Some data shows this resistance may have a significant impact on the effectiveness of medical treatments, such as antibiotics. This joint effort will help to ensure government-wide consistency in the regulation of this chemical.
The two agencies are reviewing the effects of triclosan from two different perspectives. The EPA regulates the use of triclosan as a pesticide, and is in the process of updating its assessment of the effects of triclosan when it is used in pesticides. By sharing information, the two agencies will be better able to measure the exposure and effects of triclosan and how these differing uses of triclosan may affect human health.
The EPA reevaluates each pesticide active ingredient every 15 years. Manufacturers are developing and planning to submit new safety and effectiveness data for these ingredients.
Because Triclosan is extremely powerful, very low concentrations can effectively kill bacteria. For example, Colgate toothpaste lists 0.
Although the percentage is almost negligible, 0. In addition to soaps, Triclosan is found in mouthwashes, face washes, deodorants, toothpastes, and many other household products [3].
Understanding how Triclosan functions requires some rudimentary knowledge of biology, namely the interactions of cell membranes, fatty acids, and enzymes. The cells of all organisms, including bacteria, require a cell membrane to survive. Without a permeable cell membrane, a cell would simply die.
For example, wastes would not be transported out of the cell, causing toxins to accumulate and poison the cell. Curiously, it is precisely this function of the cell membrane that Triclosan is engineered to immobilize.
Triclosan stops the fatty acid elongation process by inhibiting a bacterial enzyme. An enzyme is a protein that catalyzes, or speeds up, a chemical reaction. In a catalyzed reaction, the reactant molecule is called a substrate. The binding can be thought of as a handshake, a key entering a lock [4], or puzzle pieces fitting together.
Once applied to the hands in the form of antibacterial soap, Triclosan acts as a competitive inhibitor, and a battle between Triclosan and bacteria for active sites ensues. By stealing active sites from the natural substrate, Triclosan systematically kills bacteria by stopping fatty acid chain growth.
This, in turn, stops the growth of the cell membrane and effectively kills the cell. The process is efficient, insidious and almost perfect, and when given the opportunity, Triclosan is extremely successful. The following description of how Triclosan works should be more meaningful now that relevant terms and processes have been introduced. Fatty acid synthesis in bacteria is a multi-reaction process with different enzymes catalyzing each chemical reaction.
One gene encodes one enzyme; Triclosan interferes with the gene that regulates the entire process. For example, in E. Construction and maintenance of the cell membrane relies on synthesis of fatty acids. Triclosan impedes fatty acid synthesis in bacteria and therefore weakens the cell membrane and effectively stops bacteria from functioning properly. Bacteria can develop resistance to certain substances, especially those substances to which the bacteria are continually exposed.
Quantitation of risk reduction of E. Consumer antibacterial soaps: effective or just risky? Clin Infect Dis. Journal Curtis V, Cairncross S. Effect of washing hands with soap on diarrhoea risk in the community: a systematic review. Lancet Infect Dis. Efficacy of triclosan as an antimicrobial hand soap and its potential impact on antimicrobial resistance: a focused review. Should surgeons scrub with chlorhexidine or iodine prior to surgery?
Interact Cardiovasc Thorac Surg. Bactericidal effects of triclosan in soap both in vitro and in vivo. J Antimicrob Chemother. Triclosan and its alternatives in antibacterial soaps. You can skip it, use plain soap and water.
This might be due to the fact that antibacterial soaps specifically target bacteria, but not the viruses that cause the majority of seasonal colds and flus. Antibacterial soaps have the potential to create antibiotic-resistant bacteria. The reason that the FDA is making manufacturers prove these products' efficacy is because of a range of possible health risks associated with triclosan, and bacterial resistance is first on the list.
Heavy use of antibiotics can cause resistance , which results from a small subset of a bacteria population with a random mutation that allows it to survive exposure to the chemical. If that chemical is used frequently enough, it'll kill other bacteria, but allow this resistant subset to proliferate.
If this happens on a broad enough scale, it can essentially render that chemical useless against the strain of bacteria. This is currently a huge problem in medicine—the World Health Organization calls it a "threat to global health security. Health officials say that further research is needed before we can say that triclosan is fueling resistance, but several studies have hinted at the possibility.
The soaps could act as endocrine disruptors. A number of studies have found that, in rats, frogs and other animals, triclosan appears to interfere with the body's regulation of thyroid hormone , perhaps because it chemically resembles the hormone closely enough that it can bind to its receptor sites. If this is the case in humans, too, there are worries that it could lead to problems such as infertility, artificially-advanced early puberty, obesity and cancer.
These same effects haven't yet been found in humans, but the FDA calls the animal studies "a concern"—and notes that, given the minimal benefits of long-term triclosan use, it's likely not worth the risk.
0コメント