Evaluation of spore extraction and purification methods for selective recovery of viable Bacillus anthracis spores

Aims: To investigate methods of improving anthrax spore detection with PLET . Methods and Results: Comparisons were made of PLET and blood-supplemented P LET to recover and distinguish spores of a variety of Bacillus species. Hea t and ethanol purification of spores, and spore extraction from soil with w ater and high specific gravity sucrose plus non-ionic detergent, were also carried out. Conclusions: PLET was more selective and suitable than blood-supplemented P LET for detection of anthrax spores in the environmental specimens. However , PLET is not an optimal spore recovery medium. Purification of spores with ethanol was as effective as heat purification. High specific gravity sucro se plus detergent extraction solutions may be more sensitive than extractio n with water. Significance and Impact of the Study: This study highlights shortcomings wi th the standard PLET isolation of anthrax spores and describes ways in whic h the procedure may be improved.