Question #4 Explanation:
Linezolid and daptomycin both lack activity versus which of the following bacteria?
A. Methicillin-resistant Staphylococcus aureus (MRSA)
- Both linezolid and daptomycin have MRSA coverage. Unlike linezolid, daptomycin cannot be used for MRSA pneumonia, because it is inactivated by lung surfactant.
B. Vancomycin-resistant Enterococcus faecium (VRE)
- Both linezolid and daptomycin can be used for VRE, including VRE bloodstream infection.
C. Penicillin-resitant Streptococcus pneumoniae
- While it would be fairly unusual to need to go to an agent like linezolid or daptomycin to treat a Strep. pneumo infection, both agents will cover this Gram positive bacteria
D. Extended-spectrum beta-lactamase (ESBL) producing E. coli – CORRECT
Neither daptomycin nor linezolid provide coverage of Gram negative organisms and this is a gram negative bacteria
