Infection in patients with severe burns: causes and prevention thereof

Concise Review on Scientific Approaches to Burns and Scars

Burns are large open surgical lesions bathed in virulent pus that result in rupturing of the cutaneous membrane, which has serious consequences such as an extensive loss of proteins, and body fluids, increased chances of infections, and sometimes death. These can be classified based on their penetration levels, i.e., first-degree burns penetrating the epidermis, second-degree burns including both epidermis and dermis, third-degree burns to both layers including the hair follicular cells, sweat glands and various core tissues, fourth-degree burns to adipose tissue, fifth stage burns to muscles, and sixth stage burns to bones. Wound healing/wound repair is a very perplexing process in which the tissues of the affected/burnt area repairs themselves to attain their original form and functionality but develop a scar at the wound site. This article mainly focuses on the algorithms to differentiate various degrees of burns, general first aid approaches to burns and scars, the rationale of treatment of burns, basic mechanisms highlighting the healing processes in humans in terms of free from scar formation as well as with scar formation at their elementary levels including cellular as well as biochemical levels, utility, and progression of pre-clinical data to humans and finally approaches for the improvement of scar formation in man.

Antimicrobial efficacy of aloe-emodin mediated photodynamic therapy against antibiotic-resistant Pseudomonas aeruginosa in vitro

Multidrug-resistant Pseudomonas aeruginosa is a common pathogen that causes topical infections following burn injuries. Antimicrobial photodynamic therapy (aPDT) has emerged as a promising approach for treating antibiotic-resistant bacterial infections. The objective of this study was to evaluate the aPDT efficacy of aloe-emodin (AE), which is a photosensitizer extracted from traditional Chinese herbs, on antibiotic-sensitive and antibiotic-resistant P. aeruginosa in vitro. In this study, we confirmed the effectiveness of AE-mediated aPDT against both standard and MDR P. aeruginosa, explored the effects of irradiation time and AE concentration on bacterial survival in AE-mediated aPDT, and observed the structural damage of P. aeruginosa by using transmission electron microscope. Our results showed that neither AE nor light irradiation alone caused cytotoxic effects on P. aeruginosa. However, AE-mediated aPDT effectively inactivated both antibiotic-sensitive and antibiotic-resistant P. aeruginosa. The transmission electron microscope investigation showed that aPDT mediated by AE primarily caused damage to the cytoplasm and cell membrane. Our findings suggest that AE is a photosensitizer in the aPDT of MDR P. aeruginosa-caused topical infections following burn injuries. Future investigations will concentrate on the safety and efficacy of AE-mediated aPDT in animal models and clinical trials.

Surviving Sepsis After Burn Campaign

INTRODUCTION

The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes.

METHODS

The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported.

RESULTS

The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis.

CONCLUSION

Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

The Combination of Synoeca-MP Antimicrobial Peptide with IDR-1018 Stimulates Proliferation, Migration, and the Expression of Pro-Regenerative Genes in Both Human Skin Cell Cultures and 3D Skin Equivalents

In skin lesions, the development of microbial infection affects the healing process, increasing morbidity and mortality rates in patients with severe burns, diabetic foot, and other types of skin injuries. Synoeca-MP is an antimicrobial peptide (AMP) that exhibits activity against several bacteria of clinical importance, but its cytotoxicity can represent a problem for its positioning as an effective antimicrobial compound. In contrast, the immunomodulatory peptide IDR-1018 presents low toxicity and a wide regenerative potential due to its ability to reduce apoptotic mRNA expression and promote skin cell proliferation. In the present study, we used human skin cells and a 3D skin equivalent models to analyze the potential of the IDR-1018 peptide to attenuate the cytotoxicity of synoeca-MP, as well as the influence of synoeca-MP/IDR-1018 combination on cell proliferation, regenerative processes, and wound repair. We found that the addition of IDR-1018 significantly improved the biological properties of synoeca-MP on skin cells without modifying its antibacterial activity against S. aureus. Likewise, in both melanocytes and keratinocytes, the treatment with synoeca-MP/IDR-1018 combination induces cell proliferation and migration, while in a 3D human skin equivalent model, it can accelerate wound reepithelization. Furthermore, treatment with this peptide combination generates an up-regulation in the expression of pro-regenerative genes in both monolayer cell cultures and in 3D skin equivalents. This data suggests that the synoeca-MP/IDR-1018 combination possesses a good profile of antimicrobial and pro-regenerative activity, opening the door to the development of new strategies for the treatment of skin lesions.

Changes in Burn Wound Microbiology Profile Over 14 Years of an Adult Tertiary Burn Center

Burn wound colonization can progress to invasive infection. During 14 years of this study, the burn center was relocated to a center with improved infrastructure. This study investigates the association that infrastructure, geography, and time may have on colonization. Data were collected from October 2004 to August 2018, and relocation took place in June 2010, defining the two study periods. Admission swabs were within 48 hours. Unique isolates and resistance data were analyzed and compared statistically between the two study periods. In total, 2001 patients with 24,226 wound swabs were included. Median age was 45.4 (IQR 30.2-61.6), length of stay was 11 days (IQR 6-21), and %TBSA was 5.5 (IQR 2.5-11). Staph. aureus (33.7/100 patients) and Pseudomonas spp. (13.1/100 patients) were the most prevalent bacterial growths. After admission, the prevalence of methicillin resistant Staph. aureus, Coliform spp., and Aci. baumanni was greater in the first site, and Candida spp. colonization was higher in the second study period site. The prevalence of patients affected by multi-drug-resistant organisms was lower in the second study site (13.5/100 patients vs 16.6/100 patients; P < .05). There are differences in burn wound colonization across time, within the same region. Candida spp. growth has been shown to be increased over time and represents an added challenge. Awareness facilitates effective empirical antimicrobial therapies and protocols locally.

Survival and analysis of prognostic factors for severe burn patients with inhalation injury: based on the respiratory SOFA score

BACKGROUND

It is important to determine the severity of inhalation injury in severely burned patients. The oxygenation index PaO₂/FiO₂(PF) ratio is a key clinical indicator of inhalation injury. Sequential organ failure assessment (SOFA) is developed to assess the acute incidence of critical illness in the population. We hope to provide an assessment of survival or prognostic factor for severely burned patients with inhalation injury based on the respiratory SOFA score.

METHODS

This is a retrospective cohort study of all admissions to Department of Burn and Plastic Surgery at West China Hospital of Sichuan University from July 2010 to March 2021. Data was analyzed using Cox regression models to determine significant predictors of mortality. Survival analysis with time to death event was performed using the Kaplan-Meier survival curve with the log-rank test. All potential risk factors were considered independent variables, while survival was considered the risk dependent variable.

RESULTS

One hundred eighteen severe burn patients with inhalation injury who met the inclusion and exclusion criteria were admitted, including men accounted for 76.3%. The mean age and length of stay were 45.9 (14.8) years and 44.3 (38.4) days. Flame burns are the main etiology of burn (74.6%). Patients with the respiratory SOFA score greater than 2 have undergone mechanical ventilation. Univariate Kaplan-Meier analysis identified age, total body surface area burned (TBSA), ICU admission and the respiratory SOFA score as significant factors on survival. Cox regression analysis showed that TBSA and the respiratory SOFA score were associated with patient survival (p < 0.001). In some patients with severe burns and inhalation damage, the survival probability drops to less than 10% (TBSA greater than 80%: 8.9% and respiratory SOFA score greater than 2: 5.6%). This study statistically found that the TBSA with the respiratory SOFA score model (AUROC: 0.955) and the rBaux score (AUROC: 0.927) had similar predictive value (p = 0.175).

CONCLUSION

The study indicates that a high respiratory system SOFA score was identified as a strong and independent predictor of severely burned patients with inhalation injury during hospitalization. When combined with TBSA, the respiratory SOFA scores can dynamically assess the severity of the patient's lung injury and improve the predictive level.

Prevalence and Clinical Presentation of COVID 19 in Health Care Workers in Two Main Hospitals During the Pandemic in Shiraz, Iran

Background: Given that immunocompromised patients are more at risk for the infection of SARS-CoV-2, epidemiological data are critical for assessing the corresponding prevalence among health care workers (HCWs) and patients at health centers. Objectives: This study aims to investigate the prevalence of SARS-CoV-2 infection among the staff of two hospitals that take care of immunocompromised patients, including pediatrics and adults with special medical conditions. Methods: This cross-sectional study includes all HCWs of the two hospitals; Abu Ali Sina Transplant Hospital (AASTH) and Amir al-Momenin Burn Injury Hospital (AABIH) in Shiraz, southern Iran, conducted from April 11, 2020, to June 16, 2021. The TaqMan real-time PCR assay was used to assess the SARS-CoV-2 infection rate in the suspected HCWs. Results: Out of 1232 sampled HCWs, 694 (56%) were female. Two hundred sixty-five samples (21.5%) and 967 samples (78.5%) were prepared from AABIH, and AASTH, respectively. The results showed that 30% (373) of the clinically suspected employees had positive test results. There was a significant correlation between the risk of exposure to COVID-19 patients and the PCR positivity rate, which could be explained by the fact that 58% of the infected HCWs were in a high-risk group, 20% medium-risk, and the remaining 22% were low-risk (P < 0.0001). The rates of positive cases in females were higher than that among male counterparts (P < 0.05). Conclusions: In order to protect health care workers and reduce the prevalence and transmission of diseases, deficiencies must be identified and eliminated.

Is Antibiotic Prophylaxis Necessary in Small (≤20% TBSA) Burn Excisions? A Retrospective Study

Background:

This study investigates the effect of prophylactic perioperative antibiotic use on patients with small burns [≤20% total body surface area (TBSA)] on rates of infection, graft loss, or readmission.

Methods:

A retrospective chart review was conducted on patients admitted to our institution’s burn center between January 2020 and July 2021. Patients were included if they had a 20% or less TBSA burn with 1 or more operating room visit for burn excision and were excluded if a preoperative infection was present. Data were gathered regarding patient demographics, burn mechanism, burn characteristics, and outcome measures including infection, graft loss, and readmission. Statistical analysis was conducted by Mann–Whitney U and Fisher exact tests, and P values reported at two-sided significance of less than 0.05.

Results:

There were no significant differences in age, body mass index, TBSA, percent third-degree burn, or comorbidities between patients who received (n = 29) or did not receive (n = 47) prophylactic perioperative antibiotics. There was a nonsignificant trend toward higher length of stay in the prophylactic antibiotic group, possibly driven by a nonsignificant trend toward higher rates of flame injuries in this group. There was no difference in infection (P = 0.544), graft loss (P = 0.494), or 30-day readmission (P = 0.584) between the two groups.

Conclusion:

This study finds no significant difference in postoperative infection, graft loss, or 30-day readmission in two similar patient cohorts who received or did not receive prophylactic perioperative antibiotics for acute excision of small (≤20% TBSA) burns.

Carbon-Based Nanomaterials: Carbon Nanotubes, Graphene and Fullerenes in Control of Burns Infections and Wound Healing

Burn injuries are extremely debilitating, resulting in high morbidity and mortality rates around the world. The risk of infection escalates in correlation with impairment of skin integrity, creating a barrier to healing and possibly leading to sepsis. With its numerous advantages over traditional treatment methods, nanomaterial-based wound healing has immense capability for treating and preventing wound infections. Carbon-based nanomaterials (CNMs) owing to their distinctive physicochemical and biological properties have emerged as promising platform for biomedical applications. Carbon nanotubes, graphene, fullerenes, and their nanocomposites have demonstrated broad antimicrobial activity against invasive bacteria, fungi, and viruses causing burn wound infection. The specific mechanisms that govern the antimicrobial activity of CNMs must be understood in order to ensure the safe and effective incorporation of these structures into biomaterials. However, it is challenging to decouple individual and synergistic contributions of physical, chemical, and electrical effects of CNMs on cells. This review reported on significant advances in the application of CNMs in burn wound infection and wound healing, with brief discussion on the interaction between different families of CNMs and microorganisms to assess antimicrobial performance.

Epidemiological retrospective analysis in major burn patients: single centre medical records from 2009 to 2019

Burns cause a loss of skin barrier function, rendering it prone to infection. The prevention of infection comprises a focus on the treatment of patients with burns. Therefore, we analysed the results of microbiological tests of patients with severe and extremely severe burns to provide a basis for the prevention and treatment of infection in patients with burns. The results of microbiological tests of patients with severe and extremely severe burns admitted to our burn centre between 2009 and 2019 were retrospectively reviewed. The overall positive rate of microbial detection was 40.67% and did not significantly decline over the 10-year study period. The most common positive sites were wounds, sputum, and urine. The most common bacterial species causing the infections were Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Furthermore, the predictors of a positive detection, overall and at various sites, mainly included the burn area and depth, inhalation injury, and length of the hospital stay. Positive detection was an important predictor of the prognosis. In particular, a positive blood culture and Klebsiella pneumoniae had better predictive strength for mortality than other sites and strains. This study analysed the microbiological testing results at a single burn centre over a period of 10 years. The results provide information regarding the predictors of a positive detection and the influence of a positive detection on prognosis, and can be used as a basis for the development of clinical infection prevention and treatment strategies, as well as the selection of treatment measures.

Efficacy and Safety of High Vs Standard Daptomycin Doses Examined in Chinese Patients With Severe Burn Injuries by Pharmacokinetic Evaluation

Previous studies and the concentration-dependent antibacterial actions of daptomycin suggested that a high dose would be needed for difficult-to-treat infections in burn patients. Here, we evaluated the effects of administration of low and high doses of daptomycin in patients with severe burn injuries. The study retrospectively analyzed 10 patients with severe burn injuries, using pharmacokinetic (PK) and pharmacodynamic (PD) evaluations of daptomycin doses given to combat serious infections. Daptomycin was administered as a single dose or by multiple doses intravenously at a standard dose of 6 mg/kg/d or a high dose of 12 mg/kg/d for 7 to 14 days. The serum concentrations of daptomycin from patients were analyzed by liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS). Burn injury patients treated with high-dose daptomycin had a linear PK profile and a negative correlation between the AUC_0–24 and Baux score (R² = .953 and R² = .801). The C_max, AUC_0–24, and t(h)_½ increased significantly compared with patients given a standard dose. The efficacy of daptomycin against Staphylococcus aureus showed significantly higher rates of (AUC_0–24)/MIC and C_max/MIC after high-dose daptomycin compared with the standard dose, reflected in a significant correlation between a high dose and the Baux score (r = .976, P < .001). Positive S. aureus cultures from two of three high-dose and none of two daptomycin low-dose patients converted from positive to negative after therapy. No serious adverse events or discontinuation of the drug occurred during the treatment period. Daptomycin doses up to 12 mg/kg/d were well tolerated in Chinese patients with severe burn injuries, which were complicated by infections with S. aureus.

Mesoporous Silica Nanoparticles and Mesoporous Bioactive Glasses for Wound Management: From Skin Regeneration to Cancer Therapy

Exploring new therapies for managing skin wounds is under progress and, in this regard, mesoporous silica nanoparticles (MSNs) and mesoporous bioactive glasses (MBGs) offer great opportunities in treating acute, chronic, and malignant wounds. In general, therapeutic effectiveness of both MSNs and MBGs in different formulations (fine powder, fibers, composites etc.) has been proved over all the four stages of normal wound healing including hemostasis, inflammation, proliferation, and remodeling. The main merits of these porous substances can be summarized as their excellent biocompatibility and the ability of loading and delivering a wide range of both hydrophobic and hydrophilic bioactive molecules and chemicals. In addition, doping with inorganic elements (e.g., Cu, Ga, and Ta) into MSNs and MBGs structure is a feasible and practical approach to prepare customized materials for improved skin regeneration. Nowadays, MSNs and MBGs could be utilized in the concept of targeted therapy of skin malignancies (e.g., melanoma) by grafting of specific ligands. Since potential effects of various parameters including the chemical composition, particle size/morphology, textural properties, and surface chemistry should be comprehensively determined via cellular in vitro and in vivo assays, it seems still too early to draw a conclusion on ultimate efficacy of MSNs and MBGs in skin regeneration. In this regard, there are some concerns over the final fate of MSNs and MBGs in the wound site plus optimal dosages for achieving the best outcomes that deserve careful investigation in the future.

Diverse Treatments for Deep Burn Wounds: A Case Report

ABSTRACT

Patients with extensive deep burns usually experience infections and organ dysfunction. Proactive and effective wound repair is key to treatment. If large wounds remain open, systemic infection and multiple organ dysfunction syndrome can occur, threatening the lives of patients. Current wound repair methods include skin grafts, flap repair, negative-pressure wound therapy, and cellular and/or tissue-based products. For deep, complex burn wounds, a single form of treatment is usually ineffective. This article reports a rare case of burn wound repair. The patient was burned by a charcoal flame on multiple parts of his body after carbon monoxide poisoning. Pneumothorax and acute renal failure occurred after the injury, accompanied by multiple osteonecroses of the trunk and lower limbs. A multidisciplinary team formulated an individualized treatment plan; the diverse treatments included closed chest drainage, continuous renal replacement therapy, infection control, analgesia, wound debridement, negative-pressure wound therapy, cellular and/or tissue-based products, autologous dermal scaffold graft, skin grafts, flap transposition, platelet-rich plasma, and rehabilitation, which ultimately saved the patient's life and led to healing of all the wounds.

Ocular surface characteristics and colonization in a burn center: A prospective cohort study

We aimed to evaluate the characteristics and colonization by pathogenic microorganisms of the ocular surface in patients in a burn center and to determine their association with sedation, mechanical ventilation, and periocular burn. We prospectively evaluated 40 patients during an eight-month period. Five evaluations where performed, at baseline and weekly on four more occasions or until hospital discharge or death. On each visit, we assessed periocular burn, lid position, Bell's phenomenon, Schirmer's test, presence of chemosis, conjunctival hyperemia, and exposure keratopathy; conjunctival fornix swabs were taken for microbiology culture. Also, we documented the level of sedation, mechanical ventilation status, and systemic and ocular treatment. Absent Bell's phenomenon and chemosis were significantly different at baseline in patients under mechanical ventilation, sedation, and in those with periocular burn. The cumulative incidence of exposure keratopathy was 22.5% and the cumulative incidence of ocular surface colonization by pathogenic microorganisms was 32.5%. Both outcomes were associated with mechanical ventilation and periocular burn. The most frequent pathogenic microorganisms in the ocular surface were Candida parapsilosis, Acinetobacter baumanii, and Pseudomonas aeuroginosa. We did not observe any case of persistent epithelial defect, infectious keratitis, corneal perforation or corneal opacity in this cohort. Results from our study may benefit future patients by allowing better risk stratification and treatment strategies for the ocular surface care in burn units.

Self-reporting heavy atom-free photodynamic therapy agents

Two novel, self-reporting distyryl BODIPY-based photodynamic therapy agents functionalized with singlet oxygen responsive imidazole and tertiary amine moieties are developed. Heavy atom-free photosensitizers are demonstrated to have efficient photodynamic action in MCF7 cells. The fluorescence intensity of the photosensitizers is shown to be reduced as a result of 1O2 generation without any significant change in photodynamic activity.

Optimierung der chirurgischen Behandlung Brandverletzter: Auszüge aus der fachübergreifenden S2k-Leitlinie „Behandlung thermischer Verletzungen des Erwachsenen“

Hintergrund Trotz Brandschutzmaßnahmen und Aufklärung erleiden ca. 0,5 Millionen Menschen pro Jahr in Deutschland Verbrennungen. Im Jahr 2018 mussten fast 2000 Schwerstbrandverletzte in deutschen Verbrennungszentren behandelt werden. Brandverletzungen stellen eine schwerwiegende Erkrankung mit hoher Mortalität und langfristigen Folgen für den Patienten dar.

Methodik und Ergebnisse Ziel dieses Übersichtsartikels ist es, eine Zusammenfassung der derzeit gültigen Leitlinie zur Behandlung von Verbrennungen im Erwachsenenalter (https://www.awmf.org/leitlinien/detail/ll/044–001.html) zu präsentieren, wobei der Fokus auf folgenden Aspekten liegt: 1. der Akutbehandlung der Brandwunde am Unfallort, 2. der Entscheidungsfindung zur Verlegung in ein Brandverletztenzentrum, 3. der chirurgischen Wundversorgung mit Debridement und Hauttransplantation und 4. der Nachsorge. Die S2k-Leitlinie basiert auf aktueller Literatur und dem Konsens von 11 an der Behandlung Brandverletzter beteiligter Fachgesellschaften.

Zusammenfassung Dieser Übersichtsartikel enthält gewichtete Empfehlungen zur Behandlung von Brandwunden erwachsener Patienten in Deutschland. Der Artikel soll Ärzten und medizinischem Personal in der Akutsituation vor Ort und in der Klinik die Entscheidung über die notwendige Behandlung erleichtern. Hiermit soll die Behandlungsqualität für Patienten verbessert werden.

Effect of 632 nm He-Ne Laser on Gram-Positive Bacteria in Deep Partial Thickness Pediatric Burn: A Prospective Double-Blind Randomized Controlled Trial

Background. Burns are one of the most common injuries in pediatric population, gram-positive bacteria is the main pathogens responsible for wound infection that is the leading cause of morbidity and sometimes mortality in growing children with burn. Low level laser is a new treatment option that is increasingly used in the field of wound healing. Aim. To investigate the effect of He-Ne laser on gram-positive bacteria and healing time of deep second-degree pediatric burn. Methods. Thirty children of both genders aged from 2 to 9 years old with 2nd degree upper limb burn infected with gram-positive bacteria participated in this study. They were randomly assigned into two equal groups; either the control group (group A) received systematic antibiotic and 10 minutes’ placebo laser light, or the laser group (group B) received 632 nm laser light, 6 J/cm2 scanning technique for 10 minutes. All patients received regular wound care (dressing). The study protocol was once a day, 3 times / week for one month. Pre and post-treatment evaluation of wound culture and the healing time was recorded for both groups. Results. Wound culture of all children in both groups were negative after two weeks of the study and wound healing time was significantly shorter in the laser group (14.6±5.7 days) than the control group (27±7.3 days). Conclusion. He-Ne laser is an effective option of treatment for 2nd-degree pediatric burn as it has a bactericidal effect on gram-positive bacteria and accelerates wound healing process significantly.

Wound healing properties and antimicrobial activity of platelet-derived biomaterials

We analyzed the potential antibacterial effects of two different PdB against methicillin-resistant S. aureus and P. aeruginosa. The third-degree burn wound healing effects of PdB was also studied. Blood samples were obtained from 10 healthy volunteers and biological assays of the PdB were performed and the antimicrobial activity against MRSA and P. aeruginosa was determined using disk diffusion (DD), broth microdilution (BMD), and time-kill assay methods. 48 Wistar albino rats were burned and infected with MRSA. Two groups were injected PdB, the control groups were treated with plasma and received no treatment respectively. In the next step, the rats were euthanized and skin biopsies were collected and histopathologic changes were examined. The results of DD and BMD showed that both PdB performed very well on MRSA, whereas P. aeruginosa was only inhibited by F-PdB and was less susceptible than MRSA to PdBs. The time-kill assay also showed that F-PdB has an antibacterial effect at 4 hours for two strains. Histopathological studies showed that the treated groups had less inflammatory cells and necrotic tissues. Our data suggest that PdB may possess a clinical utility as a novel topical antimicrobial and wound healing agent for infected burn wounds.

In vivo therapeutic response monitoring by a self-reporting upconverting covalent organic framework nanoplatform

The real-time and in situ monitoring of reactive oxygen species (ROS) generation is critical for minimizing the nonspecific damage derived from the high doses of ROS required during the photodynamic therapy (PDT) process. However, phototherapeutic agents that can generate ROS-related imaging signals during PDT are rare, hampering the facile prediction of the future therapeutic outcome. Herein, we develop an upconverting covalent organic framework (COF) nanoplatform via a core-mediated strategy and further functionalized it with a singlet oxygen reporter for the efficient near-infrared activated and in situ self-reporting of PDT. In this work, the COF photodynamic efficacy is greatly improved (12.5 times that of irregular COFs) via tailoring the size. Furthermore, this nanoplatform is able to not only produce singlet oxygen for PDT, but it can also emit singlet oxygen-correlated luminescence, allowing the real-time and in situ monitoring of the therapeutic process for cancer cells or solid tumors in vivo via near-infrared luminescence imaging. Thus, our core-mediated synthetic and size-tailored strategy endows the upconverting COF nanoplatform with promising abilities for high-efficacy, deep-tissue, precise photodynamic treatment.

The Bacteriological Profile of Burn Wound Infections at a Tertiary Burns Center in Nepal

In Nepal, burn is the third most common injury after falls and road traffic accidents. Infection is the leading cause of mortality in burn injury. A profile exploring predominant flora and antimicrobial sensitivity is important to facilitate treatment ahead of microbiology results and to aid prevention of multidrug-resistant organisms. The aim of this study was to document epidemiological and bacteriological data of burn wound infections at a tertiary level burns center in Nepal. Samples were collected from January 2017 to May 2017, over a period of 5 months. Patient notes were referred to and information regarding baseline characteristics and burn wound infection data was collected. A total of 76 patients were included in the study during the 5-month period, which resulted in 113 samples being included for review. Females were injured most with burns 70% (n = 53) compared with males 30% (n = 23). Only 6 (8%) of 77 patients lived locally in Kathmandu. The average distance traveled by patients was 233 km (median 208, range 0–765, SD 181). Average TBSA% of burn was 22% (median 20, range 3–50, SD 12). Gram-negative organisms predominated, with Acinetobacter spp. in 42 cases (55%), Pseudomonas aeruginosa in 26 cases (34%), and Enterobacter spp. in 16 cases (21%). Colistin, polymyxin B, and tigecycline were found to be most sensitive covering 108, 98, and 94 organisms. Gram-negative bacteria colonized the majority of burn wounds. Colistin, polymyxin B, and tigecycline were the most sensitive to gram-negative bacteria. Gram-positive Staphylococcus aureus was sensitive most to vancomycin and tigecycline.

Skin and Soft Tissue Models for Acinetobacter baumannii Infection

Multidrug-resistant A. baumannii are important Gram-negative pathogens causing persistent wound infections in both wounded and burned victims, which often result in secondary complications such as delayed wound healing, skin graft failure, and sometimes more serious outcomes such as sepsis and amputation. The choice of antibiotics to remediate these A. baumannii infections is becoming limited; and therefore, there has been a renewed interest in the research and development of new antibacterials targeting this pathogen. However, the evaluation of safety and efficacy is made more difficult by the lack of well-established in vivo models. This chapter describes established rodent and large animal models that have been used to investigate and develop treatments for A. baumannii skin and soft tissue infections.

Current and Emerging Topical Antibacterials and Antiseptics: Agents, Action, and Resistance Patterns

Bacterial skin infections represent some of the most common infectious diseases globally. Prevention and treatment of skin infections can involve application of a topical antimicrobial, which may be an antibiotic (such as mupirocin or fusidic acid) or an antiseptic (such as chlorhexidine or alcohol). However, there is limited evidence to support the widespread prophylactic or therapeutic use of topical agents. Challenges involved in the use of topical antimicrobials include increasing rates of bacterial resistance, local hypersensitivity reactions (particularly to older agents, such as bacitracin), and concerns about the indiscriminate use of antiseptics potentially coselecting for antibiotic resistance. We review the evidence for the major clinical uses of topical antibiotics and antiseptics. In addition, we review the mechanisms of action of common topical agents and define the clinical and molecular epidemiology of antimicrobial resistance in these agents. Moreover, we review the potential use of newer and emerging agents, such as retapamulin and ebselen, and discuss the role of antiseptic agents in preventing bacterial skin infections. A comprehensive understanding of the clinical efficacy and drivers of resistance to topical agents will inform the optimal use of these agents to preserve their activity in the future.

Cutaneous Burn Injury Modulates Urinary Antimicrobial Peptide Responses and the Urinary Microbiome

OBJECTIVES

Characterization of urinary bacterial microbiome and antimicrobial peptides after burn injury to identify potential mechanisms leading to urinary tract infections and associated morbidities in burn patients.

DESIGN

Retrospective cohort study using human urine from control and burn subjects.

SETTING

University research laboratory.

PATIENTS

Burn patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Urine samples from catheterized burn patients were collected hourly for up to 40 hours. Control urine was collected from "healthy" volunteers. The urinary bacterial microbiome and antimicrobial peptide levels and activity were compared with patient outcomes. We observed a significant increase in urinary microbial diversity in burn patients versus controls, which positively correlated with a larger percent burn and with the development of urinary tract infection and sepsis postadmission, regardless of age or gender. Urinary psoriasin and β-defensin antimicrobial peptide levels were significantly reduced in burn patients at 1 and 40 hours postadmission. We observed a shift in antimicrobial peptide hydrophobicity and activity between control and burn patients when urinary fractions were tested against Escherichia coli and Enterococcus faecalis urinary tract infection isolates. Furthermore, the antimicrobial peptide activity in burn patients was more effective against E. coli than E. faecalis. Urinary tract infection-positive burn patients with altered urinary antimicrobial peptide activity developed either an E. faecalis or Pseudomonas aeruginosa urinary tract infection, suggesting a role for urinary antimicrobial peptides in susceptibility to select uropathogens.

CONCLUSIONS

Our data reveal potential links for urinary tract infection development and several morbidities in burn patients through alterations in the urinary microbiome and antimicrobial peptides. Overall, this study supports the concept that early assessment of urinary antimicrobial peptide responses and the bacterial microbiome may be used to predict susceptibility to urinary tract infections and sepsis in burn patients.

Pseudomonas aeruginosa prevalence, antibiotic resistance and antimicrobial use in Chinese burn wards from 2007 to 2014

Objective To assess the application of antibacterial agents, alongside pathogen prevalence and Pseudomonas aeruginosa drug resistance, with the aim of understanding the impact of inappropriate antibacterial use. Methods This retrospective study assessed bacteria from wounds, catheters, blood, faeces, urine and sputum of hospitalized patients in burn wards between 2007 and 2014. The intensity of use of antibacterial agents and resistance of P. aeruginosa to common anti-Gram-negative antibiotics were measured. Results Annual detection rates of Staphylococcus aureus were significantly decreased, whereas annual detection rates of P. aeruginosa and Klebsiella pneumoniae were significantly increased. Multidrug-resistant strains of P. aeruginosa were increased. The intensity of use of some anti-Gramnegative antibiotics positively correlated with resistance rates of P. aeruginosa to similar antimicrobials. Conclusion In burn wards, more attention should be paid to P. aeruginosa and K. pneumoniae. The use of ciprofloxacin, ceftazidime and cefoperazone/sulbactam should be limited to counter the related increase in resistance levels.

Burn Injury Leads to Increased Long-Term Susceptibility to Respiratory Infection in both Mouse Models and Population Studies

Background

Burn injury initiates an acute inflammatory response that subsequently drives wound repair. However, acute disruption to the immune response is also common, leading to susceptibility to sepsis and increased morbidity and mortality. Despite increased understanding of the impact of burn injury on the immune system in the acute phase, little is known about long-term consequences of burn injury on immune function. This study was established to determine whether burn injury has long-term clinical impacts on patients’ immune responses.

Methods

Using a population-based retrospective longitudinal study and linked hospital morbidity and death data from Western Australia, comparative rates of hospitalisation for respiratory infections in burn patients and a non-injured comparator cohort were assessed. In addition, a mouse model of non-severe burn injury was also used in which viral respiratory infection was induced at 4 weeks post-injury using a mouse modified version of the Influenza A virus (H3NN; A/mem/71-a).

Results and conclusions

The burn injured cohort contained 14893 adult patients from 1980–2012 after removal of those patients with evidence of smoke inhalation or injury to the respiratory tract. During the study follow-up study a total of 2,884 and 2,625 respiratory infection hospital admissions for the burn and uninjured cohorts, respectively, were identified. After adjusting for covariates, the burn cohort experienced significantly elevated admission rates for influenza and viral pneumonia (IRR, 95%CI: 1.73, 1.27–2.36), bacterial pneumonia (IRR, 95%CI: 2.05, 1.85–2.27) and for other types of upper and lower respiratory infections (IRR, 95% CI: 2.38, 2.09–2.71). In the mouse study an increased viral titre was observed after burn injury, accompanied by a reduced CD8 response and increased NK and NKT cells in the draining lymph nodes. This data suggests burn patients are at long-term increased risk of infection due to sustained modulation of the immune response.

Burns and long-term infectious disease morbidity: A population-based study

BACKGROUND

There is a growing volume of data that indicates that serious injury suppresses immune function, predisposing individuals to infectious complications. With recent evidence showing long-term immune dysfunction after less severe burn, this study aimed to investigate post-burn infectious disease morbidity and assess if burn patients have increased long-term hospital use for infectious diseases.

METHODS

A population-based longitudinal study using linked hospital morbidity and death data from Western Australia for all persons hospitalised for a first burn (n=30,997) in 1980-2012. A frequency matched non-injury comparison cohort was randomly selected from Western Australia's birth registrations and electoral roll (n=123,399). Direct standardisation was used to assess temporal trends in infectious disease admissions. Crude annual admission rates and length of stay for infectious diseases were calculated. Multivariate negative binomial and Cox proportional hazards regression modeling were used to generate adjusted incidence rate ratios (IRR) and hazard ratios (HR), respectively.

RESULTS

After adjustment for demographic factors and pre-existing health status, the burn cohort had twice (IRR, 95% confidence interval (CI): 2.04, 1.98-2.22) as many admissions and 3.5 times the number of days in hospital (IRR, 95%CI: 3.46, 3.05-3.92) than the uninjured cohort for infectious diseases. Higher rates of infectious disease admissions were found for severe (IRR, 95%CI: 2.37, 1.89-2.97) and minor burns (IRR, 95%CI: 2.22, 2.11-2.33). Burns were associated with significantly increased incident admissions: 0-30days (HR, 95%CI: 5.18, 4.15-6.48); 30days-1year (HR, 95%CI: 1.69, 1.53-1.87); 1-10 years (HR, 95%CI: 1.40:1.33-1.47); >10years (HR, 95%CI: 1.16, 1.08-1.24). Respiratory, skin and soft tissue and gastrointestinal infections were the most common. The burn cohort had a 1.75 (95%CI: 1.37-2.25) times greater rate of mortality caused by infectious diseases during the 5-year period after discharge than the uninjured cohort.

CONCLUSIONS

These findings suggest that burn has long-lasting effects on the immune system and its function. The increase in infectious disease in three different epithelial tissues in the burn cohort suggests there may be common underlying pathophysiology. Further research to understand the underlying mechanisms are required to inform clinical interventions to mitigate infectious disease after burn and improve patient outcomes.

Respiratory Morbidity After Childhood Burns: A 10-Year Follow-up Study

BACKGROUND AND OBJECTIVE

The systemic responses triggered by burns and resuscitative measures may cause pulmonary damage and edema in the acute phase. These effects may occur in the absence of inhalation injury. Currently, there is a paucity of data on the recovery of the respiratory system postburn. This study aimed to examine 10-year hospital service use for respiratory morbidity in children with cutaneous burns and no smoke inhalation injury.

METHODS

A population-based longitudinal study with 10-year follow-up using linked hospital and death from Western Australia for children <5 years when hospitalized for a first burn injury (n = 5290) between 1980 and 2012 and a frequency matched noninjury comparison cohort, randomly selected from Western Australia's birth registrations (n = 27 061). Multivariate negative binomial and Cox proportional hazards regression models were used to generate adjusted incidence rate ratios (IRR) and hazard ratios, respectively.

RESULTS

After adjustment for demographic factors and preexisting health status, the burn cohort had higher rates of admissions for influenza and viral pneumonia (IRR, 1.78; 95% confidence interval [CI], 1.10-2.87), bacterial pneumonia (IRR, 1.34; 95% CI, 1.06-1.70), and other respiratory infections (IRR, 1.65; 95% CI, 1.43-1.90. No significant difference was found for other upper respiratory tract conditions (IRR, 1.10; 95% CI, 0.98-1.23) or chronic lower respiratory diseases (IRR, 0.99; 95% CI, 0.80-1.23) compared with the uninjured cohort.

CONCLUSIONS

These findings demonstrated increased respiratory infection admissions after burns. These outcomes suggest that immune changes triggered by a burn injury may persist in some children for at least 10 years after wound healing.

Efficacy of Trans-cinnamaldehyde and Eugenol in Reducing Acinetobacter baumannii Adhesion to and Invasion of Human Keratinocytes and Controlling Wound Infection In Vitro

The study investigated the efficacy of two natural, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), and eugenol (EG) for decreasing Acinetobacter baumannii adhesion to and invasion of human keratinocytes (HEK001). Moreover, the efficacy of two PDAs for inhibiting A. baumannii biofilm formation was determined using an in vitro collagen matrix wound model. Additionally, the effect of TC and EG on A. baumannii biofilm architecture was visualized using confocal scanning microscopy. Further the effect of both PDAs on genes critical for biofilm synthesis was determined using real-time quantitative polymerase chain reaction. Both TC and EG significantly reduced A. baumannii adhesion and invasion to HEK001 by ~2 to 3 log₁₀ CFU/mL (p < 0.05) compared with the controls (p < 0.05). Further, after 24 and 48 h, TC and EG inhibited biofilm formation by ~1.5 to 2 and ~2 to 3.5 log₁₀ CFU/mL, compared with controls (p < 0.05). Confocal microscopy revealed that TC and EG disrupted the biofilm architecture. RT-qPCR results indicated that two phytochemicals significantly down-regulated the transcription of genes associated with A. baumannii biofilm production. The results suggest that both TC and EG could potentially be used to treat A. baumannii wound infections; however, their efficacy in in vivo models needs to be validated. Copyright © 2016 John Wiley & Sons, Ltd.

Macrophage polarization and MRSA infection in burned mice

Mortality associated with Staphylococcus aureus infection remains high during the sub-acute phase of burn injury. In this study, we aimed to improve antibacterial resistance of sub-acutely burned mice through macrophage polarization. Sepsis did not develop in mice at the sub-acute phase of 5% total body surface area (TBSA) burn after being infected with methicillin-resistant S. aureus (MRSA), and M1 macrophages (interleukin (IL)-10^-IL-12⁺ inducible nitric oxide synthase⁺ Mφ) were isolated from these mice. In contrast, predominantly M2b macrophages (C-C motif chemokine ligand 1 (CCL1)⁺IL-10⁺IL-12^- Mφ) were isolated from mice with >15% TBSA burn, and all of these mice died after the same MRSA infection. Comparing NOD scid gamma mice inoculated with Mφ with 25% TBSA burns, all mice treated with CCL1 antisense oligodeoxynucleotide (ODN) survived after MRSA infection, whereas all untreated mice given the same infection died within 4 days. CCL1 antisense ODN has been characterized as a specific polarizer of M2bMφ. M1Mφ were isolated from MRSA-infected mice with 25% TBSA burn after treatment with CCL1 antisense ODN, and these mice were shown to be resistant against a lethal dose of MRSA infection. M1Mφ were also isolated from 25% TBSA-burned mice infected with MRSA when the ODN was administered therapeutically, and subsequent sepsis was effectively controlled in these mice. These results indicate that the M2bMφ polarizer is beneficial for controlling MRSA infection in mice at the sub-acute phase of severe burn injury.

Smoke inhalation increases intensive care requirements and morbidity in paediatric burns

Burn survival has improved with advancements in fluid resuscitation, surgical wound management, wound dressings, access to antibiotics and nutritional support for burn patients. Despite these advancements, the presence of smoke inhalation injury in addition to a cutaneous burn still significantly increases morbidity and mortality. The pathophysiology of smoke inhalation has been well studied in animal models. Translation of this knowledge into effectiveness of clinical management and correlation with patient outcomes including the paediatric population, is still limited. We retrospectively reviewed our experience of 13 years of paediatric burns admitted to a regional burn's intensive care unit. We compared critical care requirements and patient outcomes between those with cutaneous burns only and those with concurrent smoke inhalation injury. Smoke inhalation increases critical care requirements and mortality in the paediatric burn population. Therefore, early critical care input in the management of these patients is advised.

Surveillance of antibiotic susceptibility in a Swedish Burn Center 1994-2012

Patients with burn trauma are at risk for infections caused by antibiotic resistant bacteria (ABR) with subsequent increase in morbidity and mortality. As part of the Swedish strategic program against antibiotic resistance in intensive care (ICU-Strama), we have surveyed the distribution of species and ABR in isolates from patients admitted to a Swedish burn center at Linköping University Hospital from 1994 through 2012. In an international comparison Strama has been successful in reducing the antibiotic consumption among animals and humans in primary care. The aim of this study was to investigate the antibiotic consumption pressure and resistance rates in a Swedish burn unit.

METHODS

Microbiology data, total body surface area (TBSA), patient days, and mortality were collected from a hospital database for all patients admitted to the Burn Center at the University Hospital of Linköping from April 1994 through December 2012.

RESULTS

A total of 1570 patients were admitted with a mean annual admission rate of 83 patients (range: 57-152). 15,006 microbiology cultures (approximately 10 per patient) were collected during the study period and of these 4531 were positive (approximately 3 per patient). The annual mean total body surface area (TBSA) was 13.4% (range 9.5-18.5) with an annual mortality rate of 5.4% (range 1-8%). The MRSA incidence was 1.7% (15/866) which corresponds to an MRSA incidence of 0.34/1000 admission days (TAD). Corresponding figures were for Escherichia coli resistant to 3(rd) generation cephalosporins (ESBL phenotype) 8% (13/170) and 0.3/TAD, Klebsiella spp. ESBL phenotype 5% (6/134) and 0.14/TAD, carbapenem resistant Pseudomonas aeruginosa 26% (56/209) and 1.28/TAD, and carbapenem resistant Acinetobacter spp. 3% (2/64) and 0.04/TAD.

CONCLUSIONS

Our results show a sustained low risk for MRSA and high, although not increasing, risk for carbapenem resistant P. aeruginosa.

Prophylactic Antibiotics May Improve Outcome in Patients With Severe Burns Requiring Mechanical Ventilation: Propensity Score Analysis of a Japanese Nationwide Database

BACKGROUND

The use of prophylactic antibiotics for severe burns in general settings remains controversial and is not suggested by recent guidelines owing to lack of evidence for efficacy. We examined the hypothesis that prophylactic systemic antibiotic therapy may reduce mortality in patients with severe burns.

METHODS

We identified 2893 severe burns patients (burn index ≥ 10) treated at 583 hospitals between July 2010 and March 2013 using the Japanese diagnosis procedure combination inpatient database. We categorized the patients according to whether they received mechanical ventilation within 2 days after admission (n = 692) or not (n = 2201). We further divided the patients into those with and without prophylactic antibiotics and generated 232 and 526 propensity score-matched pairs, respectively. We evaluated 28-day all-cause in-hospital mortality.

RESULTS

Among the mechanically ventilated patients, significant differences in 28-day in-hospital mortality existed between control and prophylaxis groups in both unmatched (control vs prophylaxis; 48.6% vs 38.3%; difference, 10.2%; 95% confidence interval [95% CI], 2.7 to 17.7) and propensity score-matched groups (47.0% vs 36.6%; difference, 10.3%; 95% CI, 1.4 to 19.3). Among patients without mechanical ventilation, there was no significant difference in 28-day in-hospital mortality between the 2 groups in both the unmatched (control vs prophylaxis; 7.0% vs 5.8%; difference, 1.2%; 95% CI, -1.2 to 3.5) and propensity-matched groups (5.1% vs 4.2%; difference, 0.9%; 95% CI, -1.6 to 3.5).

CONCLUSIONS

Prophylactic antibiotics use may result in improved 28-day in-hospital mortality in mechanically ventilated patients with severe burns but not in those who do not receive mechanical ventilation.

The dormant blood microbiome in chronic, inflammatory diseases

Blood in healthy organisms is seen as a ‘sterile’ environment: it lacks proliferating microbes. Dormant or not-immediately-culturable forms are not absent, however, as intracellular dormancy is well established. We highlight here that a great many pathogens can survive in blood and inside erythrocytes. ‘Non-culturability’, reflected by discrepancies between plate counts and total counts, is commonplace in environmental microbiology. It is overcome by improved culturing methods, and we asked how common this would be in blood. A number of recent, sequence-based and ultramicroscopic studies have uncovered an authentic blood microbiome in a number of non-communicable diseases. The chief origin of these microbes is the gut microbiome (especially when it shifts composition to a pathogenic state, known as ‘dysbiosis’). Another source is microbes translocated from the oral cavity. ‘Dysbiosis’ is also used to describe translocation of cells into blood or other tissues. To avoid ambiguity, we here use the term ‘atopobiosis’ for microbes that appear in places other than their normal location. Atopobiosis may contribute to the dynamics of a variety of inflammatory diseases. Overall, it seems that many more chronic, non-communicable, inflammatory diseases may have a microbial component than are presently considered, and may be treatable using bactericidal antibiotics or vaccines.

Atopobiosis of microbes (the term describing microbes that appear in places other than where they should be), as well as the products of their metabolism, seems to correlate with, and may contribute to, the dynamics of a variety of inflammatory diseases.

Orosomucoid 1 drives opportunistic infections through the polarization of monocytes to the M2b phenotype

Orosomucoid (ORM, composed of two isoforms, ORM1 and ORM2) has been described as an inducer of M2 macrophages, which are cells that decrease host antibacterial innate immunities. However, it is unknown which phenotypes of M2 macrophages are induced by ORM. In this study, healthy donor monocytes stimulated with ORM (ORM-monocytes) were characterized phenotypically and biologically. CCL1 (a biomarker of M2b macrophages) and IL-10 were detected in monocyte cultures supplemented with ORM1; however, CCL17 (a biomarker of M2a macrophages) and CXCL13 (a biomarker of M2c macrophages) were not produced in these cultures. All of these soluble factors were not detected in the culture fluids of monocytes stimulated with ORM2. Monocytes stimulated with ORM1 were characterized as CD64(-)CD209(-)CD163(+)CCL1(+) cells. MRSA and Enterococcus faecalis infections were accelerated in chimeras (NOD/scid IL-2Rγ(null) mice reconstituted with white blood cells) after inoculation with monocytes stimulated with ORM1 or treatment with ORM1; however, the infections were greatly mitigated in both chimeras inoculated with ORM1-stimulated monocytes and treated with ORM1, after an additional treatment with an inhibitor of M2b macrophages (CCL1 antisense ODN). These results indicate that ORM1 stimulates quiescent monocytes to polarize to M2b monocytes. The regulation of M2b macrophages may be beneficial in controlling opportunistic infections in patients with a large amount of plasma ORM1.

Effects of red laser, infrared, photodynamic therapy, and green LED on the healing process of third-degree burns: clinical and histological study in rats

The aim of this study was to evaluate the effects of red laser, infrared, photodynamic therapy, and green light-emitting diode (LED) on the healing process of skin burns through clinical and histopathologic analysis in rats. For this, 100 animals were randomly divided into five groups: G1-untreated control (CTR), G2-red laser (LVER), G3-infrared (LINF), G4-photodynamic therapy (PDT), and G5-green LED. Burn was induced on the dorsum of the rat and the treatment of the experimental groups was red light (10 J/cm(2), 10 s, 40 mW, and λ660 nm), infrared (10 J/cm(2), 10 s, 40 mW, and λ780 nm), green LED irradiation (60 J/cm(2), 10 s, λ520, and 550 nm), and photodynamic therapy (10 J/cm(2), 40 mW, and λ660 nm), the latter combined with methylene blue photosensitizer at concentration 0.5 μg/mL. Applications were performed daily until day prior to sacrifice of the animal at 3, 7, 14, and 21 days with intraperitoneal anesthetic overdose. The specimens collected were clinically examined and soon after processed and stained with hematoxylin-eosin and Picrosirius for analysis under light and polarized light microscopy, respectively. Animals treated with LVER, LINF, PDT (p < 0.001), and LED (p < 0.05) stimulated production and maturation of collagen, and increased the consumption of food and water compared to the CTR (p < 0.001). Laser λ660 nm and λ780 nm showed the largest wound reductions in all groups (p = 0.001). In conclusion, red laser, infrared, photodynamic therapy, and green LED favored the healing process of third-degree burns in rats.

Correlation of ciprofloxacin resistance with the AdeABC efflux system in Acinetobacter baumannii clinical isolates

Background

Acinetobacter baumannii is one of the most important pathogens capable of colonization in burn patients, leading to drug-resistant wound infections. This study evaluated the distribution of the AdeABC efflux system genes and their relationship to ciprofloxacin resistance in A. baumannii isolates collected from burn patients.

Methods

A total of 68 A. baumannii clinical strains were isolated from patients hospitalized in Motahari Burns Center in Tehran, Iran. Ciprofloxacin susceptibility was tested by the disk diffusion and agar dilution methods. PCR amplification of the adeRS-adeB drug efflux genes was performed for all resistant and susceptible isolates. To assess the role of the drug efflux pump in ciprofloxacin susceptibility, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was used as an efflux pump inhibitor (EPI).

Results

Approximately 95.6% of the Acinetobacter isolates were resistant to ciprofloxacin, with minimum inhibitory concentration (MIC) values ranging from 4 to ≥128 µg/mL. The susceptibility of 86.1% of the resistant isolates increased by factors of 2 to 64 in the presence of CCCP. All resistant isolates were positive for the adeRS-adeB genes, and 73.2% of them had mutations in the AdeRS regulatory system.

Conclusions

The results showed that AdeABC genes are common in A. baumannii, which might be associated with ciprofloxacin non-susceptibility, as indicated by the observed linkage to the presence of the genes essential for the activity of the AdeABC, several single mutations occurring in the adeRS regulatory system, and an increase of ciprofloxacin susceptibility in the presence of a CCCP EPI.

Antibiotic prophylaxis for preventing burn wound infection

BACKGROUND

Infection of burn wounds is a serious problem because it can delay healing, increase scarring and invasive infection may result in the death of the patient. Antibiotic prophylaxis is one of several interventions that may prevent burn wound infection and protect the burned patient from invasive infections.

OBJECTIVES

To assess the effects of antibiotic prophylaxis on rates of burn wound infection.

SEARCH METHODS

In January 2013 we searched the Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid MEDLINE - In-Process & Other Non-Indexed Citations (2013); Ovid EMBASE; EBSCO CINAHL and reference lists of relevant articles. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

All randomised controlled trials (RCTs) that evaluated the efficacy and safety of antibiotic prophylaxis for the prevention of BWI. Quasi-randomised studies were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted relevant data. Risk ratio (RR) and mean difference (MD) were estimated for dichotomous data and continuous data, respectively. When sufficient numbers of comparable RCTs were available, trials were pooled in a meta-analysis to estimate the combined effect.

MAIN RESULTS

This review includes 36 RCTs (2117 participants); twenty six (72%) evaluated topical antibiotics, seven evaluated systemic antibiotics (four of these administered the antibiotic perioperatively and three administered upon hospital admission or during routine treatment), two evaluated prophylaxis with non absorbable antibiotics, and one evaluated local antibiotics administered via the airway.The 11 trials (645 participants) that evaluated topical prophylaxis with silver sulfadiazine were pooled in a meta analysis. There was a statistically significant increase in burn wound infection associated with silver sulfadiazine compared with dressings/skin substitute (OR = 1.87; 95% CI: 1.09 to 3.19, I(2) = 0%). These trials were at high, or unclear, risk of bias. Silver sulfadiazine was also associated with significantly longer length of hospital stay compared with dressings/skin substitute (MD = 2.11 days; 95% CI: 1.93 to 2.28).Systemic antibiotic prophylaxis in non-surgical patients was evaluated in three trials (119 participants) and there was no evidence of an effect on rates of burn wound infection. Systemic antibiotics (trimethoprim-sulfamethoxazole) were associated with a significant reduction in pneumonia (only one trial, 40 participants) (RR = 0.18; 95% CI: 0.05 to 0.72) but not sepsis (two trials 59 participants) (RR = 0.43; 95% CI: 0.12 to 1.61).Perioperative systemic antibiotic prophylaxis had no effect on any of the outcomes of this review.Selective decontamination of the digestive tract with non-absorbable antibiotics had no significant effect on rates of all types of infection (2 trials, 140 participants). Moreover, there was a statistically significant increase in rates of MRSA associated with use of non-absorbable antibiotics plus cefotaxime compared with placebo (RR = 2.22; 95% CI: 1.21 to 4.07).There was no evidence of a difference in mortality or rates of sepsis with local airway antibiotic prophylaxis compared with placebo (only one trial, 30 participants).

AUTHORS' CONCLUSIONS

The conclusions we are able to draw regarding the effects of prophylactic antibiotics in people with burns are limited by the volume and quality of the existing research (largely small numbers of small studies at unclear or high risk of bias for each comparison). The largest volume of evidence suggests that topical silver sulfadiazine is associated with a significant increase in rates of burn wound infection and increased length of hospital stay compared with dressings or skin substitutes; this evidence is at unclear or high risk of bias. Currently the effects of other forms of antibiotic prophylaxis on burn wound infection are unclear. One small study reported a reduction in incidence of pneumonia associated with a specific systematic antibiotic regimen.

Antimicrobial photodynamic therapy with decacationic monoadducts and bisadducts of [70]fullerene: in vitro and in vivo studies

BACKGROUND

Antimicrobial photodynamic therapy uses photosensitizers designed to bind to microorganisms and generate reactive oxygen species when illuminated with visible light.

MATERIALS & METHODS

We synthesized a highly water-soluble [70]fullerene monoadduct, C70[>M(C3N6(+)C3)2]-(I(-))10 (LC17), and bisadduct, C70[>M(C3N6(+)C3)2][>M(C3N6C3)2] (LC18), both with a well-defined decacationic quaternary ammonium iodide moiety with ten positive charges per C70 to give water solubility and bacterial binding. We determined the antimicrobial effects against human pathogens, Gram-positive (Staphylococcus aureus) and Gram-negative species (Escherichia coli and Acinetobacter baumannii) when activated by UVA or white light.

RESULTS

White light was more effective with LC17, while UVA light was more effective with LC18. Both compounds were effective in a mouse model of Gram-negative third-degree burn infections determined by bioluminescence imaging.

DISCUSSION & CONCLUSION

We propose that the attachment of an additional deca(tertiary-ethylenylamino)malonate arm to C70 allowed the moiety to act as a potent electron donor and increased the generation yield of hydroxyl radicals under UVA illumination.

Three-year review of bacteriological profile and antibiogram of burn wound isolates in Van, Turkey

The risk of infection in burns is well-known. In recent decades, the antimicrobial resistance of bacteria isolated from burn patients has increased. For this reason, a retrospective study was conducted at Van Training and Research Hospital to analyze the bacterial isolates from the wounds of patients admitted to the Burn Unit and to determine the susceptibility patterns of the commonly cultured organisms over a 3-year period, January 2009 to December 2011.A total of 250 microorganisms were isolated from burn wounds of 179 patients. Our results revealed that the most frequent isolate was Acinetobacter baumannii (23.6%), Pseudomonas aeruginosa (12%), Staphylococcus aureus (11.2%), Escherichia coli (10%) respectively. Multidrug-resistance has emerged as an important concern in our burn unit. Tigecycline, and colistin were found to be the most active drugs against Acinetobacter baumannii. Carbapenems and amikacin, were found to be the most active drugs against other gram negative bacteria. Vancomycin and linezolid were active against gram positive bacteria.Aggressive infection control measures should be applied to limit the emergence and spread of multidrug-resistant pathogens.