Microbial community compositions in breast implant biofilms associated with contracted capsules

Advances in Etiology and Prevention of Capsular Contracture After Breast Implantation

Capsular contracture (CC) is one of the most common complications of breast implant usage in breast augmentation or reconstruction. The CC approach can cause breast hardening, pain, and varying degrees of deformity, affecting the quality of life of patients. Considerably, it has become one of the most common reasons for frequent surgeries. Nonetheless, the etiology and pathogenesis of CC remain unclear. Moreover, there exist still a lot of uncertainties regarding prevention and treatment measures. In this article, we present discussions on the research status of the etiology, pathogenesis, prevention, and treatment measures of CC. In summary, this study provides a reference for further research on CC and clinical use.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Systematic Review and Meta-Analysis of 16S rRNA and Cancer Microbiome Atlas Datasets to Characterize Microbiota Signatures in Normal Breast, Mastitis, and Breast Cancer

The breast tissue microbiome has been increasingly recognized as a potential contributor to breast cancer development and progression. However, inconsistencies in microbial composition across studies have hindered the identification of definitive microbial signatures. We conducted a systematic review and meta-analysis of 11 studies using 16S rRNA sequencing to characterize the bacterial microbiome in 1260 fresh breast tissue samples, including normal, mastitis-affected, benign, cancer-adjacent, and cancerous tissues. Studies published until 31 December 2023 were included if they analyzed human breast tissue using Illumina short-read 16S rRNA sequencing with sufficient metadata, while non-human samples, non-breast tissues, non-English articles, and those lacking metadata or using alternative sequencing methods were excluded. We also incorporated microbiome data from The Cancer Genome Atlas breast cancer (TCGA-BRCA) cohort to enhance our analyses. Our meta-analysis identified Proteobacteria, Firmicutes, Actinobacteriota, and Bacteroidota as the dominant phyla in breast tissue, with Staphylococcus and Corynebacterium frequently detected across studies. While microbial diversity was similar between cancer and cancer-adjacent tissues, they both exhibited a lower diversity compared to normal and mastitis-affected tissues. Variability in bacterial genera was observed across primer sets and studies, emphasizing the need for standardized methodologies in microbiome research. An analysis of TCGA-BRCA data confirmed the dominance of Staphylococcus and Corynebacterium, which was associated with breast cancer proliferation-related gene expression programs. Notably, high Staphylococcus abundance was associated with a 4.1-fold increased mortality risk. These findings underscore the potential clinical relevance of the breast microbiome in tumor progression and emphasize the importance of methodological consistency. Future studies to establish causal relationships, elucidate underlying mechanisms, and assess microbiome-targeted interventions are warranted.

Staphylococcus epidermidis biofilm in inflammatory breast cancer and its treatment strategies

Bacterial biofilms represent a significant challenge in both clinical and industrial settings because of their robust nature and resistance to antimicrobials. Biofilms are formed by microorganisms that produce an exopolysaccharide matrix, protecting function and supporting for nutrients. Among the various bacterial species capable of forming biofilms, Staphylococcus epidermidis, a commensal organism found on human skin and mucous membranes, has emerged as a prominent opportunistic pathogen, when introduced into the body via medical devices, such as catheters, prosthetic joints, and heart valves. The formation of biofilms by S. epidermidis on these surfaces facilitates colonization and provides protection against host immune responses and antibiotic therapies, leading to persistent and difficult-to-treat infections. The possible involvement of biofilms for breast oncogenesis has recently created the curiosity. This paper therefore delves into S. epidermidis biofilm involvement in breast cancer. S. epidermidis biofilms can create a sustained inflammatory environment through their metabolites and can break DNA in breast tissue, promoting cellular proliferation, angiogenesis, and genetic instability. Preventing biofilm formation primarily involves preventing bacterial proliferation using prophylactic measures and sterilization of medical devices and equipment. In cancer treatment, common modalities include chemotherapy, surgery, immunotherapy, alkylating agents, and various anticancer drugs. Understanding the relationship between anticancer drugs and bacterial biofilms is crucial, especially for those undergoing cancer treatment who may be at increased risk of bacterial infections, for improving patient outcomes. By elucidating these interactions, strategies to prevent or disrupt biofilm formation, thereby reducing the incidence of infections associated with medical devices and implants, can be identified.

Clinical Evaluation of Microbial Communities and Associated Biofilms with Breast Augmentation Failure

The incidence of breast implant illness (BII) and BII-related explant procedures has not decreased with current surgical and treatment techniques. It is speculated the main underlying cause of BII complications is the result of chronic, sub-clinical infections residing on and around the implant. The infection, and subsequent biofilm, produce antagonistic compounds that drive chronic inflammation and immune responses. In this study, the microbial communities in over 600 consecutive samples of infected explant capsules and tissues were identified via next-generation sequencing to identify any commonality between samples. The majority of the bacteria identified were Gram-positive, with Cutibacterium acnes and Staphylococcus epidermidis being the dominant organisms. No correlation between sample richness and implant filling was found. However, there was a significant correlation between sample richness and patient age. Due to the complex nature, breast augmentation failures may be better addressed from a holistic approach than one of limited scope.

Toward a Consensus Aproach for Assessing Capsular Contracture Severity and Progression: A Systematic Review

BACKGROUND

Breast implants are the most commonly used medical devices in plastic surgery, and capsular contracture (CC) is one of the most common complications. However, our assessment of CC is based largely on Baker grade, which is problematically subjective and affords only four possible values.

METHODS

The authors performed a systematic review concluding in September of 2021 in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. It identified 19 articles that propose approaches to measuring CC.

RESULTS

In addition to Baker grade, the authors identified several modalities reported to measure CC. These included magnetic resonance imaging, ultrasonography, sonoelastography, mammacompliance measuring devices, applanation tonometry, histologic evaluation, and serology. Capsule thickness and other measures of CC inconsistently correlated with Baker grade, whereas the presence of synovial metaplasia was consistently associated with Baker grade I and II, but not III and IV capsules.

CONCLUSIONS

There remains no particular method to reliably and specifically measure the contracture of capsules that form around breast implants. As such, we would recommend that research investigators use more than one modality to measure CC. Other variables that can impact breast implant stiffness and associated discomfort beyond CC need to be considered when evaluating patient outcomes. Given the value placed on CC outcomes in assessing breast implant safety, and the prevalence of breast implants overall, the need for a more reliable approach to measuring this outcome persists.

Management of Biofilm with Breast Implant Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand how bacteria negatively impact aesthetic and reconstructive breast implants. 2. Understand how bacteria infect breast implants. 3. Understand the evidence associated with common implant infection-prevention strategies, and their limitations. 4. Understand why implementation of bacteria-mitigation strategies such as antibiotic administration or "no-touch" techniques may not indefinitely prevent breast implant infection.

SUMMARY

Bacterial infection of aesthetic and reconstructive breast implants is a common and expensive problem. Subacute infections or chronic capsular contractures leading to device explantation are the most commonly documented sequelae. Although bench and translational research underscores the complexities of implant-associated infection, high-quality studies with adequate power, control groups, and duration of follow-up are lacking. Common strategies to minimize infections use antibiotics-administered systemically, in the breast implant pocket, or by directly bathing the implant before insertion-to limit bacterial contamination. Limiting contact between the implant and skin or breast parenchyma represents an additional common strategy. The clinical prevention of breast implant infection is challenged by the clean-contaminated nature of breast parenchyma, and the variable behavior of not only specific bacterial species but also their strains. These factors impact bacterial virulence and antibiotic resistance.

A prospective randomized clinical trial to assess antibiotic pocket irrigation on tissue expander breast reconstruction

Bacterial infection is the most common complication following staged post-mastectomy breast reconstruction initiated with a tissue expander (TE). To limit bacterial infection, antibiotic irrigation of the surgical site is commonly performed despite little high-quality data to support this practice. We performed a prospective randomized control trial to compare the impact of saline irrigation alone to a triple antibiotic irrigation regimen (1 g cefazolin, 80 mg gentamicin, and 50,000 units of bacitracin in 500 mL of saline) for breast implant surgery. The microbiome in breasts with cancer (n = 16) was compared to those without (n = 16), as all patients (n = 16) had unilateral cancers but bilateral mastectomies (n = 32). Biologic and prosthetic specimens procured both at the time of mastectomy and during TE removal months later were analyzed for longitudinal comparison. Outcomes included clinical infection, bacterial abundance, and relative microbiome composition. No patient in either group suffered a reconstructive failure or developed an infection. Triple antibiotic irrigation administered at the time of immediate TE reconstruction did not reduce bacterial abundance or impact microbial diversity relative to saline irrigation at the time of planned exchange. Implanted prosthetic material adopted the microbial composition of the surrounding host tissue. In cancer-naïve breasts, relative to saline, antibiotic irrigation increased bacterial abundance on periprosthetic capsules (P = 0.03) and acellular dermal matrices (P = 0.04) and altered the microbiota on both. These data show that, relative to saline only, the use of triple antibiotic irrigation in TE breast reconstruction does impact the bacterial abundance and diversity of certain biomaterials from cancer-naïve breasts. IMPORTANCE The lifetime risk of breast cancer is ~13% in women and is treated with a mastectomy in ~50% of cases. The majority are reconstructed, usually starting with a tissue expander to help restore the volume for a subsequent permanent breast implant or the women's own tissues. The biopsychosocial benefits of breast reconstruction, though, can be tempered by a high complication rate of at least 7% but over 30% in some women. Bacterial infection is the most common complication, and can lead to treatment delays, patient physical and emotional distress and escalating health care cost. To limit this risk, plastic surgeons have tried a variety of strategies to limit bacterial infection including irrigating the pocket created after removing the breast implant with antibiotic solutions, but good-quality data are scarce. Herein, we study the value of antibiotics in pocket irrigation using a robust randomized clinical trial design and molecular microbiology approaches.

Infections in patients with adverse reactions to the use of unknown modeling substances for soft tissue enhancement in Cali, Colombia

The infiltration of foreign materials not approved for medical purposes or of modeling substances used in soft tissue to modify the anatomical appearance for aesthetic purposes represents a serious health problem. These procedures lead to the development of delayed complications, including infections. The objective of this study was to characterize infections in patients with adverse reactions to the use of modeling substances in Cali, Colombia. A cross-sectional and descriptive study was used to determine the frequency of bacterial and fungal infections associated with complications from and adverse reactions to the use of modeling substances in 113 patients. We identified microorganisms in 22 patients and a frequency of 68.1% monomicrobial infections and 31.8% polymicrobial infections. The microorganisms identified in our study included Bacillus cereus, Mycobacterium fortuitum, and Pseudomonas stutzeri, among other microorganisms. The presence of adverse effects derived from the use of illegal modeling substances has been demonstrated; among these effects, infections occur with high frequency and place the health of the patient at risk and increase problems in health care.

Advances in surface modifications of the silicone breast implant and impact on its biocompatibility and biointegration

Silicone breast implants are commonly used for cosmetic and oncologic surgical indications owing to their inertness and being nontoxic. However, complications including capsular contracture and anaplastic large cell lymphoma have been associated with certain breast implant surfaces over time. Novel implant surfaces and modifications of existing ones can directly impact cell-surface interactions and enhance biocompatibility and integration. The extent of foreign body response induced by breast implants influence implant success and integration into the body. This review highlights recent advances in breast implant surface technologies including modifications of implant surface topography and chemistry and effects on protein adsorption, and cell adhesion. A comprehensive online literature search was performed for relevant articles using the following keywords silicone breast implants, foreign body response, cell adhesion, protein adsorption, and cell-surface interaction. Properties of silicone breast implants impacting cell-material interactions including surface roughness, wettability, and stiffness, are discussed. Recent studies highlighting both silicone implant surface activation strategies and modifications to enhance biocompatibility in order to prevent capsular contracture formation and development of anaplastic large cell lymphoma are presented. Overall, breast implant surface modifications are being extensively investigated in order to improve implant biocompatibility to cater for increased demand for both cosmetic and oncologic surgeries.

DNA extraction leads to bias in bacterial quantification by qPCR

Quantitative PCR (qPCR) has become a widely used technique for bacterial quantification. The affordability, ease of experimental design, reproducibility, and robustness of qPCR experiments contribute to its success. The establishment of guidelines for minimum information for publication of qPCR experiments, now more than 10 years ago, aimed to mitigate the publication of contradictory data. Unfortunately, there are still a significant number of recent research articles that do not consider the main pitfalls of qPCR for quantification of biological samples, which undoubtedly leads to biased experimental conclusions. qPCR experiments have two main issues that need to be properly tackled: those related to the extraction and purification of genomic DNA and those related to the thermal amplification process. This mini-review provides an updated literature survey that critically analyzes the following key aspects of bacterial quantification by qPCR: (i) the normalization of qPCR results by using exogenous controls, (ii) the construction of adequate calibration curves, and (iii) the determination of qPCR reaction efficiency. It is primarily focused on original papers published last year, where qPCR was applied to quantify bacterial species in different types of biological samples, including multi-species biofilms, human fluids, and water and soil samples. KEY POINTS: • qPCR is a widely used technique used for absolute bacterial quantification. • Recently published papers lack proper qPCR methodologies. • Not including proper qPCR controls significantly affect experimental conclusions.

High-Throughput Biofilm Assay to Investigate Bacterial Interactions with Surface Topographies

The specific topography of biomaterials plays an important role in their biological interactions with cells and thus the safety of medical implants. Antifouling materials can be engineered with topographic features to repel microbes. Meanwhile, undesired topographies of implants can cause complications such as breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). While the cause of BIA-ALCL is not well understood, it is speculated that textured surfaces are prone to bacterial biofilm formation as a contributing factor. To guide the design of safer biomaterials and implants, quantitative screening approaches are needed to assess bacterial adhesion to different topographic surface features. Here we report the development of a high-throughput microplate biofilm assay for such screening. The assay was used to test a library of polydimethylsiloxane (PDMS) textures composed of varying sizes of recessive features and distances between features including those in the range of breast implant textures. Outliers of patterns prone to bacterial adhesion were further studied using real-time confocal fluorescence microscopy. The results from these analyses revealed that surface area itself is a poor predictor for adhesion, while the size and spacing of topographic features play an important role. This high-throughput biofilm assay can be applied to studying bacteria–material interactions and rational development of materials that inhibit bacterial colonization.

The Current Knowledge on the Pathogenesis of Tissue and Medical Device-Related Biofilm Infections

Biofilm is the trigger for the majority of infections caused by the ability of microorganisms to adhere to tissues and medical devices. Microbial cells embedded in the biofilm matrix are highly tolerant to antimicrobials and escape the host immune system. Thus, the refractory nature of biofilm-related infections (BRIs) still represents a great challenge for physicians and is a serious health threat worldwide. Despite its importance, the microbiological diagnosis of a BRI is still difficult and not routinely assessed in clinical microbiology. Moreover, biofilm bacteria are up to 100–1000 times less susceptible to antibiotics than their planktonic counterpart. Consequently, conventional antibiograms might not be representative of the bacterial drug susceptibility in vivo. The timely recognition of a BRI is a crucial step to directing the most appropriate biofilm-targeted antimicrobial strategy.

Efficacy of Povidone Iodine Against Microbial Biofilms in Breast Implants With Different Textures: Results From an in vitro Study

Background

In the practice of breast augmentation and reconstruction, implant irrigation with various solutions has been widely used to prevent infection and capsular contracture, but to date, there is no consensus on the optimal protocol to use. Recently, application of povidone iodine (PI) for 30 min has shown in vitro to be the most effective irrigating formula in reducing contamination in smooth breast implants. However, as 30 min is not feasible intraoperatively, it is necessary to determine whether shorter times could be equally effective as well as to test it in both smooth and textured implants.

Methods

We tested the efficacy of 10% PI at 1', 3', and 5' against biofilms of 8 strains (2 ATCC and 6 clinical) of Staphylococcus spp. on silicone disks obtained from Mentor^® and Polytech^® implants of different textures. We analyzed the percentage reduction of cfu counts, cell viability and bacterial density between treatment (PI) and control (sterile saline, SS) groups for each time of application. We consider clinical significance when > 25% reduction was observed in cell viability or bacterial density.

Results

All textured implants treated with PI at any of the 3 exposure times reduced 100% bacterial load by culture. However, none of the implants reached enough clinical significance in percentage reduction of living cells. Regarding bacterial density, only 25-50 μm Polytxt^® Polytech^® implants showed significant reduction at the three PI exposure times.

Conclusion

PI is able to inhibit bacterial growth applied on the surface of breast implants regardless of the exposure time. However, no significant reduction on living cells or bacterial density was observed. This lack of correlation may be caused by differences in texture that directly affect PI absorption.

Silicon breast implants’ texture affecting bacterial biofilm formation

Introduction/Objective. The most important etiologic factors for both, capsular contracture (CC) and breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is subclinical infection, defined as a response of an organism on presence of biofilm on the implant surface. The aim of this research was to examine the possibility of biofilm formation of four different bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Ralstonia picketti) on three differently textured silicone breast implants (Siltex, Mentor, pore size 70?150 ?m; MESMORsensitive, Polytech, pore size 50?900 ?m; and SilkSurface, Motiva pores 13 ?m) in vitro. Methods. Samples of silicone breast implant capsules (sized 1 ? 1 cm) were divided into three groups according to texture. After sterilization, 30 samples in every group were contaminated with 100 ?l of examined bacterial broth, followed by incubation which led to biofilm formation. For testing the capability of biofilm formation, modified technique with microtitar plates described by Stepanovic? was used. Results. All four examined bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Ralstonia picketti) form more biofilm on implants with pore sizes 50?900 ?m compared to implants with pore size 70?150 ?m and those with 13 ?m. Statistical significance was found in biofilm formation on implants with pores 70?150 ?m compared to implants with pores 13 ?m. The only exception was P. aeuruginosa which did not show significant difference in biofilm formation on implants 70?150 ?m and 13 ?m. Conclusion. Silicone breast implants with micro and nanotexture should be chosen in order to prevent biofilm formation and possible consequent complications.