Potentially promising news on Lyme disease: Johns Hopkins researchers report a new, improved test for determining which drugs may work against Lyme disease bacteria that persist even after antibiotic treatment.
This enters the contentious realm of "chronic" Lyme disease — medical authorities agree that the effects of Lyme disease can last, but there's some disagreement over whether this is actually a persistent infection.
The paper is just out in the journal PLOS ONE with the title, "An Optimized SYBR Green I/PI Assay for Rapid Viability Assessment and Antibiotic Susceptibility Testing for Borrelia burgdorferi." (Borrelia burgorferi are the Lyme disease bacteria.) From the Johns Hopkins press release:
Study leader Ying Zhang, MD, PhD, 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," Zhang says. "This could become the new gold standard."
The most exciting part of the development of the test, 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, 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 Zhang interested in testing out the most promising of the newly identified drugs.
The new test enables researchers to analyze thousands of drugs at a time because its use can directly measure the viability of the bacteria after drug treatment and doesn't require each bacteria sample to be washed, as the currently used LIVE/DEAD BacLight assay does. In skipping that step, the new test is not only more accurate but also more efficient, is less expensive and takes less time, Zhang says.
The study was funded by the Lyme Research Alliance and LymeDisease.org, the press release says. From the abstract:
The SYBR Green I/PI assay was found to reliably assess the viability of planktonic as well as biofilm B. burgdorferi and could be used as a rapid antibiotic susceptibility test. Thus, the SYBR Green I/PI assay provides a more sensitive, rapid and convenient method for evaluating viability and antibiotic susceptibility of B. burgdorferi and can be used for high-throughput drug screens.