Evaluation of the ceftazidime/avibactam and meropenem susceptibility by MALDI-TOF MS directly from positive blood cultures

AbstractThe purpose of this study was to evaluate the MBT-ASTRA to determine susceptibility to ceftazidime/avibactam (CZA) and meropenem (MEM) ofEnterobacterales directly from positive blood cultures (BC). Bacterial suspension was incubated with antibiotic and analyzed by MALDI-TOF MS. The relative growth was calculated and cutoff values were determined to categorize isolates as “S,” “I,” and “R.”Klebsiella spp. with CZA 20/8 mg/L and 1.5-h incubation presented 1 (5.9%) major discrepancy and 96.3% category agreement; other species required 2.5 h for 100% category agreement. For MEM, 4 mg/L and 1.5h were necessary, demonstrating 2 (6.67%) minor discrepancies and 93.3% categorical agreement.
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research