Evidence map›Paper›PMID 41848331›Full record

ReviewJournal of clinical microbiology2026

The shift from "MIC-Only" back to carbapenemase testing among carbapenem-resistant Enterobacterales: what clinical laboratories need to know about updated CLSI guidance.

Patricia J Simner

Abstract readReview
In one paragraph

Review in Journal of clinical microbiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Review
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

1 author.

Patricia J SimnerDivision of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.ORCID 0000-0001-6134-151X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Carbapenem-resistant organisms (CROs) pose a major threat to global health due to limited therapeutic options and their capacity for rapid dissemination. Among these, carbapenemase-producing (CP) strains are of greatest concern, as they hydrolyze most β-lactams, and carbapenemase genes are readily spread via mobile genetic elements. Historically, clinical laboratories relied solely on minimal inhibitory concentration (MIC) results and interpretive criteria to guide therapy, with carbapenemase testing performed mainly for epidemiologic purposes. However, changing carbapenemase epidemiology, the introduction of enzyme-specific novel β-lactam combination agents for treatment, and updated Clinical and Laboratory Standards Institute (CLSI) guidance have renewed the importance of carbapenemase testing among carbapenem-resistant Enterobacterales. The 2025 CLSI M100 update now recommends carbapenemase testing for most Enterobacterales resistant to at least one carbapenem, emphasizing differentiation of key enzymes, such as KPC, NDM, and OXA-48-like, to inform therapeutic decisions and support antimicrobial stewardship. This minireview summarizes the evolution of CLSI guidance from early breakpoint establishment through the "MIC-only" era to the current antimicrobial resistance mechanism-driven framework. Key issues addressed include the clinical limitations of prior clinical breakpoints, challenges in balancing sensitivity and specificity of screening criteria to guide carbapenemase testing in different settings, and the expanding role of rapid phenotypic and molecular detection methods. Revisions to the EDTA-modified carbapenem inactivation method (eCIM) are discussed in light of increasing co-production of metallo-beta-lactamase and serine-carbapenemases. Reintegration of carbapenemase testing into clinical workflows highlights the role of the clinical microbiology laboratory as a critical component of antimicrobial stewardship.

Indexed as

Anti-Bacterial AgentsBacterial Proteinsbeta-LactamasesCarbapenem-Resistant EnterobacteriaceaeLaboratories, ClinicalCarbapenemsEnterobacteriaceae InfectionsHumansMicrobial Sensitivity TestsAnti-Bacterial AgentsBacterial Proteinsbeta-LactamasescarbapenemaseCarbapenemscarbapenemasecarbapenem-resistant EnterobacteralesCLSICRE

Identifiers

PMID41848331
PMCPMC13059724

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.