American scientists have discovered a new family of antibiotics in soil samples.
Researchers at Rockefeller University believe the natural compounds could be used to combat infections.
The work offers fresh hope in the race against the rise of antibiotic-resistant diseases, which kill 700,000 people worldwide every year.
They used a gene sequencing technique to analyse more than 1,000 soil samples taken from across the US.
Dr Sean Brady told the BBC: "It is impossible to say when, or even if, an early stage antibiotic discovery like [this] will proceed to the clinic.
"It is a long, arduous road from the initial discovery of an antibiotic to a clinically used entity."
Prof Colin Garner, from Antibiotic Research UK, said: "Our concern are the so called gram-negative bacteria which are difficult to treat and where resistance is on the increase.
"Gram-negative bacteria cause pneumonia, blood and urinary tract infections as skin infections. We need new antibiotics to treat this class."
The research was published in the Nature Microbiology academic journal.
