Researchers from the Johns Hopkins Bloomberg School of Public Health have developed a test they say will allow them to test thousands of FDA-approved drugs to see if they will work against the bacteria that causes tick-borne Lyme disease.
The researchers, reporting November 3 in the journal PLOS ONE, say doctors and patients are desperate for new treatments for Lyme disease, which in many people is cleared up with a few weeks of antibiotics but, in some, lingers long after completion of the standard drug regimen. Until now, it has been very difficult to determine on a large scale which drugs work against these lingering Borrelia burgdorferi – the bacteria that cause Lyme disease – hampering new drug discovery for the organism.
Study leader Dr. Ying Zhang, a professor in the Bloomberg School’s department of molecular microbiology and immunology, and his colleagues tweaked a test typically used for simply counting DNA in samples in the lab. Using the test, they were able to quantify how many Borrelia burgdorferi are alive and how many are dead after each drug was added to the bacteria. The method stains the living bacteria green and the dead or dying bacteria red in a way that filters out the noise that can corrupt existing tests.
“It’s superior to the current gold standard for testing Borrelia viability,” Dr. Zhang says. “This could become be the new gold standard.”
The most exciting part of the development of the test, Dr. Zhang says, is that his team has already used it to identify a series of antibiotics approved to treat other infections that show promise in the lab against the lingering Borrelia burgdorferi bacteria, known as persisters. In a study published in July in the journal Emerging Microbes and Infections, Dr. Zhang and colleagues used the new test – called the SYBR Green I/PI assay – to identify several antibiotics that showed promise against the persistent bacteria that appear immune to the current Lyme antibiotics. That paper has been the most popular on the journal’s website, and patients, doctors and researchers have been contacting Dr. Zhang interested in testing out the most promising of the newly identified drugs.