Leaf Extracts of Selected Gardening Trees Can Attenuate Quorum Sensing and Pathogenicity of Pseudomonas aeruginosa PAO1

Abstract

An increasing concern on resistance to multiple-antibiotics has led to the discovery of novel agents and the establishment of new precaution strategy. Numerous plant sources have been widely studied to reduce virulence of pathogenic bacteria by interfering cell-to-cell based communication called quorum sensing (QS). Leaf extracts of 17 gardening trees were collected and investigated for their anti-QS effects using a sensor strain CV026. Methanolic extracts of K4 (), K9 () and K13 () leaves were selected for further experiments based on their antagonism effect on QS without inhibiting CV026 growth. Subsequently, the leaf extracts on QS-mediated virulence of PAO1 involved in biofilm formation, motility, bioluminescence, pyocyanin production, QS molecules production, and killing activity were evaluated. The biofilm formation ability and swarming motility of PAO1 were decreased approximately 50% in the presence of these leaf extracts at a concentration of 1 mg/mL. The expression level of of PAO1 and pyocyanin production were also reduced. The three leaf extracts also decreased autoinducer (AI) production in PAO1 without direct degradation, suggesting that AI synthesis might have been suppressed by these extracts. The three leaf extracts also showed anti-infection activity in model. Taken together, these results suggest that methanolic leaf extracts of K4, K9 and K13 have the potential to attenuate the virulence of PAO1.

Inhibición de motilidad y Quorum sensing bacteriano por desechos de vinificación

“…Como se dijo anteriormente, un mecanismo de virulencia, dependiente de QS, es el movimiento de swarming en P. aeruginosa, el cual fue disminuido por los extractos polares de orujo y escobajo de vino Torrontés, en un rango del 44 al 67 %, mostrándose ligeramente más susceptible la cepa hospitalaria comparada con la cepa de referencia P. aeruginosa ATCC para ambas dosis ensayadas (250 µg/mL y 500 µg/mL). Análogamente, los extractos acuosos de Vaccinium angustifolium y Zingiber officinale, ricos en polifenoles, disminuyeron el swarming de P. aeruginosa PAO1 en un 50 y 53 %, respectivamente, a una concentración de 10 mg/mL [20,25]. Mientras que Huasin y colaboradores [21] informaron una disminución de la motilidad swarming P. aeruginosa PAO1 en un 74 % por acción de un extracto metanólico derivado de hojas de Magnifera indica a 800 µg/mL.…”

“…En este trabajo los extractos de orujo y escobajo de vino blanco disminuyeron notablemente la motilidad bacteriana de P. aeruginosa, lo cual coincide con los resultados obtenidos por Niu y colaboradores [25], que mostraron mayor efecto inhibitorio en la motilidad swarming que en el swimming y sugirieron que algunos compuestos presentes en los extractos metanólicos podrían tener la capacidad de suprimir la expresión de genes relacionados con la motilidad swarming. Asimismo, De Marco y colaboradores [26] informaron que los extractos hidroalcohólicos de propóleos y resinas de yemas de álamo fueron capaces de inhibir parcialmente el movimiento swimming de P. aeruginosa.…”

Pseudomonas aeruginosa Quorum Sensing and Biofilm Inhibition

“…The possible inhibitory effect of methanolic leaf extracts of Acer palmatum, Acer pseudosieboldianum, and Cercis chinensis were tested on biofilm formation, swarming motility, pyocyanin production, and Caenorhabditis elegans killing activity of P. aeruginosa PAO1. These extracts were found to be successful in the inhibition of biofilm formation, swarming motility, and AI production (Niu et al, 2017). Jakobsen et al (2012a) isolated ajoene (4,5,9-trithiadodeca-1,6,11-triene 9-oxide), the sulfurcontaining compound, from garlic extract.…”