Antimicrobial Activity of Metals and Metalloids

Abstract

Competition shapes evolution. Toxic metals and metalloids have exerted selective pressure on life since the rise of the first organisms on the Earth, which has led to the evolution and acquisition of resistance mechanisms against them, as well as mechanisms to weaponize them. Microorganisms exploit antimicrobial metals and metalloids to gain competitive advantage over other members of microbial communities. This exerts a strong selective pressure that drives evolution of resistance. This review describes, with a focus on arsenic and copper, how microorganisms exploit metals and metalloids for predation and how metal- and metalloid-dependent predation may have been a driving force for evolution of microbial resistance against metals and metalloids. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

On the origin and evolution of microbial mercury methylation

“…As the hgcAB gene pair likely evolved in LUCA (Figure 1A), Hg II methylation could have stabilised to persist as an early form of antimicrobial production. Microorganisms have evolved a wide range of attack mechanisms to compete against other microbes for limited resources (Granato et al 2019), and our hypothesis for mercury methylation as antimicrobial production mirrors a similar hypothesis recently put forward for arsM, a gene that encodes for arsenic methylation (Li et al 2021).…”

Chemical Nature of Metals and Metal-Based Materials in Inactivation of Viruses

“…The performances and mechanisms of metallic materials as antibacterial agents have been exhaustively summarized [ 31 , 39 , 40 , 41 ]. The main mechanisms of bacterial inactivation by metals are as follows: (i) metal binds to the cell wall through electrostatic interactions, destroys the cell wall and causes cytoplasmic efflux; (ii) metal accumulates in the cell membrane of bacteria and damages it, thereby causing increased cell permeability; (iii) metal enters the bacterial cell bound to enzymes and disrupts intracellular metabolism; and (iv) metal induces free radical production in the presence of light, which damages the genetic material of bacteria and hinders bacterial propagation ( Figure 1 ; all figures were created with Adobe Illustrator 2020) [ 40 , 42 , 43 , 44 , 45 ]. Nevertheless, in contrast to the structure and composition of bacteria, viruses have no cell wall, cell membrane, cytoplasm and nucleus, and they have only capsid and genetic material (RNA or DNA) [ 46 ].…”

Interactions with Arsenic: Mechanisms of Toxicity and Cellular Resistance in Eukaryotic Microorganisms

“…As is a ubiquitous element that has a very ancient origin. According to some authors [73], life has been exposed to the toxic metalloid As since the rise of the first organisms, approximately 3.5 Ga, during the Archean. Concentrations of As in marine sedimentary iron formations and shales of this period, suggest early oceans were very rich in As.…”