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Mycofabricated biosilver nanoparticles interrupt Pseudomonas aeruginosa quorum sensing systems.

Singh BR, Singh BN, Singh A, Khan W, Naqvi AH, Singh HB - Sci Rep (2015)

Bottom Line: Transcriptional studies demonstrated that mfAgNPs reduced the levels of LasIR-RhlIR.Further genes quantification analyses revealed that mfAgNPs significantly down-regulated QS-regulated genes, specifically those encoded to the secretion of virulence factors.The results clearly indicated the anti-virulence property of mfAgNPs by inhibiting P. aeruginosa QS signaling.

View Article: PubMed Central - PubMed

Affiliation: Centre of Excellence in Materials Science (Nanomaterials), Z.H. College of Engineering &Technology, Aligarh Muslim University, Aligarh-202002, India.

ABSTRACT
Quorum sensing (QS) is a chemical communication process that Pseudomonas aeruginosa uses to regulate virulence and biofilm formation. Disabling of QS is an emerging approach for combating its pathogenicity. Silver nanoparticles (AgNPs) have been widely applied as antimicrobial agents against human pathogenic bacteria and fungi, but not for the attenuation of bacterial QS. Here we mycofabricated AgNPs (mfAgNPs) using metabolites of soil fungus Rhizopus arrhizus BRS-07 and tested their effect on QS-regulated virulence and biofilm formation of P. aeruginosa. Transcriptional studies demonstrated that mfAgNPs reduced the levels of LasIR-RhlIR. Treatment of mfAgNPs inhibited biofilm formation, production of several virulence factors (e.g. LasA protease, LasB elastrase, pyocyanin, pyoverdin, pyochelin, rhamnolipid, and alginate) and reduced AHLs production. Further genes quantification analyses revealed that mfAgNPs significantly down-regulated QS-regulated genes, specifically those encoded to the secretion of virulence factors. The results clearly indicated the anti-virulence property of mfAgNPs by inhibiting P. aeruginosa QS signaling.

No MeSH data available.


Related in: MedlinePlus

Examination of mfAgNPs internalization into PAO1 cells by TEM.Red arrows indicate the accumulation of mfAgNPs inside the cells.
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f2: Examination of mfAgNPs internalization into PAO1 cells by TEM.Red arrows indicate the accumulation of mfAgNPs inside the cells.

Mentions: To examine the interaction between mfAgNPs with PAO1 cells, next we examined whether our synthesized NPs internalized into the cells of PAO1. For this, cells were treated with 25 μg/mL of mfAgNPs or distilled water (DW), as vehicle for 12 h, and then analyzed by TEM. A clear localization of the NPs into the cells was observed and PAO1 cells noticed as normal (Fig. 2). However, abnormal cells were observed, when exposed to 25 μg/mL of SBH-synthesized AgNPs which clearly indicate the toxicity of NPs.


Mycofabricated biosilver nanoparticles interrupt Pseudomonas aeruginosa quorum sensing systems.

Singh BR, Singh BN, Singh A, Khan W, Naqvi AH, Singh HB - Sci Rep (2015)

Examination of mfAgNPs internalization into PAO1 cells by TEM.Red arrows indicate the accumulation of mfAgNPs inside the cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562228&req=5

f2: Examination of mfAgNPs internalization into PAO1 cells by TEM.Red arrows indicate the accumulation of mfAgNPs inside the cells.
Mentions: To examine the interaction between mfAgNPs with PAO1 cells, next we examined whether our synthesized NPs internalized into the cells of PAO1. For this, cells were treated with 25 μg/mL of mfAgNPs or distilled water (DW), as vehicle for 12 h, and then analyzed by TEM. A clear localization of the NPs into the cells was observed and PAO1 cells noticed as normal (Fig. 2). However, abnormal cells were observed, when exposed to 25 μg/mL of SBH-synthesized AgNPs which clearly indicate the toxicity of NPs.

Bottom Line: Transcriptional studies demonstrated that mfAgNPs reduced the levels of LasIR-RhlIR.Further genes quantification analyses revealed that mfAgNPs significantly down-regulated QS-regulated genes, specifically those encoded to the secretion of virulence factors.The results clearly indicated the anti-virulence property of mfAgNPs by inhibiting P. aeruginosa QS signaling.

View Article: PubMed Central - PubMed

Affiliation: Centre of Excellence in Materials Science (Nanomaterials), Z.H. College of Engineering &Technology, Aligarh Muslim University, Aligarh-202002, India.

ABSTRACT
Quorum sensing (QS) is a chemical communication process that Pseudomonas aeruginosa uses to regulate virulence and biofilm formation. Disabling of QS is an emerging approach for combating its pathogenicity. Silver nanoparticles (AgNPs) have been widely applied as antimicrobial agents against human pathogenic bacteria and fungi, but not for the attenuation of bacterial QS. Here we mycofabricated AgNPs (mfAgNPs) using metabolites of soil fungus Rhizopus arrhizus BRS-07 and tested their effect on QS-regulated virulence and biofilm formation of P. aeruginosa. Transcriptional studies demonstrated that mfAgNPs reduced the levels of LasIR-RhlIR. Treatment of mfAgNPs inhibited biofilm formation, production of several virulence factors (e.g. LasA protease, LasB elastrase, pyocyanin, pyoverdin, pyochelin, rhamnolipid, and alginate) and reduced AHLs production. Further genes quantification analyses revealed that mfAgNPs significantly down-regulated QS-regulated genes, specifically those encoded to the secretion of virulence factors. The results clearly indicated the anti-virulence property of mfAgNPs by inhibiting P. aeruginosa QS signaling.

No MeSH data available.


Related in: MedlinePlus