Antimicrobial Susceptibility Profiles To Predict the Presence of Carbapenemase Genes among Carbapenem-Resistant Pseudomonas aeruginosa Isolates [Bacteriology]

Detection of carbapenem-resistant Pseudomonas aeruginosa (CRPA) with carbapenemase-producing (CP) genes is critical for preventing transmission. Our objective was to assess whether certain antimicrobial susceptibility testing (AST) profiles can efficiently identify CP-CRPA. We defined CRPA as P. aeruginosa with imipenem or meropenem MICs of ≥8 μg/ml; CP-CRPA was CRPA with CP genes (blaKPC/blaIMP/blaNDM/blaOXA-48/blaVIM). We assessed the sensitivity and specificity of AST profiles to detect CP-CRPA among CRPA isolates collected by CDC’s Antibiotic Resistance Laboratory Network (AR Lab Network) and the Emerging Infections Program (EIP) during 2017 to 2019. Three percent (195/6,192) of AR Lab Network CRPA isolates were CP-CRPA. Among CRPA isolates, adding not susceptible (NS) to cefepime or ceftazidime to the definition had 91% sensitivity and 50% specificity for identifying CP-CRPA; adding NS to ceftolozane-tazobactam had 100% sensitivity and 86% specificity. Of 965 EIP CRPA isolates evaluated for CP genes, 7 were identified as CP-CRPA; 6 of the 7 were NS to cefepime and ceftazidime, and all 7 were NS to ceftolozane-tazobactam. Among 4,182 EIP isolates, clinical laboratory AST results were available for 96% of them for cefepime, 80% for ceftazidime, and 4% for ceftolozane-tazobactam. The number of CRPA isolates needed to test (NNT) to identify one CP-CRPA isolate decreased from 138 to 64 if the definition of NS to cefepime or ceftazidime was used and to 7 with NS to...

Source: Journal of Clinical Microbiology - May 19, 2021 Category: Microbiology Authors: Vallabhaneni, S., Huang, J. Y., Grass, J. E., Bhatnagar, A., Sabour, S., Lutgring, J. D., Campbell, D., Karlsson, M., Kallen, A. J., Nazarian, E., Snavely, E. A., Morris, S., Wang, C., Lee, R., Koag, M., Lewis, R., Garcia, B., EIP Work Group, Brown, A. C. Tags: Bacteriology Source Type: research