Role of superoxide in the germination of Bacillus anthracis endospores.
The spore forming Gram-positive bacterium Bacillus anthracis, the causative agent of anthrax, has achieved notoriety due to its use as a bioterror agent. In the environment, B. anthracis exists as a dormant endospore. Germination of endospores during their internalization within the myeloid phagocyte, and the ability of those endospores to survive exposure to antibacterial killing mechanisms such as superoxide (O(2)*-, is a key initial event in the infective process. We report herein that endospores exposed to fluxes of O(2)*- typically found in stimulated phagocytes had no effect on viability. Further endospores of the Sterne strain of B. anthracis were found to scavenge O(2)*-, which may enhance the ability of the bacterium to survive within the hostile environment of the phagolysosome. Most intriguing was the observation that endospore germination was stimulated by a flux of O(2)*- as low as 1 microM/min. Data presented herein suggest that B. anthracis may co-opt O(2)*- which is produced by stimulated myeloid phagocytes and is an essential element of host immunity, as a necessary step in productive infection of the host.
Baillie
Les
L
Medical Biotechnology Center, University of Maryland Biotechnology Institute, Baltimore, MD 21201, USA. bailliel@nmrc.navy.mil
Hibbs
Stephen
S
Tsai
Pei
P
Cao
Guan-Liang
GL
Rosen
Gerald M
GM
D001408:Bacillus anthracis / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D015169:Colony Count, Microbial; D015964:Gene Expression Regulation, Bacterial; D013171:Spores, Bacterial / Q000187:drug effects / Q000502:physiology; D013481:Superoxides / Q000494:pharmacology*; D014969:Xanthine Oxidase / Q000378:metabolism
D013481:Superoxides; D014969:Xanthine Oxidase