Internalization Assays for Listeria monocytogenes

Area of Science:

• Microbiology
• Cell Biology
• Infectious Diseases

Background:

• Listeria monocytogenes is a key intracellular pathogen model.
• Host cell invasion is a critical step in Listeria pathogenesis.
• Quantifying bacterial internalization is essential for studying host-pathogen interactions.

Purpose of the Study:

• To describe and compare methods for quantifying Listeria monocytogenes internalization into host cells.
• To provide detailed protocols for two distinct invasion assays.
• To enable researchers to select appropriate methods for their studies.

Main Methods:

• Gentamicin protection assay: quantifies viable intracellular bacteria via colony-forming units.
• Immunofluorescence microscopy: visualizes and quantifies intracellular bacteria using fluorescent antibodies.
• Comparison of assay performance for medium- to high-throughput analysis.

Main Results:

• Both gentamicin protection assay and immunofluorescence microscopy effectively quantify Listeria monocytogenes invasion.
• Immunofluorescence offers higher throughput capabilities for invasion assays.
• Assays can be used independently or in combination for comprehensive analysis.

Conclusions:

• Standardized assays are crucial for reproducible measurement of Listeria monocytogenes host cell invasion.
• A combination of methods can provide robust data on bacterial internalization.
• These methods facilitate research into Listeria pathogenesis and host-pathogen interactions.