MDR, XDR, and PDR

 Q: What is the difference between MDR, XDR, and PDR bacteria susceptibility to antibiotics?

Answer:

Multi-drug resistant (MDR): refer to bacteria that acquire nonsusceptibility to at least one agent in three different antimicrobial classes. 

Extensively drug-resistant (XDR): refers to bacteria that acquire nonsusceptibility to at least one agent in all but two antimicrobial classes. 

Pandrug resistant (PDR): refers to bacteria that acquire nonsusceptibility to all antimicrobial agents.

#ID

References:

Magiorakos AP, Srinivasan A, Carey RB, et al. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect 2012; 18:268.