Synthesis of silver nanoparticles with antimicrobial and anti-adherence activities against multidrug-resistant isolates from Acinetobacter baumannii

Abstract

Objectives The spread of multidrug-resistant pathogens poses a major health threat. Silver nanoparticles represent a new-class of antimicrobial agents. The aim of this study is the microbial synthesis of silver nanoparticles and the evaluation of their antimicrobial and antibiofilm activities. Methods Silver nanoparticles were synthesized using cell free supernatants of Acinetobacter baumannii . Silver nanoparticles were characterized by particle size analysis and transmission electron microscopy (TEM), and the antimicrobial and antibiofilm activities of the synthesized silver nanoparticles were assessed. Results The silver nanoparticle synthesis was monitored primarily by the conversion of the pale yellow colour of the bacteria free supernatants into a dark brown colour. Silver nanoparticles had uniform spherical shape, with particle sizes ranging from 37 to 168 nm and a zeta potential of −11.7 mV. Acinetobacter silver nanoparticles were effective against multidrug-resistant Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae with minimal inhibitory concentrations of 3.1, 1.56 and 3.1 μg/ml, respectively. Moreover, acinetobacter silver nanoparticles significantly reduced the attachment activities of E. coli, P. aeruginosa and K. pneumoniae by 66.6%, 86.5% and 75%, respectively. Conclusion Silver nanoparticles, synthesized from Acinetobacter baumannii, inhibited microbial growth and eradicated biofilm assembly by multidrug-resistant isolates that were derived from uropathogenic infection. These results suggested the possibility of using silver nanoparticles as effective antimicrobial and antibiofilm agents against infections caused by resistant isolates.

In Vitro Human Microbiota Response to Exposure to Silver Nanoparticles Biosynthesized with Mushroom Extract

“…The SEM examination ( Figure 1 E) showed a homogeneous particle distribution with a roughly spherical geometry. The various sizes may result from the different time intervals when reduction was accomplished, which is in accordance with a previous study that was performed with cell-free supernatants of Acinetobacter baumannii [ 27 ]. The sizes and shapes of metal NPs are affected by various factors, including pH, time of incubation, precursor concentration, reductant concentration, temperature, and method of preparation [ 24 ].…”

Boosting Antimicrobial Activity of Imipenem in Combination with Silver Nanoparticles towards S. fonticola and Pantoea sp.

“…Antibacterial activity of silver NPs were evaluated by many previous studies [30,31], but fewer studies focused on the anti-biofilm activity of SNPs such as [32,33], and the comparative effect of both types (chemical and biological SNPs). Silver NPs were recorded to be anti-biofilm agents which were effective against biofilm bacteria formation, and were also most effective against multi-drug resistant bacteria, resulting from biofilm formation to solve most serious problem to worldwide public health [28,34,35]. Herein, the antimicrobial activity of chemo and biosynthesized SNPs on S. fonticola and Pantoea sp.…”

Silver Nanoparticles Synthesized by Using the Endophytic Bacterium Pantoea ananatis are Promising Antimicrobial Agents against Multidrug Resistant Bacteria

“…The consequences of these drug resistant infections would cost the world up to 100 trillion USD [20]. Research and development of new antibiotics are among the major interventions with a view to prevent and control the spread of AMR [3], however, several studies have suggested that AgNPs can be used in combating infections caused by MDR bacterial strains [21,22,23,24].…”