Scientists have hit upon a way to detect at one time the seven types of toxins that cause botulism by using antibodies produced by llamas, Science Daily reported today (see GSN, Sept. 12, 2008).
Botulinum toxins are roughly 100 billion times more poisonous than cyanide. The toxins have been categorized as one of the most serious possible biological weapons by the U.S. Centers for Disease Control and Prevention.
Scientists at the Southwest Foundation for Biomedical Research in San Antonio, Texas, used llama antibodies to create their botulism detection test. The researchers employed bioengineering methods to clone antibody genes of a llama that had been exposed to inert forms of the seven botulinum types. The reproduced proteins were then checked for their capacity to identify botulinum toxins in a variety of drinks
Llamas' single-domain antibodies "may allow biosensors to be regenerable and used over and over without loss of activity," said Southwest Foundation virologist Andrew Hayhurst. "Also, for some types of [botulinum toxins], conventional antibodies are not generally available and we are filling this biosecurity gap."
The single-domain antibodies could also have uses in a medical treatment for people exposed to the toxin.
This research is being funded by the U.S. Defense Department's Defense Threat Reduction Agency Medical Diagnostics Program.
Botulism attacks the nervous system and is produced by bacteria typically found in infected injuries and contaminated food. It can cause a paralysis so strong that infected individuals have to be put on life support for a period of time. There are few existing preventive or treatment measures for botulism, highlighting the importance of detection within the environment.
"We not only aim to use the antibodies in [botulinum toxin] detection tests, but also to understand how they bind and inhibit these fascinating molecules," Hayhurst said. "We are also striving to improve our test by making it more sensitive such that one day it may be able to detect much smaller amount of toxins found in patients' blood" (Science Daily, Jan. 21).