Anti-quorum Sensing and Anti-biofilm Activity of Delftia tsuruhatensis Extract by Attenuating the Quorum Sensing-Controlled Virulence Factor Production in Pseudomonas aeruginosa

Abstract

Multidrug-resistance bacteria commonly use cell-to-cell communication that leads to biofilm formation as one of the mechanisms for developing resistance. Quorum sensing inhibition (QSI) is an effective approach for the prevention of biofilm formation. A Gram-negative bacterium, Delftia tsuruhatensis SJ01, was isolated from the rhizosphere of a species of sedge (Cyperus laevigatus) grown along the coastal-saline area. The isolate SJ01 culture and bacterial crude extract showed QSI activity in the biosensor plate containing the reference strain Chromobacterium violaceum CV026. A decrease in the violacein production of approximately 98% was detected with the reference strain C. violaceum CV026. The bacterial extract (strain SJ01) exhibited anti-quorum sensing activity and inhibited the biofilm formation of clinical isolates wild-type Pseudomonas aeruginosa PAO1 and P. aeruginosa PAH. A non-toxic effect of the bacterial extract (SJ01) was detected on the cell growth of the reference strains as P. aeruginosa viable cells were present within the biofilm. It is hypothesized that the extract (SJ01) may change the topography of the biofilm and thus prevent bacterial adherence on the biofilm surface. The extract also inhibits the motility, virulence factors (pyocyanin and rhamnolipid) and activity (elastase and protease) in P. aeruginosa treated with SJ01 extract. The potential active compound present was identified as 1,2-benzenedicarboxylic acid, diisooctyl ester. Microarray and transcript expression analysis unveiled differential expression of quorum sensing regulatory genes. The key regulatory genes, LasI, LasR, RhlI, and RhlR were down-regulated in the P. aeruginosa analyzed by quantitative RT-PCR. A hypothetical model was generated of the transcriptional regulatory mechanism inferred in P. aeruginosa for quorum sensing, which will provide useful insight to develop preventive strategies against the biofilm formation. The potential active compound identified, 1,2-benzenedicarboxylic acid, diisooctyl ester, has the potential to be used as an anti-pathogenic drug for the treatment of biofilm-forming pathogenic bacteria. For that, a detailed study is needed to investigate the possible applications.

The inhibitory activity of p-coumaric acid on quorum sensing and its enhancement effect on meat preservation

“…concentration of 0.2 mg/mL, while the control group had no significant colorless circle, thus the control disc without p-coumaric acid showed no violacein inhibition. Similar activity has been reported for carvacrol in inhibiting the production of violacein by C. violaceum (Tapia-Rodriguez et al, 2017). Recently, the anti-QS properties of several citrus flavonoids against E. coli, V. harveyi and P. aeruginosa have been reported (Vandeputte et al, 2011;Vikram, Jayaprakasha, Jesudhasan, Pillai, & Patil, 2010).…”

“…Bacterial quorum sensing is the cell to cell communication by producing the signaling molecules, autoinducers which confer the ability of controlling the gene expression through the detection of small signal molecules (Bai & Rai, 2011;Banerjee et al, 2017;Hentzer & Givskov, 2003;Jakobsen et al, 2012;Singh, Mishra, & Jha, 2017). Moreover, the quorum sensing regulates various bacterial behaviours, such as virulence factor production and motility (Harmsen, Yang, Pamp, & Tolker-Nielsen, 2010;Rahman, Lou, Yu, Wang, & Wang, 2017;Williams, 2007).…”

Cladodionen Is a Potential Quorum Sensing Inhibitor Against Pseudomonas aeruginosa

“…The severity of most of the P. aeruginosa infections in patients is correlated with biofilm formation. Moreover, biofilm formation is one of the mechanisms used by P. aeruginosa to develop drug resistant [2] related to QS systems [8]. The productions of biofilms decreased with increasing concentrations of cladodionen ( Figure 4).…”

“…Antibiotics cause enormous selective pressure by killing P. aeruginosa or inhibiting its growth, leading to the development of drug resistance in this bacterium. Virulence factors and multiple mechanisms, including the formation of a biofilm, are also used by P. aeruginosa to infect hosts and protect itself from environmental stress and antibiotics [2]. The production of virulence factors and the formation of biofilms are under the control of quorum sensing (QS), a process of cell-to-cell communication to regulate group behaviors [3].…”

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“…520 These bacteria regulate a diverse array of activities include symbiosis, antibiotic production, 521 motility, sporulation, virulence and formation of biofilms (Fuqua et al, 2001;Miller & Bassler, 522 2001;Singh et al, 2017).…”