In-vitro antimicrobial activity of a carbapenem, MK-0826 (L-749,345) and provisional interpretive criteria for disc tests.

The in-vitro activity of MK-0826, a new oral carbapenem, was compared with that of imipenem by broth microdilution susceptibility tests against 545 bacterial isolates. MK-0826 had significantly greater activity against Enterobacteriaceae and poorer activity against Pseudomonas aeruginosa and many gram-positive species. MK-0826 disc diffusion tests were also performed according to the NCCLS procedure and tentative interpretive criteria were determined for possible susceptible MIC breakpoints of < or = 4.0 and < or = 2.0 mg/L.