WebMD Health News May 22, 2000 (Los Angeles) -- All that hand-washing mom pressed us to do before eating may not have been for naught. But while the average home is crawling with microscopic bacteria that could cause infection, you may want to steer clear of washing with those antibacterial soaps and detergents, according to a study presented at a microbiology meeting here. The research shows that these products may be contributing to the explosion of bacteria resistant to antibiotics.
Scientists led by Herbert P. Schweizer, PhD, grew a common strain of bacteria in a culture containing high levels of triclosan, an antiseptic often found in soaps, lotions, toothpaste, and even some fabrics and plastics. Exposure to this antiseptic caused the bacteria to gradually become resistant to triclosan and to several common antibiotics, in some cases increasing their resistance as much as 500-fold. Schweizer is an associate professor of microbiology at Colorado State University in Fort Collins.
Schweizer's group also found that in some germs, resistance to triclosan translates into resistance to the drug used to treat tuberculosis, a phenomenon known as cross-resistance. This adds to the worry that resistance to common household cleansers may also make certain bacteria resistant to important antibiotics.
"This study is very important," says Thomas J. Pallasch, DDS, MS. "It raises a number of good questions." According to Pallasch, who was not involved in these studies, the first report of antibiotic resistance occurred in 1886. In 1946, Consumer Reports magazine warned its readers ofpenicil-resistant organisms. Today, he says, 17 million people die each year around the world from infectious diseases. "Unless we all get together on this and start to work on it -- it can't be done by one hospital." Pallasch is professor of dentistry at the University of Southern California in Los Angeles.
Since liquids with triclosan take a few minutes to evaporate, bacteria on a kitchen countertop, for example, may be exposed to low levels of the compound that kill the most sensitive organisms but allow the others to mutate and develop resistance -- a "worst case scenario", Schweizer tells WebMD. "It's very difficult to see what's real: it may be that in excess of 90% of bacteria are sensitive to triclosan, while the rest are not affected," he explains. By killing those 90% and allowing the remaining 10% to thrive, "we may be imbalancing the population. We don't want to give those bacteria an unnecessary advantage."
A few studies have shown that products containing triclosan create a "marginal improvement" in rates of bacterial infection, but "proper hand washing makes any soap effective," Schweizer says. "In my opinion, [if there is] any potential impact on encouraging the growth of resistant bacteria -- it's not worth it." In addition, he says he believes that people may become a little more lax in their hygiene if they think their soaps and cleansers contain an antiseptic. "Use common sense," he warns. "Cooking meat properly and washing cutting boards appropriately will take care of most [problem organisms]."
Pallasch adds that consumers should "try and resist the use of antibiotics [in general] for situations where they're not indicated. The public has to understand that there are some very good uses of antibiotics and very poor uses." For example, antibiotics will do nothing against a viral infection such as the common cold, but they can be very effective against bacterial infections such as certain forms of pneumonia.
Adding to worries about drug-resistant bacteria are findings by Patricia Rusin, PhD, and her colleagues at the University of Arizona in Tucson, that activities such as doing laundry, cleaning house, or even just picking up a telephone can transmit germs to the hands, even if you disinfect your hands before doing the chore with antiseptic soap. Hard surfaces, such as a telephone or faucet, were the most efficient transmitters of bacteria, but even wringing out a sponge left over 100,000 to one million bacteria on the hands.
Among activities, meal preparation contaminated hands the most. Exiting a public restroom, surprisingly, was associated with the lowest level of bacterial contamination.
"These results suggest that everyday activities can result in considerable contamination of the hands, especially meal preparation and household cleaning," the investigators write. But don't put away that broom and blender just yet. The body's natural defenses usually keep these bugs at bay.
Source: http://www.webmd.com/parenting/news/20000522/fighting-germs-in-home-may-make-problem-worse
Scientists led by Herbert P. Schweizer, PhD, grew a common strain of bacteria in a culture containing high levels of triclosan, an antiseptic often found in soaps, lotions, toothpaste, and even some fabrics and plastics. Exposure to this antiseptic caused the bacteria to gradually become resistant to triclosan and to several common antibiotics, in some cases increasing their resistance as much as 500-fold. Schweizer is an associate professor of microbiology at Colorado State University in Fort Collins.
Schweizer's group also found that in some germs, resistance to triclosan translates into resistance to the drug used to treat tuberculosis, a phenomenon known as cross-resistance. This adds to the worry that resistance to common household cleansers may also make certain bacteria resistant to important antibiotics.
"This study is very important," says Thomas J. Pallasch, DDS, MS. "It raises a number of good questions." According to Pallasch, who was not involved in these studies, the first report of antibiotic resistance occurred in 1886. In 1946, Consumer Reports magazine warned its readers ofpenicil-resistant organisms. Today, he says, 17 million people die each year around the world from infectious diseases. "Unless we all get together on this and start to work on it -- it can't be done by one hospital." Pallasch is professor of dentistry at the University of Southern California in Los Angeles.
Since liquids with triclosan take a few minutes to evaporate, bacteria on a kitchen countertop, for example, may be exposed to low levels of the compound that kill the most sensitive organisms but allow the others to mutate and develop resistance -- a "worst case scenario", Schweizer tells WebMD. "It's very difficult to see what's real: it may be that in excess of 90% of bacteria are sensitive to triclosan, while the rest are not affected," he explains. By killing those 90% and allowing the remaining 10% to thrive, "we may be imbalancing the population. We don't want to give those bacteria an unnecessary advantage."
A few studies have shown that products containing triclosan create a "marginal improvement" in rates of bacterial infection, but "proper hand washing makes any soap effective," Schweizer says. "In my opinion, [if there is] any potential impact on encouraging the growth of resistant bacteria -- it's not worth it." In addition, he says he believes that people may become a little more lax in their hygiene if they think their soaps and cleansers contain an antiseptic. "Use common sense," he warns. "Cooking meat properly and washing cutting boards appropriately will take care of most [problem organisms]."
Pallasch adds that consumers should "try and resist the use of antibiotics [in general] for situations where they're not indicated. The public has to understand that there are some very good uses of antibiotics and very poor uses." For example, antibiotics will do nothing against a viral infection such as the common cold, but they can be very effective against bacterial infections such as certain forms of pneumonia.
Adding to worries about drug-resistant bacteria are findings by Patricia Rusin, PhD, and her colleagues at the University of Arizona in Tucson, that activities such as doing laundry, cleaning house, or even just picking up a telephone can transmit germs to the hands, even if you disinfect your hands before doing the chore with antiseptic soap. Hard surfaces, such as a telephone or faucet, were the most efficient transmitters of bacteria, but even wringing out a sponge left over 100,000 to one million bacteria on the hands.
Among activities, meal preparation contaminated hands the most. Exiting a public restroom, surprisingly, was associated with the lowest level of bacterial contamination.
"These results suggest that everyday activities can result in considerable contamination of the hands, especially meal preparation and household cleaning," the investigators write. But don't put away that broom and blender just yet. The body's natural defenses usually keep these bugs at bay.
Source: http://www.webmd.com/parenting/news/20000522/fighting-germs-in-home-may-make-problem-worse
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