Via the blog Controversies in Hospital Infection Prevention, Eli Perencevich writes about teixobactin: Digging in the Dirt - For Antibiotics. Excerpt:
Once the authors identified the compound teixobactin from the uncultured bacteria, they showed that it had excellent in-vitro activity against Gram-positive bacteria including enterococci, C. difficile, B. anthracis, and S. aureus (including VISA strains). They also tested the in-vivo efficacy against MRSA and S. pneumoniae in a mouse model and reported excellent results.
Intriguingly, the authors said that "resistance has not developed...suggesting that the target is not a protein" and since there exists a similar lack of resistance development to vancomycin through mutations, they postulated "that teixobactin could be acting against the same (lipid II) target."
I agree with Dr. William Schaffner's comments in the NY Times as he called the study/method “ingenious” yet also cautioned that "it’s at the test-tube and the mouse level, and mice are not men or women, and so moving beyond that is a large step, and many compounds have failed.”
I would add one additional caveat - teixobactin had little activity against most Gram-negative bacteria including E coli, Klebsiella and Pseudomonas. Since the real resistance crisis is in multi drug-resistant Gram-negatives (think CRE, NDM-1), we better get back to digging in the dirt.