Silver-, calcium-, and copper molybdate compounds: Preparation, antibacterial activity, and mechanisms

Abstract

Developing novel compounds with antimicrobial properties can be an effective approach to decreasing the number of healthcare-associated infections, particularly in the context of medical devices and touch surfaces. A variety of molybdate powders (AgMoO, CaMoO, CuMoO and CuMoO) were synthesized and characterized, and Escherichia coli was used as a model gram-negative bacterium to demonstrate their antimicrobial properties. Optical density measurements, bacterial colony growth, and stained gel images for protein expression clearly showed that silver- and copper molybdates inhibit bacterial growth, whereas CaMoO exhibited no bactericidal effect. All tests were performed in both daylight and darkness to assess the possible contribution of a photocatalytic effect on the activity observed. The main mechanism responsible for the antibacterial effect observed for AgMoO is related to Ag release in combination with medium acidification, whereas for compounds containing copper, leaching of Cu ions is proposed. All these effects are known to cause damage at the cellular level. A photocatalytic contribution to the antibacterial activity was not clearly observable. Based on the pH and solubility measurements performed for powders in contact with various media (ultrapure water and bacterial growth medium), silver molybdate (AgMoO) was identified as the best antibacterial candidate. This compound has great potential for further use in hybrid powder-polymer/varnish systems for touch surfaces in healthcare settings.

Pan-genomic analysis of transcriptional modules across Salmonella Typhimurium reveals the regulatory landscape of different strains

“…Evidence has shown that silver molybdate and copper molybdate can enhance the abilities of antimicrobial agents in killing other Gram-negative bacteria such as E. coli . The metal ions can disrupt the cell membranes while the molybdenum oxide or molybdate oxyanion modulates the local pH to inhibit further growth 30 . It is still unclear why Typhimurium MDR strains upregulate molybdate transport genes when treated with antibiotics, but this result strengthens the argument that molybdate has a major effect on the survival of Gram-negative bacteria, especially when antimicrobial agents are present.…”

Pharmacies for pain and trauma in ancient Greece

“…Metals have been also used for their antiseptic, wound healing and subsequently analgesic properties. The antiseptic and wound healing properties of copper were known since the time of Hippocrates; he used copper to disinfect ulcers from varicose veins and treated painful wounds and skin problems with copper and honey [4,8,[54][55][56][57]. Slaves rarely experienced rheumatic or arthritic problems and contaminated wounds because they were chained with copper strips in their wrists and ankles that protected them from such diseases [4,8,20,[54][55][56][57].…”

Bio-Synthesis and Characterization of Copper Molybdate Nanoparticles

“…The presence of phytochemicals in the plants have tendency to reduce the heavy metals from their higher oxidation state to zero oxidation state. For the production of nanoparticles, the electron rich phytochemicals in plants acts as the building block for conversion of metallic precursor, there by replacing the toxic reducing agents [26,27] to design engineered nanomaterials in medicine, energy, electronics, etc., the green eco-friendly technique is used. The mechanism between the nanoparticles and the microorganism takes place by the electrostatic interaction of positively charged nanoparticles with that of the negatively charged microorganisms.…”