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

Abstract

Silver nanoparticles have been considered as powerful antimicrobial agents recently, especially with the increasing incidence of diseases associated with biofilm and multi-drug resistant pathogens. The aim of this study was to synthesize silver nanoparticles by biological and chemical methods and combination with imipenem to eradicate biofilm-forming bacteria at phenotypic and genotypic levels. The biosynthesis of silver nanoparticles was done by using Enterobacter cloacae (cell-free suspension) while chemosynthesis was conducted using sodium borohydride. Biological and chemical silver nanoparticles were characterized by ultraviolet-visible spectrophotometry which showed absorbance peak at 400 and 390nm respectively. Fourier transformer infrared analysis revealed that carboxylic and polyphenolic groups were coated on surface of both silver nanoparticles. Scanning electron microscope and size analyser showed that the sizes of biologically and chemically silver nanoparticles were 63 nm and 25 nm, respectively. In addition, it showed the formation of cubical nanoparticles. The antimicrobial effect of synthesized silver nanoparticles were evaluated by agar well diffusion and macrodilution method to determine minimum inhibitory concentration value. The results showed that biological silver nanoparticles were more effective on biofilm forming bacteria (Serratia fonticola and Pantoea sp.) than chemical synthesized ones. In addition, the combination effect between silver nanoparticles and imipenem displayed synergistic effect. Gene expression of biofilm encoding genes (smaI and esaL) were evaluated by real-time quantitative polymerase chain reaction (RT-qPCR) before and after treatment with silver nanoparticles in both types and imipenem and in combination between them. The results revealed that biological silver nanoparticles alone or in combination with antibiotics were more effective on biofilm gene expression by down regulation than other treatments.

Gamma Irradiation-Assisted Synthesis of Silver Nanoparticle and Their Antimicrobial Applications: A Review

“…Their antimicrobial properties [42][43][44] are widely used in medicine sector such as antibacterial sprays, medicine, wound dressings [45], respirators, and heart valves [46][47][48][49][50]. Ag-NPs have also exhibited antimalarial [51], antiviral [52], anticancer [53][54][55], anti-plasmodial [51], larvicidal [56], antifungal [57,54,42,58,59], biofilm forming bacteria [60,61], and pupicidal activity [62], disinfections, water and air purification, agriculture [63,64], etc. These properties of silver encourage its use in, cosmetics, clothing and numerous household products, contraconceptives, detergent, dietary supplements, cutting boards, socks, shoes, cell phones, laptop keyboards, and children's toys [65,66].…”

“…Green synthesis utilizing Citrullus lanatus fruit rind as a reductant and capping agent yields stable, spherical Ag-NPs with an average diameter of 17.96 ± 0.16 nm [110]. Ag-NCs reduced using NaBH4 showed the formation of cubical NCs with size range from 22-28 nm and 56-72 nm for biological synthesis [60]. Moosa et al also reported an increase in the size of silver kaolinite nanocomposites (Ag/Kln NCs) with the increase in silver nitrate concentration.…”

Antimicrobial Effect of Eco- Friendly Silver Nanoparticles Synthesis by Iraqi Date Palm (Phoenix dactylifera) on Gram-Negative Biofilm-Forming Bacteria

“…The biofilm-forming bacteria displayed antibiotics resistant patterns. Many studies approved that biofilm bacteria were multi-drug resistance bacteria (18,19,21,22). The reasons behind their resistance were antibiotics penetration difficulty(23), extracellular matrix act at shield and chelating agent (24) and low bacterial metabolic state (25).…”

“…But there is no study about date palm AgNPs antibacterial effect on biofilm-forming bacteria. Many studies about anti-biofilm activity of AgNPs synthesis by other methods showed a high response to be antibiofilm (30)(31)(32) . Antibacterial activity of green synthesis AgNPs in the present study may be related to attach to the surface of the cell membrane disturbing permeability and respiration functions of the cell (33).…”

Silver Nanoparticles as an Effective Anti-Nanobacterial System towards Biofilm Forming Pseudomonas oryzihabitans

“…Silver has long standing antibacterial compound, and silver nanoparticles are more potent in antimicrobial effect than normal scale [7,8]. Silver nanoparticles increase bacterial susceptibility to antibiotics when combined with them as synergistic effect especially in biofilm infection [9], for example, nitrofurazone increased its effect in silver present [10].…”