Iranian Journal of Microbiology 2017. 9(1):26-32.

Inhibition of quorum sensing-controlled virulence factor production in Pseudomonas aeruginosa by Quercus infectoria gall extracts
Samaneh Mohabi, Davood Kalantar-Neyestanaki, Shahla Mansouri


Background and Objectives: This study was designed to evaluate the activity of Quercus infectoria galls extract (QIFGE) on virulence factor production and inhibition of quorum sensing (QS) in Pseudomonas aeruginosa.

Materials and Methods: Minimum inhibitory concentration (MIC) of QIFGE against 5 strains of P. aeruginosa was determined. The extract at sub-MIC was used to determine biofilm formation, level of protease LasA, LasB, swarming and twitching motility and QS using Chromobacterium violaceum CV026 as a biosensor. Effect of the extract on expression levels of lasR gene was determined by real time PCR.

Results: QIFGE inhibited the QS and all other tested virulence factors compared with the control grown in the absence of the extract (P=0.001). Real time PCR showed 2 to 8-fold reduction in lasR gene expression in presence of the extracts compared with the control. QIFGE significantly inhibited the virulence factor production, had inhibitory effect on QS, and resulted in the lower expression of lasR gene.

Conclusion: QIFGE showed novel inhibitory effect against QS related virulence factor production, which was unrelated to antimicrobial effect. The extract can down regulate the production of virulence factor and should be evaluated as a candidate for alternative treatment of pseudomonad infections in future.

Keywords: Pseudomonas aeruginosa, Quercus infectoria, Virulence Factor, Quorum Sensing, LasR gene, Chromobacterium violaceum


Pseudomonas aeruginosa, Quercus infectoria, Virulence Factor, Quorum Sensing, lasR gene, Chromobacterium violaceum

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- Breidenstein EBM, Fuente-Núñez DL, Hancock REW. Pseudomonas aeruginosa: All Roads Lead to Resistance. Trends Microbiol 2011 ; 119: 419-426.

- Lyczak JB , Cannon CL , Pier GB. Establishment of Pseudomonas aeruginosa infection: lessons from a versatile opportunist. Microbes Infect 2000; 2: 1051-1060.

- Emerson J, Rosenfeld M , Mcnamara S , Ramsey B , Gibson RL. Pseudomonas aeruginosa and other predictors of mortality and morbidity in young children with cystic fibrosis. Pediatr Pulmonol 2002; 34: 91-100.

- Pirnay JP, DE vos D, Cochez C, Bilocq F, Pirson J, Struelens M, et al. Molecular epidemiology of Pseudomonas aeruginosa colonization in a burn unit: persistence of a multidrug-resistant clone and a silver sulfadiazine-resistant clone. J Clin Microbiol 2003; 41: 1192-1202.

- Kong KF , Jayawardena SR , Indulkar SD , Del Puerto A , Koh CL , Høiby N , et al. Pseudomonas aeruginosa AmpR is a global transcriptional factor that regulates expression of AmpC and PoxB β-lactamases, proteases, quorum sensing, and other virulence factors. Antimicrob Agents Chemother 2005; 49: 4567-4575.

- Sifri DC. Quorum Sensing: Bacteria Talk Sense. Clin Infect Dis 2008; 47: 1070-1076.

- Wilder CN, Diggle SP, Schuster M. Cooperation and cheating in Pseudomonas aeruginosa: the roles of the las, rhl and pqs quorum-sensing systems. ISME J 2011; 5: 1332-1343.

- Gambello MJ , Kaye S, Iglewski BH. LasR of Pseudomonas aeruginosa is a transcriptional activator of the alkaline protease gene (apr) and an enhancer of exotoxin A expression. Infect Immun 1993; 61: 1180-1184.

- Oliver A , Mulet X , López-Causapé C, Juan C. The increasing threat of Pseudomonas aeruginosa high-risk clones. Drug Resist Update 2015; 21: 41-59.

- Adonizio A , Kong KF , Mathee K. Inhibition of quorum sensing-controlled virulence factor production in Pseudomonas aeruginosa by South Florida plant extracts. Antimicrob Agents Chemother. 2008;54: 198-203.

- Schauder S , Bassler B L . The languages of bacteria. Genes Dev. 2001. 15, 1468-1480.

- Husain F M , Ahmad I , Khan M S , Ahmad E , Tahseen Q , Khan MS , Alshabib N A. Sub-mics of mentha piperita essential oil and menthol inhibits AHL mediated quorum sensing and biofilm of Gram-negative bacteria. Front Microbiol. 2015 ;6: 420.

- Vattem D , Mihalik K , Crixell S , Mclean R . Dietary phytochemicals as quorum sensing inhibitors. Fitoterapia. 2007;78: 302-310.

- Singh B N , Singh H , Singh A , Singh B R , Mishra A , Nautiyal C. Lagerstroemia speciosa fruit extract modulates quorum sensing-controlled virulence factor production and biofilm formation in Pseudomonas aeruginosa. Microbiol 2012; 158:529-538.

- Shrestha S , Kaushik V S , Eshwarappa R S B , Subaramaihha S R, Ramanna L M , Lakkappa D B . Pharmacognostic Studies of Insect Gall of Quercus Infectoria Olivier (Fagaceae) Asian Pac J Trop Biomed. 2014; 4: 35-39.

-. Mansouri S , Safa A , Najar S G , Najar A G. Inhibitory activity of Iranian plant extracts on growth and biofilm formation by Pseudomona aeruoginosa. Malays J Microbiol. 2013; 9: 176-183.

- Medina‐Martínez M , Uyttendaele M , Meireman S , Debevere J. Relevance of N‐acyl‐L‐homoserine lactone production by Yersinia

-CLSI. Methods for dilution antimicrobial susceptibility tests for bacteria that grows aerobically, CLSI document M07-A9, Wayne, Pa, USA, Clinical and Laboratory Standards Institute. 2012

- Bradford M M. A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye Binding. Anal Biochem 1976; 7: 248-254.

- Köhler T , Curty l k , Barja F , Delden C V , Pechere J C. Swarming of Pseudomonas aeruginosa is dependent on cell-to-cell signaling and requires flagella and pili. J bacterial 2000; 182, 5990-5996.

- O'May C , Tufenkji N . The swarming motility of Pseudomonas aeruginosa is blocked by cranberry proanthocyanidins and other tannin-containing materials. Appl Environ Microbiol 2011; 77: 3061-3067.

- Déziel E , Comeau Y , Villemur R . Initiation of biofilm formation by Pseudomonas aeruginosa 57RP correlates with emergence of hyperpiliated and highly adherent phenotypic variants deficient in swimming, swarming, and twitching motilities. J Bacteriol 2001;183: 1195-1204.

- OToole G A , Kolter R . Initiation of biofilm formation in Pseudomonas fluorescens Wcs365 proceeds via Mmultiple, convergent signalling pathways: A genetic analysis. Mol Microbiol 1998; 28: 449-461.

- Fothergill J L, Daniel R N , Loman N , Winstanley C C , Kadioglu A. Pseudomonas aeruginosa adaptation in the nasopharyngeal reservoir leads to migration and persistence in the lungs. Nat Commun 2014; 5: 4780.

- Savli H , Karadenizli A , Kolayli F , Gundes S , Ozbek U , Vahaboglu H. Expression stability of six housekeeping genes: a proposal for resistance gene quantification studies of Pseudomonas aeruginosa by real-time quantitative RT-PCR. J Med Microbiol 2003; 52:403-408.

- Livak K J , Schmittgen T D. Analysis of relative gene expression data using real-time quantitative PCR and the 2− ΔΔCT method. Methods , 2001; 25: 402-408.

- Lee J , Zhang L. The hierarchy quorum sensing network in Pseudomonas aeruginosa. Protein Cell 2015; 6: 26-41.

- Davies D G , Parsek M R , Pearso J P , Iglewski B H , Costerton J T , Greenberg E .The involvement of cell-to-cell signals in the development of a bacterial biofilm. Science 1998; 10: 295-298.

- Fonseca AP, Extremina C, Fonseca AF, Sousa JC. Effect of Subinhibitory Concentration of Piperacillin/Tazobactam on Pseudomonas aeruginosa. J Med Microbiol. 53, 903-10.

- Pearson, J.P., Passador L., Iglewski B.H., Greenberg E.P., 1995. A second N-acylhomoserine lactone signal produced by Pseudomonas aeruginosa. Proc Natl Acad Sci 2004; 92: 1490-1494.


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