Abstract
Management of deep sternal wound infection (SWI), a serious complication after cardiac surgery with high morbidity and mortality incidence, requires invasive procedures such as, debridement with primary closure or myocutaneous flap reconstruction along with use of broad spectrum antibiotics. The purpose of this clinical series is to investigate the presence of biofilm in patients with deep SWI. A biofilm is a complex microbial community in which bacteria attach to a biological or non-biological surface and are embedded in a self-produced extracellular polymeric substance. Biofilm related infections represent a major clinical challenge due to their resistance to both host immune defenses and standard antimicrobial therapies. Candidates for this clinical series were patients scheduled for a debridement procedure of an infected sternal wound after a cardiac surgery. Six patients with SWI were recruited in the study. All cases had marked dehiscence of all layers of the wound down to the sternum with no signs of healing after receiving broad spectrum antibiotics post-surgery. After consenting patients, tissue and/or extracted stainless steel wires were collected during the debridement procedure. Debrided tissues examined by Gram stain showed large aggregations of Gram positive cocci. Immuno-fluorescent staining of the debrided tissues using a specific antibody against staphylococci demonstrated the presence of thick clumps of staphylococci colonizing the wound bed. Evaluation of tissue samples with scanning electron microscope (SEM) imaging showed three-dimensional aggregates of these cocci attached to the wound surface. More interestingly, SEM imaging of the extracted wires showed attachment of cocci aggregations to the wire metal surface. These observations along with the clinical presentation of the patients provide the first evidence that supports the presence of biofilm in such cases. Clinical introduction of the biofilm infection concept in deep SWI may advance the current management strategies from standard antimicrobial therapy to anti-biofilm strategy.
Highlights
Median sternotomy is the most common approach used in cardiac surgery procedures to access the heart
Stainless steel wires used for approximation of the sternum after cardiac surgery were tested in vitro for bacterial adhesion, biofilm formation, and recalcitrance to antimicrobial tobramycin
Methicillin resistance is independently associated with increased mortality and hospital charges among patients with S. aureus surgical site infections (SSI), we chose Methicillin-resistant Staphylococcus aureus (MRSA) for in vitro studies [17]
Summary
Median sternotomy is the most common approach used in cardiac surgery procedures to access the heart. The incidence of human sternotomy wound site infection ranges from 1–8% [1,2,3]. This incidence is significant, both economically as well as with respect to health care impact, considering the annual volume of patients undergoing cardiac surgery procedures (more than 600,000 cardiac surgeries per year) and associated health complications [4]. Sternal wound infection (SWI) is a serious complication even after successful surgery with mortality rates reaching 40% [2,5,6]. One of the challenges in the management of these patients is overt clinical signs of infection despite ambiguous or negative culture results
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
