title: Protective antigen as a correlative marker for anthrax in animal models.
abstract: The most aggressive form of anthrax results from inhalation of airborne spores of Bacillus anthracis and usually progresses unnoticed in the early stages because of unspecific symptoms. The only reliable marker of anthrax is development of bacteremia, which increases with disease progress. Rapid diagnosis of anthrax is imperative for efficient treatment and cure. Herein we demonstrate that the presence and level of a bacterial antigen, the protective antigen (PA), a component of B. anthracis toxins, in host sera can serve as a reliable marker of infection. This was tested in two animal models of inhalation anthrax, rabbits and guinea pigs infected by intranasal instillation of Vollum spores. In both models, we demonstrated qualitative and quantitative correlations between levels of bacteremia and PA concentrations in the sera of sick animals. The average time to death in infected animals was about 16 h after the appearance of bacteremia, leaving a small therapeutic window. As the time required for immunodetection of PA can be very short, the use of this marker will be beneficial for faster diagnosis and treatment of inhalation anthrax.
authors.affiliation: Department of Infectious Diseases, Israel Institute for Biological Research, P.O. Box 19, Ness-Ziona, Israel 74100.
authors.forename: David
authors.initials: D
authors.lastname: Kobiler
authors.forename: Shay
authors.initials: S
authors.lastname: Weiss
authors.forename: Haim
authors.initials: H
authors.lastname: Levy
authors.forename: Morly
authors.initials: M
authors.lastname: Fisher
authors.forename: Adva
authors.initials: A
authors.lastname: Mechaly
authors.forename: Avi
authors.initials: A
authors.lastname: Pass
authors.forename: Zeev
authors.initials: Z
authors.lastname: Altboum
mesh_terms: D000818:Animals; D000881:Anthrax / Q000175:diagnosis*; D000942:Antigens, Bacterial / Q000097:blood; D016470:Bacteremia / Q000175:diagnosis*; D001427:Bacterial Toxins / Q000097:blood; D015415:Biomarkers / Q000097:blood; D004195:Disease Models, Animal; D006168:Guinea Pigs; D018410:Pneumonia, Bacterial / Q000175:diagnosis*; D011817:Rabbits
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D015415:Biomarkers; C030325:anthrax toxin