Demonstration of a Capsule Plasmid in Bacillus anthracis,
ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD
Pagination or Media Count:
Virulent and certain avirulent strains of Bacillus anthracis harbor a plasmid, designated pX02, which is involved in the synthesis of capsules. Two classes of rough noncapsulated Cap- variants were isolated from the capsule-producing Cap Pasteur vaccine strain 6602 those which were cured of pX02 and those which still carried it. Reversion to Cap was demonstrable only in rough variants which had pX02. By means of a mating system in which plasmid transfer is mediated by a Bacillus thuringinensis fertility plasmid, pX012, pX02 was transferred from B. anthracis to Bacillus cereus. B. cereus transcipients which acquired pX02 produced capsules under the same conditions required for capsule synthesis by b. anthracis.