Paradoxical carbapenemase activity detected by modified carbapenemase inactivation (mCIM) method in <i>Citrobacter sedlakii</i>.

ABSTRACT: Screening for carbapenemase-producing Enterobacterales is a necessity for hospitals serving high-risk patient populations. Detection methods often incorporate the modified carbapenemase inactivation method (mCIM) test to verify carbapenemase production in suspect isolates. Here, we demonstrate the case of a Citrobacter sedlakii isolate recovered from carbapenemase-surveillance culture that was strongly mCIM positive for carbapenemase production, but phenotypically nonresistant to carbapenems. The modified carbapenemase inactivation method with EDTA (eCIM) test, which suggests the presence of a metallo-β-lactamase, was positive as well. Liquid chromatography mass spectrometry additionally confirmed the loss of meropenem during the mCIM test. Whole-genome sequencing detected only the

SUBMITTER: Brown DG 

PROVIDER: S-EPMC12506007 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature