March 19, 2009 (BRONX, NY) Researchers from the Albert Einstein College of Medicine and The University of Pittsburgh have developed an onsite method to quickly diagnose tuberculosis (TB) and expose the deadly drug-resistant strains that can mingle undetected with treatable TB strains. This study will be published in PLoS ONE, a peer-reviewed online journal from the Public Library of Science.
The researchers engineered bacteriophages, tiny viruses that attack bacteria, with a green fluorescence protein (GFP) implanted in their genome. Bacteriophages spread by injecting their DNA into bacterial cells. In this case, the GFP gene accompanies the DNA of the phage into the Mycobacterium tuberculosis cell, the bacterium that causes TB, causing the cell to glow. A clinician could detect the glow with equipment available at many clinics.
"The development of these reporter flurophages allows us to bypass the existing method of diagnosing TB, which requires cultivating slow-growing bacteria in a biosafety level 3 environment, a time-consuming and costly process," says William R. Jacobs, Jr., Ph.D., one of the authors of the study. "By infecting live M. tuberculosis cells with a flurophage, a quick and highly sensitive visual reading can be done. We are optimistic that we can move the diagnostic process from several weeks to several days or even hours, which could have a significant impact on treatment."
"A report from South Africa showed that the extensively drug-resistant TB strains can kill within 16 days, on average," says Graham Hatfull, Ph.D., the lead author and close collaborator of Dr. Jacobs. "In rural Africa, it takes too long to collect samples, send them off, do the test, and have the data sent back. Clinicians need rapid, relatively cheap, and simple methods for detecting TB and drug-resistant strains in the local clinic. This test provides a quick diagnosis so the patient can be isolated and treated."
|Contact: Deirdre Branley|
Albert Einstein College of Medicine