Resistance to last resort drug arose in patient over 3 weeks

French investigators have described development of resistance to one of the last resort therapies used to treat extremely drug-resistant Pseudomonas aeruginosa. That resistance arose in a single patient over a scant 22 days. They subsequently identified the single nucleotide mutation in P. aeruginosa that caused the resistance. The research is published in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.