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Updated: Aug 12, 2026
Experimental Infection with Listeria monocytogenes as a Model for Studying Host Interferon-γ Responses
Published on: November 16, 2016
Single-chain Fv antibody with specificity for Listeria monocytogenes
George C Paoli1, Chin-Yi Chen, Jeffrey D Brewster
1Microbial Biophysics and Residue Chemistry and Core Technologies, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Service, Wyndmoor, PA 19038, USA.
Abstract:
Single chain antibodies (scFv) exhibiting specific binding to Listeria monocytogenes strains were isolated from a pool of random scFvs expressed on the surface of filamentous bacteriophages. Positive selection (panning) using L. monocytogenes was used to enrich for phage clones with the desired binding affinity, and negative selection using L. innocua and L. ivanovii was used to remove phages expressing cross-reactive antibody fragments. A single phage clone, P4:A8, was selected using two independent panning schemes. A rapid assay was devised to determine phage antibody binding specificity and was used to develop a selectivity profile for individual phage clones. The P4:A8 clone was screened against a panel of bacteria consisting of eight strains of L. monocytogenes, one each of the other six species of Listeria and nine other relevant bacterial species. A collection of individual clones from the penultimate panning was also screened against a subset of the panel of bacteria. The selectivity profiles indicate that multiple clones, including P4:A8, exhibit binding to one or more strains of L. monocytogenes without cross-reactivity toward any other species in the panel. This is the first report of a species-specific antibody for viable cells of L. monocytogenes (i.e., the ability to bind to L. monocytogenes without cross-reactivity toward any other species of Listeria).
Insights
Researchers developed a novel assay to isolate highly specific single chain variable fragments (scFv) that bind to Listeria monocytogenes. This method successfully identified scFvs targeting L. monocytogenes without cross-reactivity to other Listeria species.
Area of Science:
- Immunotechnology
- Microbiology
- Bacteriophage Display
Background:
- Accurate detection of Listeria monocytogenes is crucial for food safety and public health.
- Developing highly specific antibodies is essential for reliable diagnostic tools.
Purpose of the Study:
- To isolate and characterize single chain variable fragments (scFv) with specific binding affinity for Listeria monocytogenes.
- To develop a species-specific antibody for viable L. monocytogenes detection.
Main Methods:
- Phage display technology was employed for antibody library construction.
- Positive selection (panning) with L. monocytogenes and negative selection with related Listeria species were used.
- A rapid assay was developed to determine antibody binding specificity and selectivity profiles.
Main Results:
- Multiple phage clones, including P4:A8, demonstrated specific binding to L. monocytogenes strains.
- Selected clones showed no cross-reactivity with other Listeria species or common bacterial pathogens.
- The study reports the first species-specific antibody for viable L. monocytogenes cells.
Conclusions:
- The developed scFvs offer high specificity for L. monocytogenes detection.
- This represents a significant advancement in developing rapid and accurate diagnostic methods for L. monocytogenes.
- The findings pave the way for improved food safety and clinical diagnostics.
