Microcalorimeters used to rapidly diagnose TB

Scientists have recently developed a more efficient means to diagnose tuberculosis that relies on the use of microcalorimeters, which measure the heat given off from bacteria as they grow.

Conventional means to diagnose TB often require growing Mycibacterium tuberculosis, the bacterium that causes the disease, and then examining it in a laboratory. The process is slow and can take up to 57 days to complete fully. Faster methods are available, but they tend to be too expensive for developing countries to fully utilize, according to

Dr. Olivier Braissant and his colleagues have developed a way to use microcalorimeters to make a positive identification of the bacterium through its growth pattern that can be completed in less than two weeks and sometimes in less than one.

The microcalorimeters identify a tiny rise in temperature that results from the bacterium’s growth and then convert it into an electrical signal that can be amplified and recorded by a computer, reports. The computer then creates a graphical footprint that is unique to every species of bacteria.

Because multiple samples from the same person can be tested simultaneously, the method can be used to test the effectiveness of new antibiotics.

Dr. Braissant and his team were able to successfully demonstrate their method in a laboratory setting and are now preparing to try it in the field.

"Microcalorimeters have already been shipped to Tanzania and we hope to start a first validation of our approach in the field before the end of the year," Dr Braissant said, reports.

Braissant’s research was recently published in the Society for Applied Microbiology’s Journal of Applied Microbiology.