Bacillus anthracis, virulence factors, PCR, and interpretation of results

Editorial Anthrax is a non-contagious infectious disease that affects a wide range of animal species, including humans, but especially sensitive are domestic and wild ruminants. The bacterial agent is Bacillus anthracis, whose main feature is to form spores that can survive in the environment for several decades. Anthrax, in susceptible animals, has a generally fatal outcome characterized by sudden death and leakage of blood from the natural openings. In humans, the disease develops in three forms, depending on the route of penetration of the bacterium: cutaneous (non-fatal), pulmonary , and gastrointestinal form (fatal). Recently a fourth fatal form (injectional anthrax) has been reported in drug users as a result of injections of heroin contaminated with anthrax spores. 1 Thanks to its strong ability to maintain the vitality and viru-lence for many decades and to the very low costs of production, B. anthracis is considered one of the pathogens of interest such as bacteriological weapon in a hypothetical bioterrorist attack. B. anthracis spends most of its existence the ground as a spore, until the ideal conditions are created, allowing it to initiate a reproductive cycle that occurs in a different habitat represented mainly by domestic and wild ruminants. Nature provides few opportunities to the bacterium for its replication cycle, and the development of an extraordinary virulence is the effective strategy to significantly increase the probability of success against the host immune mechanisms. The rapid and intense multiplication of vegetative cells within the host brings it to a speedy death. Although many of the new generations of bacteria are neutralized by putrefactive processes, a sufficient part of them survive and spread into the surrounding soil as spores. The bacterium acts within its host with an exceptional virulence because its objective is to kill the host and produce a large amount of spores able to guarantee the standard of environmental density essential for the continuation of the species. Reported are cases of animals that survive the disease, but these could represent a failure of the bacteria because this try doesn't produce spores. In summary, the few animal anthrax cases that occur each year in endemic areas of the world are nothing more than the result of a natural ecological balance that through these extraordinary events seeks to promote the maintenance of a bacterial species that otherwise would have become extinct long time ago (personal consideration). Virulent forms of B. anthracis harbor two large …