Liofilchem™ MTS™ Imipenem/Imipenem+EDTA IMI/IMD 0.125-8/0.032-2, MIC Test strips

The Liofilchem™ MTS™ Imipenem/Imipenem+EDTA (IMI/IMD) MIC Test Strips are designed for the phenotypic detection of metallo-β-lactamases (MBLs) in Gram-negative bacteria, particularly Enterobacterales and Pseudomonas aeruginosa. These dual-gradient strips allow for the detection of carbapenem resistance mechanisms by comparing the MIC of imipenem alone and imipenem in combination with the chelating agent EDTA, which inhibits MBLs.

Features

1. Dual-Component Gradient: Allows simultaneous MIC determination for imipenem and imipenem+EDTA.
2. Wide MIC Range: Covers imipenem (0.125–8 µg/mL) and EDTA synergy (0.032–2 µg/mL).
3. Easy Interpretation: Gradient diffusion results show MBL activity as a significant MIC reduction with EDTA.
4. Broad Pathogen Coverage: Effective for Enterobacterales, Pseudomonas aeruginosa, and other non-fermenters.
5. Standardized Testing: Aligns with CLSI and EUCAST guidelines.

Applications

• Detection of Metallo-β-Lactamases (MBLs): Including NDM, VIM, and IMP types.
• Phenotypic Differentiation: Distinguishes MBL-mediated resistance from other carbapenem resistance mechanisms.
• Surveillance Programs: For carbapenem-resistant Enterobacterales (CRE) and carbapenemase-producing Pseudomonas.

Technical Specifications

Test Procedures

Sample Preparation

1. Prepare a bacterial suspension equivalent to 0.5 McFarland standard.
2. Inoculate Mueller-Hinton Agar plates evenly with the suspension using a sterile swab.

Application of Strips

1. Place the Imipenem/Imipenem+EDTA MIC strip on the inoculated plate.
2. Ensure the strip adheres evenly to the agar surface.

Incubation

1. Incubate the plate at 35–37°C for 16–20 hours under aerobic conditions.

Interpretation

1. Measure the MIC values at the point where the ellipse intersects the strip.
2. Calculate the difference between the MICs for imipenem alone (IMI) and imipenem+EDTA (IMD):
   • Reduction of MIC by ≥ 3 twofold dilutions (8-fold): Indicates MBL production.

Results Interpretation

Control Data

Advantages

Comparison with Other Methods

Reference Data

1. CLSI M100 Guidelines: MIC breakpoints and interpretive criteria.
2. EUCAST Recommendations: International standards for MIC testing.
3. Scientific Studies:
   • “Phenotypic Detection of Metallo-β-Lactamases Using Imipenem-EDTA MIC Gradient Strips,” Journal of Clinical Microbiology.
   • “Comparison of Gradient Diffusion and Molecular Methods for Carbapenemase Detection,” Antimicrobial Agents and Chemotherapy.

Conclusion

The Liofilchem™ MTS™ Imipenem/Imipenem+EDTA (IMI/IMD) 0.125–8/0.032–2 MIC Test Strips provide an efficient, reliable, and standardized approach to detect metallo-β-lactamase-mediated resistance in Gram-negative bacteria. Their compatibility with international guidelines and ease of interpretation make them a valuable tool for microbiology laboratories.