Monday, June 18, 2007
Golden Eagle Eyrie (Boise Centre on the Grove)

Destruction and Detection of Bacterial Spores

Patrick J. Whitham1, Marilu Perez1, Linda DeVeaux1, Rene Rodriguez1, and Robert V. Fox2. (1) Idaho State University, Pocatello, ID, (2) Idaho National Laboratory, Idaho Falls, ID

Current methods for destruction and analysis of bacterial spores can be time consuming processes. Development of a simple and fast method for the elimination and detection of possibly harmful bacteria is essential to public health and safety. Our purpose is to both determine processes for destroying bacterial spores and to investigate chemical-based analytical techniques for the detection of burst bacterial spores, especially on hard marble and cement-like surfaces. A chemical released by certain bacterial spores upon death or germination is 2,6-pyridinedicarboxcylic acid (DPA). DPA-triggered luminescence can be used as a monitor for spore death.(1) In our studies, DPA analyte concentrations ranging from 5ÁM to 100ÁM, in 150ÁM terbium(III) chloride solutions, yielded luminescence intensities that were linear with concentration. This suggests that detection of spores and their concentrations is possible based on the DPA-triggered Tb luminescence intensity. We will present results on the destruction and subsequent assay of Bacillus subtilis bacterial spores using pressurized heat sterilization, a UV laser, or gamma-ray irradiation. The spore assay uses the DPA-triggered emission method for analysis and this type of assay is compared with spore counts derived from other techniques that determine the number of viable spores in a sample.

(1) Ponce, A, NASA Tech. Briefs, 2002, 26(7), 56