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The Growth of Superbugs
Reported January 05, 2010
(Ivanhoe Newswire) -- Using disinfectants could cause bacteria to
become resistant to antibiotics as well as the disinfectant itself,
according to new research.
Researchers from the National University of Ireland in Galway found that by
adding increasing amounts of disinfectant to laboratory cultures of
Pseudomonas aeruginosa, the bacteria could adapt to survive not only the
disinfectant but also the commonly-prescribed antibiotic ciprofloxacin --
even without being exposed to it.
Disinfectants are used to kill bacteria on surfaces to prevent their spread.
If the bacteria manage to survive and go on to infect patients, antibiotics
are used to treat them. Bacteria that can resist both these control points
pose a serious threat to hospital patients.
P. aeruginosa is an opportunistic bacterium that can cause a wide range of
infections in people with weak immune systems and in those with diseases
such as cystic fibrosis and diabetes. P. aeruginosa is an important cause of
hospital-acquired infections.
The researchers showed that the bacteria in culture adapted to more
efficiently pump out antimicrobial agents from the bacterial cell. The
adapted bacteria also had a mutation in their DNA that allowed them to
resist ciprofloxacin-type antibiotics specifically.
Importantly, the study showed that when very small non-lethal amounts of
disinfectant were added to the bacteria in culture, the adapted bacteria
were more likely to survive.
Study leader Dr. Gerard Fleming was quoted as saying, "In principle this
means that residue from incorrectly diluted disinfectants left on hospital
surfaces could promote the growth of antibiotic-resistant bacteria. What is
more worrying is that bacteria seem to be able to adapt to resist
antibiotics without even being exposed to them."
Dr. Fleming also stressed the importance of studying the environmental
factors that might promote antibiotic resistance. "We need to investigate
the effects of using more than one type of disinfectant on promoting
antibiotic-resistant strains. This will increase the effectiveness of both
our first and second lines of defense against hospital-acquired infections."
SOURCE: Microbiology, January, 2010 |
