UMD researchers find first known E. coli in fish

[Spiel]

UMD researchers find first known E. coli in fish

 

 

Tuesday, May 06, 2008

Duluth News Tribune

 

Researchers at the University of Minnesota Duluth have found E. coli in bottom-feeding bullheads, the first known case of the organism surviving in fish.

 

In a soon-to-be-published scientific paper, researchers under Randall Hicks, head of the school’s biology department, found E. coli survived in but probably wasn’t produced by the fish.

 

“We believe benthic fish are a pathway, but not a source of E. coli,’’ Hicks said Monday. The fish probably were picking up E. coli in the sediment of the Duluth harbor.

 

Until recently, scientists believed E. coli came only from mammals. But now that’s not as clear, and some E. coli can even reproduce on its own in sand and soil.

 

Other recent UMD research found the single largest source of E. coli in samples taken near the Blatnik Bridge in the harbor, but the source is not what you might think.

 

The answer is waterfowl. But there’s another surprise.

 

Just a few hundreds yards downstream from a ring-billed gull nesting island, and near the outlet of the Western Lake Superior Sanitary District sewage treatment plant, the largest source of E. coli is geese.

 

“You have to be careful not to jump to conclusions with this stuff,’’ Hicks said.

 

Scientists still are unable to trace the source of a considerable amount of E. coli samples for which they can find no DNA matches.

 

E. coli is used as an indicator species to determine whether disease-causing organisms harmful to people may be present in the water and to warn people to stay out of the water at some beaches. Some E. coli strains also can cause sickness.