Bacteriophage research is gaining more importance due to increasing antibiotic resistance. However, for treatment with bacteriophages, diagnostics have to be improved. Bacteriophages carry adhesion proteins, which bind to the bacterial cell surface, for example tailspike proteins (TSP) for specific recognition of bacterial O-antigen polysaccharide. TSP are highly stable proteins and thus might be suitable components for the integration into diagnostic tools. We used the TSP of bacteriophage Sf6 to establish two applications for detecting Shigella flexneri (S. flexneri), a highly contagious pathogen causing dysentery. We found that Sf6TSP not only bound O-antigen of S. flexneri serotype Y, but also the glucosylated O-antigen of serotype 2a. Moreover, mass spectrometry glycan analyses showed that Sf6TSP tolerated various O-acetyl modifications on these O-antigens. We established a microtiter plate-based ELISA like tailspike adsorption assay (ELITA) using a Strep-tag((R))II modified Sf6TSP. As sensitive screening alternative we produced a fluorescently labeled Sf6TSP via coupling to an environment sensitive dye. Binding of this probe to the S. flexneri O-antigen Y elicited a fluorescence intensity increase of 80% with an emission maximum in the visible light range. The Sf6TSP probes thus offer a promising route to a highly specific and sensitive bacteriophage TSP-based Shigella detection system.
O-antigen, Shigella flexneri, serotyping, bacteriophage, biomolecule, fluorescence sensor, microtiter plate assay, tailspike proteins
NCBI PubMed ID: 30111705Publication DOI: 10.3390/v10080431Journal NLM ID: 101509722Publisher: Basel, Switzerland: MDPI
Correspondence: barbirz@uni-potsdam.de; ts599@cam.ac.uk
Institutions: CNRS UMR 3523, Institut Pasteur, 75015 Paris, France, Physical Biochemistry, University of Potsdam, 14476 Potsdam, Germany, Institut Pasteur, Unite de Chimie des Biomolecules, 28 rue du Roux, 75015 Paris, France, National Reference Centre for Salmonella and other Bacterial Enterics, Robert Koch Institute, 38855 Wernigerode, Germany
Methods: PCR, ELISA, MALDI-TOF MS, cloning, fluorescence spectroscopy, SPR, serotyping, ELISA-like tailspike adsorption assay, CE-LIF, fluorescence labeling
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