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Updated: Dec 12, 2025
Author Spotlight: Peptidome Extraction from Small Extracellular Vesicles Isolated from Bone Marrow-Derived Macrophages
Published on: June 30, 2023
Extracellular Vesicles: A Potential Biomarker for Quick Identification of Infectious Osteomyelitis
Songyun Deng1,2, Yutian Wang1,2, Shiluan Liu1,2
1Department of Orthopaedics, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Abstract:
Effective management of infectious osteomyelitis relies on timely microorganism identification and appropriate antibiotic therapy. Extracellular vesicles (EVs) carry protein and genetic information accumulated rapidly in the circulation upon infection. Rat osteomyelitis models infected by Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli were established for the present study. Serum EVs were isolated 3 days after infection. The size and number of serum EVs from infected rats were significantly higher than those from controls. In addition, bacterial aggregation assay showed that the S. aureus and E. coli formed large aggregates in response to the stimulation of serum EVs from S. aureus-infected and E. coli-infected rats, respectively. Treatment of EVs-S. epidermidis led to large aggregates of S. epidermidis and E. coli, whereas stimulation of EVs-P. aeruginosa to large aggregates of S. aureus and P. aeruginosa. To evaluate the changes in EVs in osteomyelitis patients, 28 patients including 5 S. aureus ones and 21 controls were enrolled. Results showed that the size and number of serum EVs from S. aureus osteomyelitis patients were higher than those from controls. Further analysis using receiver operating characteristic curves revealed that only the particle size might be a potential diagnostic marker for osteomyelitis. Strikingly, serum EVs from S. aureus osteomyelitis patients induced significantly stronger aggregation of S. aureus and a cross-reaction with P. aeruginosa. Together, these findings indicate that the size and number of serum EVs may help in the diagnosis of potential infection and that EVs-bacteria aggregation assay may be a quick test to identify infectious microorganisms for osteomyelitis patients.
Insights
Serum extracellular vesicles (EVs) increase in size and number during osteomyelitis infection. These EVs may aid in diagnosing infections and identifying causative bacteria through an aggregation assay.
Area of Science:
- Biomedical research
- Infectious diseases
- Nanotechnology
Background:
- Osteomyelitis management requires rapid pathogen identification and targeted antibiotic treatment.
- Extracellular vesicles (EVs) in circulation reflect infection status by carrying pathogen-derived molecules.
- Current diagnostic methods for osteomyelitis can be time-consuming.
Purpose of the Study:
- To investigate the diagnostic potential of serum extracellular vesicles (EVs) in osteomyelitis.
- To explore the use of EVs in identifying infectious microorganisms causing osteomyelitis.
Main Methods:
- Established rat models of osteomyelitis using Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli.
- Isolated and characterized serum EVs from infected rats and osteomyelitis patients.
- Performed bacterial aggregation assays using stimulated EVs.
- Analyzed EV particle size and number, and employed receiver operating characteristic (ROC) curves for diagnostic marker evaluation.
Main Results:
- Serum EV size and number were significantly elevated in infected rats and osteomyelitis patients compared to controls.
- Serum EVs from infected rats induced aggregation of specific bacteria.
- Serum EVs from Staphylococcus aureus osteomyelitis patients showed enhanced aggregation of S. aureus and cross-reactivity with Pseudomonas aeruginosa.
- EV particle size emerged as a potential diagnostic marker for osteomyelitis via ROC analysis.
Conclusions:
- Serum EV size and number show promise for diagnosing potential osteomyelitis infections.
- An EVs-bacteria aggregation assay could serve as a rapid method for identifying infectious agents in osteomyelitis patients.
