caa a22 4500 605502706 CHVBK 20210128100607.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00253-015-6938-x doi (NATIONALLICENCE)springer-10.1007/s00253-015-6938-x Antimicrobial potentials of Helicteres isora silver nanoparticles against extensively drug-resistant (XDR) clinical isolates of Pseudomonas aeruginosa [Elektronische Daten] [Nikunj Mapara, Mansi Sharma, Varsha Shriram, Renu Bharadwaj, K. Mohite, Vinay Kumar] Pseudomonas aeruginosa is a leading opportunistic pathogen and its expanding drug resistance is a growing menace to public health. Its ubiquitous nature and multiple resistance mechanisms make it a difficult target for antimicrobial chemotherapy and require a fresh approach for developing new antimicrobial agents against it. The broad-spectrum antibacterial effects of silver nanoparticles (SNPs) make them an excellent candidate for use in the medical field. However, attempts made to check their potency against extensively drug-resistant (XDR) microbes are meager. This study describes the biosynthesis and biostabilization of SNPs by Helicteres isora aqueous fruit extract and their characterization by ultraviolet-visible spectroscopy, transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. Majority of SNPs synthesized were of 8--20-nm size. SNPs exhibited dose-dependent antibacterial activities against four XDR P. aeruginosa (XDR-PA) clinical isolates as revealed by growth curves, with a minimum inhibitory concentration of 300μg/ml. The SNPs exhibited antimicrobial activity against all strains, with maximum zone of inhibition (16.4mm) in XRD-PA-2 at 1000μg/ml. Amongst four strains, their susceptibilities to SNPs were in the following order: XDR-PA-2>XDR-PA-4>XDR-PA-3>XDR-PA-1. The exposure of bacterial cells to 300μg/ml SNPs resulted into a substantial leakage of reducing sugars and proteins, inactivation of respiratory chain dehydrogenases, and eventual cell death. SNPs also induced lipid peroxidation, a possible underlying factor to membrane porosity. The effects were more pronounced in XDR-PA-2 which may be correlated with its higher susceptibility to SNPs. These results are indicative of SNP-induced turbulence of membranous permeability as an important causal factor in XDR-PA growth inhibition and death. Springer-Verlag Berlin Heidelberg, 2015 Extensively drug resistant (XDR) nationallicence Pseudomonas aeruginosa nationallicence Helicteres isora nationallicence Silver nanoparticles nationallicence Antimicrobial agents nationallicence Bacterial membrane nationallicence Mapara Nikunj Department of Biotechnology, Modern College of Arts, Science and Commerce, S. P. Pune University, Ganeshkhind, 411 016, Pune, India aut Sharma Mansi Department of Biotechnology, Modern College of Arts, Science and Commerce, S. P. Pune University, Ganeshkhind, 411 016, Pune, India aut Shriram Varsha Department of Botany, Prof. Ramkrishna More Arts, Commerce and Science College, S. P. Pune University, Akurdi, 411044, Pune, India aut Bharadwaj Renu Department of Microbiology, B. J. Government Medical College, 411001, Pune, India aut Mohite K. School of Energy Studies, Department of Physics, Savitribai Phule Pune University, Ganeshkhind, 411007, Pune, India aut Kumar Vinay Department of Biotechnology, Modern College of Arts, Science and Commerce, S. P. Pune University, Ganeshkhind, 411 016, Pune, India aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/24(2015-12-01), 10655-10667 0175-7598 99:24<10655 2015 99 253 https://doi.org/10.1007/s00253-015-6938-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6938-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mapara Nikunj Department of Biotechnology, Modern College of Arts, Science and Commerce, S. P. Pune University, Ganeshkhind, 411 016, Pune, India aut NATIONALLICENCE 700 1- Sharma Mansi Department of Biotechnology, Modern College of Arts, Science and Commerce, S. P. Pune University, Ganeshkhind, 411 016, Pune, India aut NATIONALLICENCE 700 1- Shriram Varsha Department of Botany, Prof. Ramkrishna More Arts, Commerce and Science College, S. P. Pune University, Akurdi, 411044, Pune, India aut NATIONALLICENCE 700 1- Bharadwaj Renu Department of Microbiology, B. J. Government Medical College, 411001, Pune, India aut NATIONALLICENCE 700 1- Mohite K. School of Energy Studies, Department of Physics, Savitribai Phule Pune University, Ganeshkhind, 411007, Pune, India aut NATIONALLICENCE 700 1- Kumar Vinay Department of Biotechnology, Modern College of Arts, Science and Commerce, S. P. Pune University, Ganeshkhind, 411 016, Pune, India aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/24(2015-12-01), 10655-10667 0175-7598 99:24<10655 2015 99 253