New antibiotic discovered in old soil bacterium
Researchers at McMaster University in Canada have discovered a new antibiotic that kills some of the world's most dangerous drug-resistant bacteria. The compound, named manikomycin, was found hidden in a decades-old soil bacterium that was already known for producing the antibiotic oxytetracycline. Previous efforts missed manikomycin because the stronger tetracycline signal overwhelmed the smaller signal from the new compound.
Professor Gerry Wright, who led the research team, said the discovery is exciting because it is a brand new unique structure. The team used advanced fractionation techniques to isolate previously overlooked compounds. The collaboration included researchers from the University of Illinois Chicago and the University of Hamburg in Germany.
Targets a new part of the bacterial ribosome
Manikomycin works by blocking a previously unknown part of the bacterial ribosome, the protein-producing structure inside cells. This is a different target than existing antibiotics, which means that many drug-resistant bacteria have no existing defense against it. The antibiotic proved effective against priority pathogens including salmonella, E. coli, and klebsiella.
Professor Wright said all the superbugs that researchers are worried about do not have resistance to this antibiotic. This gives the medical field a new class of chemical structure, a new molecular target, and a lack of resistance in tested bacteria. Lab tests confirmed that manikomycin is not toxic to human cells and performed well in infection models.
Long road to becoming a medicine
The research team has created about 60 modified versions of manikomycin and is working to improve the compound's duration of activity in the body. The next step is to identify a candidate for clinical testing. Professor Wright said the discovery is just the first step on a long road toward making a new medicine, and that years of additional research and investment are required.
The antibiotic resistance crisis is a growing global health threat. Existing antibiotics were discovered roughly 50 years ago and are losing effectiveness as bacteria evolve. Large pharmaceutical companies have moved away from antibiotic development because these drugs are taken for short periods and generate less revenue than chronic disease medications. Governments and industry are seeking new economic models to incentivize antibiotic research and development.