PCR ANALYSIS OF TISSUE SAMPLES FROM THE 1979 SVERDLOVSK ANTHRAX VICTIMS - THE PRESENCE OF MULTIPLE BACILLUS-ANTHRACIS STRAINS IN DIFFERENT VICTIMS

An outbreak of human anthrax occurred in Sverdlovsk, Union of Soviet S ocialists Republic (now Ekaterinburg, Russia) in April 1979, Officials attributed this to consumption of contaminated meat, but Western gove rnments believed it resulted from inhalation of spores accidentally re leased from a nearby military research facility, Tissue samples from 1 1 victims were obtained and methods of efficiently extracting high-qua lity total DNA from these samples were developed, Extracted DNA was an alyzed by using PCR to determine whether it contained Bacillus anthrac is-specific sequences, Double PCR using ''nested primers'' increased s ensitivity of the assay significantly, Tissue samples from 11 persons who died during the epidemic were examined. Results demonstrated that the entire complement of B. anthracis toxin and capsular antigen genes required for pathogenicity were present in tissues from each of these victims, Tissue from a vaccination site contained primarily nucleic a cids from a live vaccine, although traces of genes from the infecting organisms were also present. PCR analysis using primers that detect th e vrrA gene variable region on the B, anthracis chromosome demonstrate d that at least four of the five known strain categories defined by th is region were present in the tissue samples, Only one category is fou nd in a single B. anthracis strain.