WASHINGTON - Only two of the nation's 114 licensed veterinary laboratories keep anthrax cultures and their form of the microbe is harmless, according to federal officials.

Following the death from anthrax in Florida, the U.S. Department of Agriculture ordered all of the labs to submit a detailed inventory of their anthrax cultures and officials said Friday that the results suggest that veterinary labs could not be the sources of anthrax that has recently infected eight people.

Hallie Pickhardt, a USDA spokesperson, said that only two vet labs reported anthrax cultures in their inventories and one of those labs, Colorado Serum of Denver, is the only U.S. firm now producing animal anthrax vaccine. The other company, which Pickhardt declined to identify, has anthrax cultures on hand, but is no longer making the vaccine.

Until recently, a third veterinary lab was licensed to have anthrax cultures, but Pickhardt said it has gone out of business and has destroyed its cultures and is returning the license. She declined to name the company.

All the anthrax cultures in the veterinarian labs are of a strain that will not cause disease in either animals or humans. The strain has been used for decades to make animal vaccine, experts said.

The Oct. 5 death of a Florida man, who was exposed at the Boca Raton offices of American Media, prompted the USDA's Animal & Plant Health Inspection Service to conduct a hurried inventory of anthrax stocks in U.S. veterinarian labs.

Joe Huff, president of Colorado Serum, said that USDA officials called his office and ordered the inventory and that his lab complied.

Colorado Serum has been making anthrax vaccine for many years, he said, using a benign bacillus that is a close relative to the deadly microbe.

"It is called the Sterne strain and has been used for at least 40 years," said Huff.

The anthrax strain was originally isolated by Max Sterne, a South African, and has been used to make animal vaccine because it is safe to work with. Although the Sterne strain is benign, it is so closely related to the deadly form of anthrax that it's antigens can be used to make an effective vaccine, said Huff.

Experts have said that it is the Ames strain of anthrax that was used in U.S. biological warfare research that ended in 1970 and is thought to be closely related to the strain that has killed the man in Florida and sickened six other Americans. The Ames strain is also used to test vaccines developed to protect humans from the disease, said Dr. Martin Hugh-Jones, an anthrax researcher at Louisiana State University.

Ames, he said, "is a hot one. It puts any vaccine through its paces."