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

Abstract

Although the molecular response of bacteria exposed to metal nanoparticles (NPs) is intensively studied, many phenomena related to their survival, metal uptake, gene expression and protein production are not fully understood. Therefore, this work aimed to study Ag-NPs, Cu-NPs, ZnO-NPs and TiO2-NPs-induced alterations in the expression level of selected oxidative stress-related genes in connection with the activity of antioxidant enzymes: catalase (CAT), peroxidase (PER) and superoxide dismutase (SOD) in Escherichia coli, Bacillus cereus and Staphylococcus epidermidis. The methodology used included: the extraction of total RNA and cDNA synthesis, the preparation of primers for selected housekeeping and oxidative stress genes, RT-qPCR reaction and the measurements of CAT, PER and SOD activities. It was established that the treatment of E. coli and S. epidermidis with NPs resulted mainly in the down-regulation of targeted genes, whilst the up-regulation of genes was confirmed in B. cereus. The greatest differences in the relative expression levels of tested genes occurred in B. cereus and S. epidermidis treated with TiO2-NPs, while in E. coli, they were observed under ZnO-NPs exposure. The changes found were mostly related to the expression of genes encoding proteins with PER and CAT-like activity. Among NPs, ZnO-NPs and Cu-NPs increased the activity of antioxidants in E. coli and B. cereus. In turn, TiO2-NPs had a major effect on enzymes activity in S. epidermidis. Considering all of the collected results for tested bacteria, it can be emphasised that the impact of NPs on the antioxidant system functioning was dependent on their type and concentration.

Elucidating the effect of TiO2 nanoparticles on mung bean rhizobia via in vitro assay: Influence on growth, morphology, and plant growth promoting traits

“…The predominant mechanism via which TiO 2 NPs confer cellular toxicity has been identified to be the oxidative stress [58][59][60] that results in profuse damage of various types of biomacromolecules including lipids, carbohydrates, proteins, and DNA in the treated cell [61][62][63][64][65][66][67]. The ROS are produced as a result of redox reactions and can occur as either radical (hydroxyl and superoxide ions) or nonradical species (hydrogen peroxide) [68] which can be measured via different methods.…”

Toxicity Assessment of Environmental Liquid Crystal Monomers: A Bacteriological Investigation on Escherichia coli and Staphylococcus epidermidis

“…cDNA synthesis and qPCR were integrated into one step via TransScript II Green One-Step qRT-PCR SuperMix (catalog AQ111, Transgen, Beijing, China). Primers were synthesized in advance according to the previous study . Analysis was performed on 96-well plates in three technical replicates.…”

“…Primers were synthesized in advance according to the previous study. 28 Analysis was performed on 96-well plates in three technical replicates. RT-qPCR analysis was carried out using 7500 Real-Time PCR System (ABI7500FAST System, China) under the following experiment settings: preincubation at 50 °C for 5 min, 2 steps amplification in 45 cycles consisting of 94 °C for 5 s and 60 °C for 30 s. Melting curves were utilized to check for abnormal amplification.…”

Investigating the Role of Classical Ayurveda-Based Incineration Process on the Synthesis of Zinc Oxide Based Jasada Bhasma Nanoparticles and Zn2+ Bioavailability

“…Immune system dysfunction, growth retardation, emergence of liver problems, and cognitive deficits can all be caused directly or indirectly by Zn deficiency. , Zn 2+ supplementation has been seen to reduce patients’ risk of developing metabolic disorders and diseases linked to Zn deficiency. JB acting as a source of Zn 2+ therapeutic supplement has been proven to support the antibacterial activity, delay the onset of diabetes, and show potential as an anticancer medicine. − …”