Silver Nanoparticles Offer Effective Control of Pathogenic Bacteria in a Wide Range of Food Products

Abstract

According to the Food and Agriculture Organization (FAO), food wastage still causes massive economic loss. A major role in this loss is played by the activities of microbial organisms. Treatments such as heat and irradiation can reduce microorganisms in fruits and vegetables and hence reduce postharvest loss. However, some of these treatments can injure the fruit. Effective chemical treatments against bacterial infestations can result in resistance. A more recent method is the use of silver nanoparticles. These can act in a number of ways including at cellular level by inhibiting the cell wall synthesis, by binding to the surface of the cell membrane and by interposing between the DNA base pairs, and by inhibiting biofilm formation, affecting the thiol group of enzymes, affecting bacterial peptides and hence interfering with cell signaling and attaching to the 30S ribosome subunit. A ground-breaking way to survey the effects of the silver nanoparticles on bacterial populations is by flow cytometry. It allows measurement of many characteristics of single cells, including their functional characteristics such as viability and cell cycle. Bacterial viability assays are used with great efficiency to evaluate antibacterial activity by evaluating the physical rupture of the membrane of the bacteria.

Metal nanoparticles against fungicide resistance: alternatives or partners?

“…Other modes of antimicrobial action of MNPs against plant pathogens include: protein/enzyme deactivation, production of reactive oxygen species and antioxidant depletion, disruption of ion homeostasis and DNA damage. 14 These mechanisms result from ion release or are NP-specific and are often interlinked, resulting in a multitargeted action ideal for effectively controlling plant pathogens. 4,15 Although MNPs share this multisite mode of action with their bulk/ionic metal counterparts, in the majority of cases MNPs exceed the efficacy of their counterparts against pathogens.…”

“…Positively charged MNPs adhere to the microbial cell membrane because of electrostatic attraction with the negatively charged cell membrane of microbes, damaging membrane integrity and eventually leading to cell death. Other modes of antimicrobial action of MNPs against plant pathogens include: protein/enzyme deactivation, production of reactive oxygen species and antioxidant depletion, disruption of ion homeostasis and DNA damage 14 . These mechanisms result from ion release or are NP‐specific and are often interlinked, resulting in a multitargeted action ideal for effectively controlling plant pathogens 4,15 .…”

Antibacterial Studying of Silver Nanoparticles Synthesized by Chemical Reduction Method Using Different Stabilized Concentrations

“…The cell wall of Gram-negative bacteria is narrower than that of Gram-positive strains. A thicker cell wall may reduce the penetration of nanoparticles into cells [24]. Alterations in the bacterial membrane could lead to the first bacterial contact with AgNP, triggering an antibacterial mechanism by facilitating the entry of AgNPs into bacterial cells.…”