Antimicrobials: Healthcare's Silver Bullet Against HAIs?

Antimicrobial Agents and Resistance Issues

American consumers’ love affair with antimicrobial products doesn’t seem to be fading. According to data from Tufts University’s APUA, within the last 20 years, residue-producing antibacterials — once used almost exclusively in healthcare institutions — have been added to increasing numbers of household products and cleaning agents. A recent survey reported that 76 percent of liquid soaps contained triclosan and approximately 30 percent of bar soaps contained triclocarban. Triclosan is a popular antimicrobial that has been bonded to the surfaces of everything from kitchen cutting boards to toys, and is an active ingredient in shampoos, facial cleansers, mouth rinses and toothpastes.

“There is a significant overuse of antiseptics in consumer goods,” Rupp observes. “I think triclosan is overused; it is found in toothpaste, soap, mouthwash, even cutting boards and mattress covers — you name a product and it seems triclosan has been incorporated into it these days. I think this practice is not doing any good in people’s households. “Having said that, however, it makes good sense to use antiseptics in medical/surgical applications within healthcare facilities. I think the concern over the development of antiseptic resistance and whether that co-develops with antimicrobial and antibiotic resistance is theoretical to some degree, but also is a justified concern. There are some data that indicate that there are specific genes and mechanisms of action for some antiseptics and specific mutations in those genes that are linked to resistance. We know that triclosan can serve as a substrate for the antibiotic multi efflux pumps, so I think there is some concern that if we use certain antiseptics they may actually co-promote antibiotic resistance. The judicious application of some antiseptics, chlorhexidine in particular, or those that don’t leave a residuum, like alcohol, make a lot of sense in hospital settings. Likewise, I think the use of alcohols in hand gels that consumers use as a convenient way to achieve good hand hygiene, is great. When they evaporate they don’t leave any residuum behind, so there is no risk of development of resistance.”

Tufts University’s APUA explains, “Because of their rapid killing effect, the non-residue producing antibacterial agents are not believed to create resistant bacteria. Resistance results from long-term use at low-level concentrations, a condition that occurs when consumer use residue-producing agents such as triclosan and triclocarban. Until recently, it was accepted that these agents did not affect a specific process in bacteria, and because of this, it was unlikely that resistant bacteria could emerge. However, recent laboratory evidence indicates that triclosan inhibits a specific step in the formation of bacterial lipids involved in the cell wall structure. Additional experiments found that some bacteria can combat triclosan and other biocides with export systems that could also pump out antibiotics. It was demonstrated that these triclosan-resistant mutants were also resistant to several antibiotics, specifically chloramphenicol, ampicillin, tetracycline and ciprofloxacin. Resistance to antibacterials has been found where these agents are used continuously (as in the hospital and food industry); however, at the present time, this modest increase in resistance has not yet created a clinical problem.”