Related Experiment Video
Updated: May 14, 2026
An Analytical Tool-box for Comprehensive Biochemical, Structural and Transcriptome Evaluation of Oral Biofilms Mediated by Mutans Streptococci
Published on: January 25, 2011
Imaging of Staphylococcus aureus infections and biofilms using a selective covalent probe for the unique serine
Emily C Woods1, Tulsi Upadhyay1, Ki Wan Park2
1Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Abstract:
Staphylococcus aureus is the leading cause of soft tissue infections that can be treated with antibiotics. However, it can also cause significant mortality and morbidity due to systemic infections and infections of surgical implants. Implant infections typically require invasive surgery, and treatment often necessitates removal of the implant because S. aureus biofilms are extremely difficult to eradicate with antibiotic treatment alone. Therefore, there is a significant need for improved diagnostic tools for rapid, non-invasive confirmation of S. aureus infections. We recently developed an activity-based probe containing an oxadiazolone electrophile that selectively labels the S. aureus-specific serine hydrolase, FphE, by covalent binding to its active site serine residue. Here we describe a Cy5-labeled version of the probe, JJ-OX-012, and its characterization as an imaging agent for detecting biofilms both in vitro and in vivo. The probe labeled S. aureus biofilms in vitro, with virtually no background labeling of bacteria that lack FphE expression. Furthermore, we demonstrate that JJ-OX-012 can be used for non-invasive fluorescent imaging as a way to detect S. aureus biofilms in vivo. Overall, these findings support the potential for using covalent probes targeting FphE as imaging agents for rapid detection and diagnosis of staphylococcal infections in vivo.
Insights
A new imaging probe, JJ-OX-012, can detect Staphylococcus aureus biofilms in vivo. This advance offers a potential new tool for diagnosing staphylococcal infections non-invasively.
Area of Science:
- Microbiology
- Biochemistry
- Medical Imaging
Background:
- Staphylococcus aureus causes significant morbidity and mortality, particularly through difficult-to-treat biofilms on surgical implants.
- Current diagnostics for S. aureus infections can be invasive, and biofilm eradication often requires implant removal.
- There is a critical need for rapid, non-invasive methods to confirm S. aureus infections.
Purpose of the Study:
- To develop and characterize a novel imaging agent for the detection of Staphylococcus aureus biofilms.
- To evaluate the efficacy of a Cy5-labeled activity-based probe (JJ-OX-012) targeting the S. aureus-specific enzyme FphE.
- To assess the probe's utility for non-invasive in vivo imaging of S. aureus biofilms.
Main Methods:
- Development of a Cy5-labeled oxadiazolone-based activity-based probe (JJ-OX-012).
- In vitro characterization of probe specificity against S. aureus biofilms.
- In vivo imaging studies to detect S. aureus biofilms using non-invasive fluorescence imaging.
Main Results:
- The probe JJ-OX-012 selectively labeled Staphylococcus aureus biofilms in vitro.
- Minimal background labeling was observed in bacteria lacking FphE expression.
- JJ-OX-012 successfully enabled non-invasive fluorescent imaging for the detection of S. aureus biofilms in vivo.
Conclusions:
- Covalent probes targeting FphE are effective imaging agents for Staphylococcus aureus.
- JJ-OX-012 demonstrates potential for the rapid, non-invasive diagnosis of S. aureus infections.
- This approach may improve patient outcomes by enabling earlier and more accurate diagnosis of staphylococcal infections.
Related Concept Videos
01:13Special Staining Techniques
03:31Labeling DNA Probes
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...