DAYTONA BEACH -- Evidence is mounting that painful skin lesions on 10 commercial fishermen in Volusia County probably were not caused by the ocean, and lesions on their fish did not pose a public health hazard.

Reports released Monday from pathological tests on two grouper with skin lesions caught by the fishermen showed the lesions were not caused by the same organism believed to have caused the infections in the deep-sea fishermen.

The fish posed no threat to human health, said Dr. Craig Harms of the North Carolina State University College of Veterinary Medicine, who tested the two snowy grouper caught by the fishermen about 200 miles offshore.

"We didn't find anything that would support a link between the fish and the fishermen," Harms said.

Harms found four types of bacteria on the fish, all of them bacteria normally found on marine organisms and none related to the methicillin-resistant staphylococcus aureus, commonly known as MRSA, which caused the fishermen's lesions.

The fishermen had worried their disease could have come from the ocean. That's why they gave the grouper to a biologist with the National Oceanic and Atmospheric Administration.

The antibiotic-resistant staph infections are becoming more common worldwide and are easily spread. Local health officials have maintained the infections among local swimmers and fishermen were most likely spread from person to person, and did not come from the ocean.

But a University of Hawaii microbiologist, who has sampled ocean water for bacterial pathogens, including MRSA, said he has found it in water close to shore on some of Hawaii's congested beaches, likely washed off of infected swimmers. The microbiologist, Roger Fujioka, said it's unlikely the land-borne bacteria would be found 150 to 200 miles offshore, causing lesions in the commercial fishermen.

Harms said he does not know what caused the lesions in the grouper. He could not completely test the fish because they were frozen rather than preserved in a chemical that would have allowed proper biological testing, he said.

"There's any number of things that could cause skin ulcers in fish," Harms said.

Officials with the Florida and Volusia County departments of public health are looking into the infections reported among the fishermen here and in other parts of the state.

Bacterial infections are common among commercial fishermen and others who handle fish. MRSA usually affects people with weakened immune systems, including cigarette smokers and patients in hospitals, nursing homes and other medical facilities.

The skin disorder commonly starts with small pustules that can expand to the size of silver dollars within days. Left untreated, MRSA can result in massive infection, amputation and even death.

-- Staff Writer Ray Weiss contributed to this report.