Scientists target bacterial transfer of resistance genes

October 24, 2012
Researchers report they have found a way to disrupt the spread of antibiotic-resistance genes among S. pneumoniae bacteria, which can contribute to pneumonia (pictured), meningitis and other dangerous ailments. Credit: US Centers for Disease Control and Prevention

The bacterium Streptococcus pneumoniae – which can cause pneumonia, meningitis, bacteremia and sepsis – likes to share its antibiotic-defeating weaponry with its neighbors. Individual cells can pass resistance genes to one another through a process called horizontal gene transfer, or by "transformation," the uptake of DNA from the environment.

Now researchers report that they can interrupt the cascade of cellular events that allows S. pneumoniae to swap or suck up DNA. The new findings, reported in the journal , advance the effort to develop a reliable method for shutting down the spread of in bacteria.

"Within the last few decades, S. pneumoniae has developed resistance to several classes of antibiotics," said University of Illinois pathobiology professor Gee Lau, who led the study. "Importantly, it has been shown that antibiotic stress – the use of antibiotics to treat an infection – can actually induce the transfer of among S. pneumoniae. Our approach inhibits resistance gene transfer in all strains of S. pneumoniae, and does so without increasing selective pressure and without increasing the likelihood that resistant strains will become dominant."

Lau and his colleagues focused on blocking a protein that, when it binds to a receptor in the bacterial , spurs a series of events in the cell that makes the bacterium "competent" to receive new genetic material. The researchers hypothesized that interfering with this protein (called CSP) would hinder its ability to promote gene transfer.

In previous work published late last year in the journal , Lau's team identified proteins that could be made in the lab that were structurally very similar to the CSP proteins. These artificial CSPs can dock with the membrane receptors, block the bacterial CSPs' access to the receptors and reduce bacterial competence, as well as reducing the infectious capacity of S. pneumoniae.

In the new study, the researchers fine-tuned the amino acid structure of more than a dozen artificial CSPs and tested how well they inhibited the S. pneumoniae CSPs. They also tested their ability (or, more desirably, their inability) to mimic the activity of CSPs in bacterial cells.

"The chemical properties of individual amino acids in a protein can greatly influence the protein's activity," Lau said.

The team identified several artificial CSPs that both inhibited the bacterial CSPs and reduced S. pneumoniae competence by more than 90 percent.

"This strategy will likely help us reduce the spread of antibiotic-resistance genes among S. pneumoniae and perhaps other species of streptococcus bacteria," Lau said.

Explore further: A new strategy for developing meningitis vaccines

Related Stories

A new strategy for developing meningitis vaccines

May 24, 2012
Bacterial meningitis is an infection of the meninges, the protective membrane that covers the spinal cord and brain. Children, elderly patients and immunocompromised patients are at a higher risk for the development of severe ...

Flu helps spread pneumonia

April 11, 2011
Bacteria that cause pneumonia and meningitis are only able to spread when individuals are infected with flu, says a scientist reporting at the Society for General Microbiology's Spring Conference in Harrogate. The work could ...

Recommended for you

Scientists find key to regenerating blood vessels

November 23, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) identifies a signaling pathway that is essential for angiogenesis, the growth of new blood vessels from pre-existing vessels. The ...

Researchers find infectious prions in Creutzfeldt-Jakob disease patient skin

November 22, 2017
Creutzfeldt-Jakob disease (CJD)—the human equivalent of mad cow disease—is caused by rogue, misfolded protein aggregates termed prions, which are infectious and cause fatal damages in the patient's brain. CJD patients ...

Surprising roles for muscle in tissue regeneration, study finds

November 22, 2017
A team of researchers at Whitehead has illuminated an important role for different subtypes of muscle cells in orchestrating the process of tissue regeneration. In a paper published in the November 22 issue of Nature, they ...

Study reveals new mechanisms of cell death in neurodegenerative disorders

November 22, 2017
Researchers at King's College London have discovered new mechanisms of cell death, which may be involved in debilitating neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

How rogue immune cells cross the blood-brain barrier to cause multiple sclerosis

November 21, 2017
Drug designers working on therapeutics against multiple sclerosis should focus on blocking two distinct ways rogue immune cells attack healthy neurons, according to a new study in the journal Cell Reports.

New simple test could help cystic fibrosis patients find best treatment

November 21, 2017
Several cutting-edge treatments have become available in recent years to correct the debilitating chronic lung congestion associated with cystic fibrosis. While the new drugs are life-changing for some patients, they do not ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.