Unearthing new antibiotics
Internationally, more than 700,000 people die from antimicrobial-resistant bacterial diseases each year.1 With superbugs developing resistance to even the antibiotic of last resort, vancomycin, scientists are racing to expand options. Currently, research is investigating the potential of antibiotics derived from natural products of bacteria residing within petri dishes. However, the diversity of bacteria being examined within cultures is limited, and rediscovery rates for antibiotics are high.2
Currently, researchers from Rockefeller University are extracting antibiotics from soil microorganisms.3 Since only 1% of bacterial species found in the soil can be cultured in labs, the team has developed a method to extract and sequence DNA from soil without growing bacteria.4 Specifically, the researchers inserted clusters corresponding to the production of antibiotics into bacteria; with this method, they discovered malacidin — a novel molecule similar to daptomycin. Experiments with Staphylococcus aureus (MRSA), a superbug resistant to many antibiotics, detected no resistance to malacidin. In fact, this antibiotic completely eliminated MSRA in rat subjects.3
Although malacidin is a promising solution for controlling gram-positive bacteria, it is ineffective against gram-negative bacteria, which are responsible for pneumonia and Lyme disease, for instance. New antibiotics for gram-negative bacteria needed, especially because their relatively impermeable cell wall allows them to be more antibiotic resistant.3 Although it is impossible to conclude whether malacidin will be clinically useful, the methodology of this study may prove valuable to other scientists searching for antibiotics in unexplored environments, from deserts to oceans.
Written by James Yu
References may be found in the journal.