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Bacteria-Targeted MRI Probe-Based Imaging Bacterial Infection and Monitoring Antimicrobial Therapy In Vivo
Linyao Li1, Peilin Gu1, Mengqi Hao1
1Key Laboratory of Luminescence Analysis and Molecular Sensing, College of Pharmaceutical Sciences, Southwest University, Chongqing, 400715, China.
Abstract:
Despite the significant advances of imaging techniques nowadays, accurate diagnosis of bacterial infections and real-time monitoring the efficacy of antibiotic therapy in vivo still remain huge challenges. Herein, a self-assembling peptide (FFYEGK) and vancomycin (Van) antibiotic molecule co-modified gadolinium (Gd) MRI nanoaggregate probe (GFV) for detecting Staphylococcus aureus (S. aureus) infection in vivo and monitoring the treatment of S. aureus-infected myositis by using daptomycin (Dap) antibiotic as model are designed and fabricated. The as-prepared GFV probe bears Van molecules, making itself good bacteria-specific targeting, and the peptide in the probe can enhance the longitudinal relaxivity rate (r1 ) after self-assembly due to the π-π stacking. The study showed that, based on the GFV probe, bacterial infections and sterile inflammation can be discriminated, and as few as 105 cfu S. aureus can be detected in vivo with high specificity and accurately. Moreover, the T1 signal of GFV probe at the S. aureus-infected site in mice correlates with the increasing time of Dap treating, indicating the possibility of monitoring the efficacy of antibacterial agents for infected mice based on the as proposed GFV probe. This study shows the potential of GFV probe for diagnosis, evaluation, and prognosis of infectious diseases in clinics.
Insights
A novel gadolinium-based MRI nanoaggregate probe (GFV) effectively detects Staphylococcus aureus infections in vivo. This probe also monitors antibiotic treatment efficacy, showing potential for diagnosing and evaluating infectious diseases.
Area of Science:
- Biomedical Imaging
- Nanotechnology
- Infectious Disease Diagnosis
Background:
- Accurate diagnosis of bacterial infections and monitoring antibiotic therapy efficacy in vivo remain challenging.
- Advanced imaging techniques are crucial for real-time assessment of treatment response.
Purpose of the Study:
- To design and fabricate a novel gadolinium (Gd) MRI nanoaggregate probe (GFV) for detecting Staphylococcus aureus (S. aureus) infection.
- To evaluate the probe's ability to discriminate bacterial infections from sterile inflammation and monitor antibiotic treatment efficacy in vivo.
Main Methods:
- Co-modification of a self-assembling peptide (FFYEGK) and vancomycin (Van) with gadolinium (Gd) to create the GFV probe.
- In vivo detection of S. aureus infection and monitoring of daptomycin (Dap) treatment in a mouse model.
- Assessment of probe specificity, sensitivity, and correlation of MRI signals with treatment progression.
Main Results:
- The GFV probe demonstrated specific targeting of S. aureus due to surface-bound vancomycin.
- Bacterial infections were successfully discriminated from sterile inflammation with high specificity.
- As few as 10^5 colony-forming units (cfu) of S. aureus were detectable in vivo.
- The T1 signal intensity at the infection site correlated with the duration of daptomycin treatment, indicating treatment monitoring capability.
Conclusions:
- The GFV probe shows significant potential for the accurate diagnosis and real-time monitoring of bacterial infections and antibiotic therapy efficacy.
- This nanotechnology-based approach offers a promising tool for evaluating infectious diseases in clinical settings.
