Among the MDR strains, IDSA has identified diseases
due to the following bacteria as especially difficult to treat: the Gram positive vancomycinresistant
Enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA), the
Gram negative extended spectrum β-lactamase (ESβL)-producing Enterobacteriaaceae, carbapenem-
resistant Enterobacteriaceae (CRE), metallo-β-lactamase (MβL)-producing Pseudomonas
aeruginosa and Acinetobacter baumannii