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Showing posts with label 'Immunized' bacteria may halt antibiotic resistance. Show all posts
Showing posts with label 'Immunized' bacteria may halt antibiotic resistance. Show all posts

Thursday, February 3, 2011

War on bacteria

 Frisky bacteria war on drugs revealed By James Gallagher

Health reporter, BBC News

Ever since medicine declared war on bacteria with the discovery of penicillin, the two have been locked in an arms race.Antibiotics are met by resistance from germs; so researchers develop new drugs and germs become resistant again.Now some scientists believe genetics will be the new weapon in the fight, with doctors consulting bacterial genomes when treating disease.This week a team at the Wellcome Trust Sanger Institute published a paper in the journal Science, which they say shows the first genetic picture of the evolutionary war between medicine and bacteria.

"Potentially every time someone is ill we could isolate the genome of a bacterial infection” Bacterial genetics can be tricky. With humans, one person's DNA is passed on to their children, then to their children, and so on down the family tree.
Bacteria are altogether more frisky.

They pass DNA onto their descendants when they divide in two, but they also swap DNA with other bacteria, changing their genetic code. It is like popping to the shop and changing eye colour with someone at the checkout.This study has managed to tease out the differences between the two ways of passing on DNA in Streptococcus pneumoniae and draw its family tree.

From the lab to the hospital

The researchers were able to show how the species responded to different antibiotics, how it became resistant, where it became resistant and how the resistance spread around the world.It is the first time the whole of a genome has been studied to measure the genetic response to medicine. Other studies have come to some of the same conclusions, but as a review in the same journal said: "Suggesting that we knew all this before however misses the importance of their study, in which a single experiment provided more information than has been achieved over 15 years of research."

Studying the whole of a genome is getting cheaper and Dr Stephen Bentley, from the Sanger Institute, believes it could change the way we treat illnesses. He told the BBC: "Potentially every time someone is ill we could isolate the genome of a bacterial infection, determine if it is resistant, how it will behave in humans and match it up to a database to monitor the spread of an outbreak."

Writing in Science, Professors Mark Enright and Brian Spratt, reviewed the study: "The ease with which investigators can now obtain whole genomes of bacterial pathogens is opening up a number of questions that previously were impossible or difficult to address. "One of these is how virulent or high drug resistant strains of bacterial pathogens spread within hospitals and nursing homes within a region."
Dr Bentley thinks pathogen genomics could become part of normal hospital practice in five to 10 years' time.

Saturday, November 6, 2010

'Immunized' bacteria may halt antibiotic resistance

Altering bacteria's immune systems could one day help prevent their resistance to antibiotics, a new study has found. Researchers at Laval University in Quebec City and food company Danisco say they've discovered how bacteria take "pieces" of foreign DNA and embed them within their genome. When the bacteria come in contact with that foreign DNA down the road, they fight it off in an immune-style attack.The scientists inserted plasmids — DNA molecules that bacteria routinely exchange — into the bacteria. These plasmids contained a gene for antibiotic resistance.Once the plasmids were placed, the bacteria integrated parts of the DNA from the antibiotic resistance gene into their genome. This meant that when researchers tried to reinsert the plasmids, the bacteria fought them off.
"These bacteria had simply been immunized against acquiring the resistance gene," Sylvain Moineau, a professor at Laval's department of biochemistry, microbiology and bioinformatics, said in a release. "This phenomenon could explain, among other things, why some bacteria develop antibiotic resistance while others don't."The finding could pave the way for the development of bacteria that are not immune to antibiotics. Antibiotic resistance develops when antibiotics fail to kill all bacteria, leaving some to grow into a new, resistant strain.

Bacteria that develop resistance to common antibiotics affect more than 250,000 Canadians a year, according to the Canadian Medical Association. About 8,000 people die from those infections.
The study also found that the immune response demonstrated by the bacteria also causes them to effectively fight off viruses known as bacteriophages. Future research could identify how food companies that sell food with bacterial cultures such as yogurt and cheese could prevent bacterial contamination.
The study is published in Thursday's issue of Nature.

Read more: http://www.cbc.ca/technology/story/2010/11/05/antibiotic-resistance-bacteria.html#ixzz14VoNaIKz