Inching closer to a soft spot in antibiotic-resistant tuberculosis
Originally published on News Wise
Antibiotic-resistant tuberculosis is a public health threat. TB and other bacteria become resistant to antibiotics by evolving genetic changes over time, which they can do quite quickly because bacterial lifecycles are short. In fact, it takes only a single genetic mutation to grant TB resistance to isoniazid, one of the first-line antibiotics.
Intrigued that such a small change results in such a consequential outcome, researchers led by Karen Dobos at Colorado State University undertook a study to determine what other effects might result from that same gene tweak. If they could uncover changes that make antibiotic-resistant TB vulnerable in other ways, Dobos’ team reasoned, they or others might be able to one day target those weaknesses.
The team’s results, including new information about a potential TB soft spot, recently were published in the journal Molecular & Cellular Proteomics.
In order to understand why Dobos’ team did what it did, you have to keep in mind that TB, as the infection progresses, is constantly evolving. An antibiotic that beats back TB at first can lose its effectiveness.
You also have to know that the antibiotic isoniazid depends on a protein produced by TB to extinguish TB. That is, the genetic change that makes TB resistant to isoniazid actually hinders production of that key TB protein. If the protein, called KatG, isn’t there or is there but is in poor shape, the infection can rage on unencumbered by the antibiotic.