Sensitive detection of bacteria and spores using a portable bioluminescence ATP measurement assay system distinguishing from white powder materials

The CheckLite(TM) 250 Plus portable bioluminescence assay system for measuring bacterial adenosine 5'-triphosphate (ATP) was investigated for its performance with respect to the field detection of bacteria in bioterrorism incidents. Vegetative bacteria, Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), Staphylococcus aureus, and Yersinia pseudotuberculosis gave considerably high luminescence in a dose-dependent manner with responses of 10(4)-10(5) relative light units (RLU) per 10(7) cells, whereas spore forms of B. subtilis showed considerably low luminescence with 214 RLU per 10(9) spores. Typical white powder materials such as wheat flour, sugar, and bovine serum albumin at concentrations of 0.1 and 0.5% (w/v) gave only negligible luminescence (lower than 400 RLU), and did not change the luminescence of E. coli cells significantly (42-102% of the control). The luminescence of B. subtilis spores increased considerably to over 10(4) RLU per 10(7) spores by pretreatment consisting of 37degreesC incubation for 30 min in nutrient broth medium containing 4 mM L-alanine. The increased luminescence by this pretreatment was not changed considerably (42-145% of the control) in the presence of the above tested white powder materials (0.1 and 0.5%).