Multidrug-resistant (MDR)

Lack of susceptibility to at least one agent in three or more chemical classes of antibiotic (e.g. a beta-lactam, an aminoglycoside, a macrolide).

See also: Pandrug-resistant (PDR) and Extensively drug-resistant (XDR).

Video definition by Marc Mendelson, University of Cape Town (South Africa).

Multidrug‐resistant, extensively drug‐resistant and pandrug‐resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance (Clinical Microbiology and Infection, 2011)