by VR Sreeraman on  July 27, 2009 at 12:58 PM Research News
 Researchers Develop TB 'Tracker' That Helps Speed Up Drug, Vaccine Studies
Researchers led by an Indian origin scientist at Johns Hopkins have developed a TB tracker that can monitor in real time the behaviour of the TB bacterium in mouse lungs and non-invasively pinpointing the exact location of Mycobacterium tuberculosis.

The new monitoring system could speed up the slow and cumbersome process to test the safety and efficacy of various TB drug regimens and vaccines in animals.

Already, plans are under way for developing a similar system to monitor TB disease in humans.

"Worldwide there are some 9.2 million new infections with TB each year, and new drug combinations are needed fast to treat increasingly resistant strains of the bacterium. Because virtually all drugs are tested in animals first, the TB tracker will play a critical role in such preclinical studies," said senior investigator Dr. Sanjay Jain.

He added: "This new way to locate and study the disease and its behavior in animals should speed studies of TB's response to experimental vaccines, to new drugs and old ones and should accelerate our assessment of whether a treatment is working or not."

B treatment in humans and animals takes much longer than treating other bacterial infections, which makes compliance with lengthy and complicated regimens quite problematic.

In addition, some strains are already resistant to all drugs currently available, thus making it essential to find clues to how the bacterium responds to drug treatment.

In mice, the tracker works by infecting them with a "designer" strain of TB, developed by the Hopkins team to absorb radio-tracing chemicals.

The chemicals light up the germ and any infected tissues in the lung, permitting an image captured by CT, PET and SPECT scanners.

As the new system tracks disease progression over time within the same group of live animals, fewer animals are needed than in conventional animal testing protocols.

The tracker could be useful for studying TB in larger animals, including rabbits, guinea pigs and nonhuman primates, whose TB infection mimics human disease much more closely than infection in mice.

The study on the system has been published in the latest issue of the online journal Public Library of Science (PLoS One).

Source: ANI

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