Comparable antibacterial effects and action mechanisms of silver and iron oxide nanoparticles on Escherichia coli and Salmonella typhimurium

Abstract

The current research reports the antibacterial effects of silver (Ag) and citric acid coated iron oxide (Fe 3 O 4 ) NPs on Escherichia coli wild type and kanamycin-resistant strains, as well as on Salmonella typhimurium MDC1759. NPs demonstrated significant antibacterial activity against these bacteria, but antibacterial effect of Ag NPs is more pronounced at low concentrations. Ag NPs inhibited 60–90% of S. typhimurium and drug-resistant E. coli. The latter is more sensitive to Fe 3 O 4 NPs than wild type strain: the number of bacterial colonies is decreased ~ 4-fold. To explain possible mechanisms of NPs action, H + -fluxes through the bacterial membrane and the H + -translocating F O F 1 -ATPase activity of bacterial membrane vesicles were studied. N,N′- Dicyclohexylcarbodiimide (DCCD)-sensitive ATPase activity was increased up to ~ 1.5-fold in the presence of Fe 3 O 4 NPs. ATPase activity was not detected by Ag NPs even in the presence of DCCD, which confirms the bactericidal effect of these NPs. The H + -fluxes were changed by NPs and by addition of DCCD. H 2 yield was inhibited by NPs; the inhibition by Ag NPs is stronger than by Fe 3 O 4 NPs. NPs showed antibacterial effect in bacteria studied in concentration-dependent manner by changing in membrane permeability and membrane-bound enzyme activity. The F O F 1 -ATPase is suggested might be a target for NPs.

MAPLE Coatings Embedded with Essential Oil-Conjugated Magnetite for Anti-Biofilm Applications

“…The main antimicrobial mechanism of Eucalyptus globulus EO is the membrane cell damage and interference with proton pumps and electrolyte channels [ 105 , 106 ]. On the other hand, magnetite nanoparticles are known for their cell wall damage properties, as well as stimulation of the intracellular release of reactive oxygen species (ROS), which interfere with vital mechanisms, such as cell division and signaling [ 107 ]. Improved antimicrobial activity of synthetic [ 108 , 109 ] and natural [ 110 , 111 ] antibiotics were reported when conjugated with magnetite nanoparticles.…”

Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

“…The study of antibacterial activity of GS and ultrasound-treated Ag NPs was performed on S. typhimurium MDC1759 and S. aureus MDC5233 strains (Microbial Depository Center, National Academy of Science, Yerevan, Armenia). The mentioned strains were grown in Nutrient Broth (NB) media at 37 °C and pH 7.5 (Gabrielyan et al 2020 ). Anaerobic conditions were maintained as described (Gabrielyan et al 2020 ).…”

“…The high demand for Ag NPs is conditioned by the commercial utilization of Ag NPs in optics, electronics, catalysis, household items, and a broad range of medical applications (Ge et al 2014 ; Gabrielyan and Trchounian 2019 ). Ag NPs are known for their broad-spectrum antimicrobial and antiviral activities (Gabrielyan and Trchounian 2019 ; Gabrielyan et al 2020 ). These NPs are widely applied in different industries in the disinfection of ailments, water, medical instruments, etc.…”

Antibacterial Activity of Positively and Negatively Charged Hematite (α-Fe2O3) Nanoparticles to Escherichia coli, Staphylococcus aureus and Vibrio fischeri

“…During the past decade, iron oxide’s antimicrobial activity [ 3 , 5 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ] and the respective mechanism of action have been studied. Analogously to ecotoxic properties of iron oxide NPs, their antimicrobial properties are not comparable to powerful antimicrobials such as copper and silver compounds that act at a few mg/L levels [ 38 ].…”

“…Thus, there was more strong effect to E. coli (a gram-negative bacterium) than to E. hirae (a gram-positive bacterium), probably due to the differences in the bacterial cell wall structure. The same authors in their following paper reported more remarkable antibacterial effects of citric acid coated magnetite Fe 3 O 4 NPs towards E. coli : 250 mg/L of citric acid coated Fe 3 O 4 NPs inhibited the growth of E. coli by 2-fold (a bacteriostatic effect), whereas the kanamycin resistant E. coli was inhibited slightly more at up to 3-fold [ 43 ]. Almost similar results (MIC = 150 mg/L) were reported for hematite Fe 2 O 3 NPs towards E. coli and Vibrio cholerae [ 21 ].…”