Teixobactin
Antibiotics have received a great deal of media attention in the wake of the recent discovery of teixobactin, a new soil bacterium with strong antibiotic properties. Northeasten University professor Kim Lewis and a team of scientists found teixobactin in soil samples from a grass field in Maine through the use of an iChip, a board with holes that allows both the isolation and culture of previously uncultured soil bacteria. This finding is a much-needed change from the dire headlines usually accompanying antibiotic topics, as we are now in desperate need of novel drugs to combat the rapid rise of bacterial resistance.
To ensure that the drug would be a serious contender for FDA approval and clinical use, Lewis rigorously tested teixobactin for both potency and resistance mechanisms, and when screened for antibiotic strength via exposure to other bacterial species—especially the reviled Staphlyoccus aureus—teixobactin emerged victorious. More importantly, it was also found to be non-toxic when exposed to human cells in vitro. As for resistance, teixobactin works by preventing bacteria from building a cell wall essential for its survival. Lewis is optimistic that, as teixobactin interferes with two different components of the cell wall, bacteria will not be able to evolve to combat its effects, given that the cell wall components are highly conserved across bacterial strains. This means that chances of evolved bacterial survival without these parts or with altered versions of said parts would be slim. The emphasis is on the word “slim,” because if we learned anything from Jurassic Park, it is that “life finds a way.” And while resistance may be decades away, it is still too early to proclaim teixobactin to be “a fool-proof case of no resistance,” as Lewis would like to think.
Though even without the debate over potential resistance evasion, there are still many lingering questions that will determine whether or not an antibiotic drug will actually come to pharmaceutical fruition. To obtain FDA approval drugs have to go through three rigorous phases of clinical testing, and this process often takes five to 10 years. Then, assuming that it earns approval, there is the question of mass production. Will the drug be grown from the microbe, or will it be synthesized? How difficult will the compound be to recreate synthetically? And potentially most importantly, how expensive will production be? Will the drug be available to the ordinary consumer, or will it be exorbitantly expensive and given only in the most extreme cases? All of these questions must be taken into consideration amidst the excitement of discovery, and many media outlets have irresponsibly glossed over them. We do not yet have a miracle drug, though what we do have is still very promising.
However this is not to say that the discovery and hype is unwarranted; teixobactin could very well be the equivalent to this generation’s penicillin, which we sorely need. From approximately 1940-1970, antibiotics were discovered rapidly, leading to what is commonly referred to as ‘the golden age of antibiotics.’ It was believed that any and all bacterial infections could be treated with modern medicine, though unfortunately we know now that this cannot always be the case. Between 1968-1990s, the United States (along with the rest of the world) witnessed a rise in methicillin-resistant Staphylococcus aureus (MRSA), a bacterium resistant to most antibiotics that hints at a scary future for antibiotic resistance. Antibiotics are typically overprescribed and often unnecessary in human patients, and are also frequently given to livestock so the opportunity for bacteria to evolve for resistance is widespread. Thus, the potential for a drug that could not only treat against MRSA but also lend us another few decades of antibiotic protection is nothing to scoff at.
Yet perhaps the most fascinating takeaway from this breakthrough is the tool that Lewis’ team used for the discovery, which imparts a great deal of hope to our current antibiotic crisis. The iChip allows microbes to be grown in the lab by isolating microbe cells in agar (a gelatinous substance), then covering them with their native soil to mimic a natural environment. This is a fantastic method that will hopefully lead to many more similar discoveries, as approximately 99 percent of naturally occurring microbes have yet to be cultured. Teixobactin may not be the be-all-end-all of antibiotics. However, we may have found a new way to keep our heads above water in the midst of constantly evolving antibiotic-resistant bacteria.
