Digging in the Dirt for New Antibiotics

An article in The Telegraph caught my eye the other day. Headline “First new antibiotic in 30 years discovered in major breakthrough”. I was embarrassed to be learning about Teixobactin not from a scientific journal but from regular news media but hey, learning is learning.

The article highlighted a report from a recent publication of Nature in which scientists at Northeastern University had discovered a novel cell wall inhibitor that they call Teixobactin by screening soil from a grassy field in Maine with an “iChip” device. The novelty apparently was their ability to do so, but if you’ve read my earlier entry on the discovery of vancomycin and other antibiotics in the 1950s, you will know that soil exploration is not new.

What caught my eye is that this new compound is unlikely to promote the development of drug resistance in microbes. I’m not a believer yet, but if that’s true, then that’s excellent news. Teixobactin has been found so far to have excellent in-vitro activity against a myriad of Gram-positive bacteria and in-vivo efficacy against Streptococcus pneumoniae and methicillin resistant Staphylococus aureus (MRSA) in a mouse model. That’s excellent if we will be able to make that jump from petri dishes and mouse models to humans one day.

Unfortunately, new gram-positive coverage antibiotics are not what we are desperate for. This past year alone the FDA has approved dalbavancin, tedizolid, and oritavancin through the new expedited Generating Antibiotic Incentives Now (GAIN) program, which offers incentives such as extended exclusivity to manufacturers of new antibiotics.

No, the antibiotic resistance crisis that is looming is the lack of antibiotics for multi-drug resistant Gram-negative organisms (CRE, NDM-1). A recent economic report estimates that if we continue to do nothing to combat antimicrobial resistance, by 2050 attributable economic losses could total $100 trillion US dollars and resultant deaths could exceed 10 million cases annually.

Though ceftolozane-tazobactam is another new antibiotic the FDA approved last year that does indeed have Gram-negative coverage, it does nothing for the aforementioned resistant organisms.We still have a long way to go to develop new and more effective antibiotics and when we do we need to learn how to properly use them to avoid further development of resistances.