The prevention of infection is perhaps less of a mystery. Despite gaping wounds and deep flesh tears, those who observe dolphins following shark bites have not noted significant rates of infection. Zasloff says it's likely that the animal's blubber holds key answers.
Blubber and its composition have been studied extensively for many years because it accumulates many toxic pollutants of human origin, such as heavy metals from its food sources, which allows scientists to monitor environmental pollution, Zasloff says. It is therefore well documented that blubber also contains natural organohalogens which are known to have antimicrobial properties and antibiotic activity.
"It's most likely that the dolphin stores its own antimicrobial compound and releases it when an injury occurs," Zasloff predicts. "This action could control and prevent microbial infection while at the same time prevent decomposition around the animal's injury."
Finally, Zasloff explores the ability of the dolphin's wound to heal in a way that restores the dolphin's body contour. He says the dolphin's healing ability is less like human healing and more like regeneration.
"The repair of a gaping wound to an appearance that is near normal requires the ability of the injured animal to knit newly formed tissues with the existing fabric of adipocytes, collagen and elastic fibers," he explains. "The dolphin's healing is similar to how mammalian fetuses are able to heal in the womb."
Brent Whitaker, M.S., D.V.M., deputy executive director for biological programs at the National Aquarium in Baltimore describes Zasloff's letter as "thought provoking." Zasloff consulted with Whitaker as part of his research.
"It makes sense that the dermal tissues of the dolphins would evolve mechanisms to protect them from the microbes ever present in the water in which these animals live," Whitaker says. "Other aquatic animals
|Contact: Karen Mallet|
Georgetown University Medical Center