Aptamers as Novel Binding Molecules on an Antimicrobial Peptide-Armored Composite Hydrogel Wound Dressing for Specific Removal and Efficient Eradication of Pseudomonas aeruginosa.

Here we present for the first time a potential wound dressing material implementing aptamers as binding entities to remove pathogenic cells from newly contaminated surfaces of wound matrix-mimicking collagen gels. The model pathogen in this study was the Gram-negative opportunistic bacterium Pseudomonas aeruginosa, which represents a considerable health threat in hospital environments as a cause of severe infections of burn or post-surgery wounds. A two-layered hydrogel composite material was constructed based on an established eight-membered focused anti-P. aeruginosa polyclonal aptamer library, which was chemically crosslinked to the material surface to form a trapping zone for efficient binding of the pathogen. A drug-loaded zone of the composite released the C14R antimicrobial peptide to deliver it directly to the bound pathogenic cells. We demonstrate that this material combining aptamer-mediated affinity and peptide-dependent pathogen eradication can quantitatively remove bacterial cells from the "wound" surface, and we show that the surface-trapped bacteria are completely killed. The drug delivery function of the composite thus represents an extra safeguarding property and thus probably one of the most important additional advances of a next-generation or smart wound dressing ensuring the complete removal and/or eradication of the pathogen of a freshly infected wound.

Rapid Colorimetric Detection of Wound Infection with a Fluidic Paper Device.

Current procedures for the assessment of chronic wound infection are time-consuming and require complex instruments and trained personnel. The incidence of chronic wounds worldwide, and the associated economic burden, urge for simple and cheap point-of-care testing (PoCT) devices for fast on-site diagnosis to enable appropriate early treatment. The enzyme myeloperoxidase (MPO), whose activity in infected wounds is about ten times higher than in non-infected wounds, appears to be a suitable biomarker for wound infection diagnosis. Herein, we develop a single-component foldable paper-based device for the detection of MPO in wound fluids. The analyte detection is achieved in two steps: (i) selective immunocapture of MPO, and (ii) reaction of a specific dye with the captured MPO, yielding a purple color with increasing intensity as a function of the MPO activity in infected wounds in the range of 20-85 U/mL. Ex vivo experiments with wound fluids validated the analytic efficiency of the paper-based device, and the results strongly correlate with a spectrophotometric assay.

TLC-Ag dressings: a prospective, multicentre study on 728 patients with wounds at risk of or with local infection.

OBJECTIVE: This study aimed to evaluate the management of an unselected cohort of patients with wounds at risk of or with clinical signs of local infection, treated with two antimicrobial contact layers impregnated with silver (TLC-Ag healing matrix), under real-life conditions during the COVID-19 pandemic. METHOD: A large, prospective, multicentre, observational study with two TLC-Ag dressings (UrgoTul Ag/Silver and UrgoTul Ag Lite Border, Laboratoires Urgo, France) was conducted in Germany between May 2020 and May 2021. The main outcomes included a description of the treated patients and their wound management, the changes in wound infection and wound healing outcomes over a maximum period of four weeks of treatment, as well as the overall clinical assessment of the performance, local tolerance and acceptability of dressings. RESULTS: A total of 728 patients with wounds of various aetiologies and wound infection status were treated with the evaluated dressings in 39 centres for a mean duration of 26±19 days, with an intermediate visit conducted in 712 (97.8%) patients after a mean period of 12±9 days. At the initial visit, it was established that the majority of patients (60.4%) had a wound infection, while the remaining cohort presented first clinical signs of a local wound infection (25.1%) or were at risk of wound infection (13.2%) (unclear status in 1.2%). Throughout the study period, all the parameters of wound infection continuously decreased, resulting at the final visit in a reduction by 78.9% of the prevalence of local wound infections and by 72.0% of the clinical signs of wound infection, the most rapidly diminished clinical sign being wound deterioration. Concurrently, in terms of the healing process, 92.1% of the wounds healed or improved, 3.2% remained unchanged and 1.7% worsened (data missing for 3.0%), and an improvement of the periwound skin was reported in 65.7% of the patients. Overall, the two dressings were 'very well accepted' by the majority of patients, with no uncomfortable feeling at wearing and no pain at dressing removal, and were assessed by the physicians as 'very useful' in the majority of the cases with a 'very good' efficacy in terms of antimicrobial activity and promotion of the wound healing process. Similar results were reported regardless of the wound type treated or of the TLC-Ag dressing evaluated. CONCLUSION: These results are consistent with previous clinical evidence on TLC-Ag dressings. They support the good efficacy, good tolerability and usefulness of these antimicrobial dressings in the management of patients with wounds at risk or with clinical signs of local infection, in association with appropriate standard of care.

Animal bite wounds and their management in tropical Australia.

OBJECTIVE: To define the microbiologic characteristics of animal bites in tropical Australia and the appropriateness of current Australian antimicrobial guidelines for their management. METHODS: This retrospective audit examined hospitalizations in tropical Australia after an animal bite or animal-associated penetrating injury between 2013 and 2020. The primary outcome was a composite of death, intensive care unit admission, amputation, quaternary center transfer, or unplanned rehospitalization. RESULTS: A wide variety of animals were implicated, but snakes (734/1745, 42%), dogs (508/1745, 29%), and cats (153/1745, 9%) were the most common. Hospital presentation after 24 hours (odds ratio (OR) (95% confidence interval (CI)): 68.67 (42.10-112.01)) and a cat-related injury (OR (95% CI): 22.20 (11.18-44.08)) were independently associated with an increased risk of infection. A pathogen not covered by the relevant antimicrobial regimen recommended in Australian guidelines was identified in only 12/1745 (0.7%) cases. The primary outcome occurred in 107/1745 (6%) and was independently associated with tissue trauma (OR (95% CI): 9.29 (6.05-14.25), p<0.001), established deep infection at presentation (OR (95% CI): 2.95 (1.31-6.61), p=0.009) and hospital presentation after 24 hours (OR (95% CI): 1.77 (1.12-2.79), p=0.01). CONCLUSIONS: A wide variety of animals bite humans in tropical Australia, but empiric antimicrobial regimens recommended in current national guidelines cover almost all the microbiologic isolates from the resulting wounds.

Risk Factors for Infection of Sutured Maxillofacial Soft Tissue Injuries.

Background: Maxillofacial soft tissue injuries (STIs) are common and frequent in emergency departments. The aim of this study was to analyze factors causing infection of maxillofacial STIs. Patients and Methods: Patients with maxillofacial STIs who received sutures and had complete medical records were evaluated. Gender, age, American Society of Anesthesiologists (ASA) grade, diabetes mellitus, wound age, wound length, wound contamination, wound type, and sites were analyzed using univariable analysis and binary logistic regression. Results: There were 3,276 cases included. In the univariable analysis, there was no significant difference in the infection rate between genders or between the wound age groups. In binary logistic regression, age, wound length, wound type, and physician level were risk factors for infection: age of 18-44 years (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.7-2.9), 44-64 years (OR, 3.1; 95% CI, 2.3-4.3), and ≥65 years (OR, 2.6; 95% CI, 1.7-4.1); wound length of 4-8 cm (OR, 1.7; 95% CI, 1.3-2.2) and >8 cm (OR, 2.4; 95% CI, 1.1-5.1); intra-oral wounds (OR, 1.6; 95% CI, 1.1-2.4) and communicating wounds (OR, 3.2; 95% CI, 2.3-4.4); junior specialists (OR, 1.6; 95% CI, 1.2-2.2); and lip (OR, 3.7; 95% CI, 1.1-12.0) and cheek (OR, 4.7; 95% CI, 2.3-17.1) sites. Wound contamination, ASA grade, and diabetes mellitus were not significantly different from wound infection in binary regression analysis. Conclusions: Age (>18 years old), wound length (>4 cm), intra-oral wounds, communicating wounds, suturing by junior surgeons, and lip or cheek injuries may be risk factors for maxillofacial STI infection. Even if the penetrating wound age exceeds 24 hours, it is meaningful to suture if there is no serious infection. For wounds at high risk of infection, further measures should be considered to reduce the possibility of infection, such as improving the surgical training of junior surgeons and improving the patient's wound care.

The catastrophic impact of COVID-19 infection in patients with chronic limb-threatening ischemia.

BACKGROUND: To determine the impact of COVID-19 infection in patients with chronic limb-threatening ischemia, mainly the limb salvage estimates rate and the overall survival. METHODS: This was a retrospective, consecutive cohort study of chronic limb-threatening ischemia in patients with COVID-19 infection. RESULTS: Overall, 35 patients with chronic limb-threatening ischemia and COVID-19 infection were evaluated. The mean age of the patients was 72.51 years, and most of them were male (60%), with arterial hypertension (85.7%), followed by diabetes mellitus (80%) and tobacco user (71.4%). There was a higher prevalence of wound, ischemia and foot infection (WIfI) classification 4 with 58.8% and Rutherford grade 5 (74.3%). The factors related to overall mortality rate were: D-dimer >1,000 mg/dL (hazard ratio = 22.7, P < .001, confidence interval = 10.49-26.52), respiratory symptoms (hazard ratio = 16.6, P < .001, confidence interval = 9.87-20.90), chest computed tomography compromising higher than 50% of the pulmonary tract (hazard ratio = 16,0, P < .001, confidence interval = 10.41-20.55), acute kidney failure (hazard ratio = 21.58, P < .001, confidence interval = 16.5-30.5), chronic kidney disease (hazard ratio = 4.4, P = .036, confidence interval = 1.45-10.1), therapeutic anticoagulation (hazard ratio = 8.37, P = .004, confidence interval = 1.35-8.45), and WIfI classification (hazard ratio = 5.28, P = .022, confidence interval = 1.34-10.01). The following were related to limb loss: D-dimer >1,000 mg/mL (hazard ratio = 5.47, P = .02, confidence interval = 1.94-10.52), respiratory symptoms (hazard ratio = 5.42, P = .02, confidence interval = 1.87-10.90), and WIfI classification (hazard ratio = 4.44, P = .035, confidence interval = 1.34-8.01). CONCLUSION: This study concluded that COVID-19 has a catastrophic impact among patients with chronic limb-threatening ischemia. The main factors related to overall mortality were D-dimer >1,000 mg/dL, respiratory symptoms, chest computed tomography compromising higher than 50% of the pulmonary tract, acute kidney failure, chronic kidney disease, therapeutic anticoagulation, and WIfI classification. The factors related to limb loss were WIfI classification, D-dimer >1,000 mg/mL and respiratory symptoms.

Wound Botulism Among Persons Who Inject Black Tar Heroin in New Mexico, 2016.

Outbreaks of wound botulism are rare, but clinicians and health departments should maintain suspicion for signs, symptoms, and risk factors of wound botulism among persons who inject drugs in order to initiate treatment quickly. This report describes an outbreak of three wound botulism cases among persons in two adjacent counties who injected drugs. Provisional information about these cases was previously published in the CDC National Botulism Surveillance Summary. All three cases in this outbreak were laboratory-confirmed, including one case with detection of botulinum toxin type A in a wound culture sample taken 43 days after last possible heroin exposure. Findings highlight the delay in diagnosis which led to prolonged hospitalization and the persistence of botulinum toxin in one patient.

Update on the role of antiseptics in the management of chronic wounds with critical colonisation and/or biofilm.

Biofilms play a major role in delaying chronic wounds from healing. A wound infiltrated with biofilm, or "critically colonised" wound, may become clinically infected if the number of microbes exceeds a critical level. Chronic wound biofilms represent a significant treatment challenge by demonstrating recalcitrance towards antimicrobial agents. However, a "window of opportunity" may exist after wound debridement when biofilms are more susceptible to topical antiseptics. Here, we discuss the role of antiseptics in the management of chronic wounds and biofilm, focusing on povidone-iodine (PVP-I) in comparison with two commonly used antiseptics: polyhexanide (PHMB) and silver. This article is based on the literature reviewed during a focus group meeting on antiseptics in wound care and biofilm management, and on a PubMed search conducted in March 2020. Compared with PHMB and silver, PVP-I has a broader spectrum of antimicrobial activity, potent antibiofilm efficacy, no acquired bacterial resistance or cross-resistance, low cytotoxicity, good tolerability, and an ability to promote wound healing. PVP-I represents a viable therapeutic option in wound care and biofilm management, with the potential to treat biofilm-infiltrated, critically colonised wounds. We propose a practical algorithm to guide the management of chronic, non-healing wounds due to critical colonisation or biofilm, using PVP-I.

Human Wound and Its Burden: Updated 2020 Compendium of Estimates.

Significance: Chronic wounds impact the quality of life (QoL) of nearly 2.5% of the total population in the United States and the management of wounds has a significant economic impact on health care. Given the aging population, the continued threat of diabetes and obesity worldwide, and the persistent problem of infection, it is expected that chronic wounds will continue to be a substantial clinical, social, and economic challenge. In 2020, the coronavirus disease (COVID) pandemic dramatically disrupted health care worldwide, including wound care. A chronic nonhealing wound (CNHW) is typically correlated with comorbidities such as diabetes, vascular deficits, hypertension, and chronic kidney disease. These risk factors make persons with CNHW at high risk for severe, sometimes lethal outcomes if infected with severe acute respiratory syndrome coronavirus 2 (pathogen causing COVID-19). The COVID-19 pandemic has impacted several aspects of the wound care continuum, including compliance with wound care visits, prompting alternative approaches (use of telemedicine and creation of videos to help with wound dressing changes among others), and encouraging a do-it-yourself wound dressing protocol and use of homemade remedies/substitutions. Recent Advances: There is a developing interest in understanding how the social determinants of health impact the QoL and outcomes of wound care patients. Furthermore, addressing wound care in the light of the COVID-19 pandemic has highlighted the importance of telemedicine options in the continuum of care. Future Directions: The economic, clinical, and social impact of wounds continues to rise and requires appropriate investment and a structured approach to wound care, education, and related research.

Use of domestic tools to downstage the reconstructive ladder in a patient with severe crush and degloving injury: a case report.

In the COVID-19's crisis, elective surgery and non-emergent cases were postponed; all other procedures have to be minimized. A 17-year male patient with severe crush and degloving injury over the thigh, gluteal, sacral, and perineum areas was admitted to our Department on the 16th of March 2020. The patient presented soft tissue skin and muscle loss. A double Latissimus Dorsi and Anterolateral Thigh free flaps were indicated. However, due to the particular circumstance of the COVID-19 crisis, we applied domestic negative wound therapy (NPWT) using gauzes and wall suction. We obtained suitable granulation tissue after 17 consecutive days with this treatment. The raw area was then covered with an expanded split-thickness skin graft. The wound healed at 95%, and the patient was discharged on 25th of April 2020. He was followed up in an outpatient setting with wound care and physiotherapy. This case showed that in a limited-resource setting, with available wall suction, the domestic NPWT is a versatile tool to promote granulation tissue.

Exposure risk of patients with chronic infectious wounds during the COVID-19 outbreak and its countermeasures.

BACKGROUND: A large number of cases of pneumonia caused by novel ß-coronavirus emerged in Hubei Province, China, at the end of 2019 and demonstrated great potential for transmission. At present, known independent risk factors include age, diabetes, and other chronic diseases, which may be similar to the patients with chronic wound; thus, we try to explore the clinical characteristics, prognostic factors, and management recommendation of patients with chronic infective wounds during the COVID-19 epidemic period. METHODS: In this single-center, retrospective observational study, we included all cases with chronic infective wounds that came to our hospital between the full outbreak of the COVID-19 in China (January 23, 2020) and the latest date prior to posting (20 April 2020). Demographic data, comorbidities, laboratory and imaging findings, consultation history, and clinical outcomes (lesion cured, uncontrolled, amputated, etc. as of May 10, 2020) were collected for all individuals. Patients were subdivided into gangrene, traumatic infection, and other types of soft tissue infection wound (including bedsores, gout ruptures, stab wounds, and so on) according to the causes of wound, and their disease-related information were compared group by group. RESULTS: Among the total 81 patients with chronic infective wounds, 60% were male, with a mean age of 60.8 years (SD 18.6), including 38 (47%) patients with traumatic infection, 29 (36%) gangrene cases, and 14 (17%) other soft tissue infection wounds. Common comorbidities are hypertension (32%), diabetes (32%), cardiovascular disease (24%), and kidney injury (12%), and the patients with gangrenes have the most comorbidities. As of May 10, 2020, there were 78 patients discharged, and their average stay time is 15.8 days (SD 14.2), while people still at the hospital is 39.7 days (SD 8.7) much longer than the discharged and also has more comorbidities. But there is no significant difference in the hospitalization time of three types of wounds. And fortunately, none of all the patients were infected by coronavirus. CONCLUSION: The majority of patients with chronic wounds are severely ill with high risk of infection and poor prognosis; therefore, management of patients with chronic wounds should be improved.