychrobacter sp. also demonstrated a pronounced activity in controlling the biofilm formation in different bacteria and biofilm-associated virulence factors’ production in P. aeruginosa PAO1. Solvent extraction, heat inactivation, and proteinase K treatment assays clearly evidence the enzymatic nature of the bioactive lead. Furthermore, AHL’s lactone ring cleavage was confirmed with experiments including ring closure assay and chromatographic analysis, and thus the AHL-lactonase enzyme production in Psychrobacter sp. To conclude, this is the first report stating the AHL-lactonase mediated QQ activity from marine sediment bacteria Psychrobacter sp. Future work deals with the characterization, purification, and mass cultivation of the purified protein and should pave the way to assessing the feasibility of the identified protein in controlling QS and biofilm-mediated multidrug resistant bacterial infections in mono or multi-species conditions.

scholarly journals Trp-Containing Antibacterial Peptides Impair Quorum Sensing and Biofilm Development in Multidrug-Resistant Pseudomonas aeruginosa and Exhibit Synergistic Effects With Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Dejing Shang ◽  
Xue Han ◽  
Wanying Du ◽  
Zhiru Kou ◽  
Fengquan Jiang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Biofilm Development ◽  
Antibiotic Efflux

Pseudomonas aeruginosa uses quorum sensing (QS) to control virulence, biofilm formation and antibiotic efflux pump expression. The development of effective small molecules targeting the QS system and biofilm formation represents a novel attractive strategy. In this present study, the effects of a series of Trp-containing peptides on the QS-regulated virulence and biofilm development of multidrug-resistant P. aeruginosa, as well as their synergistic antibacterial activity with three classes of traditional chemical antibiotics were investigated. The results showed that Trp-containing peptides at low concentrations reduced the production of QS-regulated virulence factors by downregulating the gene expression of both the las and rhl systems in the strain MRPA0108. Biofilm formation was inhibited in a concentration-dependent manner, which was associated with extracellular polysaccharide production inhibition by downregulating pelA, algD, and pslA transcription. These changes correlated with alterations in the extracellular production of pseudomonal virulence factors and swarming motility. In addition, the combination of Trp-containing peptides at low concentration with the antibiotics ceftazidime and piperacillin provided synergistic effects. Notably, L11W and L12W showed the highest synergy with ceftazidime and piperacillin. A mechanistic study demonstrated that the Trp-containing peptides, especially L12W, significantly decreased β-lactamase activity and expression of efflux pump genes OprM, MexX, and MexA, resulting in a reduction in antibiotic efflux from MRPA0108 cells and thus increasing the antibacterial activity of these antibiotics against MRPA0108.

scholarly journals Study of quorum-sensing LasR and RhlR genes and their dependent virulence factors in Pseudomonas aeruginosa isolates from infected burn wounds

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Aya Ahmad Elnegery ◽  
Wafaa Kamel Mowafy ◽  
Tarek Ahmed Zahra ◽  
Noha Tharwat Abou El-Khier
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Proteolytic Activity ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Type Species ◽  
Assay Method ◽  
Content Type ◽  
Burn Wounds ◽  
Link Type

Background. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen responsible for burn-wound infection. High incidence, infection severity and increasing resistance characterize P. aeruginosa -induced burn infection. Purpose. To estimate quorum-sensing (QS)-dependent virulence factors of P. aeruginosa isolates from burn wounds and correlate it to the presence of QS genes. Methods. A cross-sectional descriptive study included 50 P . aeruginosa isolates from burn patients in Mansoura University Plastic and Burn Hospital, Egypt. Antibiotic sensitivity tests were done. All isolates were tested for their ability to produce biofilm using a micro-titration assay method. Protease, pyocyanin and rhamnolipid virulence factors were determined using skimmed milk agar, King’s A medium and CTAB agar test, respectively. The identity of QS lasR and rhlR genes was confirmed using PCR. Results. In total, 86 % of isolates had proteolytic activity. Production of pyocyanin pigment was manifested in 66 % of isolates. Altogether, 76 % of isolates were rhamnolipid producers. Biofilm formation was detected in 96 % of isolates. QS lasR and rhlR genes were harboured by nearly all isolates except three isolates were negative for both lasR and rhlR genes and two isolates were positive for lasR gene and negative for rhlR gene. Forty-nine isolates were considered as extremely QS-proficient strains as they produced QS-dependent virulence factors. In contrast, one isolate was a QS deficient strain. Conclusions. QS affects P. aeruginosa virulence-factor production and biofilm in burn wounds. Isolates containing lasR and rhlR seem to be a crucial regulator of virulence factors and biofilm formation in P. aeruginosa whereas the lasR gene positively regulates biofilm formation, proteolytic activity, pyocyanin production and rhamnolipid biosurfactant synthesis. The QS regulatory RhlR gene affects protease and rhamnolipid production positively.

scholarly journals Cephalosporins target quorum sensing and suppress virulence of Pseudomonas aeruginosa in Caenorhabditis elegans infection model

2020 ◽  
Author(s):  
Lokender Kumar ◽  
Nathanael Brenner ◽  
John Brice ◽  
Judith Klein-Seetharaman ◽  
Susanta K. Sarkar
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Caenorhabditis Elegans ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Host Cells ◽  
Infection Model ◽  
Host Immune System ◽  
Bacterial Cells

ABSTRACTPseudomonas aeruginosa utilizes a chemical social networking system referred to as quorum sensing (QS) to strategically co-ordinate the expression of virulence factors and biofilm formation. Virulence attributes damage the host cells, impair the host immune system, and protect bacterial cells from antibiotic attack. Thus, anti-QS agents may act as novel anti-infective therapeutics to treat P. aeruginosa infections. The present study was performed to evaluate the anti-QS, anti-biofilm, and anti-virulence activity of β-lactam antibiotics (carbapenems and cephalosporins) against P. aeruginosa. The anti-QS activity was quantified using Chromobacterium violaceum CV026 as a QS reporter strain. Our results showed that cephalosporins including cefepime (CP), ceftazidime (CF), and ceftriaxone (CT) exhibited potent anti-QS and anti-virulence activities against P. aeruginosa PAO1. These antibiotics significantly impaired motility phenotypes, decreased pyocyanin production, and reduced the biofilm formation by P. aeruginosa PAO1. In the present study, we studied isogenic QS mutants of PAO1: ΔLasR, ΔRhlR, ΔPqsA, and ΔPqsR and found that the levels of virulence factors of antibiotic-treated PAO1 were comparable to QS mutant strains. Molecular docking predicted high binding affinities of cephalosporins for the ligand-binding pocket of QS receptors (CviR, LasR, and PqsR). In addition, our results showed that the anti-microbial activity of aminoglycosides increased in the presence of sub-inhibitory concentrations (sub-MICs) of CP against P. aeruginosa PAO1. Further, utilizing Caenorhabditis elegans as an animal model for the in vivo anti-virulence effects of antibiotics, cephalosporins showed a significant increase in C. elegans survival by suppressing virulence factor production in P. aeruginosa. Thus, our results indicate that cephalosporins might provide a viable anti-virulence therapy in the treatment of infections caused by multi-drug resistant P. aeruginosa.

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