A completely new and unusual antibiotic compound has been extracted from a marine microorganism found in sediments off the coast of California.
The discovery of genuinely novel antibiotics is rare, and experts say resistance to the drugs poses a grave threat to human health.
US scientists say the new compound, called anthracimycin, seems to be effective against MRSA and anthrax.
Details appear in the German journal Angewandte Chemie.
The unique chemical structure of the compound could lead to a new class of antibiotic medicines.