Researchers from the
The method must next undergo clinical trials, but it has potential as a valuable, time-saving tool in rural African areas besieged by TB, explained the paper's senior author Graham Hatfull, chair and Eberly Family Professor of Biological Sciences in Pitt's
"A report from South Africa showed that the extensively drug-resistant TB strains can kill within 16 days, on average," Hatfull said. "In rural
The group constructed bacteriophages specific to TB that have 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 into the TB cell, causing the cell to glow. A clinician can detect the GFP's glow with equipment available at many clinics.
Besides quick diagnosis, the test also could be used to distinguish treatable TB strains from those that are drug resistant, a chore that can normally take months, Hatfull said. Hatfull and his colleagues treated M. tuberculosis with antibiotics at the same time the bacteriophages were introduced; the TB strains that were sensitive to antibiotics died, but the drug-resistant cells survived and continued to glow.
The group's research was funded as part of a major new research initiative from Howard Hughes Medical Institute (HHMI). The institute announced March 19 that it will partner with
"The development of reporter flurophages," Jacobs said, "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. 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."