Immobilized phage proteins for specific detection of staphylococci

Area of Science:

• Microbiology
• Biotechnology
• Materials Science

Background:

• Rapid and specific detection of pathogenic bacteria is crucial for diagnosing infectious diseases.
• Bacteriophages offer high specificity for bacterial detection, but individual phage proteins for biosensing remain underexplored.

Purpose of the Study:

• To investigate the potential of using specific bacteriophage proteins (endolysins LysK, Φ11, and bacteriocin lysostaphin) for bacterial detection.
• To develop a robust and generalizable biosensor platform for staphylococci detection.

Main Methods:

• Functionalization of silicon wafers with purified phage proteins (LysK, Φ11, lysostaphin).
• Quantification of bacterial binding using solution-based clearing assays and surface-based light microscopy.
• Testing protein binding specificity against various bacterial species, including Staphylococcus aureus, S. epidermidis, Escherichia coli, and Micrococcus.

Main Results:

• Phage proteins LysK, Φ11, and lysostaphin demonstrated specific binding to clinical isolates of Staphylococcus aureus and S. epidermidis.
• Minimal to no binding was observed for Escherichia coli and limited binding for Micrococcus.
• Bacterial binding densities on functionalized surfaces reached approximately 3 cells/100 μm(2).

Conclusions:

• Individual bacteriophage proteins can be effectively immobilized on surfaces for specific bacterial capture.
• This protein-based approach provides a robust, scalable, and versatile platform for developing novel diagnostic biosensors.
• The principle is adaptable to various biosensor technologies, including label-free optical microresonators.