The workers are not at risk of contracting tuberculosis even if they were exposed to the bacteria, said Sheila Allen, dean of UGA’s College of Veterinary Medicine.
The bacteria was released Nov. 9 inside a lab in the college’s main building on D.W. Brooks Drive, she said.
The only potential consequence is that workers might have false-positive TB tests in the future, she said.
The bacteria, called Bacillus Calmette-Guérin, or BCG for short, is actually used as a vaccine against tuberculosis in many countries.
It is the most widely used vaccine in the world, said Fred Quinn, head of the college’s department of infectious diseases.
In the United States, BCG is an effective treatment for bladder cancer.
Scientists investigating tuberculosis like to use BCG in research because it will induce immune system responses similar to infectious strains of the bacteria, but has been deliberately changed so it will not cause disease, Quinn said.
First developed in the 1920s, BCG is a weakened form of Mycobacterium bovis, the cause of tuberculosis in cattle.
It can cause infection in people with a compromised immune system, but workers in the UGA lab have undergone tests to make sure they have normal immune systems, Allen said.
A scientist used the wrong kind of container for the bacterium in a machine, Allen said.
The researcher put a plastic tube containing BCG into a centrifuge, a machine used to separate heavier materials in a liquid by whirling them rapidly in a circle.
The scientist should have used a tube with stronger walls; as the centrifuge spun, the tube wall collapsed, releasing the contents out into the machine.
The scientist and other lab workers cleaned up the rotor right after the spill, Allen said.