We need new antibiotics that are immune to resistance. For every new antibiotic that humans have produced (most of which are merely derived from the natural molecules made by bacteria), bacteria have developed resistance mechanisms that are rapidly spread by horizontal gene transfer (HGT). HGT is the set of processes that allow bacteria to share genes, especially the genes that make them resistant to antibiotics.

Princeton University researchers have recently found a new antibiotic compound, which they named Irresistin, because it does not induce antibiotic resistance. They published their findings in the journal Cell. Irresistin works by puncturing bacterial walls and destroying folate (vitamin B9, which bacteria need to produce their DNA) within the bacterial cells. 

The scientists assert that Irresistin's dual mechanism of action may account for its immunity to resistance. Their experiments demonstrate that Irresistin works against many bacteria, including the notorious superbug MRSA. But given the history of pathogens developing antibiotic resistance to every known antibiotic, plus the natural tendency of bacteria to spread resistance genes via HGT, how likely is it that Irresistin will thwart Nature’s ability to evolve resistance once it is introduced in the clinic? That question remains to be answered.

If Irresistin can sustain immunity to antibiotic resistance — and proving that might take years of clinical use — the dual mechanism strategy employed by the Princeton scientists might point the way for the future development of resistant-immune antibiotic drugs.