Insight into the Antibacterial Activity of Selected Metal Nanoparticles and Alterations within the Antioxidant Defence System in Escherichia coli, Bacillus cereus and Staphylococcus epidermidis

Abstract

The antimicrobial activity of nanoparticles (NPs) is a desirable feature of various products but can become problematic when NPs are released into different ecosystems, potentially endangering living microorganisms. Although there is an abundance of advanced studies on the toxicity and biological activity of NPs on microorganisms, the information regarding their detailed interactions with microbial cells and the induction of oxidative stress remains incomplete. Therefore, this work aimed to develop accurate oxidation stress profiles of Escherichia coli, Bacillus cereus and Staphylococcus epidermidis strains treated with commercial Ag-NPs, Cu-NPs, ZnO-NPs and TiO2-NPs. The methodology used included the following determinations: toxicological parameters, reactive oxygen species (ROS), antioxidant enzymes and dehydrogenases, reduced glutathione, oxidatively modified proteins and lipid peroxidation. The toxicological studies revealed that E. coli was most sensitive to NPs than B. cereus and S. epidermidis. Moreover, NPs induced the generation of specific ROS in bacterial cells, causing an increase in their concentration, which further resulted in alterations in the activity of the antioxidant defence system and protein oxidation. Significant changes in dehydrogenases activity and elevated lipid peroxidation indicated a negative effect of NPs on bacterial outer layers and respiratory activity. In general, NPs were characterised by very specific nano-bio effects, depending on their physicochemical properties and the species of microorganism.

Evaluation of the Effects of Ag, Cu, ZnO and TiO2 Nanoparticles on the Expression Level of Oxidative Stress-Related Genes and the Activity of Antioxidant Enzymes in Escherichia coli, Bacillus cereus and Staphylococcus epidermidis

“…Considering this, the increase in CAT activity in E. coli cells treated with NPs may result from stimulated HPI activity dependent on the presence of H 2 O 2 . This is in agreement with our previous findings, which revealed that the tested NPs, especially ZnO-NPs and Cu-NPs, induced the formation of H 2 O 2 along with other types of ROS in bacterial cells [40]. Additionally, a positive correlation between CAT and PER activity along with the expression of katG and katE genes was confirmed by statistical analysis.…”

“…•− [40]. Similarly, the increased relative expression level of katE in B. cereus under Cu-NPs exposure was associated with a stimulation of CAT activity.…”

Current Knowledge on the Oxidative-Stress-Mediated Antimicrobial Properties of Metal-Based Nanoparticles

“…Overall, Metryka and colleagues demonstrate that most of these NPs induce a strong production of all ROS (i.e., H 2 O 2 , •OH, 1 O 2 , O 2 • − ) mainly in S. epidermidis; while this increase is more contrasted in B. cereus and E. coli. Conversely, CuNPs seem to be the particles most likely to stimulate the production of ROS, regardless of the bacteria tested [87].…”

Ecotoxicological assessment of Zn, Cu and Ni based NPs contamination in Arenosols

“…The mechanism of the inhibitory effect of metal NPs on enzymes seems to be due to their interaction with sulfhydryl groups (Manceau et al, 2008;Metryka et al, 2021;Slavin et al, 2017). The degree of ecotoxicity of NPs depends not only on the dose but also on the class of the enzyme.…”