Microbial biofilms are factions of surface-colonized cells encompassed in a matrix of extracellular polymeric substances. Profound application of antibiotics in order to treat infections due to microbial biofilm has led to the emergence of several drug-resistant microbial strains. In this context, a novel type of 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz)-capped silver nanoparticles (TzAgNPs) was synthesized, and efforts were given to test its antimicrobial and antibiofilm activities against Pseudomonas aeruginosa, a widely used biofilm-forming pathogenic organism. The synthesized TzAgNPs showed considerable antimicrobial activity wherein the MIC value of TzAgNPs was found at 40 μg/mL against Pseudomonas aeruginosa. Antibiofilm activity of TzAgNPs was also tested against Pseudomonas aeruginosa by carrying out an array of experiments like microscopic observation, crystal violet assay, and protein count using the sub-MIC doses of TzAgNPs. Since TzAgNPs showed efficient antibiofilm activity, thus, in the present study, efforts were put together to investigate the underlying cause of biofilm attenuation of Pseudomonas aeruginosa by using TzAgNPs. To this end, we discerned that the sub-MIC doses of TzAgNPs increased ROS level considerably in the bacterial cell. The result showed that the ROS level and microbial biofilm formation are inversely proportional. Thus, the attenuation in microbial biofilm could be attributed to the accumulation of ROS level. Furthermore, it was also duly noted that microorganisms upon treatment with TzAgNPs exhibited considerable diminution in virulence factors (protease and pyocyanin) in contrast to the control where the organisms were not treated with TzAgNPs. Thus, the results indicated that TzAgNPs exhibit considerable reduction in the development of biofilms and spreading of virulence factors. Taken together, all the results indicated that TzAgNPs could be deemed to be a promising agent for the prevention of microbial biofilm development that might assist to fight against infections linked to biofilm.

Department of Biotechnology Neotia Institute of Technology Management and Science Sarisha West Bengal 743368 India

Department of Biotechnology The Neotia University Sarisha West Bengal 743368 India

Department of Chemistry Indian Institute of Engineering Science and Technology Shibpur Howrah 711103 India

Department of Human Physiology Tripura University Suryamani Nagar Bikramnagar Tripura 799022 India

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Curr Opin Microbiol. 2009 Oct;12(5):482-9 PubMed

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J Bacteriol. 1990 Feb;172(2):884-900 PubMed

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PLoS One. 2014 Nov 17;9(11):e111289 PubMed

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Antimicrob Agents Chemother. 2001 Apr;45(4):999-1007 PubMed

J Appl Microbiol. 2016 Apr;120(4):842-59 PubMed

Bioconjug Chem. 2011 Nov 16;22(11):2263-70 PubMed

Chem Biol. 2012 Dec 21;19(12):1503-13 PubMed

J Clin Microbiol. 1999 Jun;37(6):1771-6 PubMed

Chem Rev. 2010 Jun 9;110(6):3299-314 PubMed

Nature. 2001 Oct 25;413(6858):860-4 PubMed

J Am Coll Nutr. 2003 Feb;22(1):18-35 PubMed

Antonie Van Leeuwenhoek. 2018 Jan;111(1):89-99 PubMed

J Biol Chem. 1951 Nov;193(1):265-75 PubMed

ACS Nano. 2012 Sep 25;6(9):8316-24 PubMed

FEMS Microbiol Lett. 2013 Jan;338(2):177-83 PubMed

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