Targeting Spore-Forming Bacteria: A Review on the Antimicrobial Potential of Selenium Nanoparticles

Abstract

Spore-forming bacterial species pose a serious threat to food plants and healthcare facilities that use high-temperature processing and sterilizing techniques to sanitize medical equipment and food items. These severe processing conditions trigger sporulation, which is the process by which spore-forming bacteria, such as those of the Bacillus and Clostridium species, begin to produce spores, which are extremely resilient entities capable of withstanding adverse environmental circumstances. Additionally, these spores are resistant to a wide range of disinfectants and antibacterial therapies, such as hydrolytic enzymes, radiation, chemicals, and antibiotics. Because of their ability to combat bacteria through several biological pathways, selenium nanoparticles (SeNPs) have emerged as an effective method for either eliminating or preventing the formation of spore-forming bacteria. This review aims to investigate every potential pathway of entry and mechanism by which SeNPs impact bacterial species that produce spores. Additionally, SeNPs' antibacterial efficacy against several infections is reviewed. To precisely explain the antibacterial mechanism of SeNPs and the various factors that can affect their effectiveness, more research is necessary.

Keywords: SeNPs’ mode of action; SeNPs’ oxidative stress; antibacterial SeNPs; spore inhibition mechanisms.

Figure 1

Summary of antibacterial mechanisms of SeNPs.

Figure 2

Mechanism of bacterial reduction of selenate/selenite into elemental selenium, Se.

Figure 3

Potential mechanisms for NP synthesis in probiotic bacteria include the following: (A) lactose-N-triose-dependent extracellular synthesis, (B) lipid-mediated synthesis associated with the bacterial membrane, (C) the enzymatic synthesis of NPs, and (D) the capsular exopolysaccharide (CPS)-associated reduction in the sugar-mediated synthesis of NPs. In these processes, key components include glycosyl glycosyl diacylglycerol (DGDG), tri glycosyl diacylglycerol (TGDG), and reduced nicotinamide adenine dinucleotide (NADH). CPS plays a significant role in reducing sugars that facilitate NP formation.

Figure 4

Mechanism of sporulation.

Figure 5

The antibacterial mechanisms of bio-SeNPs emphasize their capacity to enter the bacterial cell wall, damage the cell membrane, allow intracellular contents to seep out, prevent the formation of biofilms, and cause oxidative stress.