Whole Genome Sequencing / Enterobacteriaceae Infections · Journal article

Efficacy of the NMIC-150 system in identifying extended-spectrum beta-lactamases in clinical isolates.

Diagnostic Microbiology and Infectious Disease · July 26, 2026

Promising Why this matters to you Expert discussion

Encouraging direction, but not yet definitive.

AI Summary

The NMIC-150 System achieved >90% categorical and essential agreement with broth microdilution (BMD) reference method for ceftazidime and ceftriaxone susceptibility testing in a cohort of 278 clinical isolates. The study reports that an ≥eight-fold MIC reduction with ceftazidime-avibactam or aztreonam-avibactam may serve as a phenotypic indicator of ESBL production in carbapenem-resistant Enterobacterales (CREs), and that Random Forest analysis demonstrated robust predictive performance.

What was studied

Prospective diagnostic accuracy study with machine learning validation. Non-duplicate clinical isolates (Klebsiella pneumoniae, E. coli, and Proteus mirabilis); laboratory setting not specified.. Intervention: NMIC-150 System antimicrobial susceptibility testing platform. Compared with: Reference broth microdilution (BMD) method. n = 278.

Key findings

NMIC-150 System demonstrated over 90% categorical and essential agreement with BMD for ceftazidime and ceftriaxone. ESBL production defined as ≥eight-fold reduction in MIC of 3GCs in presence of clavulanic acid per CLSI criteria. Random Forest model showed robust predictive performance for ESBL-producing isolates based on MIC values.

Safety

Safety was not reported in the material analysed. Check the source before drawing any conclusion about harm.

Who this may help

These results suggest the NMIC-150 System may be suitable for routine antimicrobial resistance surveillance and rapid identification of ESBL-producing CREs in clinical laboratories, pending validation in multi-centre settings and confirmation against clinical outcomes.

Plain-language summary

A single-centre diagnostic accuracy study of moderate size with sound methodology but surrogate endpoints (categorical agreement, MIC prediction) rather than clinical outcomes, showing the NMIC-150 system performs comparably to reference broth microdilution for ESBL detection.

Study design

As stated by the source record.

Methods278 non-duplicate clinical isolates were tested using both reference broth microdilution (BMD) and the NMIC-150 System for susceptibility to third-generation cephalosporins. ESBL production was defined as an ≥eight-fold reduction in MIC of 3GCs in the presence of clavulanic acid (CLSI criteria). Whole-genome sequencing characterized ESBL and carbapenemase genes in 3GC-resistant isolates. A Random Forest model was used to predict ESBL production based on MIC values from the NMIC-150 System. Categorical and essential agreement between methods was assessed.

DesignProspective diagnostic accuracy study with machine learning validation

PopulationNon-duplicate clinical isolates (Klebsiella pneumoniae, E. coli, and Proteus mirabilis); laboratory setting not specified.

Sample size278

InterventionNMIC-150 System antimicrobial susceptibility testing platform

ComparatorReference broth microdilution (BMD) method

Reported figures

Quoted from the source exactly as published.

Categorical and essential agreement with BMDover 90%

Sample size278

ESBL definition≥eight-fold reduction in MIC of 3GCs with clavulanic acid

Clinical bottom line

Caveats

No p-values or confidence intervals reported for agreement percentages.
Single-centre study with limited species representation; generalizability to other Enterobacterales unclear.
Machine learning model performance metrics (sensitivity, specificity, AUC) not quantified in abstract.
Clinical utility and impact on patient outcomes not evaluated; study uses surrogate endpoints (MIC agreement).

Evidence assessment

Graded across the dimensions that decide whether you should act, each from what the source actually supports. There is no single score, and where a dimension was not assessed it says so.

Study design

moderate

Prospective analytical comparison using reference standard (BMD) and machine learning validation.

Directness

moderate

Evaluates antimicrobial susceptibility testing performance; endpoints are categorical agreement and MIC prediction, not clinical outcomes.

Consistency

limited

Single study; no comparison with other automated platforms or data from multiple centres reported.

Risk of bias

moderate

Study methodology described; blinding status and sequence generation not explicitly stated.

Sample adequacy

moderate

278 non-duplicate clinical isolates across three Enterobacterales species; size adequate for diagnostic accuracy but limited species diversity.

Source abstract

Extended-spectrum beta-lactamases (ESBLs) are significant contributors to the growing global crisis of antimicrobial resistance. This study evaluated the performance of the NMIC-150 System for susceptibility testing of third-generation cephalosporins (3GCs) and assessed whether ceftazidime-avibactam and aztreonam-avibactam could identify ESBL-producing carbapenem-resistant Enterobacterales (CREs). A total of 278 non-duplicate clinical isolates (Klebsiella pneumoniae, E. coli, and Proteus mirabilis) were analyzed. Antimicrobial susceptibility was determined using reference broth microdilution (BMD) and the NMIC-150 System. ESBL production was defined as an ≥eight-fold reduction in the minimum inhibitory concentration (MIC) of 3GCs in the presence of clavulanic acid, according to CLSI criteria. Whole-genome sequencing was performed to characterize ESBL and carbapenemase genes among 3GC-resistant isolates. A Random Forest model was used to predict ESBL-producing isolates based on MIC values. The NMIC-150 System demonstrated over 90% categorical and essential agreement with BMD for ceftazidime and ceftriaxone, along with robust predictive performance via Random Forest analysis. These findings suggest that the NMIC-150 System is a reliable platform for 3GC susceptibility testing and that an ≥eight-fold MIC reduction with ceftazidime-avibactam or aztreonam-avibactam may serve as a phenotypic indicator of ESBL production in CRE isolates. In conclusion, the NMIC-150 System shows potential for routine antimicrobial resistance surveillance and may facilitate the rapid identification of ESBL-producing CREs in clinical settings.

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Whole Genome SequencingJingxin MaLiyan MaEnterobacteriaceae InfectionsYana LiYan Gao