Comparison of the performance of three carbapenem inactivation methods for the detection of carbapenemase-producing gram-negative bacilli. Issue 11 (November 2021)

• Record Type: Journal Article
• Authors: Kuchibiro, Tomokazu; Komatsu, Masaru; Yamasaki, Katsutoshi; Nakamura, Tatsuya; Nishio, Hisaaki; Kimura, Keigo; Niki, Makoto; Kida, Kaneyuki; Ohama, Masanobu; Fukuda, Nozomi; Sawa, Kana; Nakamura, Akihiro; Nishi, Isao
• Is Part Of: Journal of infection and chemotherapy. Volume 27:Issue 11(2021)
• Page Start: 1634
• Page End: 1638
• Publication Date: 2021-11
• Subjects: Modified carbapenem inactivation method test -- Carbapenem inactivation method-tris (CIMt) test -- Simple-carbapenem inactivation method (sCIM) test -- Carbapenemase-producing gram-negative bacilli; mCIM modified carbapenem inactivation method -- CIMt carbapenem inactivation method-tris test -- sCIM simple-carbapenem inactivation method (sCIM) test -- CPE Carbapenemase-producing Enterobacterales -- CPO carbapenemase-producing organism -- ESBLs extended-spectrum β-lactamases -- IMP imipenem -- MEPM meropenem -- MHA Mueller Hinton agar -- MICs minimum inhibitory concentrations -- TSB trypticase soy broth; Chemotherapy -- Periodicals; Infection -- Periodicals; Communicable diseases -- Chemotherapy -- Periodicals; 615.5805
• DOI: 10.1016/j.jiac.2021.07.021
• Languages: English
• ISSNs: 1341-321X

Abstract

Abstract: Introduction: The carbapenem inactivation method test (CIM) was developed as a method for detecting carbapenemase-producing Gram-negative bacilli, and the modified CIM (mCIM) was recommended by the CLSI for as an improved method in M100-S27. However, few studies have evaluated the influence of bacterial species and genotype on its sensitivity and specificity. In this study, we evaluate the performance of these improved modified CIM methods with mCIM. Methods: As strains, clinical isolates from Naga Municipal Hospital and stored strains from the Study of Bacterial Resistance in the Kinki Region of Japan were used. The mCIM, CIM-Tris, and simple CIM (sCIM) test methods were applied to 120 Enterobacterales, 40 Pseudomonas aeruginosa, and 37 Acinetobacter spp. The procedure and criteria for each method were based on the original papers and the CLSI M − 100 S27 documents. Results: The sensitivity of the test methods in the detection of carbapenemase in Enterobacterales, Pseudomonas spp., and Acinetobacter spp. was as follows: mCIM, 98.9%, 90.0%, and 76.5%, respectively; CIM-Tris, 94.4%, 100%, 100%; and sCIM 98.9%, 85.0%, 76.5%. All methods showed 100% specificity in Enterobacterales, Pseudomonas spp., and Acinetobacter spp. Each method performed well in the detection of metallo β-lactamase-producing strains, however, the sensitivity tended to be low in the detection of the organisms producing serine-type carbapenemase, such as GES, OXA-23, and OXA-51. Conclusions: Care must be taken when selecting test methods because the sensitivity of the detection differs depending on the bacterial species and genotype.