| Summary: | Multidrug resistance is an emerging healthcare issue, especially concerning <i>Pseudomonas aeruginosa</i>. In this multicenter study, <i>P. aeruginosa</i> isolates with resistance against meropenem detected by routine methods were collected and tested for carbapenemase production and susceptibility against ceftazidime-avibactam. Meropenem-resistant isolates of <i>P. aeruginosa</i> from various clinical materials were collected at 11 tertiary care hospitals in Germany from 2017–2019. Minimum inhibitory concentrations (MICs) were determined via microdilution plates (MICRONAUT-S) of ceftazidime-avibactam and meropenem at each center. Detection of the presence of carbapenemases was performed by PCR or immunochromatography. For meropenem-resistant isolates (<i>n</i> = 448), the MIC range of ceftazidime-avibactam was 0.25–128 mg/L, MIC<sub>90</sub> was 128 mg/L and MIC<sub>50</sub> was 16 mg/L. According to EUCAST clinical breakpoints, 213 of all meropenem-resistant <i>P. aeruginosa</i> isolates were categorized as susceptible (47.5%) to ceftazidime-avibactam. Metallo-β-lactamases (MBL) could be detected in 122 isolates (27.3%). The MIC range of ceftazidime-avibactam in MBL-positive isolates was 4–128 mg/L, MIC<sub>90</sub> was >128 mg/L and MIC<sub>50</sub> was 32 mg/L. There was strong variation in the prevalence of MBL-positive isolates among centers. Our in vitro results support ceftazidime-avibactam as a treatment option against infections caused by meropenem-resistant, MBL-negative <i>P. aeruginosa</i>.
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