NG-Test® CTX-M MULTI

The NG-Test® CTX-M MULTI is an in vitro rapid immunochromatographic assay that qualitatively detects CTX-M enzymes (groups 1, 2, 8, 9, and 25) from pure bacterial colonies of Enterobacterales suspected of producing extended-spectrum beta-lactamase (ESBL). The test is intended as an aid for infection control in healthcare settings to identify CTX-M enzyme-producing organisms, and is not designed to guide treatment or rule out other antibiotic resistance mechanisms.

Like the predicate device, the NG-Test® CTX-M MULTI uses an immunochromatographic format with monoclonal antibodies immobilized on a nitrocellulose membrane, visual interpretation with red control and test lines, and a built-in procedural control. The key difference is the analyte: this device detects CTX-M enzymes whereas the predicate (NG-Test® CARBA 5) detects carbapenemases (KPC, OXA-48-like, VIM, IMP, NDM). Both use the same sample preparation method (touching 3 colonies with a 1 µL loop) and share identical culture media options (blood agar, MacConkey agar) with specialized chromogenic variants.

The clinical performance was compared to reference method PCR and antimicrobial susceptibility testing (AST) according to CLSI M100, 34th edition breakpoints. Organism identification and AST were performed using FDA-cleared systems. No specific ISO, IEC, or ASTM standards are cited in this summary.

Substantial equivalence is supported by: (1) identical regulatory classification (Class II, 21 CFR 866.1640, product code PTJ) and format (rapid visual immunochromatographic assay with colloidal gold detection); (2) same intended use context (infection control in healthcare, not for treatment guidance); (3) identical sample preparation and culture media requirements (blood agar, MacConkey agar); (4) strong analytical performance showing 100% sensitivity (95% CI: 97.5-100%) and 99.4% specificity (95% CI: 96.5-99.9%) compared to PCR reference method across 309 clinical isolates; and (5) 100% agreement across 57 characterized CTX-M strains during analytical reactivity testing and zero cross-reactivity among 55 non-target organisms representing other resistance mechanisms.