The discovery of the MCR-1 gene marked a significant shift in the global antibiotic resistance landscape. Unlike chromosomal mutations, MCR-1 is plasmid-borne, enabling horizontal gene transfer across bacterial populations. This gene encodes a phosphoethanolamine transferase that modifies lipid A, reducing the affinity of colistin, a last-resort antibiotic used to treat multi-drug-resistant Gram-negative infections.

As colistin resistance spreads, the need for fast, reliable, and accessible detection methods becomes urgent. Molecular assays dominate current diagnostics, but monoclonal antibodies (mAbs) targeting MCR-1-associated epitopes offer a promising, complementary approach for research use only (RUO) in-vitro diagnostic platforms.

MCR-1 modifies the bacterial outer membrane by catalyzing the addition of phosphoethanolamine (pEtN) to the lipid A component of lipopolysaccharides. This modification reduces the negative charge of the membrane, decreasing colistin binding and rendering it ineffective.

This modification pathway creates unique molecular patterns that can serve as epitopes for antibody-based detection, provided the antibodies exhibit high specificity and sensitivity to these subtle changes.

The pEtN-lipid A structure is small and embedded in the bacterial outer membrane, posing challenges for immune recognition. SynAbs addresses this through hapten engineering and membrane mimicry in immunization protocols.

Since lipid A is a conserved structure in Gram-negative bacteria, cross-reactivity must be meticulously avoided. Achieving this demands finely tuned selection and screening processes that differentiate between native and MCR-1-modified lipid A.

As the MCR-1 protein itself can be poorly immunogenic, SynAbs uses recombinant protein fragments and structural analogs as immunogens. Carrier protein conjugation strategies help break immune tolerance and enhance antibody responses.

We produce high-purity, functionally active MCR-1 protein fragments to immunize mice using optimized adjuvant systems. This ensures the elicitation of high-affinity B cell clones specific to conformational or linear MCR-1 epitopes.

For lipid-based detection, SynAbs engineers synthetic lipid A mimics displaying pEtN-modified motifs. These are conjugated to KLH and used to generate targeted immune responses.

We apply high-throughput hybridoma screening to isolate antibody-secreting clones with:

• Specificity to MCR-1 protein or pEtN-lipid A

• No binding to native lipid A or unrelated LPS structures

• High affinity in physiological conditions

All mAbs are validated via ELISA, Western blotting, and flow cytometry using MCR-1-expressing and non-expressing strains. Antibodies are purified and quality controlled under stringent SOPs for RUO-grade use.

Monoclonal antibodies against MCR-1 open the door to rapid, field-deployable diagnostics:

• ELISA kits for research labs and surveillance programs

• Lateral Flow Assays for hospital infection control

• Multiplex platforms for simultaneous resistance marker detection

Such tools can aid in mapping resistance outbreaks, informing treatment decisions, and guiding antibiotic stewardship programs.

As the world faces an era of superbugs, SynAbs stands at the forefront of monoclonal antibody innovation for hard-to-target antibiotic resistance mechanisms. Our MCR-1 program delivers:

• Bespoke antibody generation

• Advanced hybridoma screening

• RUO-grade antibody production for diagnostics

Let SynAbs be your trusted partner in developing reliable, rapid, and research-grade solutions for combating MCR-1-mediated colistin resistance.

SynAbs – Immunological precision for global health resilience.