Infection in prosthetic material

Surgical site infection (SSI) occurs when a wound created as part of a surgical procedure becomes infected. SSI is one of the most common healthcare-associated infections and occurs in approximately 5% of patients undergoing a surgical procedure. SSI may lead to patients suffering considerable morbidity or mortality and have significant cost implications. The aetiology involves the interplay of host, environmental and pathogen factors all of which should be addressed in seeking to reduce the risk of developing an infection. The presence of prosthetic material reduces the number of bacteria necessary for an infection to develop and can give rise to treatment and diagnostic difficulties. The responsible organisms are most commonly Staphylococcus aureus and S. epidermidis. Diagnosis is frequently problematic and antibiotic treatment alone is often ineffective due to biofilm formation necessitating removal of prosthesis in many cases. Prevention of infection is by far the most important aspect of prosthetic implant surgery. Patient optimization is equally important as the cutting edge research into biological prostheses in reducing the incidence of prosthetic infection in future practice

Characterisation of baseline microbiological and host factors in an inception cohort of people with surgical wounds healing by secondary intention reveals circulating IL-6 levels as a potential predictive biomarker of healing [version 1; peer review: awaiting peer review]

Background: More than 2 million people per year are treated for surgical wounds in the UK. Over a quarter of these wounds are estimated to heal by secondary intention (from the “bottom up”) resulting in further complications and requiring increased healthcare resources. Identification of microbiological or host biomarkers that can predict healing outcomes may help to optimize the management of surgical wounds healing by secondary intention. However, the microbial and host factor heterogeneity amongst this diverse population is completely unexplored. Methods: We demonstrate feasibility of determining presence and levels of wound microbes and systemic host factors in an inception cohort of 54 people presenting with surgical wounds healing by secondary intention, who were subsequently followed-up for a period of 12-21 months. We present descriptive statistics for plasma levels of inflammatory, angiogenic cytokines and microRNAs, and we identify a range of wound colonizing microbes. We tentatively explore association with healing aiming to generate hypotheses for future research. Results: We report a potential correlation between poor healing outcomes and elevated interleukin (IL)-6 plasma levels at presentation (ρ=0.13) which requires confirmation. Conclusions: This study demonstrates the degree of biological heterogeneity amongst people with surgical wounds healing by secondary intention and proves the feasibility of embedding a biomarker discovery study in a cohort study in surgical wounds. Our results are essential for designing large biomarker discovery studies to further investigate the potential validity of circulating IL-6 or other factors as novel predictive biomarkers of healing for surgical wounds healing by secondary intention