Bacteria with worrisome superbug genes found in U.S.

Researchers said the strain of bacteria was found in a76-year-old man who was treated in 2014 for a complicatedurinary tract infection. Further analysis in 2016 showed thebacterium carried mcr-1, a gene that creates resistance to thelast-ditch antibiotic colistin. It was also shown to carryblaNDM-5, a gene that blocks effectiveness of carbapenems, whichare considered medicine's most reliable current antibiotics nowthat bacteria have found ways of outwitting other families ofantibiotics.

• Health officials concerned over spread of resistance to last-resort antibiotic
  

Although the patient was treated successfully with otherantibiotics, researchers said the bacterium had the potential tospread and become a powerful superbug.