Scientists have discovered a new antibiotic that could help in the battle against drug-resistant bacteria, or superbugs, the journal Nature reported Wednesday. Researchers at Northeastern University in Boston identified the promising antibiotic teixobactin through a novel method of extracting drugs from bacteria that live in dirt rather than in a petri dish. Teixobactin easily cured mice infected with the bacteria Methicillin-resistant Staphylococcus aureus (MRSA), which also causes infections in humans. Researchers also said the drug attacks bacteria in such a different way that makes it very unlikely that bacteria will become resistant to it. Antibiotic resistance is fast becoming a public-health concern as antibiotic-resistant bacteria have caused at least 2 million infections and 23,000 deaths in the U.S. annually. Safety and effectiveness are still unknown, with human studies not expected to begin for another two years, said Kim Lewis, the director of the Antimicrobial Discovery Center at Northeastern University.