Gum arabic capped‐silver nanoparticles inhibit biofilm formation by multi‐drug resistant strains of Pseudomonas aeruginosa

Abstract

Clinical isolates (n = 55) of Pseudomonas aeruginosa were screened for the extended spectrum β-lactamases and metallo-β-lactamases activities and biofilm forming capability. The aim of the study was to demonstrate the antibiofilm efficacy of gum arabic capped-silver nanoparticles (GA-AgNPs) against the multi-drug resistant (MDR) biofilm forming P. aeruginosa. The GA-AgNPs were characterized by UV-spectroscopy, X-ray diffraction, and high resolution-transmission electron microscopy analysis. The isolates were screened for their biofilm forming ability, using the Congo red agar, tube method and tissue culture plate assays. The biofilm forming ability was further validated and its inhibition by GA-AgNPs was demonstrated by performing the scanning electron microscopy (SEM) and confocal laser scanning microscopy. SEM analysis of GA-AgNPs treated bacteria revealed severely deformed and damaged cells. Double fluorescent staining with propidium iodide and concanavalin A-fluorescein isothiocyanate concurrently detected the bacterial cells and exopolysaccharides (EPS) matrix. The CLSM results exhibited the GA-AgNPs concentration dependent inhibition of bacterial growth and EPS matrix of the biofilm colonizers on the surface of plastic catheters. Treatment of catheters with GA-AgNPs at 50 µg ml(-1) has resulted in 95% inhibition of bacterial colonization. This study elucidated the significance of GA-AgNPs, as the next generation antimicrobials, in protection against the biofilm mediated infections caused by MDR P. aeruginosa. It is suggested that application of GA-AgNPs, as a surface coating material for dispensing antibacterial attributes to surgical implants and implements, could be a viable approach for controlling MDR pathogens after adequate validations in clinical settings.

Silver Nanocomposite Biosynthesis: Antibacterial Activity against Multidrug-Resistant Strains of Pseudomonas aeruginosa and Acinetobacter baumannii

“…The effect of AgNPs against Gram-negative and Gram-positive bacteria can be interesting in the treatment, prophylaxis and control of infectious microbial diseases. Moreover, these properties also affect multidrug-resistant microorganisms, according to our results and other published works [23,25,28]. As shown in Figure 2, The biosynthesis of AgNPs, with sizes between 5-40 nm and~9.1 nm, and their stabilization with xanthan gum, had already been reported by Xu et al and Emam and Zahran, respectively [14,21].…”

“…The effect of AgNPs against Gram-negative and Gram-positive bacteria can be interesting in the treatment, prophylaxis and control of infectious microbial diseases. Moreover, these properties also affect multidrug-resistant microorganisms, according to our results and other published works [23,25,28]. As shown in Figure 2, the silver nanocomposite inhibited the growth of A. baumannii and P. aeruginosa multidrug-resistant clinical strains.…”

“…According to different authors, AgNPs at a concentration lower than 50 µg/mL have a potential inhibition against Gram-positive and Gram-negative strains [25,26].…”

Nanomedicine opened new horizons for metal nanoparticles to treat multi-drug resistant organisms

“…The anti-biofilm activity of metal nanoparticles was also demonstrated in other studies mainly focused on bacteria showing resistance to conventional antibiotics (88,89). The biofilm formation by methicillin resistant S. aureus (MRSA) and methicillin resistant S. epidermidis (MRSE) isolated from infected wounds was also analyzed by confocal laser scanning microscopy (CLSM) techniques which provided concrete evidence of the ability of NPs to block bacterial growth and to prevent the glycocalyx formation.…”

Antibiotic Effect on Planktonic and Biofilm-Producing Staphylococci

“…Some substances, including silver nanoparticles, have been used to decrease biofilm formation [12]. These 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, thereby preventing biofilm formation [13].…”