April 13, 2022 admin
What is a Biofilm?
Microorganisms are planktonic, free-floating single cells growing in a nutritionally rich culture media. The microbes commonly colonise in groups and attach to surfaces by means of biofilm. The bacterial communities secret a matrix of exopolymeric substance (EPS) that is termed the biofilm. The biofilm protects the bacterial cells colonised in that biofilm. The biofilms can be formed on living and non-living surfaces and are prevalent in natural, industrial or healthcare facilities. The biofilm formation is initiated by the physical attraction of bacterial cells to surfaces and the EPS is secreted. The bacterial clusters are released from the biofilm layers for proliferation at the end of the biofilm cycle. The bacterial cells in a biofilm communicate by a mechanism called quorum sensing which regulates the formation and release of bacterial clusters in biofilm. Bacterial biofilms play a major role in causing infectious diseases. The evidence suggests that biofilms have considerable levels of pathogenicity that make their presence in hospitals and industry a cause of concern.
Risks associated with Biofilm:
The bacterial biofilms are associated with various harms such as chronic infections, nosocomial infections, industrial pipeline fouling, spoilage of food, pharmaceutical or dairy industry products, as well as instrument contamination etc. The development of biofilms in a hospital environment is linked to the emergence of several nosocomial infections. They may develop on medical devices or surfaces in a hospital. They may contaminate biomedical devices such as prosthetic heart valves, catheters, implants, pacemakers, cerebrospinal shunts or contact lenses. The frequently reported biofilm-forming bacteria in the hospital environment are Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa(2). The Staphylococcal biofilms are mostly found in dental implants, contact lenses, pacemakers, orthopaedic implants, etc. The water distribution systems in hospitals can get contaminated with biofilms if disinfection is not maintained. The cases of infection of chronic wounds with biofilm-forming Pseudomonas aeruginosa are commonly reported as hospital-associated infections (HAI). Due to the presence of biofilm, most consortiums of bacteria are able to resist a broad spectrum of antimicrobial agents.
The increased drug resistance makes it difficult to treat the infection as well as the disinfection of hospital facilities. According to an investigation, more than 65% of infections caused because of bacteria are related to the biofilm-forming organism(2). The stability of bacteria is increased when they are colonised in a biofilm. Therefore, biofilms have an immense impact on the health of patients and healthcare workers(1). It also affects the economy of the healthcare system, as the biofilm disinfection puts forward new challenges to the healthcare industry. Most of the HAI’s related to the contaminated medical devices are due to biofilm formation. The life-threatening HAI caused due to biofilm formation on medical devices are catheter-associated urinary tract infection (CAUTI), central-line associated septicaemia, or ventilator-associated pneumonia.
Prevention and treatment strategies for biofilm control:
The biofilm formation in bacterial colonies is initiated by the attachment of the bacterial cells to a compatible surface. The proliferation and formation of mature biofilm are only possible after the adherence of bacterial cells to the surface. Hence it is mandatory to keep the surfaces in the hospital environment sanitized. Therefore, the surfaces in the hospital should have an antimicrobial coating that will prevent the adherence of bacteria to the surfaces. The biofilms formed in the water pipes, wet surfaces, or sinks are known as hydrated biofilms which can be controlled by proper cleaning and frequently drying of the infection sites. The dry biofilms are formed on furniture and surfaces that have no moisture. The biofilm formed on the medical instrument is termed build-up biofilm. These all types of biofilms are formed after the surface adherence and quorum sensing mechanism of bacterial colonies. The mechanism of quorum sensing consists of the signalling of cells to form a biofilm. The signalling between cells can be inhibited if the cells are not in proper orientation or proximity(3). These mechanisms can be targeted to inhibit biofilm formation. The resistance developed by bacterial cells to the disinfectants is generally because of the biofilm.
MEDNTEK R82 and MEDNTEK W10 help in combating the biofilms:
IMAEC MEDNTEK equips healthcare facilities with high-level disinfectants that can also contribute in combating the formation of biofilms. MEDNTEK R82 is a fifth-generation quaternary ammonium compound that gives prolonged residual activity after the disinfection. The residual activity of disinfectant is necessary to inhibit the adherence of bacterial cells to the surfaces which in turn inhibits the formation of biofilms. Another solution to fight against biofilms is MEDNTEK W10 which is a combination of hydrogen peroxide and silver ions. The silver ions give antimicrobial activity and hydrogen peroxide is the oxidating agent that helps in the formation of free radicals. The silver ions in MEDNTEK W10 enhance the penetration of the disinfectant. It leads to disruption of the cell membrane of the microorganisms. These disinfectants give the residual activity and inhibit biofilm formation.
- Dewasthale, S., Mani, I., & Vasdev, K. (2018). Microbial biofilm: Current challenges in health care industry. Journal of Applied Biotechnology & Bioengineering, 5(3). https://doi.org/10.15406/jabb.2018.05.00132
- Muhammad, M. H., Idris, A. L., Fan, X., Guo, Y., Yu, Y., Jin, X., Qiu, J., Guan, X., & Huang, T. (2020). Beyond Risk: Bacterial Biofilms and Their Regulating Approaches. Frontiers in Microbiology, 11, 928. https://doi.org/10.3389/fmicb.2020.00928
- Vickery, K. (2019). Special Issue: Microbial Biofilms in Healthcare: Formation, Prevention and Treatment. Materials, 12(12), 2001. https://doi.org/10.3390/ma12122001