FDA uses firefly chemistry to evaluate TB vaccines
The current system used to test the Bacille Calmette-Guerin vaccine, the colony-forming unit assay, takes up to four weeks to complete, requires complicated growth conditions for bacteria and does not always yield the same results in repeated tests. The new test uses adenosine triphosphate molecules, or ATP, and can be completed in one day with reproducible results.
The ATP test triggers luminescence, the release of tiny light packets, to indicate the presence of energy-rich ATP molecules. The test measures the intensity of light that results from the luminescence, which demonstrates the number of living TB-causing Mycobacterium bovis bacteria in a sample.
The researchers used the test to evaluate six vaccines with freeze-dried tuberculosis bacteria that were reconstituted in a special culture liquid and genetically engineered live bacteria. The study determined that there was a significant correlation between the ATP concentrations in the bacteria and the number of attenuated bacteria that were still viable and likely to result in an effective immune response.
The new test could be able to replace the existing one and additional studies are underway to evaluate the findings to determine if the test is adoptable. The ATP test could also allow researchers to more effectively develop newer vaccines against the deadly disease.