Thiol-Mediated Reduction of <i>Staphylococcus aureus</i> Tellurite Resistance

Abstract

The goal of this work was to enhance tellurite toxicity against Gram positive bacteria, especially Staphyloccocus aureus. Using a combination of assays (growth inhibition zones, growth curves, and minimal inhibitory concentrations), tellurite toxicity against this bacterium was tested in the presence of various SH-and OH-containing compounds. Results showed that the noxiousness of tellurite was strongly enhanced in the presence of 2-mercaptoethanol or dithiothreitol. The potentiating effect was observed in S. aureus ATCC 6538 (the model organism of this study) and in other Gram positive bacteria such as Bacillus subtillis ATCC 6051 and the methicillin-resistant S. aureus strain 622-4. No enhancing effect was observed in Gram negative bacteria such as Escherichia coli BW25113, Salmonella Typhimurium LT2 and Klebsiella pneumoniae ATCC 11388. These results open new perspectives for studying the treatment of multidrug-resistant Gram positive bacteria, which are responsible for numerous nosocomial infections.

Glutathione Reductase-Mediated Synthesis of Tellurium-Containing Nanostructures Exhibiting Antibacterial Properties

“…The significant increase of ROS detected in E. coli cells exposed to tellurium NSs is also a usual response to tellurite exposure. As previously reported, S. aureus is much more resistant to tellurite than E. coli and generates smaller amounts of ROS in the presence of tellurite (23). The same trend is observed in Fig.…”

“…As shown in Fig. S3 in the supplemental material, 2-ME greatly enhanced the antibacterial effect of the tellurium NSs, a phenomenon that was previously reported when both tellurite and 2-ME were simultaneously administered to S. aureus (23), supporting the putative tellurite release from the Te-containing nanostructures.…”

“…As shown in Fig. S3 in the supplemental material, 2-ME greatly enhanced the antibacterial effect of the TeNSs against this Gram-positive coccus, a phenomenon that was previously reported when tellurite and 2-ME were combined (23).…”

Synthesis and investigations on tellurium myconanoparticles

“…This suggestion was confirmed when tellurium nano-rods were observed inside E. coli after being exposed to TeNPs. Alternatively, it has been reported by Pugin et al [ 34 ] that S. aureus exhibits much more resistance to tellurite and generates lower amounts of ROS which explains the resistance of S. aureus to TeNPs in the present study.…”

“…Although it may be surprising to obtain a resistant Staph aureus and sensitive MRSA, S. aureus resistance of methicillin has a different mechanism from that of ROS [ 39 ] and therefore the resistance of S. aureus to methicillin does not influence or interfere with its sensitivity to TeNPs. Furthermore, Pugin et al [ 34 ] showed no growth inhibition of S. aureus ATCC 6538 in presence of tellurium nano-particles.…”