LONDON
(AP) -- Scientists have deciphered the genetic code of staph, a common but particularly
dangerous germ that can be deadly for hospital patients and is becoming increasingly
immune to drugs.
Japanese scientists report in The Lancet medical journal
the first genetic blueprint of the bacterium Staphylococcus aureus. Researchers
hope the information will help them develop better ways of fighting staph, one
of the most notorious superbugs.
In decoding the genes of two tough-to-treat
strains of staph, the scientists from Juntendo University in Tokyo discovered
five new classes of genes that produce potentially lethal toxins and 70 new genes
that determine how virulent the germ is.
Experts say the findings are
a major contribution to the understanding of how antibiotic resistance develops
in the parasite.
"These (genes) ... may become possible targets for the
design of novel therapeutic agents as well as vaccines," said Dlawer A. A. Ala'
Aldeen, a bacteriologist at the University of Nottingham Hospital in Nottingham,
England, who was not involved in the research.
Staphylococcus aureus is
considered the most successful of all bacterial germs because it produces such
a wide range of infections in so many people.
It is the leading cause
of infections acquired in hospitals worldwide and causes ailments ranging from
boils and urinary tract infections to toxic shock syndrome and pneumonia.
Half
of all staph that circulates in hospitals is resistant to meticillin, the standard
drug used to treat it. Now it is developing resistance to the last line of defense,
the antibiotic vancomycin.
Staphylococcus aureus is a common and ordinarily
harmless inhabitant of the human nasal tract. One person in three carries it.
It can live for days outside the body on almost any surface and spreads
easily, taking any opportunity to colonize humans, such as around the site of
needle punctures, through surgical wounds or through the airways.
Ala'
Aldeen said staph is so adaptable that it is here to stay. However, he said, insight
into how it interacts with humans and how its genes work might make it possible
to create vaccines that prevent the infections caused by staph, even if they don't
prevent the germ from living in the human body.
The secrets revealed by
its genes may help scientists keep up with staph's ability to constantly mutate
itself into new forms that protect it from bacteria killers, Ala' Aldeen said. |
