UH finds staph-fighting ocean organism
University of Hawaii researchers have isolated a bacterium from a marine organism in Kaneohe Bay that knocked out an antibiotic-resistant strain of staphylococcus.
The discovery could lead to development of oral and topical antibiotics for resistant strains of staph infections, the scientists said.
Staph infections are a big issue in Hawaii, "arguably one of the best places in the world to study this problem," said Ed Laws, who heads a UH-Manoa center that is investigating the link between the oceans and human health.
The UH group is collaborating with San Diego-based Diversa Corp. under a 2004 agreement to isolate and screen novel strains of marine microbes for compounds to fight tumors and infections.
The scientists are excited about the potential for new medicines from marine microorganisms, one of three major areas they are investigating.
"We're isolating these strains of staph from recreational waters around Hawaii," Laws said in a recent interview. "We have a nice collection now, and we're screening them to see if we can identify new antibiotics to treat people with staph."
Robert Bidigare, director of the Center for Marine Microbial Ecology and Diversity, said research at the center shows a higher diversity of resistant staph strains at Hawaii beaches "because of tourists coming from different places."
Using Diversa's cultivation technologies, he said, "We've been getting organisms into culture that have never been cultured before."
Screening results are producing "very, very active extracts," said Bidigare, who heads the culture collection.
"We've got several exciting hits that have wide spectrum antimicrobial activity," he said. "They knock out methicillin-resistant staphylococcus."
The researchers are also looking at the possibility of antibiotics to apply to the skin for infections swimmers or paddlers might pick up from the Ala Wai Canal or coastal waters, Bidigare said.
Promising organisms are given to UH chemistry professor Thomas Hemscheidt to determine the molecular structure. Then, they are sent to pharmaceutical companies for further evaluation to see if they are suitable for drug development, Bidigare said.
The UH Center for Oceans and Human Health was one of four centers established nationally two years ago to explore benefits or harm to human health from marine organisms.
The centers work together on various problems, including a large study organized by Laws after Hurricane Katrina to study its effects on Lake Pontchartrain.
Researchers from the centers shared results of their work at a recent national ocean conference in Honolulu.
Marine pathogens in coastal waters and harmful effects of algal blooms, which produce ciguatoxins, are other prime areas of research.
"We're working on molecular techniques, which are a lot faster than standard incubation methods the Department of Health has been using over the years to monitor coastal waters, to decide whether the water is safe for people to go into," Laws said.
The big problem with marine toxins is that the organism that presumably causes the illness is a "natural inhabitant of the marine environment" rather than a product of sewage, Laws said.
"The big issue is, Why do organisms occasionally produce large amounts of neurotoxin that find their way up the food chain and get into fish, specifically herbivorous reef fish people eat?"
Ciguatera has not been much of a problem in Hawaii, probably because people have learned from experience which fish to avoid, Laws said.