Table 1.

Names and Acronyms of Resistant Bacteria.

Name	Acronym	Resistant to:
Pan-drug-resistant	PDR	All antibiotics. even including colistin and tegacyclin
Difficult-to-treat drug-resistant	DTR	All first-line agents, including all β-lactams (carbapenems and β-lactamase inhibitor combinations) and fluoroquinolones
Extensively drug-resistant	XDR	All drugs except for colistin and tegacyclin
Multidrug-resistant	MDR	Three or even more antimicrobial agents
Carbapenems-resistant	CR	Carbapenems
Extended-spectrum β-lactamase	ESBL	Extended-spectrum β-lactamase, including penicillins, cephalosporins (also the third generation), and the monobactam aztreonam