Antibiotic Resistance: A Rising Concern In Marine Ecosystems
At the 2009 annual meeting of the American Association for the Advancement of Science, a team of researchers, including Bigelow Senior Research Scientist Dr. Ramunas Stepanauskas, called for new awareness of the potential for antibiotic resistant illnesses from the marine environment, while also pointing to marine resources as the source of possible cures for those threats. (2/16/2009)
February 13, 2009
National Oceanographic and Atmospheric Administration
Contact: Ben Sherman, 202-253-5256 (Cell)
Chicago, IL. -- A team of scientists, speaking today at the annual meeting of the American Association for the Advancement of Science, called for new awareness of the potential for antibiotic resistant illnesses from the marine environment, while also pointing to marine resources as the source of possible cures for those threats.
The group stated that newly completed studies of ocean beach users point to an increasing risk of staph infections; that current treatments for seafood poisoning may be no longer effective due to increased antibiotic resistance; and that new research has identified sponge and coral-derived chemicals with the potential for breaking down antibiotic resistant compounds and that could lead to new personalized medical treatments.
“This panel shows that while the marine environment can indeed be hostile to man, it can also potentially provide new resources that can help us reduce our risks from such illnesses as those caused by water born staph or seafood poisoning,” stated Paul Sandifer, Ph.D., former member of the U.S. Commission on Ocean Policy, chief scientist of NOAA’s Oceans and Human Health Initiative, and co-organizer of the symposium. “It is critically important that we continue to research the complex interactions between oceans and human health. If we don’t succeed, new insights --- from beach to bench to bedside – will be lost and possible solutions to critical public health issues will be left unsolved.”
Coral, Sponges Point To Personalized Medicine Potential
“We’ve found a significant new tool to fight the antibiotic resistance war,” says NOAA research scientist Peter Moeller, Ph.D. in describing the identification of new compounds derived from a sea sponge and corals.
“The first hit originates with new compounds that remove the shield bacteria utilize to protect themselves from antibiotics. The second hit is the discovery of novel antibiotics derived from marine organisms such as corals, sponges and marine microbes that fight even some of the worst infectious bacterial strains. With the variety of chemicals we find in the sea and their highly specific activities, medicines in the near future can be customized to individuals’ needs, rather than relying on broad spectrum antibiotics.”
The research team, a collaboration between scientists at NOAA’s Hollings Marine Laboratory in Charleston, S.C. and researchers at North Carolina State University in Raleigh, N.C. noticed a sponge that seemed to thrive despite being located in the midst of a dying coral reef. After extracting novel chemicals, testing showed that the one of the isolated chemicals, algeliferin, breaks down a biofilm barrier that bacteria use to protect themselves. The same chemical can also disrupt or inhibit formation of biofilm on a variety of bacteria previously resistant to antibiotics which could lead to both palliative and curative response treatment depending on the problem being addressed.
“This could lead to a new class of helper drugs and result in a rebirth for antibiotics no longer thought effective,“ notes Moeller. “Its potential application to prevent biofilm build-up in stents, intravenous lines and other medical uses is incredible.”
The compound is currently being tested for a variety of medical uses and has gone through a second round of sophisticated toxicity screening and shows no toxic effects.
Staph: A Beach Going Concern
Research, funded by multiple agencies and conducted by the University of Miami's Rosenstiel's School of Ocean Sciences and the Miller School of Medicine, found that swimmers using public ocean beaches increase their risk for exposure to staph organisms, and they may increase their risk for potential staph infections once they enter the water.
"Our study found that if you swim in subtropical marine waters, you have a significant chance -- approximately 37 percent - of being exposed to staph -- either yours or possibly that from someone else in the water with you," explained Dr. Lisa Plano, a pediatrician and microbiologist with the University of Miami's Leonard M. Miller School of Medicine. Plano collaborated in the first large epidemiologic survey of beach users in recreational marine waters without a sewage source of pollution. "This exposure might lead to colonization or infection by water-borne bacteria which are shed from every colonized person when entering the water. Those who have open wounds or are immune compromised are at greatest risk of infection."
The Miami research team does not advise avoiding beaches, but recommends taking precautions to reduce risk by showering thoroughly before entering the water and after getting out. They also point out that while antibiotic resistant staph, commonly known as MRSA, has been increasingly found in diverse environments, including in the marine environment, that less than three per cent of staph from the beach waters was of the potentially virulent MRSA variety in their study. More research is needed to understand how long staph (including MRSA) can live in coastal waters, and the uptake and infection rate associated with the beach exposures.
Antibiotic Resistance in Seafood-borne Pathogens Increasing
Researchers at the Bigelow Laboratory for Ocean Science in West Boothbay Harbor, Maine report that the frequency of antibiotic resistence in vibrio bacterial species which are the leading cause of seafood-bourne illness and death in the United States were significantly higher than expected, suggesting that the current treatment of vibrio infections needs to be re-examined. The severity of these infections makes antibiotic resistance in vibrios a critical public health concern.
Naturally-occurring resistance to antibiotics among Vibrios may undermine the effectiveness of antibiotic treatment, but as yet this has not been extensively studied. Furthermore, antibiotics and other toxicants discharged into the waste stream by humans may increase the frequency of antibiotic-resistant Vibrio strains in contaminated coastal environments.
“We found resistance to all major classes of antibiotics routinely used to treat Vibrio infections, including aminoglycosides, tetracyclines, and cephalosporins,“ stated Bigelow Laboratory’s Ramunas Stepanauskas, Ph.D. “In contrast, we found that Vibrios were highly susceptible to carbapenems and new-generation fluoroquinolones, such as Imipenem and Ciprofloxacin. This information may be used to design better strategies to treat Vibrio infections.” ###