Home
Update: October 28, 2008 
SUPERBUGS AND SMELLS
By Pam Eastlick for THE DEEP on line
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

BAD NEWS ABOUT THE SUPERBUGS

Researchers in England have recently discovered that some types of bacteria that form communities called 'biofilms' collectively produce a poison that's very similar to rattlesnake venom. These biofilms, produced by a bacterium called Pseudomonas aeruginosa are up to a thousand times more resistant to antibiotics than single bacterial cells. This is the first time that scientists have successfully proved that the way bacteria grow, either as a biofilm, or living as individuals, affects the proteins they secrete, and therefore how dangerous they can potentially be to our health.

Scientists had believed that the diseases caused by free-living bacteria were the most dangerous because the infection advances so rapidly. In contrast, chronic or long-term infections were thought to be associated with biofilms, which were seen as much less aggressive.

A widely-held view is that biofilms serve as reservoirs of bacteria that do relatively little harm; they just sit there. The main danger is thought to be from 'blooms' of free living cells which occasionally break away from the biofilm and cause disease outbreaks. The UK researchers found that biofilms do produce harmful chemicals. However, the tissue-degrading enzymes and toxins made by the biofilm bacteria differ from those produced by free-floating bugs, which may help them to survive attacks by our immune systems.

The scientists also discovered that the biofilm bacteria produced a protein that is similar to one of the active ingredients in rattlesnake venom. This protein causes the host cells to commit suicide and die, one reason rattlesnake venom is so dangerous. The research team is currently studying the protein to see if it functions in the same way.

The researchers also found evidence that the bacteria start producing these toxins very shortly after the biofilm begins to form. Once they have fully identified the toxins produced by the biofilm bacteria, the proteins and enzymes may be targeted to develop drugs for a variety of uses, including the treatment of hospital superbugs, cancer and cystic fibrosis.

Superbugs are a concern for all of us. I'm battling a superbug infection in my big toe even as I type this. But there's lots of research going on, looking for more ways to fight them. And it may be in ways you don't expect.

 

GOOD NEWS ABOUT THE SUPERBUGS

Well, we can find new antibiotics to combat them maybe, but some scientists just want to paint them away. New nanotechnology paints for walls, ceilings, and surfaces could kill hospital superbugs when the lights are turned on.

The new paints contain tiny particles of titanium dioxide, the dazzling white compound often used as a brightener in commercial paints. If the paint is bright white, it's a sure bet it contains titanium dioxide.

Scientists have discovered that extremely small, nanoparticle-sized forms of titanium dioxide can kill bacteria when they absorb ultraviolet light energy from the sun. They produce active molecules that clean up the painted surfaces.

The researchers looked at the survival of the food poisoning bacterium Escherichia coli on different paint formulae that contained the titanium nanoparticles and they used several different types and intensities of light. They found that paints containing titanium dioxide are more successful at killing bacteria if the concentration of the nanoparticles is stronger than in normal commercial paint.

Unfortunately they also discovered that other common paint additives, like calcium carbonate, silica or talc decreased the antibacterial efficiency of the titanium particles. If the paint contained calcium carbonate the kill rate dropped by up to 80%. The tests on a commercially available paint showed that the ability of the paint to inactivate bacteria was massively reduced compared with a paint formulation that didn't contain the additives.

With rising concern about the spread of hospital superbugs, healthcare providers are increasingly looking to find better ways to maintain hygienic standards in hospitals. These new nanoparticle paints could provide a simple and cost-effective solution.

Titanium may do wonders against the bacteria, but other common products may not be so benign. Have you ever made yourself sick by cleaning? Do the scents of common household products make you ill? Hold onto your hat. There may be a very interesting reason. Please read the following item very carefully. It could have direct bearing on you and your family.
CLEANING MAY MAKE YOU ILL

A University of Washington study of six top-selling laundry products and air fresheners found the products emitted dozens of different chemicals. All six products gave off at least one chemical regulated as toxic or hazardous under federal laws, but none of those chemicals was listed on the product labels.

"I first got interested in this topic because people were telling me that the air fresheners in public restrooms and the scent from laundry products vented outdoors were making them sick," said Anne Steinemann, a UW professor of civil and environmental engineering and of public affairs. "And I wanted to know, 'What's in these products that is causing these effects?'"

So, she analyzed the products to discover the chemicals' identity. "I was surprised by both the number and the potential toxicity of the chemicals that were found," Steinemann said. Chemicals included acetone, the active ingredient in paint thinner and nail-polish remover; limonene, a molecule with a citrus scent; and acetaldehyde, chloromethane and 1,4-dioxane (a known carcinogen).

"Nearly 100 volatile organic compounds were emitted from these six products, and none were listed on any product label. Plus, five of the six products emitted one or more carcinogenic 'hazardous air pollutants,' which are considered by the Environmental Protection Agency to have no safe exposure level," Steinemann said.

Steinemann chose not to disclose the brand names of the six products she tested in her published study. In a larger study of 25 cleaners, personal care products, air fresheners and laundry products, now submitted for publication, she found that many other brands contained similar chemicals.

Because manufacturers of consumer products are not required to disclose the ingredients, Steinemann analyzed the products to discover their contents. She studied three common air fresheners (a solid deodorizer disk, a liquid spray and a plug-in oil) and three laundry products (a dryer sheet, fabric softener and a detergent), selecting a top seller in each category. She bought household items at a grocery store and asked companies for samples of industrial products.

In the laboratory, each product was placed in an isolated space at room temperature and the surrounding air was analyzed for volatile organic compounds, small molecules that evaporate from the product's surface into the air.

Results showed 58 different volatile organic compounds above a concentration of 300 micrograms per cubic meter, many of which were present in more than one of the six products. For instance, a plug-in air freshener contained more than 20 different volatile organic compounds. Of these, seven are regulated as toxic or hazardous under federal laws. The product label lists no ingredients, and information on the Material Safety Data Sheet, required for workplace handling of chemicals, lists the contents as "mixture of perfume oils."

This study does not address links between exposure to chemicals and health effects. However, two national surveys published by Steinemann and a colleague in 2004 and 2005 found that about 20 percent of the population reported adverse health effects from air fresheners, and about 10 percent complained of adverse effects from laundry products vented to the outdoors. Among asthmatics, such complaints were roughly twice as common.

Manufacturers are not required to list the ingredients used in laundry products and air fresheners. Personal-care products and cleaners often contain similar fragrance chemicals, Steinemann said. And although cosmetics are required by the Food and Drug Administration to list ingredients, no law requires products of any kind to list chemicals used in fragrances.

"Fragrance chemicals are of particular interest because of the potential for involuntary exposure, or second-hand scents," Steinemann said.

"Be careful if you buy products with fragrance, because you really don't know what's in them," she added. "I'd like to see better labeling. In the meantime, I'd recommend that instead of air fresheners people use ventilation, and with laundry products, choose fragrance-free versions." The European Union recently enacted legislation requiring products to list 26 fragrance chemicals when they are present above a certain concentration in cosmetic products and detergents. No similar laws exist in the United States. "I hope this study will raise public awareness, and reduce exposures to potentially hazardous chemicals," said Steinemann.

Now isn't that interesting. Why do you suppose Dr. Steinemann chose not to mention which products she tested? Why do you suppose that laundry products are not required to list their ingredients? What do you want to bet that the upswing in asthma and other respiratory problems (and other problems with chemical links like autism) just could be laid at the feet of certain very large and powerful producers of these 'scented products'.

I'm one of those people that is sickened by fragrances (which explains why I avoid you like the plague if you've drowned yourself in perfume). My major criterion for choosing a laundry product is not how well it cleans but how much it smells. I wouldn't have an air freshener in my house if you paid me. I'm really healthy. How are you feeling today?

Cruise on over to the Deep Website at www.thedeepradioshow.com to learn more about healthy pregnancy, cats, medical mysteries and many other topics. Enjoy!