Published on : Sep 14, 2012
According to a recent research published in Nature Chemistry, scientists have revealed that a certain sensitive fluorescent molecule is capable of efficiently and quickly tracing TB (tuberculosis) bacteria from the sputum samples.
The year 2010 registered approximately 4000 deaths per day because of TB. TB diagnosis takes a few weeks and the disease being contagious puts others at risk. The WHO has estimated that an untreated TB patient can infect approximately 15 people at risk of contracting the disease.
According to Bill Jacobs, a renowned microbiologist, the risk of contracting TB rises owing to the prolonged time taken for diagnosis and the resultant delay in further treatment. Sputum smear microscopy is the most commonly performed diagnosis test wherein the sputum sample of the patient is observed under the microscope. However such sample to be diagnosed accurately requires high level of presence of the TB bacteria. Also, the diagnosing staff must be well trained. The other conventional methods like blood sample tests and chest X-rays are relatively expensive and have a limited reach.
A research team lead by Jianghong Rao at the Stanford University has harnessed a natural TB protein called BlaC to chalk out a methodology which utilizes fluorescent molecule. BlaC is a β-lactamase enzyme which breaks β-lactams. The β-lactam chemical class comprises antibiotics like penicillin. The fluorescent molecule has been designed so that it resembles β-lactam and splits BlaC into half. Under normal conditions the probe remains colorless; after being cleaved it gives out a fluorescent material and can be detected through a common LED – Light emitting diode and filters. This fluorescence can be captured by mobile-cameras and thus can be easily shared with the other clinical intermediaries; hence, reducing the requirement of high end lab equipment.
The previous probes which used similar method and technology had the demerit of the chances of being triggered by other β-lactamase producing bacteria thus making the end results vague and ambiguous. This new probe has been developed so that it cleaves BlaC alone. This test is thus highly specific in nature and also can give accurate diagnosis with a relatively less bacterial count in the sputum sample. It can thus give effective results with bare minimum requirement.
The prototype of this test is being developed further by Global BioDiagnostics, Texas. The final product is expected to be launched in 2015.