Inoculum effect of CTX-M-15, OXA-48, and KPC-2 producing Klebsiella pneumoniae on meropenem and ceftazidime-avibactam efficacy

In this study, 20Klebsiella pneumoniae isolates were tested with different inocula (1 –5 × 105 and 1 –5 × 107 cfu/ml) using broth microdilution methods. The inoculum effect was observed in meropenem against OXA-48 + CTX-M-15- and KPC-2-producing isolates but not with ceftazidime/avibactam. Notably, meropenem exhibited inoculum effect against carbapenemase-producing strains, whereas ceftazidime-avibact am remained effective. We conclude that ceftazidime-avibactam is recommended for high-inoculum infections.
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research