Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living). Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH) revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease.

Bacterial biofilm and associated infections

https://www.cidjournal.com/article/S0738-081X(10)00033-7/pdf

Chronic wound infection: Facts and controversies

Biofilms contain group(s) of microorganisms that are found to be associated with the biotic and abiotic surfaces. Biofilms contain either homogenous or heterogeneous populations of bacteria which remain in the matrix made up of extracellular polymeric substances secreted by constituent population of the biofilm. Biofilms can be either single or multilayered. Biofilms are an increasing issue of concern that is gaining importance with each passing day. Due to the ubiquitous nature of biofilms, it is difficult to eradicate them. It has been seen that many infectious diseases harbour biofilms of bacterial pathogens as the reservoir of persisting infections which can prove fatal at times. The presence of biofilms can be seen in diseases like endocarditis, cystic fibrosis, periodontitis, rhinosinusitis and osteomyelitis. The presence of biofilms has been mostly seen in medical implants and urinary catheters. Various signalling events including two-component signalling, extra cytoplasmic function and quorum sensing are involved in the formation of biofilms. The presence of an extracellular polymeric matrix in biofilms makes it difficult for the antimicrobials to act on them and make the bacteria tolerant to antibiotics and other drugs. The aim of this review was to discuss about the basic formation of a biofilm, various signalling cascades involved in biofilm formation, possible mechanisms of drug resistance in biofilms and recent therapeutic approaches involved in successful eradication of biofilms.

Biofilm, pathogenesis and prevention—a journey to break the wall: a review

Significance: The incidence, cost, morbidity, and mortality associated with non-healing of chronic skin wounds are dramatic. With the increasing numbers of people with obesity, chronic medical conditions, and an increasing life expectancy, the healthcare cost of non-healing ulcers has recently been estimated at $25 billion annually in the United States. The role played by bacterial biofilm in chronic wounds has been emphasized in recent years, particularly in the context of the prolongation of the inflammatory phase of repair. Recent Advances: Rapid high-throughput genomic approaches have revolutionized the ability to identify and quantify microbial organisms from wounds. Defining bacterial genomes and using genetic approaches to knock out specific bacterial functions, then studying bacterial survival on cutaneous wounds is a promising strategy for understanding which genes are essential for pathogenicity. Critical Issues: When an animal sustains a cutaneous wound, understanding mechanisms involved in ada...

Biofilms and Inflammation in Chronic Wounds.

Biofilm is the predominant mode of life for bacteria and today it is implicated in numerous human diseases. A growing body of scientific and clinical evidence now exists regarding the presence of biofilm in wounds. This review summarizes the clinical experiences and in vivo evidence that implicate biofilm in delayed wound healing. The various mechanisms by which biofilm may impede healing are highlighted, including impaired epithelialization and granulation tissue formation, and reduced susceptibilities to antimicrobial agents and host defenses. Strategies to manage biofilm and encourage progression to wound healing are discussed; these include debridement and appropriate antimicrobial therapies which may be improved upon in the future with the emergence of anti-biofilm technologies.

/pdf/biofilm-delays-wound-healing-a-review-of-the-evidence-4t8uoprj1o.pdf

Biofilm delays wound healing: A review of the evidence

Significance: Biofilms have been implicated in a variety of wound complications. Recent Advances: Research has confirmed that biofilms form in wounds of patients experiencing delayed healing and may be a precursor to infection. Critical Issues: Research into the strength of this association is still in its infancy. Is biofilm formation a cause of these complications, a step toward them, or a signal that unresolved factors injuring tissue or delaying healing are setting the stage for biofilm formation, infection, and healing delay? To qualify biofilms for use in informing clinical practice decisions, biofilm characteristics supporting those decisions need standardized definitions and valid evidence that they predict or diagnose healing or infection outcomes. Literature searches of relevant terms reviewed biofilm definitions and validation of their role in predicting and diagnosing delayed wound healing or infection. Future Directions: Further research is needed to provide a rapid accurate technique to identify and characterize biofilms in ways that optimize their validity in diagnosing or screening patient risk of infection or delayed healing and to inform clinical decisions. This research will help validate biofilm's capacity to support wound care clinical practice decisions and establish their importance in guiding clinical practice.

/pdf/clinical-biofilms-a-challenging-frontier-in-wound-care-1yihjrufa7.pdf

Clinical Biofilms: A Challenging Frontier in Wound Care.

Biofilm is a relatively new concept in the fields of infectious disease, wound infection, and healing. Although scientific research and "noise" regarding wound biofilm is increasing, little is known about the presentation, diagnosis, potential implications, and management strategies regarding wound biofilms. A series of four clinical cases is utilized to demonstrate the existence of wound biofilm. All patients presented with or developed a film on the wound bed that appeared to be distinct from slough; wounds also were failing to progress. Although the slough in some of the wounds was easily removed with traditional debridement methods, removal of the film required physical disruption with a curette or dry gauze. All wounds eventually progressed to healing. Considering the biofilm concept and available preclinical research, it is evident from this small case series that the appearance of biofilm in wounds is quite different from slough and requires different management strategies for its control. The evolving biofilm paradigm could profoundly change approaches to wound management. Additional research is needed in this evolving aspect of wound management.

Clinical experience with wound biofilm and management: a case series

Recognition of the existence of biofilm in chronic wounds is increasing among wound care practitioners, and a growing body of evidence indicates that biofilm contributes significantly to wound recalcitrance. While clinical guidelines regarding the involvement of biofilm in human bacterial infections have been proposed, there remains uncertainty and lack of guidance towards biofilm presence in wounds. The intention of this report is to collate knowledge and evidence of the visual and indirect clinical indicators of wound biofilm, and propose an algorithm designed to facilitate clinical recognition of biofilm and subsequent wound management practices.

A clinical algorithm for wound biofilm identification

Biofilm has been implicated as a barrier to wound healing and it is widely accepted that the majority of wounds not following a normal healing trajectory contain biofilm. Therefore, strategies that inform and engage clinicians to reduce biofilm and optimise the wound tissue environment to enable wound progression are of interest to wound care providers. In March 2019, an advisory board was convened where experts considered the barriers and opportunities to drive a broader adoption of a biofilm-based approach to wound care. Poor clarity and articulation of wound terminology were identified as likely barriers to clinical adoption of rigorous and proactive microbial decontamination that is supportive of wound healing advancement. A transition to an intuitive term such as 'wound hygiene' was proposed to communicate a comprehensive wound decontamination plan with an associated message of expected habitual routine. 'Wound hygiene', is a relatable concept that supports meticulous wound practice that addresses barriers to wound healing, such as biofilm, while aligning with antimicrobial stewardship programmes.

https://www.magonlinelibrary.com/doi/pdf/10.12968/jowc.2020.29.Sup3b.S1

Defying hard-to-heal wounds with an early antibiofilm intervention strategy: wound hygiene

/pdf/a-clinical-algorithm-for-wound-biofilm-identification-4ipeqo7cgt.pdf

Jennifer Hurlow

Papers

Clinical Biofilms: A Challenging Frontier in Wound Care.

Clinical experience with wound biofilm and management: a case series

A clinical algorithm for wound biofilm identification

Defying hard-to-heal wounds with an early antibiofilm intervention strategy: wound hygiene

A clinical algorithm for wound biofilm identification.