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

Dereje Damte

doi:10.4172/1948-5948.1000098

Abstract

Quorum sensing (QS) is a recently discovered chemical communication system that enhances survival of bacteria, as a group allowing resident bacteria to assume specialized roles vital for intra- and inter bacterial gene regulation, and for keeping bacterial colonies intact. Furthermore, with the continuing emergence and spread of multidrug-resistant bacteria, antipathogenic strategy to combat bacterial infections through the interruption of quorum sensing controlled virulence factors had been shown to receive increased attention. With this prospect in the current study, we attempt to screen anti-quorum sensing activity of 97 indigenous plant extracts from Korea, through biomonitor bacterial strains, Chromobacterium violaceum (CV12472) and Pseudomonas aeruginosa (PAO1). Standard disc-diffusion assays were used to detect anti-quorum sensing activity (ring of colorless, but viable cells around the disk), of the plant extracts for CV12472. A special swarm media that allow swarming motility growth of POA1 was used to conduct inhibition of swarming motility assay. Minimum Inhibitory Concentration (MIC) test for the 97 plant extracts against bioreporter strains (CV12472 and PAO1) revealed antibacterial activity of three plant extracts (Potentilla cryptotaeniae, Viburnum carlesii and Prunus armeniaca var. ansu). Out of the 97 plant extracts, significant inhibition of pigment production were detected by six plant extracts in CV12472, while 16 plant extracts had shown inhibition of swarming motility in POA1. In conclusion, a total of 18 plant extracts were screened for their anti-quorum sensing activity by the two bioreporter strains. Of the 18 plant extracts, four had shown anti-quorum activities in both bioreporter strains.

Highlights

The rising challenge paused by infectious bacterial drug resistance could be recognized from the loss of susceptibility observed in about 70% of the bacteria, that cause infections to a minimum of one drug among the routinely used treatment [1]
97 plant extracts (Table 1) were screened for anti-quorum sensing activities, out of which significant inhibition of pigment production were detected by six plant extracts (Table 2)
Besides the Minimum Inhibitory Concentration (MIC) test, additional experiments of disc diffusion assay at higher doses by all the 97 plant extract shown inhibition zones, only by the three plant extracts similar to the MIC test, indicating the tested plant extracts have less antibacterial effect on the growth of C. violaceum

Summary

Introduction

The rising challenge paused by infectious bacterial drug resistance could be recognized from the loss of susceptibility observed in about 70% of the bacteria, that cause infections to a minimum of one drug among the routinely used treatment [1]. Quorum sensing is a recently discovered chemical communication system that enhances survival of bacteria, as a group allowing resident bacteria to assume specialized roles vital for intra- and inter bacterial gene regulation, and for keeping bacterial colonies intact These involve several processes, such as specific signaling molecules that bind to and activate receptors that transduce the quorum-sensing signal into intracellular second messenger responses, in a similar fashion to ligand-receptor interaction [3]. Quorum-sensing inhibition offers new hope in combating resistant bacteria with inhibitor drugs that might have novel mechanisms of action, and could, be more effective against antibioticresistant strains of bacteria In this aspect, the already known quorum sensing inhibitor halogenated furanones from Delisea pulchra failed to pass for clinical therapeutic use due to its toxicity, and still there are no such drug inhibitors that are currently used clinically, the attempt is an indicative of the potential of the alternative option in combating antibiotic resistance and good example of proving this hypothesis [5]. We aim to screen antiquorum sensing activity of 97 indigenous plant extracts from Korea through biomonitor bacterial strains, Chromobacterium violaceum and Pseudomonas aeruginosa

Objectives

Methods

Results

Conclusion