Chemists find new compounds to curb staph infection

May 23, 2013 by Terry Devitt  
Chemists find new compounds to curb staph infection
These assays were used to assess the effects of new agents to disrupt communication among pathogenic staph bacteria. Research shows promise for a new approach to thwarting staph infections, which are increasingly resistant to conventional antibiotics. Credit: Blackwell Lab

(Phys.org) —In an age when microbial pathogens are growing increasingly resistant to the conventional antibiotics used to tamp down infection, a team of Wisconsin scientists has synthesized a potent new class of compounds capable of curbing the bacteria that cause staph infections.

Writing online in the Journal of the American Chemical Society, a group led by University of Wisconsin-Madison chemistry professor Helen Blackwell describes agents that effectively interfere with the "quorum sensing" behavior of Staphylococcus aureus, a bacterium at the root of a host of ranging from acne to life-threatening conditions such as pneumonia, and sepsis.

"It's a whole new world for us," says Blackwell, whose group identified peptide-based signaling molecules that effectively outcompete the native molecules the bacterium uses to communicate and activate the genes that cause disease.

Bacteria use quorum sensing to assess their population density and coordinate certain behaviors. They do so through the use of pheromone-like chemicals, which bind to receptors either in the bacterial cell or on its surface and tell it if there are enough companion bacteria around to switch on genes that perform certain functions. In the case of Staphylococcus aureus, quorum sensing activates toxin production, manifesting disease in the host.

Interfering with bacterial quorum sensing to stymie disease is considered a promising new antibiotic strategy, says Blackwell. Staph, she adds, is an excellent target as the bacterium is not only a prevalent pathogen, but some strains, notably methicillin-resistant Staphylococcus aureus or , have developed resistance to commonly used antibiotics such as penicillin and its derivatives.

The new compounds synthesized by Blackwell and her colleagues are peptides that work at very low concentrations by blocking the chemical receptors the uses to regulate quorum sensing. The new agents devised by Blackwell and her group work on the four subtypes of staph, all of which use different quorum sensing signals and are found in different infection types.

"We had not worked much in this area because the (signaling molecules) are somewhat challenging to synthesize," explains Blackwell. "We now have developed methods to make these molecules and analogs much more efficiently, which helped fuel this new study."

For now, the compounds devised by the Wisconsin team will have their greatest impact in the lab as research probes to further study the role of quorum sensing in Staphylococcus aureus. In addition, the gritty details of how these synthetic agents work in the cell need to be determined in order to optimize their potential use in both the lab and clinic. Such studies are ongoing.

"The impact of these new peptides could be significant because staph is an important and increasingly scary pathogen. There is plenty of scope," notes Blackwell.

Explore further: Receptor proteins could hold clues to antibiotic resistance in MRSA

Related Stories

Learning the language of bacteria

Dec 06, 2010

Bacteria are among the simplest organisms in nature, but many of them can still talk to each other, using a chemical "language" that is critical to the process of infection. Sending and receiving chemical signals allows bacteria ...

Turning on cell-cell communication wipes out staph biofilms

Apr 30, 2008

University of Iowa researchers have succeeded in wiping out established biofilms of Staphylococcus aureus (staph) by hijacking one of the bacteria's own regulatory systems. Although the discovery is not ready for clinical ...

Recommended for you

Breakthrough points to new drugs from nature

Apr 16, 2014

Researchers at Griffith University's Eskitis Institute have developed a new technique for discovering natural compounds which could form the basis of novel therapeutic drugs.

World's first successful visualisation of key coenzyme

Apr 16, 2014

Japanese researchers have successfully developed the world's first imaging method for visualising the behaviour of nicotine-adenine dinucleotide derivative (NAD(P)H), a key coenzyme, inside cells. This feat ...

User comments : 0

More news stories

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...