MDR, XDR, and pandrug resistance
XDR
Definitions for drug‐resistant organisms are as follows: MDR refers to nonsusceptibility to equal or more than one agent in equal and more than three effective antimicrobial categories. XDR refers to nonsusceptibility to equal or more than one agent in all but equal or less than two antimicrobial categories. Nonsusceptibility to all antimicrobial agents tested was defined as pandrug resistance.