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Differences of microbial growth and biofilm formation among periprosthetic joint infection-causing species: an animal
Mehmet Batu Ertan1, Mehmet Yağız Ayduğan2, Ebru Evren3
1Department of Orthopedics and Traumatology, Atılım Unıversity School of Medicine, Ankara, Turkey. mbatuertan@gmail.com.
Purpose:
The most frequently used surgical procedures for periprosthetic joint infections (PJIs) are debridement, antibiotics, and implant retention (DAIR), as well as single- or two-stage revision arthroplasty. The choice of surgery is made depending on the full maturation of the biofilm layer. The purpose of this study was to evaluate the biofilm formation and microbial growth using common PJI-causing agents and compare its development on the implant surface.
Methods:
The in vivo study was performed using 40 Sprague-Dawley rats divided into five groups (n = 8/group): Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Candida albicans, and control. Six standard titanium alloy discs were placed into the subcutaneous air pouches of the interscapular areas of the rats. After the inoculation of microorganisms, disc and soft tissue cultures were collected at 2-week intervals for 6 weeks, and the microbial load and the microscopic appearance of the biofilm were compared.
Results:
The disc samples from the S. aureus group had the highest infection load at all time points; however, in soft tissue samples, this was only observed at week 4 and 6. Electron microscopic images showed no distinctive differences in the biofilm structures between the groups.
Conclusion:
S. aureus microbial burden was significantly higher in implant cultures at week 2 compared to other PJI-causing agents examined. These results may explain the higher failure rate seen if the DAIR procedure was performed at < 3-4 weeks after the PJI symptom onset and support the observation that DAIR may not be effective against PJIs caused by S. aureus.
Insights
Staphylococcus aureus showed the highest infection load on implants in periprosthetic joint infections (PJIs). This suggests debridement, antibiotics, and implant retention (DAIR) may be less effective for S. aureus PJIs within the first 3-4 weeks.
Area of Science:
- Biomedical Engineering
- Infectious Diseases
- Orthopedic Surgery
Background:
- Periprosthetic joint infections (PJIs) are serious complications following arthroplasty.
- Common surgical interventions include debridement, antibiotics, and implant retention (DAIR) and revision arthroplasty.
- Treatment choice depends on biofilm maturation, necessitating understanding of microbial growth dynamics.
Purpose of the Study:
- To evaluate biofilm formation and microbial growth of common PJI pathogens.
- To compare microbial development on implant surfaces in an in vivo model.
Main Methods:
- An in vivo study using 40 Sprague-Dawley rats, divided into five groups (S. aureus, S. epidermidis, P. aeruginosa, C. albicans, control).
- Titanium alloy discs were implanted subcutaneously and inoculated with microorganisms.
- Cultures of discs and soft tissues were collected bi-weekly for 6 weeks to assess microbial load and biofilm structure.
Main Results:
- Staphylococcus aureus exhibited the highest infection load on implant discs throughout the study.
- Significant S. aureus infection load in soft tissues was observed from week 4 onwards.
- Microscopic analysis revealed no distinct differences in biofilm structures across the tested microbial groups.
Conclusions:
- Staphylococcus aureus demonstrated a significantly higher microbial burden on implant cultures by week 2 compared to other agents.
- These findings may explain the higher failure rates of DAIR when performed within 3-4 weeks of PJI symptom onset.
- The results support the notion that DAIR might be less effective for PJIs caused by Staphylococcus aureus.
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