Scientists eye bad bugs at Great Lakes beaches

By CAROL THOMPSON
Capital News Service
LANSING — While health agencies look for faster ways to detect harmful E. coli bacteria on public beaches, including those on lakes Michigan, Huron and Erie, they are overlooking another germ that may cause even greater problems, scientists warn.
Staphylococcus aureus, or staph, is a newly recognized beach threat by research teams across the country.
“This organism is tenacious, it can reoccur and it can be very difficult to get rid of,” said Marilyn Roberts, a University of Washington professor who has studied the bacteria on marine and freshwater beaches near Seattle. “It can cause a huge amount of destruction of tissue, and in the worst case scenario it can cause death.”
The federal Environmental Protection Agency doesn’t require local governments to check beaches for staph. Instead, they test for E. coli, a bacteria usually spread through feces from farm runoff or leaky sewers. The detectors pick up on some strains of harmful bacteria but not staph.
But runoff and sewers aren’t the culprits that spread staph. Staph usually lives on skin, which leads some scientists such as Lisa Fogarty to believe its source is beachgoers themselves.
“We can’t identify a contaminant offsite that’s bringing it to the beach,” said Fogarty, supervisory hydrologist at the U.S. Geological Survey’s Michigan Water Science Center. “It’s probably coming from the swimmers.”
Fogarty is studying the germs on Great Lakes beaches.
Staph infections can be complicated because some strains are resistant to methicillin, an antibiotic usually reserved for last-resort hospital cases. Those strains are called MRSA – pronounced “mersa” – which stands for methicillin-resistant staphylococcus aureus.
“Organisms that are resistant to methicillin are typically resistant to a large class of antibiotics, so treatment of MRSA is very difficult,” Fogarty said.
In 2010, Fogarty found staph on all five Lake Erie beaches she tested. One of two she examined on Lake Huron and three of six she checked on Lake Michigan also tested positive.
Almost half the beaches she tested had the potential to harbor the antibiotic-resistant staph bacteria.
However, the beaches were not closed because their E. coli levels were within regulatory limits.
However, she says she doesn’t know whether anyone has contracted staph infections from Great Lakes beaches or how much bacteria are needed to pose a health risk.
Toxicologist Shannon Briggs of the Department of Environmental Quality said beachgoers should practice good hygiene and wash after playing in the sand until scientists learn more about staph and the antibiotic-resistant staph.
“Different types of bacteria could be present in beach sand, but we’re just now detecting them and need to know a lot more about it,” Briggs said. “For most of us, when we go to the beach it isn’t a problem because we can play and then wash our hands.”
Roberts recommends people take hygiene a step further by washing toys and animals that have been on the beach, and covering up scrapes and wounds that are more vulnerable to infection.
MRSA and staph can be present anywhere there are people, but Briggs said beaches may have a natural disinfectant. “The ultraviolet light from the sun is a natural killer of bacteria, so we have that going for us.”
Fogarty said management of the potential threat is uncertain until research shows more about the risks and how to detect them.
“There’s a lot of concern for beach managers, but what do we do? You can’t stop people from going to the beach,” she said.
Carol Thompson writes for Great Lakes Echo.
© 2012, Capital News Service, Michigan State University School of Journalism. Nonmembers cannot reproduce CNS articles without written permission.