Analysis and identification on Bacillus anthracis virulence in the event of the anthrax vaccine suspected virulence recovery

Objective To investigate the virulence and the environmental contamination of Bacillus anthracis used in a teaching experiment in the event of a anthrax vaccine suspected virulence recovery, and provide scientific basis for disposing the event.

Methods Weinvestigated the event and collected the experimental culture, frozen strain and the environmental samples concerning the teaching experiments; The culture was identified by phage lysis and penicillin sensitivity test; The rpoB gene on chromosome, pagA gene on plasmids pXO1 and capC gene on plasmids pXO2 of the culture, frozen strain and the related environmental samples were detected by TaqMan real-time PCR assay.

Results The results showed that there were obvious phage plaque and clear zone around penicillin slip on the culture. The detection of rpoB and pagA genes was positive, but the capC gene was negative in the culture and the frozen strain. The detection of rpoB, pagA and capC genes of Bacillus anthracis was all negative in the environment samples from the teaching sites.

Conclusion The culture and the frozen strain were Bacillus anthracis without capC gene, and the virulence recovery of anthrax vaccine was not found in the event. There was no contamination of Bacillus anthracis in the teaching sites.