Sponges' secret weapon

Published: 07/02/2010

Bacteria are tiny, single-celled organisms that can cause disease in humans through infection. Bacteria can live almost anywhere: in soil, water, food or your body. We can cure many types of bacterial infections with the use of medicine called antibiotics, which kill the germy organisms.
Unfortunately, some types of bacteria do not respond to antibiotics. This resistance can be a big problem for humans — if our antibiotics don’t kill the bacteria, then a bacterial infection can be deadly. Some bacteria that cause ear infections, food poisoning and whooping cough, for example, can resist antibiotics.
Scientists recently discovered a new way to fight these tough bacteria. And it was in a very unusual place: under the sea.
Peter Moeller, a chemist at the Hollings Marine Laboratory in Charleston, S.C., and his team found a place on the ocean floor where all the organisms were dead — except for a sponge.
Sponges are simple aquatic animals, many of which look like tubes. (Historically, humans have used dead sponges for scrubbing and cleaning, but most modern sponges — like the one by your kitchen sink — are made from synthetic, or man-made, materials.)
“How is this thing surviving when everything else is dead?” Moeller asked about the lone sponge. He knew that the sea is like a playground for disease — ocean water is literally swimming with bacteria.
In the body of the sponge, the scientists found a chemical called ageliferin. That chemical, which is nontoxic, might make it possible to fight against bacteria that don’t respond to antibiotics. When the scientists put ageliferin on some particularly tough bacteria in the laboratory and then added antibiotics, the germy organisms died. Ageliferin’s power to resist bacteria can help explain why the sponge is able to survive in a place where other organisms cannot.
In February, Moeller announced that ageliferin might be used against bacteria that threaten humans. In the laboratory, he has found that ageliferin can boost the power of antibiotics against bacteria that cause whooping cough, ear infections and food poisoning. It might also be used to fight bacterial infections that occur among wounded soldiers.
That news is promising. But right now, ageliferin works only in the laboratory. The scientists don’t know how ageliferin works, and they don’t know if it will ever really help humans fight back against bacteria. Nonetheless, it works for sponges — and it just may work for us.