Quorum sensing of pathogenic bacteria and quorum-sensing inhibitors

2012 ◽  
Vol 57 (21) ◽  
pp. 1964-1977 ◽  
Author(s):  
ZongHui YUAN ◽  
ZhenLi LIU ◽  
MengHong DAI ◽  
HaiHong HAO ◽  
GuYue CHENG
2006 ◽  
Vol 4 (2) ◽  
pp. 55-64
Author(s):  
NUR AINI ◽  
SUTARNO SUTARNO ◽  
ARI SUSILOWATI

Aeromonas hydrophila is pathogenic bacteria in fish. One of its virulence factors is exoprotease. The production of exoprotease is controlled by a quorum sensing system. Quorum sensing is an intercellular communication of bacteria that using a signal molecule of C4-HSL. The exoprotease production of A. hydrophila can be blocked by using quorum sensing inhibitors. The inhibition of quorum sensing of A. hydrophila can be conducted by C4-HSL analogs molecules. In this research, the molecules that predicted as quorum sensing inhibitors and act as C4-HSL analog molecules were furanone from tomato fruits. The inhibition of quorum sensing of A. hydrophila could be shown by a reduction of exoprotease production. The aim of this research was to determine the reduction of exoprotease production of A. hydrophila by extracts of n-hexane, ethyl acetate and methanol of tomato fruits with the concentrations of 0%, 2%, 4%, 6% and 8%, respectively. The qualitative exoprotease assay result showed that n-hexane extract of tomato had no effect on growth and exoprotease production of A. hydrophila. As much as 4% of ethyl acetate extract of tomato fruits could inhibit exoprotease production, but affect A. hydrophilla growth. Meanwhile, 4% methanol extract of tomato fruits could inhibit exoprotease production, without affect A. hydrophilla growth. The quantitative exoprotease assay result showed that 4% of methanol extract could inhibit exoprotease production by 71.68% without affect the growth of A. hydrophila.


2018 ◽  
Vol 62 ◽  
pp. 17-29
Author(s):  
A. Blouza ◽  
L. El Alaoui

In the present paper we propose a bi-dimensional non-linear reaction-diffusion model de-scribing the action of antibiotics as well as quorum sensing inhibitors agents on the virulence of bacteria biofilms. We thus approximate the system by a standard finite element scheme in space and an implicit Euler method in time. We prove the existence and uniqueness of a solution to this system and prove its convergence to a weak solution of the model we introduce. We present numerical results for simulating the quorum sensing of the very human pathogenic bacteria Pseudomenas aeruginosa.


2020 ◽  
Vol 26 ◽  
Author(s):  
Madison Tonkin ◽  
Shama Khan ◽  
Mohmmad Younus Wani ◽  
Aijaz Ahmad

: 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.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1620
Author(s):  
Victor Markus ◽  
Karina Golberg ◽  
Kerem Teralı ◽  
Nazmi Ozer ◽  
Esti Kramarsky-Winter ◽  
...  

Quorum sensing (QS), a sophisticated system of bacterial communication that depends on population density, is employed by many pathogenic bacteria to regulate virulence. In view of the current reality of antibiotic resistance, it is expected that interfering with QS can address bacterial pathogenicity without stimulating the incidence of resistance. Thus, harnessing QS inhibitors has been considered a promising approach to overriding bacterial infections and combating antibiotic resistance that has become a major threat to public healthcare around the globe. Pseudomonas aeruginosa is one of the most frequent multidrug-resistant bacteria that utilize QS to control virulence. Many natural compounds, including furanones, have demonstrated strong inhibitory effects on several pathogens via blocking or attenuating QS. While the natural furanones show no activity against P. aeruginosa, furanone C-30, a brominated derivative of natural furanone compounds, has been reported to be a potent inhibitor of the QS system of the notorious opportunistic pathogen. In the present study, we assess the molecular targets and mode of action of furanone C-30 on P. aeruginosa QS system. Our results suggest that furanone C-30 binds to LasR at the ligand-binding site but fails to establish interactions with the residues crucial for the protein’s productive conformational changes and folding, thus rendering the protein dysfunctional. We also show that furanone C-30 inhibits RhlR, independent of LasR, suggesting a complex mechanism for the agent beyond what is known to date.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Orit Malka ◽  
Dorin Kalson ◽  
Karin Yaniv ◽  
Reut Shafir ◽  
Manikandan Rajendran ◽  
...  

Abstract Background Probiotic milk-fermented microorganism mixtures (e.g., yogurt, kefir) are perceived as contributing to human health, and possibly capable of protecting against bacterial infections. Co-existence of probiotic microorganisms are likely maintained via complex biomolecular mechanisms, secreted metabolites mediating cell-cell communication, and other yet-unknown biochemical pathways. In particular, deciphering molecular mechanisms by which probiotic microorganisms inhibit proliferation of pathogenic bacteria would be highly important for understanding both the potential benefits of probiotic foods as well as maintenance of healthy gut microbiome. Results The microbiome of a unique milk-fermented microorganism mixture was determined, revealing a predominance of the fungus Kluyveromyces marxianus. We further identified a new fungus-secreted metabolite—tryptophol acetate—which inhibits bacterial communication and virulence. We discovered that tryptophol acetate blocks quorum sensing (QS) of several Gram-negative bacteria, particularly Vibrio cholerae, a prominent gut pathogen. Notably, this is the first report of tryptophol acetate production by a yeast and role of the molecule as a signaling agent. Furthermore, mechanisms underscoring the anti-QS and anti-virulence activities of tryptophol acetate were elucidated, specifically down- or upregulation of distinct genes associated with V. cholerae QS and virulence pathways. Conclusions This study illuminates a yet-unrecognized mechanism for cross-kingdom inhibition of pathogenic bacteria cell-cell communication in a probiotic microorganism mixture. A newly identified fungus-secreted molecule—tryptophol acetate—was shown to disrupt quorum sensing pathways of the human gut pathogen V. cholerae. Cross-kingdom interference in quorum sensing may play important roles in enabling microorganism co-existence in multi-population environments, such as probiotic foods and the gut microbiome. This discovery may account for anti-virulence properties of the human microbiome and could aid elucidating health benefits of probiotic products against bacterially associated diseases.


2012 ◽  
pp. 93-97 ◽  
Author(s):  
P. Truchado ◽  
F.A. Tomás-Barberán ◽  
A. Allende ◽  
A. Ponce

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