Definitive identification of Bacillus anthracis - a review

The word 'problem' is seen with some frequency in relation to clear differe ntiation between Bacillus anthracis and B. cereus. In fact, although the cl ose relationship of these tn two species is undisputed, it is only in the c ase of a few borderline isolates, rarely encountered in practice, that any sort of identification problem exists. Until recently this was only importa nt to the taxonomist who found it unsatisfactory not to be able to identify definitively such isolates. To most others, if the isolate was unable to p roduce anthrax in a laboratory animal, it was discarded as irrelevant witho ut being named, or it was called B. cereus or given a name such as B. anthr acis similis, or even a totally unrelated name. More recently, in view of t he new light in which B. anthracis is increasingly seen, resulting from its putative association with bioaggression, clear identification has become a more critical issue. This paper reviews the current state of the art and s uggests the way forward for the future.