A faster, cheaper way to diagnose TB

Aug 17, 2011

Researchers have discovered a faster, cheaper method for the diagnosis of tuberculosis (TB). A major barrier in TB prevention, especially in developing countries, is that diagnosis is slow and costly. Dr Olivier Braissant and his colleagues have developed a method which could potentially decrease the time taken to make a diagnosis. Their method is also cheaper than the current fastest methods. This research has been published today in the Society for Applied Microbiology's Journal of Applied Microbiology.

The which causes TB is called Mycobacterium tuberculosis and of this disease is often done by growing and examining the bacteria in a laboratory. This process is slow and can take up to 57 days.

Faster methods have been developed, but these tend to be very expensive and are, therefore often unavailable in . Dr Braissant and his colleagues used a microcalorimeter to detect the growth of Mycobacterium . This method proved to be faster than growing the bacteria in the lab and as fast as other more expensive methods (between 5.5 and 12.5 days).

Microcalorimeters, like the one used in this research, measure the heat given off during a chemical, physical or , in this case when the bacteria grow. They convert this tiny temperature rise into an which can be amplified and recorded by a computer. This then produces a graphical footprint which is unique to each .

As multiple samples from the same person can be tested at the same time using the microcalorimeter it is also possible to test drug susceptibilities of the bacteria. This is done by measuring the growth of different samples in the presence of different : if no growth is detected with one antibiotic, this drug can be used to fight the infection. With the growing resistance of TB to antimicrobials, this is essential.

A further important feature of this method is that it uses readily available, cheap materials. Other fast TB detection methods often use consumables such as fluorescent or radioactive probes, meaning that every individual test comes at a significant cost. This is on top of the initial cost of the equipment, which can be around $39,000 (US). Whilst relatively inexpensive microcalorimeters are commercially available, a recent study1 estimated that a simple calorimeter can be built for around $1000 (US).

Dr Braissant and his team have shown this new method works in a laboratory setting, but this is not necessarily representative of the way it would work in outside world. So the next step is to test their method outside the lab.

"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 explained.

One third of the world's population are infected with TB and in 2009 there were 1.7 million deaths from the disease. The highest number of these deaths was in Africa. TB is spread through the air via sneezing, coughing and spitting and it is estimated that every untreated person infects between 10 and 15 people per year. Prompt and affordable diagnosis is therefore essential. This new technique could potentially provide a method for the rapid diagnosis of TB and due to the relatively low cost, it could be used worldwide.

Explore further: Chromosome-folding theory shows promise

Related Stories

Experts say Toronto unprepared for TB

Feb 24, 2008

Health experts warn there could be an outbreak of tuberculosis in Toronto, which reportedly lacks a centralized system of TB clinics.

Recommended for you

A CRISPR antiviral tool

1 hour ago

Emory scientists have adapted an antiviral enzyme from bacteria called Cas9 into an instrument for inhibiting hepatitis C virus in human cells.

Chromosome-folding theory shows promise

2 hours ago

Human chromosomes are much bigger and more complex than proteins, but like proteins, they appear to fold and unfold in an orderly process as they carry out their functions in cells.

New 3-D method improves the study of proteins

Apr 27, 2015

Researchers have developed a new computational method called AGGRESCAN3D which will allow studying the 3D structure of folded globular proteins and substantially improve the prediction of any propensity for ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.