Science

About Biofilms

Microbial biofilms are structured communities of bacterial cells encased in a self-produced extracellular matrix. This matrix acts as a protective barrier, enabling bacteria to thrive and resist a wide range of environmental threats, including antimicrobials and host defense mechanisms. Biofilm-encased microbes are highly resistant to disinfectants and antibiotics, which can result in prolonged and chronic infections, amputation, long-term disability, and even death. Conventional antimicrobial drugs were not developed to target bacteria within biofilms and are therefore often ineffective against biofilm-associated infections. Persistent, pathogenic biofilms drive chronic inflammation and facilitate the development and spread of antibiotic resistance.

Biofilms play a complex role in a variety of chronic conditions, including chronic wounds, diabetic foot ulcers, urinary tract infections (UTIs), upper and lower respiratory tract diseases, endocarditis, chronic ear infections, eye infections, and periodontitis.¹ Biofilms can also form on medical devices such as orthopedic prostheses, artificial cardiac valves, coronary stents, intravascular and urinary catheters, neurosurgical, cochlear, and breast implants, dentures, and ventricular-assist and ocular devices.¹

Microbion is developing novel therapeutics to effectively manage these difficult-to-treat, biofilm-associated diseases, while also addressing chronic and dysfunctional inflammation—often the result of the immune system’s ongoing, unsuccessful attempts to eradicate biofilms.

Major mechanisms of biofilm antibiotic resistance:

• Limited antibiotic penetration: The biofilm matrix can slow or prevent antibiotics from reaching bacteria deep within the biofilm.
• Nutrient limitation and stress response: Bacteria in biofilms often experience nutrient scarcity, leading to slower growth rates and increased antibiotic resistance.
• Altered microenvironments: Gradients in pH and other factors within the biofilm can neutralize antibiotics.²
• Persister cells: A subpopulation of bacteria within biofilms can enter a dormant state, making them highly tolerant to antibiotics. If other bacteria are eliminated, these persister cells can repopulate the biofilm.²
• Genetic exchange: Biofilms provide an environment for the exchange of genetic material, including antibiotic resistance genes, often facilitated by extracellular DNA (eDNA).³

According to the National Institutes of Health (NIH), at least 80% of human infections involve bacterial pathogens growing as microbial biofilms.

References

1. Magana M et al. Options and limitations in clinical investigation of bacterial biofilms. Clin Microbiol Rev. 31:e00084-16.
2. Stewart PS and Costerton JW. Antibiotic resistance of bacteria in biofilms. Lancet. 2001;358:135-138.
3. Ravaioli S et al. Biofilm extracellular-DNA in 55 Staphylococcus epidermidis clinical isolates from implant infections. Int J Artif Organs. 2011;34:840-846.