USF sponge discovery in antarctic kills MRSA

Posted at 1:16 PM, May 18, 2016

A serious and sometimes fatal bacterial infection known as MRSA may soon be curable thanks to a discovery by scientists from the University of South Florida.

USF scientists extracted a chemical from a sponge found in Antarctica that killed 98 percent of MRSA, or (methicillin-resistant Staphylococcus aureus) cells in a lab test.

The naturally-produced chemical has been named “darwinolide.”

The study and results were published this week in the American Chemical Society’s journal Organic Letters.

According to the Centers for Disease Control and Prevention (CDC), the highly-resistant MRSA infection continues to be a problem in Florida in places like hospitals and nursing homes, gyms and locker rooms 

“In recent years, MRSA has become resistant to vancomycin and threatens to take away our most valuable treatment option against staph infections,” said study co-author and USF microbiologist Dr. Lindsey N. Shaw.

MRSA is unique in that it can cause infections in almost every part of the human body, from skin infections to pneumonia, to endocarditis, a serious infection of tissues lining the heart.

In the U.S. alone there are two million hospital-acquired infections annually with at least 100,000 deaths, many resulting from bacteria resistant to current antibiotics.

Unfortunately, the pace of the pharmaceutical industry’s efforts to find new antibiotics to replace those no longer effective has slowed in recent years, Shaw said.

Like many other bacterium, the MRSA bacteria forms a biofilm.

“Biofilms, formed by many pathogenic bacteria during infection, are a collection of cells coated in a variety of carbohydrates, proteins and DNA,” Shaw said. “Up to 80 percent of all infections are caused by biofilms and are resistant to therapy. We desperately need new anti-biofilm agents to treat drug resistant bacterial infections like MRSA.”

USF chemistry professor Dr. Bill Baker and colleagues have literally gone to the ends of the Earth to help in the fight against MRSA. Baker, who also serves as director of the USF Center for Drug Discovery and Innovation, studies the chemical ecology of Antarctica and dives in the frigid waters near Palmer Station to retrieve marine invertebrates, such as sponges, to carry out “natural product isolation,” which means drawing out, modifying and testing natural substances that may have pharmaceutical potential.

“When we screened darwinolide against MRSA we found that only 1.6 percent of the bacterium survived and grew. This suggests that darwinolide may be a good foundation for an urgently needed antibiotic effective against biofilms,” Baker told ABC Action News on Wednesday.

“We suggest that darwinolide may present a highly suitable scaffold for the development of urgently needed, novel, anti-biofilm-specific antibiotics,” concluded the researchers.