Brown Univ Team Maps Out Biofilm Formation Patterns

When a festival of microorganisms get together, thus creating a biofilm, trouble is in store for surgeon and patient alike.

A multicenter team recently developed a novel method for mapping and visualizing biofilm formation. Their work, “In vitro visualization and quantitative characterization of Pseudomonas aeruginosa biofilm growth dynamics on polyether ether ketone,” appears in the December 21, 2021, edition of the Journal of Orthopaedic Research.

Detailing the “why” behind the work was co-author Dioscaris Garcia, Ph.D., assistant professor of orthopedics (research) at Brown University in Providence, Rhode Island. He told OTW, “Prior to the arrival of the COVID-19 Pandemic, the one of the biggest concerns in medicine was the prospect of a fast-advancing ‘Post-Antibiotic Era.’ The Post-Antibiotic Era referred to the increase in antibiotic resistance amongst clinically relevant pathogens, and the concurrent decrease in the production of novel antibiotics, which would eventually bring forth a period where infections could pose a very significant risk to life.”

“A significant part of antibiotic resistance is the formation of protective structures of protein, carbohydrates and exogenous DNA termed ‘biofilms,’ which essentially protect the pathogens from antibiotics, allow for the horizontal transfer of genetic information, and pose a significant challenge to removal via clinical methodologies.”

“This is particularly important in orthopaedics, where the use of implants from different materials and textures are an important part of the fracture fixation. One of the difficulties in successfully treating infections in which a biofilm is present is the lack of understanding of how biofilms develop, and how the interaction between surface, and pathogen alter the dynamics of the biofilm structure. With the alteration of life caused by the current pandemic, staying ahead of coming microbial maladies is of absolute paramount.”

Working from their own in vitro model, the researchers inoculated PEEK (polyether ether ketone) discs with P. aeruginosa and incubated them for 4−48 hour intervals (fixed with 10% neutral-buffered formalin). They used fluorescent dyes to stain the samples and measure biofilm components and performed imaging (confocal laser scanning microscopy and scanning electron microscopy). The result was that the researchers were able to visualize and quantify P. aeruginosa biofilm growth on PEEK implants over 48 hours.

“This study showed that through a combined methodology of scanning electron microscopy and confocal laser scanning microscopy we can visualize and quantify the main components of biofilm structure and provide a tool towards understanding the pathogen-implant biofilm dynamics,” stated Dr. Garcia. “This is a very important advancement in our field due to the challenges posed by biofilms in orthopaedics. The study utilized a model organism known for producing biofilms, and a material commonly utilized in the field, however the methodology can be utilized for any pathogen and implant material, which certainly adds a much-needed layer of characterization for choice of implant material and selection of irrigation agents.”

“Our ability to visually and quantifiably follow the dynamics of biofilm formation will certainly help in the selection of implants for specific surgical interventions, which may be best suited for the prevention of bacterial adherence and subsequent biofilm formation. Furthermore, being able to visualize and quantify the biofilm structure is a very important tool for the development and validation of irrigation agents that are tailored against the specific components of biofilms. Until now, infections which were complicated by biofilms had few options for management other than removal of the implant, which is by no means a guaranteed procedure, or aggressive irrigation and debridement, which also suffer from poor outcomes.”