Triclosan and Antimicrobial Resistance in Bacteria: An Overview

Abstract

Triclosan is a widely used biocide that is considered as an effective antimicrobial agent against different microorganisms. It is included in many contemporary consumer and personal health-care products, like oral and dermal products, but also in household items, including plastics and textiles. At bactericidal concentrations, triclosan appears to act upon multiple nonspecific targets, causing disruption of bacterial cell wall functions, while at sublethal concentrations, triclosan affects specific targets. During the 1990s, bacterial isolates with reduced susceptibility to triclosan were produced in laboratory experiments by repeated exposure to sublethal concentrations of the agent. Since 2000, a number of studies have verified the occurrence of triclosan resistance amongst dermal, intestinal, and environmental microorganisms, including some of clinical relevance. Of major concern is the possibility that triclosan resistance may contribute to reduced susceptibility to clinically important antimicrobials, due to either cross-resistance or co-resistance mechanisms. Although the number of studies elucidating the association between triclosan resistance and resistance to other antimicrobials in clinical isolates has been limited, recent laboratory studies have confirmed the potential for such a link in Escherichia coli and Salmonella enterica. Thus, widespread use of triclosan may represent a potential public health risk in regard to development of concomitant resistance to clinically important antimicrobials.

The RNA Processing Enzyme Polynucleotide Phosphorylase Negatively Controls Biofi lm Formation by Repressing Poly-N-Acetylglucosamine (PNAG) Production in Escherichia coli C

“…micF, acrAB, marA bcsA, bcsE) in Salmonella that might help induce further resistance [16]. Schweizer [17] reported that some bacterial strains (such as gram-negative bacteria) use a multiple triclosan resistance mechanism, including active efflux from cell where bacteria actively pump TCS out of the cell [18]. Moreover, some bacteria have been shown to produce triclosan-insusceptible enzymes [19] or triclosan-degradative enzymes [20] and also the capability to modify the outer membrane permeability barriers [21].…”

“…A subsample of the supernatant was finally mixed with 3 mL of the scintillation cocktail Ultima Gold MV. The bacterial division rate (cells cm -3 h -1 ) was calculated by the internal standard quenching curve (Liquid scintillation analyzer ''TRI-CARB 2000'') while assuming that 1 mol -1 incorporated thymidine equivalents the production of 2610 18 bacterial cells [61,62]. The data have been corrected by a blank (mean of two replicates) that corresponds to pre-fixed sediment cores submitted to the protocol described above.…”

Oxidation of triclosan by ferrate: Reaction kinetics, products identification and toxicity evaluation

“…Risk assessment has shown that triclosan in surface waters could negatively affect a range of aquatic organisms [4,15,16]. It has also been speculated that triclosan resistance can promote the development of concomitant resistance to other clinically important antimicrobials through cross-or co-resistance mechanisms [17]. Given the persistency as well as toxicity of triclosan, the removal of triclosan during wastewater treatment by advanced treatment processes, particularly advanced oxidation, has been the focus of many recent scientific studies.…”

Antibacterial Modification of Textiles Using Nanotechnology

“…Among halogenated phenols, triclosan 5-chloro-2-(2.4-dichlorophenoxy) phenol ( Figure 6) [39] is the most widely used biocide; it is present in many contemporary consumer and personal health-care products, detergents and household objects, including textiles and plastics. At bactericidal concentration, triclosan is very effective against a broad range of microorganisms, including antibiotic-resistant bacteria.…”

“…At bactericidal concentration, triclosan is very effective against a broad range of microorganisms, including antibiotic-resistant bacteria. As the widespread use of triclosan could represent a potential risk in terms of the development of resistant microorganisms [39], strong binding to solid surfaces with subsequent controlled release is important. Triclosan has therefore been applied to cellulose fibers in combination with polycarboxylic acids as crosslinking agents [40].…”