Rhenium and yttrium ions as antimicrobial agents against multidrug resistant Klebsiella pneumoniae and Acinetobacter baumannii biofilms

Abstract

Antimicrobial resistance presents major global concerns to patient health. In this study, metal ions of molybdenum, rhenium, yttrium and thallium were tested against bacteria in planktonic and biofilm form using one strain of Klebsiella pneumoniae and Acinetobacter baumannii. The antimicrobial efficacy of the metal ions was evaluated against the planktonic bacterial strains using minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations, whilst the efficacy of the metal ions against biofilms was tested using a crystal violet biofilm assay. Live Dead staining was used to visualize the antimicrobial activity elicited by the metal ions on the bacterial cell. The results showed that higher concentrations of the metals were required to inhibit the growth of biofilms (72·9 mg l−1 to 416·7 mg l−1), in comparison to their planktonic counterparts. MICs of the metal ions (<46·9 mg l−1) (planktonic cells) did not affect biofilm formation. Overall, rhenium and yttrium were effective antimicrobial agents. Molybdenum demonstrated the greatest level of biotoxicity. When taking into account these results and the known toxicity of thallium, it is possible that rhenium or yttrium ions could be developed as effective biocidal formulations in order to prevent transmission in healthcare environments. Significance and Impact of the Study The metal ions, molybdenum, rhenium, thallium and yttrium were tested against both Klebsiella pneumoniae and Acinetobacter baumannii in planktonic and biofilm forms. This research demonstrated that all the metal ions may be effective antimicrobial agents. However, molybdenum induced high levels of cytotoxicity, whilst, there was no significant difference in the toxicity of the other metal ions tested. When considering the results for the antimicrobial efficacy and biotoxicity of the metal ions, in conjunction with the known toxicity of thallium in certain chemical compositions, it was concluded that overall rhenium or yttrium ions may be effective antimicrobial agents, one potential application may be utilizing these metal ions in hospital surface cleaning formulations.

Graphene Matrices as Carriers for Metal Ions against Antibiotic Susceptible and Resistant Bacterial Pathogens

“…The emergence of AMR has resulted in enhanced morbidity and mortality rates, which in turn results in longer hospital stays, thus placing a financial burden on healthcare services worldwide [34][35][36]. There is currently a lack of effective therapies to combat AMR infections [4], if this is not addressed it has been proposed that that by 2050, AMR infection will supersede cancer as the leading cause of mortality worldwide [37].…”

“…There is currently a lack of effective therapies to combat AMR infections [4], if this is not addressed it has been proposed that that by 2050, AMR infection will supersede cancer as the leading cause of mortality worldwide [37]. One potential avenue to be explored is the use of metal ions as alternative therapeutic options [19,36,38,39]. The utilization of graphene has grown rapidly in the last decade due to the unique properties of graphene and its derivatives, such materials have been widely explored for use as potential biomaterials [40][41][42][43].…”

A traditional Ugandan Ficus natalensis bark cloth exhibits antimicrobial activity against methicillin-resistant Staphylococcus aureus

“…2015; Slate et al . 2019). Chlorine affects bacterial cell viability by chlorinating the lipid protein in the cell wall, which results in macromolecule leakage from the cell (Kim et al .…”

The Influence of Surface Topography and Wettability on Escherichia coli Removal from Polymeric Materials in the Presence of a Blood Conditioning Film

“…It is important to note that biofilm formation, which can result in bacteria not being exposed to the sanitising chemicals due to extracellular polymeric substance (EPS) production, is not the same problem as biocidal resistance generation. However, when bacterial biofilms are compared to their planktonic counterparts, increased resistance to biocide treatment is conferred [ 60 , 61 ]. Sodium hypochlorite is an effective disinfectant used in the maintenance of food preparation surfaces, and a low concentration (1%) is effective in disinfecting vacutainers within 10 min whilst maintaining good biocompatibility [ 62 ].…”