CPO Complete, a novel test for fast, accurate phenotypic detection and classification of carbapenemases

Rapid, accurate detection of carbapenemase-producing organisms (CPOs) and the classification of their carbapenemases are valuable tools for reducing the mortality of the CPO-associated infections, preventing the spread of CPOs, and optimizing use of new β-lactamase inhibitor combinations such as ceftazidime/avibactam and meropenem/vaborbactam. The current study evaluated the performance of CPO Complete, a novel, manual, phenotypic carbapenemase detection and classification test. The test was evaluated for sensitivity and specificity against 262 CPO isolates of Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii and 67 non-CPO isolates. It was also evaluated for carbapenemase classification accuracy against 205 CPOs that produced a single carbapenemase class. The test exhibited 100% sensitivity 98.5% specificity for carbapenemase detection within 90 minutes and detected 74.1% of carbapenemases within 10 minutes. In the classification evaluation, 99.0% of carbapenemases were correctly classified. The test is technically simple and has potential for adaptation to automated instruments. With lyophilized kit storage at temperatures up to 38oC the CPO Complete test has the potential to provide rapid, accurate carbapenemase detection and classification in both limited resource and technologically advanced laboratories.