Evaluation of Anti-Quorum Sensing Activity of 97 Indigenous Plant Extracts From Korea through Bioreporter Bacterial Strains Chromobacterium violaceum and Pseudomonas aeruginosa

Author(s):  
Dereje Damte
2021 ◽  
Vol 5 (1) ◽  
pp. 009-018
Author(s):  
Dramane Paré ◽  
Jotham Yhi-pênê N’do ◽  
Vincent Ouédraogo ◽  
Abdel Magid Arsène Ouoba ◽  
Adama Hilou

The abuse of antibiotics has led to the widespread development of resistant bacterial strains, there is a need for the development of antimicrobial agents with new properties. Aim of this study was to determine the anti-quorum sensing potential (expression of virulence factor inhibition) of ethanolic extracts of S. birrea and S. setigera on Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. The ability of the extracts to inhibit the production of violacein by C. violaceum and the biofilm formation of Pseudomonas aeruginosa was examined to determine anti-quorum sensing activity. The phytochemical screening and the determination of total polyphenols and total flavonoids were carried out. The antioxidant activity of the extracts was measured using anti-free radical DPPH model and the reducing of the ferric ion capacity. For the inhibition of the production of violacein, S. setigera presented the best result with an inhibition of 70.19% compared to the negative control which is 1% DMSO. This inhibition is greater than that of ascorbic acid used as a reference. This species was also the most active on biofilm formation with an inhibition of 72.24% compared to the negative control, it thus showed greater activity than that of ascorbic acid used as a positive reference. The phytochemical study revealed the presence of tannin, flavonoids, triterpenes, saponosides, coumarin in our two extracts. S. birrea gave the best total polyphenol content with 326.05 ± 117.90 mg EAG / g of extract and showed the best result on the DPPH radical with an inhibition of 73.33 ± 1.46% which is statistically equal to that of gallic acid used as a reference. These extracts showed good antibacterial activity by inhibiting the quorum sensing system. Thus, they could therefore be used for the manufacture of anti-quorum sensing phytomedicines without a bactericidal effect.


2021 ◽  
Author(s):  
Nicole E Smalley ◽  
Amy L Schaefer ◽  
Kyle L Asfahl ◽  
Crystal Perez ◽  
E Peter Greenberg ◽  
...  

The bacterium Pseudomonas aeruginosa is an opportunistic pathogen and it thrives in many different saprophytic habitats. In this bacterium acyl-homoserine lactone quorum sensing (QS) can activate expression of over 100 genes, many of which code for extracellular products. P. aeruginosa has become a model for studies of cell-cell communication and coordination of cooperative activities. We hypothesized that long-term growth of bacteria under conditions where only limited QS-controlled functions were required would result in a reduction in the size of the QS-controlled regulon. To test this hypothesis, we grew P. aeruginosa for about 1000 generations in a condition in which expression of QS-activated genes is required for growth. We compared the QS regulons of populations after about 35 generations to those after about 1000 generations in two independent lineages by using quorum quenching and RNA-seq technology. In one evolved lineage the number of QS-activated genes identified was reduced by about 70% and in the other by about 45%. Our results lend important insights about the variations in the number of QS-activated genes reported for different bacterial strains and, more broadly, about the environmental histories of P. aeruginosa.


2018 ◽  
Author(s):  
◽  
Elizabeth Contreras Aguilar

En este trabajo de tesis doctoral se sintetizaron y caracterizaron cuatro familias de compuestos, las que se pueden describir como: i) carbonil isocianatos, ii) carbonil isotiocianatos, iii) carbonil ureidos y iv) carbonil tioureidos. El grupo isocianato está compuesto por enlaces dobles acumulados N=C y C=O. Gran parte de la reactividad de este grupo radica en la alta electronegatividad del oxígeno y del nitrógeno, lo cual hace que el carbono central sea altamente electrofílico, a la vez que el grupo concentra una alta densidad electrónica en sus enlaces pi. La alta reactividad química en solución acuosa de los isocianatos los hace particularmente tóxicos que se refleja en el efecto irritante directo sobre los pulmones, los ojos, la piel y la mucosa expuesta. Los efectos directos pueden ser instantáneos como en el caso de MIC (metilisocianato) o manifestarse después de un tiempo. Los polímeros derivados de isocianatos, que incluyen poliureas, poliisocianuratos y poliuretanos, resultan una de las aplicaciones más importantes. Esto se debe a la alta reactividad del grupo isocianato con cualquier molécula que contenga un hidrógeno activo, como por ejemplo alcoholes, aminas, agua y tioles. Para testear la potencial bioactividad de los nuevos (tio)ureidos estudiados en este trabajo, algunos de los compuestos obtenidos fueron evaluados por su inhibición de Quorum sensing (QS) en Pseudomonas aeruginosa y Chromobacterium violaceum.


Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 494 ◽  
Author(s):  
José Carlos Reina ◽  
Ignacio Pérez-Victoria ◽  
Jesús Martín ◽  
Inmaculada Llamas

The cell density-dependent mechanism, quorum sensing (QS), regulates the expression of virulence factors. Its inhibition has been proposed as a promising new strategy to prevent bacterial pathogenicity. In this study, 827 strains from the microbiota of sea anemones and holothurians were screened for their ability to produce quorum-sensing inhibitor (QSI) compounds. The strain M3-10, identified as Vibrio alginolyticus by 16S rRNA gene sequencing, as well as ANIb and dDDH analyses, was selected for its high QSI activity. Bioassay-guided fractionation of the cell pellet extract from a fermentation broth of strain M3-10, followed by LC–MS and NMR analyses, revealed tyramine and N-acetyltyramine as the active compounds. The QS inhibitory activity of these molecules, which was confirmed using pure commercially available standards, was found to significantly inhibit Chromobacterium violaceum ATCC 12472 violacein production and virulence factors, such as pyoverdine production, as well as swarming and twitching motilities, produced by Pseudomonas aeruginosa PAO1. This constitutes the first study to screen QSI-producing strains in the microbiota of anemones and holothurians and provides an insight into the use of naturally produced QSI as a possible strategy to combat bacterial infections.


2013 ◽  
Vol 44 (7) ◽  
pp. 488-494 ◽  
Author(s):  
Israel Castillo-Juárez ◽  
Rodolfo García-Contreras ◽  
Norma Velázquez-Guadarrama ◽  
Marcos Soto-Hernández ◽  
Mariano Martínez-Vázquez

2006 ◽  
Vol 74 (12) ◽  
pp. 7029-7031 ◽  
Author(s):  
Kazunori Gomi ◽  
Toshiaki Kikuchi ◽  
Yutaka Tokue ◽  
Shigeru Fujimura ◽  
Akiko Uehara ◽  
...  

ABSTRACT Chromobacterium violaceum produces autoinducers, including homoserine lactones (HSLs), for genetic regulation. Among the seven HSLs derived from C. violaceum we evaluated, only C12-HSL stimulated the production of inflammatory cytokines in mammalian monocytic cell lines through the activation of the NF-κB signaling pathway besides their quorum-sensing role, like 3-oxo-C12-HSL from Pseudomonas aeruginosa.


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