Influence of surface copper content onStenotrophomonas maltophiliabiofilm control using chlorine and mechanical stress

Abstract

This work aimed to evaluate the action of materials with different copper content (0, 57, 96 and 100%) on biofilm formation and control by chlorination and mechanical stress. Stenotrophomonas maltophilia isolated from drinking water was used as a model microorganism and biofilms were developed in a rotating cylinder reactor using realism-based shear stress conditions. Biofilms were characterized phenotypically and exposed to three control strategies: 10 mg l À1 of free chlorine for 10 min, an increased shear stress (a fluid velocity of 1.5 m s À1 for 30s), and a combination of both treatments. These shock treatments were not effective in biofilm control. The benefits from the use of copper surfaces was found essentially in reducing the numbers of non-damaged cells. Copper materials demonstrated better performance in biofilm prevention than chlorine. In general, copper alloys may have a positive public health impact by reducing the number of non-damaged cells in the water delivered after chlorine exposure.

Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens

“…Bench-scale studies examining copper's antimicrobial efficacy have found discrepancies between culture-based and molecular-based numbers of L. pneumophila [121,122] that are also suggestive of a copper-induced VBNC state. Similar discrepancies have been noted for P. aeruginosa, Stenotrophomonas maltophilia, and M. avium [104,109,127,132,133]. Evidence of copper-induced VBNC activity is particularly strong in the case of P. aeruginosa, where one study applied multiple non-culture-based measures of viability [127,132].…”

“…Addition of copper ions to solution from pipes or via CSI, at the bench and building-scale, has also been shown to inhibit the growth or reduce the frequency of OPs such as Staphylococcus spp. [98,99], Stenotrophomonas maltophilia [91,92,104], Acinetobacter baumannii [58,91,92], NTM [108,109], and P. aeruginosa [91,92,98,99,127,130].…”

Biosynthesis of Copper Oxide Nanoparticles and Evaluation of Their Antimicrobial Properties

“…The mechanism by which copper materials act to kill fungi is not well understood [17]. The proposed mechanism of antifungal activity of synthesized CuONPs could be that CuONPs might have induced stress on C. albicans which led to the endogenous generation of reactive oxygen species (ROS) and subsequently caused damage to the cell membrane of C. albicans [18]. It might also be possible that the synthesized CuONPs inhibited ergosterol biosynthesis in C. albicans thus leading to the death of the fungi.…”