Biofilm-Innate Immune Interface: Contribution to Chronic Wound Formation

Delayed wound healing can cause significant issues for immobile and ageing individuals as well as those living with co-morbid conditions such as diabetes, cardiovascular disease, and cancer. These delays increase a patient’s risk for infection and, in severe cases, can result in the formation of chronic, non-healing ulcers (e.g., diabetic foot ulcers, surgical site infections, pressure ulcers and venous leg ulcers). Chronic wounds are very difficult and expensive to treat and there is an urgent need to develop more effective therapeutics that restore healing processes. Sustained innate immune activation and inflammation are common features observed across most chronic wound types. However, the factors driving this activation remain incompletely understood. Emerging evidence suggests that the composition and structure of the wound microbiome may play a central role in driving this dysregulated activation but the cellular and molecular mechanisms underlying these processes require further investigation. In this review, we will discuss the current literature on: 1) how bacterial populations and biofilms contribute to chronic wound formation, 2) the role of bacteria and biofilms in driving dysfunctional innate immune responses in chronic wounds, and 3) therapeutics currently available (or underdevelopment) that target bacteria-innate immune interactions to improve healing. We will also discuss potential issues in studying the complexity of immune-biofilm interactions in chronic wounds and explore future areas of investigation for the field.

Orthosis Comfort Score: Establishing initial evidence of reliability and validity in ankle foot orthosis users

BACKGROUND

Comfort of an orthosis is an important characteristic that is likely to dictate use of and satisfaction with a device. However, instruments to assess only orthosis user comfort do not exist. The Prosthetic Socket Fit Comfort Score, developed previously for prosthesis users, may be adapted to serve this purpose.

OBJECTIVES

This study's purpose was to assess the validity and reliability of the Orthosis Comfort Score, a self-report instrument adapted from the Prosthetic Socket Fit Comfort Score.

STUDY DESIGN

This is a prospective, observational study designed to establish initial evidence of validity and reliability for an outcome measure that assesses comfort.

METHODS

Ankle foot orthosis users completed the Orthosis Comfort Score and two validated patient satisfaction questionnaires. An orthotist documented an assessment of fit. Post-visit Orthosis Comfort Scores were documented after the appointment and 2-4 weeks later. Orthosis Comfort Scores were compared to the patient satisfaction questionnaires, assessment of fit and orthosis use (hours per week).

RESULTS

There were 46 study participants. Orthosis Comfort Scores had a moderate positive correlation with their orthotist's assessment of fit, very strong positive correlations with patient satisfaction questionnaires and fair positive correlation with orthosis use (all correlations p < 0.05).

CONCLUSION

This study demonstrates initial evidence for the validity and reliability of the Orthosis Comfort Score in ankle foot orthosis users.

CLINICAL RELEVANCE

The Orthosis Comfort Score is a simple patient-reported outcome measure that can be readily incorporated into clinical practice or research study to obtain a rapid assessment of comfort. It can be used to facilitate communication about device fit, evaluate comfort over time and/or assess changes in comfort with a new device.

Quantitative and functional characterization of the hyper-conserved protein of Prochlorococcus and marine Synechococcus

A large fraction of any bacterial genome consists of hypothetical protein-coding open reading frames (ORFs). While most of these ORFs are present only in one or a few sequenced genomes, a few are conserved, often across large phylogenetic distances. Such conservation provides clues to likely uncharacterized cellular functions that need to be elucidated. Marine cyanobacteria from the Prochlorococcus/marine Synechococcus clade are dominant bacteria in oceanic waters and are significant contributors to global primary production. A Hyper Conserved Protein (PSHCP) of unknown function is 100% conserved at the amino acid level in genomes of Prochlorococcus/marine Synechococcus, but lacks homologs outside of this clade. In this study we investigated Prochlorococcus marinus strains MED4 and MIT 9313 and Synechococcus sp. strain WH 8102 for the transcription of the PSHCP gene using RT-Q-PCR, for the presence of the protein product through quantitative immunoblotting, and for the protein's binding partners in a pull down assay. Significant transcription of the gene was detected in all strains. The PSHCP protein content varied between 8±1 fmol and 26±9 fmol per ug total protein, depending on the strain. The 50 S ribosomal protein L2, the Photosystem I protein PsaD and the Ycf48-like protein were found associated with the PSHCP protein in all strains and not appreciably or at all in control experiments. We hypothesize that PSHCP is a protein associated with the ribosome, and is possibly involved in photosystem assembly.