FRIDAY, SEPTEMBER 30, 2016

Scientists discover new antibiotics class to treat MDR-TB

Scientists recently discovered a promising new class of antibiotics that could help global efforts to defeat multi-drug-resistant tuberculosis, according to a study published in Nature Medicine.

Researchers at St. Jude Children's Hospital tested the new antibiotics, called spectinamides, in multiple trials of mice with both active and chronic TB infections. One version of the new drug, 1599, was as good as or better than current TB drugs at reducing lung bacteria levels in the mice while causing no serious side effects.

The scientists developed the antibiotics by changing the chemical structure of an existing antibiotic, spectinomycin, which is not effective against TB. The researchers used structure-based design to re-engineer how the drug binds to the ribosomes of TB.

"This study demonstrates how classic antibiotics derived from natural products can be redesigned to create semi-synthetic compounds to overcome drug resistance," Richard Lee, a corresponding author of the study, said. "I hope the result will be drugs that are more effective against tuberculosis and offer a faster route to a cure with fewer side effects."

The scientists also found that 1599 and two other spectinomycin analogs were more successful at avoiding a TB resistance mechanism compared to current TB drugs. TB bacteria use efflux pumps to remove drugs and threats from the cell before the drugs can work against the bacteria. Efflux pumps were not successful in protecting TB against spectinamides

The new drugs were also effective against MDR-TB strains grown in the lab.

The next step for the research is to identify a multi-drug therapy to test in a clinical trial of patients with drug-resistant TB.