- 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
- 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
- From: http://www.theatlantic.com/issues/99feb/germs.htm
- A New Germ Theory ------------------
- 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.