Scientists have identified a second patient in the United States infected with bacteria carrying the mcr-1 “superbug” gene, which makes bacteria highly resistant to a last-resort class of antibiotics. The gene, found in a sample of E. coli bacteria from a patient in New York, follows the discovery late last month of a patient in Pennsylvania who had a urinary tract infection caused by E. coli that carried the gene.

The finding was published on Monday in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology. The mcr-1 gene makes bacteria resistant to colistin, an antibiotic used to treat multi-drug-resistant infections, including carbapenem-resistant Enterobacteriaceae or CRE, which U.S. health officials have dubbed a “nightmare” bacteria. READ MORE