Title and lede are both wrong.
"U.S. health officials on Thursday reported the first case in the country of a patient with an infection resistant to all known antibiotics,"
Actually, what they saw was an infection specifically resistant to colistin. That's normally the "last ditch" antibiotic, but it turned out that it wasn't resistant to some of the less extreme antibiotics and the patient is doing fine. The big news is that a lab test found traces of the MCR-1 gene that confers colistin resistance.