Scientific Publications by FDA Staff

J Infect Dis 2017 Dec 12;216(11):1471-5

Gastric pH and toxin factors modulate infectivity and disease progression following gastrointestinal exposure to Bacillus anthracis.

Xie T, Rotstein D, Sun C, Fang H, Frucht DM

Gastrointestinal (GI) anthrax is the most prevalent form of naturally acquired B. anthracis infection, associated with exposure to vegetative bacteria in infected meat (carnivores) or to fermented rumen contents (herbivores). We assessed whether key host and pathogen factors modulate infectivity and progression of infection using a mouse model of GI infection. Gastric acid neutralization increases infectivity, but 30-40% of mice succumb to infection without neutralization. Mice either fed or fasted prior to exposure show similar infectivity rates. Finally, the pathogen's anthrax lethal factor is required to establish lethal infection, whereas its edema factor modulates progression and dissemination of infection.