Polymyxin antibiotics are used as a last resort to treat certain multidrug resistant bacteria. A team of investigators in China has discovered a new variant on a well-known gene that causes resistance to polymyxins and others. More troubling, the gene containing this mechanism was found in a healthy individual during a routine medical examination, suggesting that other healthy carriers may be spreading this resistance unknowingly. Unlike any other members of its class, the gene was found in the food-borne pathogen, Salmonella. The research is published in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.