Related Experiment Video
Updated: Sep 26, 2026
Animal Model of Implant-Associated Infections in Mice
Published on: June 27, 2025
Detection of subclinical infection in significant breast implant capsules
Aniko Pajkos1, Anand K Deva, Karen Vickery
1Department of Infectious Diseases, University of Sydney, Australia.
Abstract:
The pathogenesis of fibrous capsular contracture after augmentation mammaplasty is still debated. One hypothesis implicates low-grade bacterial infections as a cause. The presence of a staphylococcal biofilm in a patient with recurrent capsular contracture was previously reported. A comparative, prospective, blinded, clinical study of implants and capsules removed from patients with or without significant capsular contracture was conducted to investigate the association of biofilm contamination, breast implants, and capsular contracture. Capsule and implant samples obtained during explantation were tested by routine microbiological culture, sensitive broth culture (after maceration and sonication), and scanning electron microscopy. Clinical parameters were correlated with microbiological findings. A total of 48 implant and/or capsule samples were obtained from 27 breasts during a 22-month period. Of the 27 breasts, 19 exhibited significant contracture (Baker grade III/IV). The mean duration of implantation was 9.2 years (range, 0.4 to 26.0 years). Routine swab cultures obtained at the time of explantation were negative for bacterial growth for all samples. The sensitive broth culture technique yielded 24 positive samples (50 percent, n = 48). An analysis of capsules demonstrated that 17 of 19 samples obtained from patients with significant contracture were positive, compared with only one of eight samples obtained from patients with minimal or no contracture (p = 0.0006). Fourteen of the 17 positive cultures from significantly contracted breasts yielded coagulase-negative staphylococci, mainly, species of the Staphylococcus epidermidis group. The presence of coagulase-negative staphylococci was also significantly associated with capsular contracture (p = 0.01). There was no significant difference in the frequency of culture positivity for saline versus silicone implants (p = 0.885). Scanning electron microscopy confirmed the presence of extensive biofilm on implants and within capsules.Biofilm, in particular, S. epidermidis biofilm, was detected for a significant proportion of patients with capsular contracture. This implicates biofilm disease in the pathogenesis of contracture, and strategies for its prevention should be explored.
Insights
Bacterial biofilm, particularly Staphylococcus epidermidis, is frequently found in breast implants with capsular contracture. This study suggests biofilm disease contributes to contracture development, necessitating new prevention strategies.
Area of Science:
- Plastic Surgery
- Microbiology
- Biomaterials Science
Background:
- Fibrous capsular contracture is a common complication following augmentation mammaplasty.
- The exact cause of capsular contracture remains debated, with low-grade bacterial infections hypothesized.
- Previous reports suggest a link between staphylococcal biofilm and recurrent capsular contracture.
Purpose of the Study:
- To investigate the association between biofilm contamination, breast implants, and capsular contracture.
- To compare microbiological findings in implants and capsules from patients with and without significant contracture.
Main Methods:
- A prospective, blinded clinical study involving explanted breast implants and capsules.
- Samples were analyzed using routine microbiological culture, sensitive broth culture (post-maceration and sonication), and scanning electron microscopy.
- Clinical parameters, including contracture severity (Baker grade III/IV), were correlated with microbiological results.
Main Results:
- Routine cultures were negative, but sensitive broth cultures yielded positive results in 50% of samples.
- Significantly higher positive culture rates were found in samples from breasts with contracture (17/19) compared to those without (1/8).
- Coagulase-negative staphylococci, primarily Staphylococcus epidermidis, were the predominant organisms identified and were significantly associated with contracture.
- Scanning electron microscopy confirmed extensive biofilm presence on implants and within capsules.
Conclusions:
- Biofilm, particularly Staphylococcus epidermidis biofilm, is detected in a significant proportion of patients with capsular contracture.
- These findings implicate biofilm disease in the pathogenesis of fibrous capsular contracture after augmentation mammaplasty.
- Development of strategies to prevent biofilm formation on breast implants should be explored.
