Antibiofilm efficacy of silver nanoparticles against biofilm of extended spectrum β-lactamase isolates of Escherichia coli and Klebsiella pneumoniae

Abstract

The ability of bacteria to develop antibiotic resistance and colonize abiotic surfaces by forming biofilms is a major cause of medical implant-associated infections and results in prolonged hospitalization periods and patient mortality. Different approaches have been used for preventing biofilm-related infections in health care settings. Many of these methods have their own demerits that include chemical-based complications; emergent antibiotic-resistant strains, and so on. Silver nanoparticles (AgNPs) are renowned for their influential antimicrobial activity. We demonstrate the biofilm formation by extended spectrum b-lactamases-producing Escherichia coli and Klebsiella spp. by direct visualization applying tissue culture plate, tube, and Congo red agar methods. Double fluorescent staining for confocal laser scanning microscopy (CLSM) consisted of propidium iodide staining to detect bacterial cells and concanavalin A-fluorescein isothiocyanate staining to detect the exopolysaccharides matrix were used. Scanning electron microscopy observations clearly indicate that AgNPs reduced the surface coverage by E. coli and Klebsiella spp. thus prevent the biofilm formations. Double-staining technique using CLSM provides the visual evidence that AgNPs arrested the bacterial growth and prevent the exopolysaccharides formation. The AgNPs-coated surfaces effectively restricted biofilm formation of the tested bacteria. In our study, we could demonstrate the complete antibiofilm activity AgNPs at a concentration as low as 50 lg/ml. Our findings suggested that AgNPs can be exploited towards the development of potential antibacterial coatings for various biomedical and environmental applications. These formulations can be used for the treatment of drug-resistant bacterial infections caused by biofilms, at much lower nanosilver loading with higher efficiency.

Crataeva nurvala nanoparticles inhibit virulence factors and biofilm formation in clinical isolates of Pseudomonas aeruginosa

“…Furthermore, Masurkar et al [48] reported antibiofilm activity of green synthesized silver nanoparticles (32 nm) from the plant cymbopogan citratus. Ansari et al [49,50] also reported the inhibition of biofilm formation by silver nanoparticles. Our study highlights a novel approach of using Bark extract mediated silver nanoparticles on the QS linked virulence factors as antipathogenic agents.…”

Anti-biofilm efficacy of silver nanoparticles against MRSA and MRSE isolated from wounds in a tertiary care hospital

“…[34] Moreover, nanoparticles have a higher capacity to attach to and penetrate bacterial membranes and accumulate inside cells, providing a continuous release of silver ions inside the cell. [35][36][37] …”

Combination of essential oil and ciprofloxacin to inhibit/eradicate biofilms in multidrug-resistant Klebsiella pneumoniae

“…Scanning electron microscopy (SEM) was employed for investigating the effect of thyme oil, peppermint oil, thymol, menthol and bromelain enzyme on KP biofilm. Sections of the interior of polystyrene tubes coated with bacterial biofilm were processed similarly with the method described by Ansari et al (2013) with modifications. Briefly, samples were fixed for 2 h in equal volumes of 4% (v/v) glutaraldehyde and 0Á2 mole ml À1 caccodylate, and washed in equal volumes of 0Á4 mole ml À1 saccharose and 0Á2 mole ml À1 caccodylate for 2 h and then postfixed in 2% (w/v) osmium tetroxide (Carl Roth, Karlsruhe, Germany) and 0Á3 mole ml À1 caccodylate for 1 h. The samples were washed with deionized water and finally dehydrated in ascending grades of ethanol for 5 min each (30, 50, 70, 90%) and finally 100% absolute ethanol for 10 min three times, then examined with Philips XL30 scanning electron microscope (Eindhoven, the Netherlands) operated at 20 kV.…”