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While there are numerous variants of CIM that have been proposed [[1]], the "rCIM-A" name has already been published almost a year ago to define a rapid CIM (rCIM) protocol that optimizes results for chromosomal cephalosporinase (AmpC) hyper-producing Enterobacterales [[3]]. The Carbapenem Inactivation Method became "rapid" with the work by Muntean et al. [[6]] with final test results in less than 3 h, a time-to-result similar to those of other rapid CPE confirmation methods (colorimetric, spectrometry, etc.), thus changing the paradigm of CIM testing. As stated by Gauthier et al. interpretation of growth of I E. coli i ATCC 25922 on Mueller-Hinton agar in relation to the antibiotic is not always interpretable at 6 h [[5]]. References 1 Mitteregger D., Wessely J., Barisi'c I., Bedeni'c B., Kosak D., Kundi M. A Variant Carbapenem Inactivation Method (CIM) for Acinetobacter Baumannii Group with Shortened Time-to-Result: RCIM-A. Pathogens. [Extracted from the article]

Objectives: Fast and accurate diagnostic tests to identify carbapenemase-producing Enterobacteriaceae (CPE) are mandatory for proper antimicrobial therapy and implementing infection control measures. Here, we have developed a rapid Carbapenem Inactivation Method (rCIM) for CPE detection. Methods: The rCIM consists of the incubation of a potential carbapenemase producer with meropenem discs and use of the resulting supernatant to challenge a susceptible indicator strain. Growth of the indicator strain is monitored using a nephelometer. The performances of the rCIM were compared with theCIM and Carba NPtests using a collection of 113 well-characterized carbapenem-resistant enterobacterial isolates, including 85 carbapenemase producers and 28 non-carbapenemase producers. In addition, rCIM was compared with the Carba NP test and PCR sequencing in a prospective analysis of 101 carbapenem-resistant enterobacterial isolates addressed to the French National Reference Center for Antimicrobial Resistance in July 2017. Results and discussion: The rCIM correctly identified 84/85 carbapenemase producers and 28/28 non-carbapenemase producers, yielding a sensitivity of 99% and a specificity of 100%, slightly higher than the CIM and Carba NP test. In the prospective validation study, the rCIM showed a sensitivity and specificity of 97% and 95%, respectively. Two cephalosporinase-hyperproducing Enterobacter cloacae gave false-positive results, whereas an IMI-17-producing Enterobacter asburiae gave a false-negative result. The result was, however, positive when the isolate was grown on selective antibiotic-containing media. Conclusions: The rCIM is a rapid (less than 3 h), cheap and accurate test for the detection of CPEs, which can be implemented in low-resource settings, making it a useful tool for microbiology laboratories. [ABSTRACT FROM AUTHOR]