Clinical management of chronic wound infections: The battle against biofilm.

Bacteria constitute the most abundant life form on earth, of which the majority exist in a protective biofilm state. Since the 1980s, we have learned much about the role of biofilm in human chronic infections, with associated global healthcare costs recently estimated at ~$386 billion. Chronic wound infection is a prominent biofilm-induced condition that is characterised by persistent inflammation and associated host tissue destruction, and clinical signs that are distinct from signs of acute wound infection.

Chronic wounds: Treatment consensus.

The Wound Healing Foundation (WHF) recognised a need for an unbiased consensus on the best treatment of chronic wounds. A panel of 13 experts were invited to a virtual meeting which took place on 27 March 2021. The proceedings were organised in the sub-sections diagnosis, debridement, infection control, dressings, grafting, pain management, oxygen treatment, outcomes and future needs.

Early clinical performance of an adaptive self-assembling barrier scaffold in nonhealing chronic wounds: a review of six cases.

Introduction: Chronic nonhealing wounds pose a serious concern for patient health and the health care system. Management of chronic wounds becomes especially challenging in the setting of systemic comorbidities and patient nonadherence.

Objective: Authors evaluated the performance of a proprietary adaptive self-assembling barrier scaffold (aSABS) in the management and healing of complex chronic wounds.

Urethral Catheter Biofilms Reveal Plasticity in Bacterial Composition and Metabolism and Withstand Host Immune Defenses in Hypoxic Environment.

Biofilms composed of multiple microorganisms colonize the surfaces of indwelling urethral catheters that are used serially by neurogenic bladder patients and cause chronic infections. Well-adapted pathogens in this niche are , and spp., species that cycle through adhesion and multilayered cell growth, trigger host immune responses, are starved off nutrients, and then disperse.

Biofilm and catheter-related bloodstream infections.

Careful attention to detail and adherence to procedure guidelines when inserting and managing intravascular catheters has decreased the incidence of catheter-related bloodstream infections (CRBSIs). In order to limit these, health professionals must understand the underlying microbiology. Biofilms can explain the clinical findings most often seen with CRBSIs, yet they are poorly understood within medicine.

Biofilm exacerbates antibiotic resistance: Is this a current oversight in antimicrobial stewardship?

Objective: To raise awareness of the role of environmental biofilm in the emergence and spread of antibiotic resistance and its consideration in antimicrobial stewardship.

Background: Antibiotic resistance is a major threat to public health. Overuse of antibiotics, increased international travel, and genetic promiscuity amongst bacteria have contributed to antibiotic resistance, and global containment efforts have so far met with limited success.

A review of iodine-based compounds, with a focus on biofilms: results of an expert panel.

Biofilms play a central role in the chronicity of non-healing lesions such as venous leg ulcers and diabetic foot ulcers. Therefore, biofilm management and treatment is now considered an essential part of wound care. Many antimicrobial treatments, whether topical or systemic, have been shown to have limited efficacy in the treatment of biofilm phenotypes.

Patient genetics is linked to chronic wound microbiome composition and healing.

The clinical importance of microbiomes to the chronicity of wounds is widely appreciated, yet little is understood about patient-specific processes shaping wound microbiome composition. Here, a two-cohort microbiome-genome wide association study is presented through which patient genomic loci associated with chronic wound microbiome diversity were identified. Further investigation revealed that alternative TLN2 and ZNF521 genotypes explained significant inter-patient variation in relative abundance of two key pathogens, Pseudomonas aeruginosa and Staphylococcus epidermidis.

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

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.

Chronic wound microbiome colonization on mouse model following cryogenic preservation.

Chronic wound infections are increasingly recognized to be dynamic and polymicrobial in nature, necessitating the development of wound models which reflect the complexities of infection in a non-healing wound. Wound slough isolated from human chronic wounds and transferred to mice was recently shown to create polymicrobial infection in mice, and there is potential this tool may be improved by cryogenic preservation. The purpose of this study was to investigate the application of cryogenic preservation to transferring polymicrobial communities, specifically by quantifying the effects of cryopreservation and wound microbiome transplantation.

Fungal Diversity and Onychomycosis .

Background: Onychomycosis is a fungal infection of the nail that is often recalcitrant to treatment and prone to relapse. Traditional potassium hydroxide and culture diagnosis is costly and time-consuming. Therefore, molecular methods were investigated to demonstrate effectiveness in diagnosis and to quantify the microbial flora present that may be contributing to disease.

Bacterial fitness in chronic wounds appears to be mediated by the capacity for high-density growth, not virulence or biofilm functions.

While much is known about acute infection pathogenesis, the understanding of chronic infections has lagged. Here we sought to identify the genes and functions that mediate fitness of the pathogen Pseudomonas aeruginosa in chronic wound infections, and to better understand the selective environment in wounds. We found that clinical isolates from chronic human wounds were frequently defective in virulence functions and biofilm formation, and that many virulence and biofilm formation genes were not required for bacterial fitness in experimental mouse wounds.

Improving the quality of clinical research on chronic wound infection treatment: expert-based recommendations.

Objective:: To produce recommendations for the design of reliable and informative clinical investigations in chronic wound infection.

Method:: A multidisciplinary panel of international experts from four countries (Italy, UK, Ireland and the US) were involved in a detailed, semi-structured discussion on how to better select and describe a target population, interventions and outcomes, and which infection-related criteria to apply in order to achieve a high-quality trial. Consent among the experts was measured using the Delphi method and GRADE Working Group suggestions.

transcriptome during human infection.

Laboratory experiments have uncovered many basic aspects of bacterial physiology and behavior. After the past century of mostly in vitro experiments, we now have detailed knowledge of bacterial behavior in standard laboratory conditions, but only a superficial understanding of bacterial functions and behaviors during human infection. It is well-known that the growth and behavior of bacteria are largely dictated by their environment, but how bacterial physiology differs in laboratory models compared with human infections is not known.

Efficacy of hyperbaric oxygen therapy in bacterial biofilm eradication.

Objective: Chronic wounds typically require several concurrent therapies, such as debridement, pressure offloading, and systemic and/or topical antibiotics. The aim of this study was to examine the efficacy of hyperbaric oxygen therapy (HBOT) towards reducing or eliminating bacterial biofilms in vitro and in vivo.

Method: Efficacy was determined using in vitro grown biofilms subjected directly to HBOT for 30, 60 and 90 minutes, followed by cell viability determination using propidium monoazide-polymerase chain reaction (PMA-PCR).

Consensus guidelines for the identification and treatment of biofilms in chronic nonhealing wounds.

Background: Despite a growing consensus that biofilms contribute to a delay in the healing of chronic wounds, conflicting evidence pertaining to their identification and management can lead to uncertainty regarding treatment. This, in part, has been driven by reliance on in vitro data or animal models, which may not directly correlate to clinical evidence on the importance of biofilms. Limited data presented in human studies have further contributed to the uncertainty.

Understanding biofilm in practice: a global survey of health professionals.

Objective: The aim of this survey was to examine health professionals' views and practices relating to biofilm in chronic wounds.

Method: A global online survey was conducted to assess the current understanding of biofilm and wound management practices. The survey consisted of 20 questions designed to evaluate health professional knowledge of biofilm, perception and understanding of biofilm behaviour, detection and diagnosis, and treatment.

Wound Biofilm: Current Perspectives and Strategies on Biofilm Disruption and Treatments.

The presence of bio lm remains a challenging factor that contributes to the delayed healing of many chronic wounds. The major threat of chronic wound bio lms is their substantial protection from host immunities and extreme tolerance to antimicrobial agents. To help guide the development of wound treatment strategies, a panel of experts experienced in clinical and laboratory aspects of biofilm convened to discuss what is understood and not yet understood about biofilms and what is needed to better identify and treat chronic wounds in which biofilm is suspected.

Temporal dynamics of relative abundances and bacterial succession in chronic wound communities.

Polymicrobial bacterial infection is an important factor contributing to wound chronicity. Consequently, clinicians frequently adopt a biofilm-based wound care approach, in which wounds are treated utilizing DNA sequencing information about microbial communities. While more successful than treatment not using community information, there is little information about temporal dynamics of wound communities and optimal approaches over the course of treatment.

The prevalence of biofilms in chronic wounds: a systematic review and meta-analysis of published data.

The presence of biofilms in chronic non-healing wounds, has been identified through in vitro model and in vivo animal data. However, human chronic wound studies are under-represented and generally report low sample sizes. For this reason we sought to ascertain the prevalence of biofilms in human chronic wounds by undertaking a systematic review and meta-analysis.