Scientists reportedly were able to match DNA from a specific strain of E. coli bacteria found in the Ag-Venture Farms livestock with DNA in the humans who were afflicted.

The infected animals include two goats, two sheep and two cows. All of the zoo's 37 animals have been placed under quarantine, however.

Although no deaths have resulted from the outbreak, 22 victims have required hospitalization and eight remain in hospital care, including one who is in critical condition, according to press reports. The patients acquired the disease after attending petting zoos at Florida fairs.

Animal Owner Expresses Sadness

Tom Umiker, owner of Ag-Venture has expressed great sorrow over the outbreak, Agriculture Department spokesman Terence McElroy told the St. Petersburg Times.

"He's devastated that this occurred," McElroy is quoted as saying. "He said under no circumstances would he consider reintroducing the animals to the public."

Ag-Venture is co-operating fully with the investigation, according to Florida Agriculture Commissioner Charles Bronson.

Rarely Spread by Petting Zoo Animals

The strain of E. coli involved in the Florida outbreak, O157:H7, is harmless to the animals who carry it, but can be deadly to people. Its most common symptom is severe, bloody diarrhea, but it can lead to life-threatening complications, such as kidney failure.

Outcomes of the disease can include permanent damage that requires a lifetime of dialysis or a kidney transplant.

This type of E. coli usually is associated with eating contaminated food products, most often undercooked beef. Other food products also can be affected. Just 3% of E. coli outbreaks since 1982 have been connected to petting zoos, according to reports.