Antibacterial activities of gold and silver nanoparticles against Escherichia coli and bacillus Calmette-Guérin

Abstract

BackgroundDiseases such as tuberculosis (TB) have always had a large impact on human health. Bacillus Calmette-Guérin (BCG) is used as a surrogate for TB during the development of anti-TB drugs. Nanoparticles (NPs) have attracted great interest in drug development. The purpose of this study was to examine the potential of NPs as anti-TB compounds by studying the interacting mechanisms between NPs and bacteria.ResultsWe investigated effects of gold and silver NPs on BCG and Escherichia coli. Experimentally, particle size and shape were characterized using transmission electron microscopy (TEM). Different concentrations of NPs were applied in bacterial culture. The growth of E. coli was monitored through colony forming units (CFU). The mechanism of interaction between NPs and bacteria was analyzed through bacterial thin sections followed by TEM and scanning electron microscopy. Antibacterial effects on BCG were observed by recording fluorescent protein expression levels.ConclusionsThe results suggest NPs have potential applications as anti-TB compounds. The antibacterial effects and mechanism of action for NPs were dependent upon composition and surface modifications.

Antiprotozoal effects of metal nanoparticles againstIchthyophthirius multifiliis

“…The antimicrobial activity of the nanoparticles is attributed to their attachment to microbial cell membranes, followed by alteration of membrane potential, decrease of ATP level and inhibition of tRNA binding to the ribosome (Cui et al 2012). However, particles can aggregate when weakly bound capping agents like citrate are used, which leads to reduced surface area and decreased interactions with the nanoparticles (Zhou et al 2012). In contrast, gold nanoparticles with the same shape and size but capped with strongly bound agent may exhibit enhanced antimicrobial properties (Zhou et al 2012;Dizaj et al 2014).…”

“…However, particles can aggregate when weakly bound capping agents like citrate are used, which leads to reduced surface area and decreased interactions with the nanoparticles (Zhou et al 2012). In contrast, gold nanoparticles with the same shape and size but capped with strongly bound agent may exhibit enhanced antimicrobial properties (Zhou et al 2012;Dizaj et al 2014). The antimicrobial activity of zinc oxide nanoparticles is due to contact between nanoparticles and pathogen cells, which alters surface charges and electrostatic interactions (Stoimenov et al 2002;Neal, 2008;Zhang et al 2010), leading to rupture of the cell membrane (Zhang et al 2007;Jiang et al 2009).…”

“…In aquaculture, metal and metal oxide nanoparticles exhibit effective antimicrobial properties against fish pathogens (Swain et al 2014), and have been utilized in water decontamination and as antimicrobial agents (Li et al 2008;Rana & Kalaichelvan, 2011;Saleh et al 2016;Shaalan et al 2016). Due to their nontoxicity, high ability for functionalization and polyvalent effects, gold nanoparticles are promising in the development of novel antimicrobial agents (Tiwari et al 2011;Zhou et al 2012;Lima et al 2013;Lolina & Narayanan, 2013;Saleh et al 2016). The antimicrobial activity of the nanoparticles is attributed to their attachment to microbial cell membranes, followed by alteration of membrane potential, decrease of ATP level and inhibition of tRNA binding to the ribosome (Cui et al 2012).…”

Synthesis and Characterization of Copolymeric and Terpolymeric Hydrogel-Silver Nanocomposites Based on Acrylic Acid, Acrylamide and Itaconic Acid: Investigation of Their Antibacterial Activity Against Gram-Negative Bacteria

“…In recent years, silver nanoparticles have been preferred because of their antimicrobial effect to fight against infection and diseases (Ravindra et al, 2012). Silver exhibits strong cytotoxicity for various microorganisms and it has been extensively used to control infections since ancient times (Travan et al, 2009;Pinto et al, 2009;Zhou et al, 2012). Metallic and ionic forms of silver have a bacteriostatic (growth inhibition) or a bactericidal (antibacterial) impact (Pinto et al, 2009).…”

In Vitro Study for Comparing the Cytotoxicity of Silver and Gold Nanospheres on Raw 264.7 Murine Macrophage Cell Line

“…Nano-based drug delivery systems have attracted the attention of many research groups, which concluded that metal nanoparticles as gold and silver could be promising noble nanomaterials in biomedicine and drug delivery [13][14][15]. However the gold and silver nanoparticles have shown antimicrobial activities against Gram-negative and Grampositive bacteria [16,17], they revealed antimycobacterial activities against extracellular TB [18]. Other different nanoparticles were investigated in vitro and in vivo as drug delivery vehicle for anti-TB drugs.…”