Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacterial 'battle for survival' leads to new antibiotic

26.02.2008
Holds promise for treating stomach ulcers

MIT biologists have provoked soil-dwelling bacteria into producing a new type of antibiotic by pitting them against another strain of bacteria in a battle for survival.

The antibiotic holds promise for treatment of Helicobacter pylori, which causes stomach ulcers in humans. Also, figuring out the still murky explanation for how the new antibiotic was produced could help scientists develop strategies for finding other new antibiotics.

The work is reported in the February issue of the Journal of the American Chemical Society.

... more about:
»Genome »MIT »Rhodococcus »Streptomyces »antibiotic »strain

A combination of luck, patience and good detective work contributed to the discovery of the new antibiotic, according to Philip Lessard, research scientist in Professor Anthony Sinskey's laboratory at MIT.

Sinskey's lab has been studying Rhodococcus, a type of soil-dwelling bacteria, for many years. While sequencing the genome of one Rhodococcus species, the researchers noticed that a large number of genes seemed to code for secondary metabolic products, which are compounds such as antibiotics, toxins and pigments.

However, Rhodococcus does not normally produce antibiotics. Many bacteria have genes for antibiotics that are only activated when the bacteria are threatened in some way, so the researchers suspected that might be true of Rhodococcus.

Kazuhiko Kurosawa, a postdoctoral associate in the Department of Biology, decided to try to provoke the bacteria into synthesizing antibiotics by placing them in stressful environments. He tried turning the temperature up and down, then altered the bacteria's growth medium, but nothing worked.

Kurosawa then decided to stress the Rhodococcus bacteria by forcing them to grow in the presence of a competing bacteria, a strain of Streptomyces. Streptomyces produces an antibiotic that normally kills other bacteria, but in one of the experimental test tubes, Rhodococcus started producing its own antibiotic, which wiped out the Streptomyces.

The researchers isolated the antibiotic, dubbed it rhodostreptomycin, and started testing it to see what else it would kill. It proved effective against many other strains of bacteria, most notably Helicobacter pylori. Rhodostreptomycin is a promising candidate to treat H. pylori because it can survive in very acidic environments such as the stomach.

The antibiotic turned out to be a type of molecule called an aminoglycoside, composed of peculiar sugars, one of which has a ring structure that has not been seen before. The ring structure could offer chemists a new target for modification, allowing them to synthesize antibiotics that are more effective and/or stable.

"Even if (rhodostreptomycin) is not the best antibiotic, it provides new structures to make chemical derivatives of," said Lessard. "This may be a starting point for new antibiotics."

One mystery still to be solved is why Rhodococcus started producing this antibiotic. One theory is that the presence of the competing strain of bacteria caused Rhodococcus to "raise the alarm" and turn on new genes.

The version of Rhodococcus that produces the antibiotic has a "megaplasmid," or large segment of extra DNA, that it received from Streptomyces. A logical conclusion is that the plasmid carries the gene for rhodostreptomycin, but the researchers have sequenced more than half of the plasmid and found no genes that correlate to the antibiotic.

Another theory is that the plasmid itself served as the "insult" that provoked Rhodococcus into producing the antibiotic. Alternatively, it is possible that some kind of interaction of the two bacterial genomes produced the new antibiotic.

"Somehow the genes in the megaplasmid combined with the genes in Rhodococcus and together they produced something that neither parent could make alone," said Lessard.

If scientists could figure out how that happens, they could start to manipulate bacterial genomes in a more methodical fashion to design new antibiotics.

Other authors of the paper are T.G. Sambandan, research scientist in MIT's Department of Biology, MIT professors Anthony Sinskey of biology and ChoKyun Rha of the Biomaterials Science and Engineering Laboratory, and Ion Ghiviriga and Joanna Barbara of the University of Florida.

The research was funded by the Cambridge-MIT Institute and the Malaysia-MIT Biotechnology Partnership Program.

Written by Anne Trafton, MIT News Office

Elizabeth A. Thomson | MIT News Office
Further information:
http://www.mit.edu

Further reports about: Genome MIT Rhodococcus Streptomyces antibiotic strain

More articles from Life Sciences:

nachricht Navigational view of the brain thanks to powerful X-rays
18.10.2017 | Georgia Institute of Technology

nachricht Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>