Ulcer And Cancer
Bacteria In Tapwater?
By Jon Copley
>The New Scientist
The slime that coats water pipes could be a haven for bacteria that cause stomach ulcers and gastric cancer, according to researchers at Robert Gordon University in Aberdeen.
Helicobacter pylori has been implicated in a wide variety of gastrointestinal diseases, from stomach inflammation to ulcers and even cancer. In developed countries, half of people over 50 years old carry the bacterium in their guts, and in developing countries an even larger proportion of people are affected. Several animals may harbour the microorganism, but so far no one has found a reservoir in the environment.
Donald Reid and his colleagues in Scotland thought that H. pylori might thrive in biofilms. These form when microorganisms colonise surfaces such as the insides of water pipes, often surrounding themselves with a sticky protective film. "Biofilms occur naturally in all water distribution systems," says Reid.
The researchers grew a biofilm inside stainless steel pipes in the laboratory and inoculated it with H. pylori. Even after unchlorinated water was flushed through the pipes for 192 hours, H. pylori still infested the biofilm. The team's findings will be published in the Journal of Applied Microbiology.
"Anywhere there is a biofilm, there is a potential haven for Helicobacter pylori," says Reid. This is particularly likely in unchlorinated private wells and water supplies in developing countries. Although most public supplies in developed countries are chlorinated, Reid believes the bacteria could still survive inside the biofilm. "Chlorine is only going to attack the upper layers," he says. "By the time those are destroyed, the chlorine is gone." As the biofilm builds up, Reid says that bacteria may be washed away a few at a time or occasionally released as large clumps.
A spokesman for Severn Trent, one of the largest suppliers of drinking water in Britain, says there are no studies that show H. pylori in treated water, so it is not included in routine water testing. "If a study showed it in treated water, we would want to investigate further," says the spokesman. © Copyright New Scientist, RBI Limited 1999
A New Germ Theory ------------------ <snip
There is now little doubt that Helicobacter pylori, found in the stomachs of a third of adults in the United States, causes inflammation of the stomach lining. In 20 percent of infected people it produces an ulcer. Nearly everyone with a duodenal ulcer is infected. H. pylori infections can be readily diagnosed with endoscopic biopsy tests, a blood test for antibodies, or a breath test. In 90 percent of cases the infections can be cured in less than a month with antibiotics. (Unfortunately, many doctors still haven't gotten the news. A Colorado survey found that 46 percent of patients seeking medical attention for ulcer symptoms are never tested for H. pylori by their physicians.)
H. pylori, the ulcer pathogen, confers a sixfold greater risk of stomach cancer, and accounts for at least half of all stomach cancers. Also, the lymphoid tissue of the stomach can produce a low-grade gastric lymphoma under the influence of this bacterium. Early reports indicate that the lymphoma is cured in 50 percent of cases by resolving the H. pylori infection -- which may mark the first time in medical history that cancer has been cured with an antibiotic.