For just the second time in the U.S., researchers have found evidence of E. coli bacteria that are genetically resistant to a last-resort antibiotic, according to a report published today in the medical journal Antimicrobial Agents and Chemotherapy. The superbug has a gene that makes it resistant to treatment with colistin, an antibiotic often used by doctors as a last resort for antibiotic-resistant infections, the report states.

In this case, the bacteria were genetically resistant to colistin but not to other forms of antibiotics that could be used to kill the E. coli. However, researchers are concerned that these bacteria could transfer genes to other E. coli and different bacteria that are already resistant to all forms of antibiotics except colistin, leading to the chance of a fully antibiotic-resistant strain of bacterium. READ MORE