How Some Bacteria Survive Antibiotics

[Guest guest]

I wonder how these bacteria

would be affected by MMS...

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How Some Bacteria Survive Antibiotics

ScienceDaily (May 2, 2008) — Researchers at the University of Illinois

at Chicago have discovered how some bacteria can survive antibiotic

treatment by turning on resistance mechanisms when exposed to the

drugs. The findings, published in the April 24 issue of the journal

Molecular Cell, could lead to more effective antibiotics to treat a

variety of infections.

"When patients are treated with antibiotics some pathogenic microbes

can turn on the genes that protect them from the action of the drug,"

said Mankin, professor and associate director of the

University of Illinois at Chicago's Center for Pharmaceutical

Biotechnology and lead investigator of the study. "We studied how

bacteria can feel the presence of erythromycin and activate production

of the resistance genes."

Erythromycin and newer macrolide antibiotics azithromycin and

clarithromycin are often used to treat respiratory tract infections, as

well as outbreaks of syphilis, acne and gonorrhea. The drugs can be

used by patients allergic to penicillin.

Macrolide antibiotics act upon the ribosomes, the protein-synthesizing

factories of the cell. A newly-made protein exits the ribosome through

a tunnel that spans the ribosome body. Antibiotics can ward off an

infection by attaching to the ribosome and preventing proteins the

bacterium needs from moving through the tunnel.

Some bacteria have learned how to sense the presence of the antibiotic

in the ribosomal tunnel, and in response, switch on genes that make

them resistant to the drug, Mankin said. The phenomenon of inducible

antibiotic expression was known decades ago, but the molecular

mechanism was unknown.

Mankin and his team of researchers -- Nora Vazquez-Laslop, assistant

professor in the Center for Pharmaceutical Biotechnology, and

undergraduate student Celine Thum -- used new biochemical and genetic

techniques to work out the details of its operation.

"Combining biochemical data with the knowledge of the structure of the

ribosome tunnel, we were able to identify some of the key molecular

players involved in the induction mechanism," said Vazquez-Laslop.

"We only researched response to erythromycin-like drugs because the

majority of the genetics were already known," she said. "There may be

other antibiotics and resistance genes in pathogenic bacteria regulated

by this same mechanism. This is just the beginning."

The research was funded through a grant from the National Science

Foundation.

http://www.sciencedaily.com/releases/2008/04/080430154945.htm

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