A common marine bacteria caused the lesions on diseased fish caught by Port Orange commercial fishermen, not the staphylococci bacteria associated with resistant infections, national marine scientists said Monday.

National Oceanic and Atmospheric Administration officials, who oversaw the tests, had cautioned from the beginning that no link was made between the lesions on the diseased deepwater fish and the severe lesions several fishermen have suffered in recent months.

Even so, a lab in Beaufort, N.C., tested the two snowy grouper.

Scientists found no evidence of staphylococci or fungi.

The Volusia County Health Department has confirmed three cases of methicillin resistant Staphylococcus aureus (MRSA) infections but says the disease most likely has been passed by person-to-person contact, not by contaminated seawater.

The department also is conducting investigations to determine whether fishermen and two swimmers have contracted the MRSA infection.

MRSA infections are common, health officials say, and have increased in recent years. Hospitals say they treat several cases each month.

Jeff Libby can be reached at jlibby@orlandosentinel.com or 386-253-2316.