Several detection systems have been developed to identify B. anthracis such as very complex, time-consuming and expensive genetic methods. In contrast, immunological tests are easy to handle. However, the development of a reliable immunological test for Anthrax has been elusive. The spore cell surface of Anthrax is too similar to the spore cell surface of other bacteria. Therefore, the antibodies developed to date had been lacking specificity and resulted in false positives.
Recently, a unique sugar on the surface of Anthrax spores was discovered. Prof. Peter H. Seeberger and his team at Eidgenössische Technische Hochschule (ETH) Zürich's Laboratory of Organic Chemistry chose this carbohydrate as target for their new immunological approach. To produce antibodies, the carbohydrate molecule to be targeted has to be produced. Since isolation from the deadly bacteria is not possible, Seeberger and postdoc Daniel Werz chose chemical synthesis to create the sugar from scratch.
Attached to a special protein as a carrier the carbohydrate was injected into mice that produced antibodies. Monoclonal antibodies bind Anthrax spores in a highly specific manner. Even close relatives of Bacillus anthracis did not bind. "Our results demonstrate that small, but distinct differences in cell surface sugars can be used to create highly specific immunological reagents," comments Seeberger. "This new antibody will be the basis for a highly sensitive Anthrax diagnostic system and contribute to the development of novel therapeutic or preventive approaches."
Spores of Bacillus anthracis have been used as biowarfare agents to terrorize civilian populations. Once this durable form of the pathogen has been inhaled it will kill most victims if treatment does not commence within 24-48 hours. Therefore, a fast and highly reliable diagnostic test is important.
MEDICA.de; Source: Eidgenössische Technische Hochschule