MCR-1 Rapid Test – EZER™ Colistin Resistance Assay

What is in the MCR-1 Rapid Test?

The EZER™ MCR-1 Enzyme Rapid Test kit includes:

• 20 lateral flow test devices

• 20 extraction tubes prefilled with buffer

• 1 instruction leaflet

Each cassette contains a Test (T) line with MCR-1 monoclonal antibodies and a Control (C) line for assay validation. Three drops of prepared bacterial suspension are added to the sample well. Results appear within 15 minutes.

Red lines at both C and T indicate a MCR-1-positive result. A line at C only is negative. If no C line appears, the result is invalid.

Role of MCR-1 in Antimicrobial Resistance

MCR-1 is a transferable resistance mechanism that inactivates colistin, a polymyxin-class antibiotic often used against carbapenem-resistant Enterobacterales (CRE). It modifies lipid A in the bacterial membrane, preventing colistin binding.

Discovered in 2016, MCR-1-positive plasmids have since been reported in over 70 countries across:

• E. coli

• Klebsiella pneumoniae

• Salmonella spp.

• Pseudomonas spp.

Its emergence threatens last-line treatments and accelerates the global AMR crisis. Early identification of MCR-1-producing organisms is vital for patient management, outbreak control, and epidemiological surveillance.

About the EZER™ MCR-1 Rapid Test

Developed by Genesis Biotech, the EZER™ MCR-1 test uses gold-labeled monoclonal antibodies in a nitrocellulose membrane format. It enables rapid and reliable detection of MCR-1 protein with minimal handling.

Performance Characteristics:

• Sensitivity: 100%

• Specificity: 100%

• Accuracy: 100%

• Detection Limit: 250 pg/mL (recombinant MCR-1 protein)

Cross-Reactivity:

No cross-reactions were observed with over 50 common resistance markers, including:

• ESBLs: CTX-M, SHV, TEM

• Carbapenemases: KPC, NDM, OXA, VIM, IMP

• Aminoglycoside, fluoroquinolone, tetracycline, macrolide resistance genes

Validated across 243 clinical isolates (105 positive, 138 negative) against molecular PCR reference methods, the test showed complete concordance.

Principle and Workflow

The test operates on a simple lateral flow format and requires no instrumentation:

Sample Preparation:

1. Touch 3 bacterial colonies from culture plate (blood or MacConkey agar) with a 1 µL loop

2. Suspend in extraction buffer tube

3. Vortex to homogenize

Test Execution:

1. Add 3 drops (80 µL) of extract into the test cassette sample well

2. Wait 15 minutes

3. Interpret the result:

   • Positive: Red lines at C and T

   • Negative: Red line at C only

   • Invalid: No C line present

The test must be read within 15 minutes and discarded after 30 minutes.

Clinical Application

The EZER™ MCR-1 Rapid Test is ideal for:

• Clinical microbiology labs screening for colistin resistance

• Infection control units monitoring high-risk patients

• Public health labs conducting AMR surveillance

• Hospitals and reference centers in outbreak response mode

It enables timely identification of MCR-1-positive isolates, supporting:

• Patient isolation and contact tracing

• Rational antimicrobial therapy selection

• Avoidance of unnecessary polymyxin use

• Real-time surveillance in endemic regions

With fast, clear, and accurate results, this test is a powerful tool in global efforts against antimicrobial resistance.