Infection in Burns

Antivirulence and antipathogenic activity of Mayan herbal remedies against Pseudomonas aeruginosa

ETHNOPHARMACOLOGICAL RELEVANCE

The Yucatan Peninsula has a privileged wealth of vascular plants with which various Mayan herbal formulations have been developed. However, studies on their antipathogenic and antivirulence properties are scarce.

AIM OF THE STUDY

Identify antivirulence properties in Mayan herbal remedies and determine their antipathogenic capacity in burn wounds infected with Pseudomonas aeruginosa.

MATERIALS AND METHODS

An ethnobotanical study was conducted in Mayan communities in central and southern Quintana Roo, Mexico. Furthermore, the antipathogenic capacity of three Mayan herbal remedies was analyzed using an animal model of thermal damage and P. aeruginosa infection. Antivirulence properties were determined by inhibiting phenotypes regulated by quorum sensing (pyocyanin, biofilm, and swarming) and by the secretion of the ExoU toxin. The chemical composition of the most active herbal remedy was analyzed using molecular network analysis.

RESULTS

It was found that topical administration of the remedy called "herbal soap" (HS) for eleven days maintained 100% survival of the animals, reduced establishment of the bacteria in the burn and prevented its systemic dispersion. Although no curative effect was recorded on tissue damaged by HS treatment, its herbal composition strongly reduced swarming and ExoU secretion. Through analysis of Molecular Networks, it was possible to carry out a global study of its chemical components, and identify the family of oxindole monoterpenoid alkaloids and carboline and tetrahydropyrididole alkaloids. In addition, flavonols, flavan-3-ols, and quinic acid derivatives were detected.

CONCLUSIONS

The antipathogenic and antivirulence capacity of ancient Mayan remedies makes them a potential resource for developing new antibacterial therapies to treat burns infected by P. aeruginosa.

Composite antibacterial hydrogels based on two natural products pullulan and ε-poly-l-lysine for burn wound healing

Antibacterial hydrogels as burn wound dressings are capable of efficaciously defending against bacterial infection and accelerating burn wound healing. Thus far, a large plethora of antibacterial hydrogels have adopted numerous components and intricate preparation processes, yet restricting their practical industrialization applications. Simple and effective preparation methods of antibacterial hydrogels are hence urgently needed. Herein, an easy but efficacious strategy with the employment of two natural products pullulan and ε-poly-l-lysine (ε-PL) was designed to fabricate composite antibacterial hydrogels for burn wound healing for the first time. The hydrogel crosslinking networks were formed through amidation reactions between carboxylated pullulan derivative (CP) and ε-poly-l-lysine hydrochloride (ε-PL·HCl). The resulting hydrogels possessed high transparency, porous structures, tunable gelation time and gel content, relatively low swelling ratios, appropriate self-degradability, proper mechanical properties, strong in vitro bacteriostatic activities, non-cytotoxicity, capacities of facilitating cell migration and excellent hemocompatibility. In the infected burn model of mice, the hydrogels were observed to display prominent in vivo antibacterial activities and enable the acceleration of burn wound healing. We opine the simply and effectively prepared antibacterial hydrogels as promising dressings for burn wound recovery have broad industrialization prospects.

Retrospective analysis of pathogens for guided creation of an EMPIRIc antibiotic prEscribing pathway (EMPIRE)

The objective of this study was to evaluate the susceptibilities of pathogens isolated from cultures within the first 7 days of admission to the burn center and in the absence of healthcare-associated infection risk factors (HAIRF) to determine if current empiric antibiotics can be narrowed for refinement of an empiric antibiotic prescribing pathway according to the suspected source. A 3-year sample of patients and cultures was utilized in hopes of obtaining at least 30 isolates of the most common pathogens and their respective susceptibilities. A total of 268 clinically relevant (e.g., deemed infectious, versus colonization) pathogens were included in the final sample with sources including wounds, respiratory, blood, urine, and bone. Of the 268 pathogens included, 45% were Gram-negative and 69% of all pathogens were isolated from wound cultures. The existing empiric pathway, vancomycin plus cefepime, covered 98% and 84% of all Gram-positive and Gram-negative pathogens, respectively. In patients without HAIRF, coverage rose to 98% and 90%, respectively. Initial use of vancomycin and cefepime remains adequate for pathogens isolated within 1 week of admission in patients without HAIRF. For pneumonias, a narrower spectrum beta-lactam would not sufficiently cover respiratory pathogens isolated within the first week of admission. Regarding early wound infections, difficult-to-treat pathogens remain as a rare isolate of wound cultures within 1 week of admission.

Characterization of an Escherichia coli phage Tequatrovirus YZ2 and its application in bacterial wound infection

The increasing prevalence of drug-resistant Escherichia coli (E. coli) resulting from the excessive utilization of antibiotics necessitates the immediate exploration of alternative approaches to counteract pathogenic E. coli. Phages, with their unique antibacterial mechanisms, are considered promising candidates for treating bacterial infections. Herein, we isolated a lytic Escherichia phage Tequatrovirus YZ2 (phage YZ2), which belongs to the genus Tequatrovirus. The genome of phage YZ2 consists of 168,356 base pairs with a G + C content of 35.34% and 269 putative open reading frames (ORFs). Of these, 146 ORFs have been annotated as functional proteins associated with nucleotide metabolism, structure, transcription, DNA replication, translation, and lysis. In the mouse model of a skin wound infected by E. coli, phage YZ2 therapy significantly promoted the wound healing. Furthermore, histopathological analysis revealed reductions in IL-1β and TNF-α and increased VEGF levels, indicating the potential of phages as effective antimicrobial agents against E. coli infection.

Multifunctional silver nanoparticle embedded eri silk cocoon scaffolds against burn wounds-associated infection

Antimicrobial wound dressings offer enhanced efficacy compared to conventional dressing platforms by limiting bacterial infections, expediting the healing process, and creating a barrier against additional wound contamination. The use of silk derived from silkworm cocoons in wound healing applications is attributed to its exceptional characteristics. Compared to mulberry silk, sericin from non-mulberry cocoons has higher water exchange mobility and moisture retention. Eri, a non-mulberry silkworm, is an unexplored source of silk with an eco-friendly nature of production where the natural life cycle of silkworms is not disrupted, and no moths are sacrificed. This work reports on an eri silk cocoon-based scaffold decorated with silver nanoparticles as a wound dressing material effective against burn-wound-associated multiple-drug-resistant bacteria. The UV-vis spectroscopy showed maximum absorbance at 448 nm due to the surface plasmon resonance of silver nanoparticles. FT-IR spectra exhibited the functional groups in the eri silk proteins accountable for the reduction of Ag+ to Ag0 in the scaffold. SEM-EDX analysis revealed the presence of elemental silver, and XRD analysis confirmed their particle size of 5.66-8.82 nm. The wound dressing platform showed excellent thermal stability and hydrophobicity, fulfilling the criteria of a standard waterproof dressing material, and anticipating the prevention of bacterial biofilm formation in chronic wounds. The scaffold was found to be effective against both Staphylococcus aureus (MTCC 87) and Pseudomonas aeruginosa (MTCC 1688) multiple-drug-resistant pathogens. Electron microscopy revealed the bacterial cell damage, suggesting its bactericidal property. The results further revealed that the scaffold was both hemocompatible and cytocompatible, suggesting its potential application in chronic wounds such as burns. As an outcome, this study presents a straightforward, cost-effective, and sustainable way of developing a multifunctional wound dressing platform, suggesting its significant therapeutic potential in clinical and biomedical sectors and facile commercialization.

Farnesol Emulsion as an Effective Broad-Spectrum Agent against ESKAPE Biofilms

The family of ESKAPE pathogens is comprised of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter. Together they are the main contributors of nosocomial infections and are well established for their ability to "escape" antibiotics. Farnesol is an FDA-approved cosmetic and flavoring agent with significant anti-biofilm properties. In a proprietary emulsion, farnesol has been shown to be capable of disrupting S. aureus, P. aeruginosa, and A. baumannii biofilms. The current work demonstrates that this farnesol emulsion reduces the number of viable bacteria, while also leading to reductions in biomass, of the other three ESKAPE pathogens: Enterococcus faecium, Klebsiella pneumoniae, and Enterobacter, both in vitro and in an ex vivo human skin model. A concentration of 0.5 mg/mL was effective for impeding biofilm development of all three bacteria, while 1 mg/mL for E. faecium and K. pneumoniae, or 0.2 mg/mL for E. cloacae, was able to kill bacteria in established biofilms. Contrary to antibiotics, no resistance to farnesol was observed for E. faecium or K. pneumoniae. The results indicate that farnesol is effective for direct cell killing and also has the ability to induce biofilm detachment from surfaces, as confirmed using Live/Dead image analysis. Our findings confirm that farnesol emulsion is an effective broad-spectrum agent to impede ESKAPE biofilms.

Multidrug-Resistant Organisms: The Silent Plight of Burn Patients

The global increasing spread of multidrug-resistant organisms (MDROs) is threatening the control of various infections in vulnerable populations and patient groups. One of the most affected groups is patients with burns, who are prone to hyperinfection as they suffer from a hypermetabolic state and weaken immune barriers. Those patients also share the infection risk of patients hospitalized for a long time, including ventilator-associated pneumonia and urinary tract infections. While some preventative and therapeutic management styles are still controversial, we discuss consensuses here. In this review, we aim to present the current knowledge on multidrug resistance with a special focus on patients with burns, discuss various causative organisms and their treatment options, and highlight the importance of antibiotic stewardship and teamwork in responding to an outbreak of MDROs.

Nanozybiotics: Advancing Antimicrobial Strategies Through Biomimetic Mechanisms

Infectious diseases caused by bacterial, viral, and fungal pathogens present significant global health challenges. The rapid emergence of antimicrobial resistance exacerbates this issue, leading to a scenario where effective antibiotics are increasingly scarce. Traditional antibiotic development strategies are proving inadequate against the swift evolution of microbial resistance. Therefore, there is an urgent need to develop novel antimicrobial strategies with mechanisms distinct from those of existing antibiotics. Nanozybiotics, which are nanozyme-based antimicrobials, mimic the catalytic action of lysosomal enzymes in innate immune cells to kill infectious pathogens. This review reinforces the concept of nanozymes and provides a comprehensive summary of recent research advancements on potential antimicrobial candidates. Initially, nanozybiotics are categorized based on their activities, mimicking either oxidoreductase-like or hydrolase-like functions, thereby highlighting their superior mechanisms in combating antimicrobial resistance. The review then discusses the progress of nanozybiotics in treating bacterial, viral, and fungal infections, confirming their potential as novel antimicrobial candidates. The translational potential of nanozybiotic-based products, including hydrogels, nanorobots, sprays, bandages, masks, and protective clothing, is also considered. Finally, the current challenges and future prospects of nanozybiotic-related products are explored, emphasizing the design and antimicrobial capabilities of nanozybiotics for future applications.

Effect of glycemic variability on infectious outcomes in critically Ill burn patients

After acute burn injury, patients experience a hypermetabolic state often complicated by a stress-induced hyperglycemia. Recent research points towards glycemic variability as a contributing factor in adverse outcomes in critically ill patients. In burn patients, greater glycemic variability has been associated with increased rates of mortality and sepsis. However, no studies to date have examined the impact of glycemic variability on rates of infection in this population or determined which measure may be most useful. Infection, and subsequent sepsis, remains the leading contributor to morbidity and mortality after burn injury. The primary objective of this study is to evaluate the relationship between different measures of glycemic variability and infectious complications in burn patients. This retrospective study included patients admitted to a single American Burn Association-verified burn center between January 1, 2020 and December 31, 2020 with burn or inhalation injury. The primary outcome was a composite of autograft loss, mortality, and proven infection. Secondary outcomes included hospital length of stay and a further analysis of the proven infection component of the composite primary outcome. In addition to mean glucose, several different measures of glycemic variability were used for comparison, including standard deviation, coefficient of variation, mean amplitude of glycemic excursions, and J-index. Outcomes were analyzed using multiple logistic regression analysis while controlling for revised Baux score. A quantile analysis was performed to do determine the optimal mean threshold. Three hundred and ninety-two patients were admitted and screened for inclusion during the study period. Most patients were excluded due to a LOS less than 72 h. 112 patients were included in the study. Of the 112 patients, 22.3% experienced an infectious complication (25 patients with 28 complications). Mean glucose (OR 1.024; 95% CI 1.004-1.045) and J-index (OR 1.044; 95% CI 1.003-1.087) were associated with occurrence of infectious complications. Regarding target mean glucose threshold, a daily mean glucose above 150 mg/dL showed the strongest association with infectious complications (OR 3.634; 95% CI 1.008-13.101). Mean glucose, standard of deviation, and J-index were all independently associated with proven infection.

Phage Therapy in a Burn Patient Colonized with Extensively Drug-Resistant Pseudomonas aeruginosa Responsible for Relapsing Ventilator-Associated Pneumonia and Bacteriemia

Pseudomonas aeruginosa is one of the main causes of healthcare-associated infection in Europe that increases patient morbidity and mortality. Multi-resistant pathogens are a major public health issue in burn centers. Mortality increases when the initial antibiotic treatment is inappropriate, especially if the patient is infected with P. aeruginosa strains that are resistant to many antibiotics. Phage therapy is an emerging option to treat severe P. aeruginosa infections. It involves using natural viruses called bacteriophages, which have the ability to infect, replicate, and, theoretically, destroy the P. aeruginosa population in an infected patient. We report here the case of a severely burned patient who experienced relapsing ventilator-associated pneumonia associated with skin graft infection and bacteremia due to extensively drug-resistant P. aeruginosa. The patient was successfully treated with personalized nebulized and intravenous phage therapy in combination with immunostimulation (interferon-γ) and last-resort antimicrobial therapy (imipenem-relebactam).

Distribution of Nosocomial Pathogens and Antimicrobial Resistance among Patients with Burn Injuries in China: A Comprehensive Research Synopsis and Meta-Analysis

INTRODUCTION

Over the past decade, numerous studies have described the types of pathogens and their antibiotic resistance patterns in patients with burn injuries in China; however, the findings have generally been inconsistent. We conducted a literature search and meta-analysis to summarize the infection spectra and antimicrobial resistance patterns in patients with burn injuries.

METHODS

We searched the PubMed, Embase, Web of Science, China National Knowledge Infrastructure, China Biomedical Literature, Wanfang, and Weipu databases for relevant articles published between January 2010 and December 2023. The DerSimonian-Laird random-effects model was used to estimate the proportions and 95% confidence intervals (CIs) of pathogens among Chinese patients with burn injuries. Meta-regression analyses were performed to explore differences in the proportions of pathogens among different subgroups and their resistance patterns. This study was registered with PROSPERO (CRD42024514386).

RESULTS

The database searches yielded 2017 records; after removing duplicates and conducting initial screening, 219 articles underwent full-text screening. Ultimately, 60 studies comprising a total of 62,819 isolated strains reported the proportions of pathogens in patients with burn injuries and were included in this meta-analysis. Meta-analyses were conducted on 18 types of pathogens. The most common pathogens causing infections in Chinese patients with burn injuries were Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Staphylococcus epidermidis. Similar results were observed in the subgroup analysis focusing on wound infections. Since 2015, there has been a significant decrease in the proportion of Pseudomonas aeruginosa (R2 = 4.89%) and a significant increase in the proportion of Klebsiella pneumoniae (R2 = 9.60%). In terms of antibiotic resistance, there has been a significant decrease in the resistance of Staphylococcus aureus to multiple antibiotics and an increasing trend in the resistance of Klebsiella pneumoniae.

CONCLUSIONS

We systematically summarized the epidemiological characteristics and antibiotic resistance patterns of pathogens among individuals suffering from burns in China, thus providing guidance for controlling wound infections and promoting optimal empirical antimicrobial therapy. The observed high levels of antibiotic resistance underscore the need for ongoing monitoring of antibiotic usage trends.

Evaluation of White Blood Cell Count, Lymphocyte Percentage, Neutrophil Percentage, and Elevated Temperature as Predictors of Wound Infection in Burn Patients

INTRODUCTION

Infection remains a chief cause of morbidity and mortality among burn patients. The burn wound surface is initially sterile after a thermal injury but eventually gets colonized by microorganisms. A burn wound is considered infected upon the presence of high concentrations of microorganisms in the wound and scab. Burn wound infections can lead to a delay in epidermal maturation, higher scar formation, and sepsis. However, burn patients are commonly misclassified as septic due to the manifestation of systemic inflammatory response syndrome (SIRS) after their injury, despite the presence or absence of an infection.

METHODS

This is a retrospective review of medical records of patients admitted to the burn unit in Salmaniya Medical Complex in Manama, Bahrain, between the years 2018 and 2020. Demographic data, total body surface area (TBSA), initial temperature, white blood cell count, lymphocyte percentage, neutrophil percentage, and wound cultures were obtained for all subjects. Logistic regression analysis was performed to compare the presence or absence of wound infection by the aforementioned parameters.

RESULTS

Of 412 cases, 68.2% were male patients, with a mean age for the studied population of 25.1 years (standard deviation (SD)=20.7). Staphylococcus aureus was the most prevalent organism across all of the study population (n=31)(34.4%). Staphylococcus aureus was the most prevalent organism in patients under the age of five, while Pseudomonas aeruginosa was the most common organism among adults older than 65 years of age. TBSA was not found to be a good predictor of wound infection. There was no statistically significant relation between initial temperature and wound culture (p-value=0.056). However, logistic regression revealed that the initial temperature increases the likelihood of positive wound culture by almost three times.

CONCLUSION

White blood cell count, lymphocyte percentage, and neutrophil percentage were not clinically reliable in predicting burn wound infection. However, initial temperature might be a helpful predictor. Further research is needed to identify reliable clinical parameters of burn wound infections.

Multi-resistant organisms in burn patients: an end or a new beginning

Infections are a major cause of morbidity and mortality in burn patients, and the rise of multidrug-resistant organisms (MDROs) has made it more challenging to manage and prevent infections. This review examines the available treatment options for MDROs in burn patients and anticipates the future challenges posed by their increasing prevalence. The review covers new antibiotics, such as Eravacycline and Plazomicin, as well as non-antibiotic therapies, such as bacteriophages and nanoparticles. Future research should focus on examining the long-term efficacy, cost-effectiveness, and in vivo efficacy of different treatment modalities. The potential of alternative therapies, such as probiotics and low-frequency magnetic fields, should also be explored. Accurate and rapid diagnostic and monitoring tools for detecting MDROs in burn patients should be developed. The emergence of MDROs in burn care is a challenge and a new beginning in infection innovation and novel treatments.

Damage-induced basal epithelial cell migration modulates the spatial organization of redox signaling and sensory neuron regeneration

Epithelial damage leads to early reactive oxygen species (ROS) signaling, which regulates sensory neuron regeneration and tissue repair. How the initial type of tissue injury influences early damage signaling and regenerative growth of sensory axons remains unclear. Previously we reported that thermal injury triggers distinct early tissue responses in larval zebrafish. Here, we found that thermal but not mechanical injury impairs sensory axon regeneration and function. Real-time imaging revealed an immediate tissue response to thermal injury characterized by the rapid Arp2/3-dependent migration of keratinocytes, which was associated with tissue-scale ROS production and sustained sensory axon damage. Isotonic treatment was sufficient to limit keratinocyte movement, spatially restrict ROS production and rescue sensory neuron function. These results suggest that early keratinocyte dynamics regulate the spatial and temporal pattern of long-term signaling in the wound microenvironment during tissue repair.

Microbial infections in burn patients

Polymicrobial infections are the leading causes of complications incurred from injuries that burn patients develop. Such patients admitted to the hospital have a high risk of developing hospital-acquired infections, with longer patient stays leading to increased chances of acquiring such drug-resistant infections. Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis are the most common multidrug-resistant (MDR) Gram-negative bacteria identified in burn wound infections (BWIs). BWIs caused by viruses, like Herpes Simplex and Varicella Zoster, and fungi-like Candida spp. appear to occur occasionally. However, the preponderance of infection by opportunistic pathogens is very high in burn patients. Variations in the causative agents of BWIs are due to differences in geographic location and infection control measures. Overall, burn injuries are characterized by elevated serum cytokine levels, systemic immune response, and immunosuppression. Hence, early detection and treatment can accelerate the wound-healing process and reduce the risk of further infections at the site of injury. A multidisciplinary collaboration between burn surgeons and infectious disease specialists is also needed to properly monitor antibiotic resistance in BWI pathogens, help check the super-spread of MDR pathogens, and improve treatment outcomes as a result.

Epidemiology and early bacterial colonization of minor and moderate pediatric burns: A retrospective study from a developing country

OBJECTIVES

Infection is still the leading cause of morbidity and mortality among burn patients worldwide. Isolation and identification of pediatric burn wound bacterial colonizers can prevent infection and improve burn trauma treatment. In this study, we explored early microbial colonizers within the burn wounds and the susceptibility of those isolates to antibiotics among hospitalized pediatric patients with minor and moderate burns, clinically significant infections and outcomes.

METHODS

A retrospective analysis of pediatric patients admitted to the inpatient pediatric surgical ward and treated for minor and moderate burns from 2009 to 2018 was performed.

RESULTS

One hundred six patients met the inclusion criteria. The mean age was 3.6 ± three years (0.2-14.1 years). The most common type of burn was scald burns (82.1%). The mean TBSA of the hospitalized pediatric burn cases was 8.5% (IQR, 6-12%). Seventy-nine (74.5%) patients had positive wound cultures at admission, regardless of the hospital admission day. Fifty-eight (73.4%) had one bacterial growth (mono isolate), while 21 (26.6%) had mixed growth or poly isolates. Among patients with mixed growth or poly isolate, 16 had two bacteria, three had three bacteria, and one had four bacteria isolated, totaling 105 isolated microorganisms (14 different species, 70.5% Gram-positive bacteria and 29.5% Gram-negative bacteria). Twelve patients (11%) developed clinically significant infections (eleven got burn wound infection, and one had septicemia). All patients received prophylactic systemic antibiotics. Only 35.2% of the isolated bacteria from the wounds were sensitive to the prophylactic antibiotics, and only ∼17% in case of clinically significant infections. We found a statistically significant difference in the length of hospital stay between patients with initially colonized samples of burn wounds compared with patients with initial negative samples (p = 0.008). All patients in the cohort survived hospital discharge.

CONCLUSION

Despite common bacterial colonization of acute burn wounds, only ∼10% of the patients developed clinically significant infections, a minority of which were sensitive to prophylactic antibiotics. Our findings indicate the need to refine the antibiotic approach in pediatric patients with minor/moderate burns in our local setting.

The incidence of surgical site infections in China

Surgical site infections (SSIs) are a common type of healthcare-associated infection. We performed a literature review to demonstrate the incidence of SSIs in mainland China based on studies since 2010. We included 231 eligible studies with ≥30 postoperative patients, comprising 14 providing overall SSI data regardless of surgical sites and 217 reporting SSIs for a specific site. We found that the overall SSI incidence was 2.91% (median; interquartile range: 1.05%, 4.57%) or 3.18% (pooled; 95% confidence interval: 1.85%, 4.51%) and the SSI incidence varied remarkably according to the surgical site between the lowest (median, 1.00%; pooled, 1.69%) in thyroid surgeries and the highest (median, 14.89%; pooled, 12.54%) in colorectal procedures. We uncovered that Enterobacterales and staphylococci were the most common types of micro-organisms associated with SSIs after various abdominal surgeries and cardiac or neurological procedures, respectively. We identified two, nine, and five studies addressing the impact of SSIs on mortality, the length of stay (LOS) in hospital, and additional healthcare-related economic burden, respectively, all of which demonstrated increased mortality, prolonged LOS, and elevated medical costs associated with SSIs among affected patients. Our findings illustrate that SSIs remain a relatively common, serious threat to patient safety in China, requiring more action. To tackle SSIs, we propose to establish a nationwide network for SSI surveillance using unified criteria with the aid of informatic techniques and to tailor and implement countermeasures based on local data and observation. We highlight that the impact of SSIs in China warrants further study.

Multidrug-Resistant Pathogens in Wound Infections: A Systematic Review

This systematic review aimed to explore the antimicrobial activity of a silver-containing gelling fiber dressing against multidrug-resistant organisms (MDROs) in wound infections. It particularly focuses on burn wounds and evaluates its potential clinical significance in combating antimicrobial resistance. A comprehensive literature search was conducted across multiple databases over the past ten years. It is used to identify relevant studies addressing MDRO infections in wound care and exploring novel antimicrobial approaches. The included studies underwent rigorous methodological assessment. Additionally, the data were synthesized to evaluate the efficacy of silver-containing dressings in inhibiting MDRO growth and eradicating biofilm-associated bacteria. Moreover, this review revealed that silver-containing dressings have constant in vitro antimicrobial activity against 10 MDROs over seven days in simulated wound fluid. However, inhibitory and bactericidal effects were consistently observed against free-living and biofilm phenotypes. The findings suggest potential clinical significance in managing MDRO infections in wounds. This highlights its role in mitigating treatment failure and antimicrobial resistance. Despite the promising implications for wound management practices, this study acknowledges some limitations. In vitro models and the absence of direct clinical validation have also been included. However, the review explains the importance of new approaches. Nanotechnology has been used to address antimicrobial resistance in wound care. Thus, further research and innovation are needed to improve patient outcomes and combat antimicrobial resistance.

Prevention and Management of Wound Infections in Burn Patients

The leading cause of morbidity in burn patients is infection with pneumonia, urinary tract infection, cellulitis, and wound infection being the most common cause. High mortality is due to the immunocompromised status of patients and abundance of multidrug-resistant organisms in burn units. Despite the criteria set forth by American Association of Burn, the diagnosis and treatment of burn infections are not always straightforward. Topical antimicrobials, isolation, hygiene, and personal protective equipment are common preventive measures. Additionally medical and nutritional optimization of the patients is crucial to reverse the immunocompromised status triggered by burn injury.

Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing

This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168 h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds.

Fusariosis in burn patients: A systematic review of case reports

Burns can cause skin damage, facilitating the entry of fungi and other microorganisms into the body, leading to infections. Fusarium is a fungus capable of infecting individuals with burn injuries. Diagnosing and treating Fusarium infections in burn patients can be challenging due to the manifestation of nonspecific symptoms. This study aims to investigate case reports and case series from published literature describing Fusarium infection in burned patients, in order to assess treatment regimens, clinical outcomes, and make recommendations for future management. We conducted searches on Web of Science, PubMed, ScienceDirect, and Medline for all case reports and case series containing keywords 'Burn', 'Burns', 'Burned', 'Fusarium', or 'Fusariosis' in the title or abstract. All burn patients who developed Fusarium fungal infections between January 1974 and March 2023 were included in the study. Demographic and clinical data were analyzed retrospectivity. The final analysis incorporates 24 case reports encompassing a total of 87 burn patients with Fusarium infection. Patient ages ranged from one to 85 years, with the majority being male (53%). The median percentage of burn surface area was 78%, and the skin in the face, upper limbs, and lower limbs were the most commonly infected sites. Fungal infections appeared around 10 days after the burn injury on average. The majority of the patients were identified through culture or histopathology. The Fusarium dimerum species complex, which was found in nine patients, was the most frequently identified Fusarium species complex. Amphotericin B was the most preferred treatment drug, followed by voriconazole, and 62% of patients underwent debridement. In our study, 23 patients (37%) died from fungal infections. Implementing early and effective treatment protocols targeting Fusarium spp. in burn treatment units can significantly reduce mortality rates. It is critical to enhance the understanding of fusariosis epidemiology and emphasize the importance of maintaining a high clinical suspicion for this condition in burn patients.

Associations Among Wound-Related Factors Including Biofilm, Wound-Related Symptoms and Systemic Inflammation in Older Adults with Chronic Venous Leg Ulcers

Objective: The purposes of this observational prospective study were to (1) characterize the wound-related factors (wound area, the presence of biofilm, and total bacteria), wound-related symptoms (fatigue, pain, exudate, itching, and edema or swelling), and systemic inflammation (level of serum C-reactive protein [CRP]), and (2) explore associations between wound-related factors, wound-related symptoms, and systemic inflammation in older individuals with chronic venous leg ulcers (CVLUs) over 8 weeks of wound treatment. Approach: A total of 117 participants who received standardized care (weekly sharp debridement) for chronic venous ulcer were enrolled. We collected clinical data every 2 weeks during the 8 weeks of the study period or until the wound was healed (if healed before 8 weeks). Associations among variables were estimated using a Bayesian approach applied to general linear mixed models. Results: Based on Bayes factor (BF) value, there was extremely strong evidence for the association of biofilm with mean total bacteria (BF >1,000). There was moderate evidence of a direct association between biofilm presence and levels of CRP (BF 4.3) and moderate evidence of direct associations between biofilm and wound-related symptoms, pain and exudate (BF 5.12, 8.49, respectively). Innovation: Wound-related symptoms and the level of systemic CRP were associated with biofilm among patients who were receiving weekly sharp debridement. Symptom severity associated with CVLUs requires assessment and management of wound-related factors and levels of inflammation in addition to symptom assessment. Conclusion: This study is the first to examine associations among biofilm, as wound-related factors, systemic inflammation, wound-related symptoms, and wound healing in clinical settings. Symptom severity, level of systemic CRP, and wound-related factors should be considered as well as assessment of biofilm in CVLU in older individuals with CVLU.

Patterns of antibiotic administration in patients with burn injuries: A TriNetX study

BACKGROUND

In the advent of increasing antibiotic resistance, several studies sought to determine antibiotic prescription trends; however, no pattern has been firmly identified particularly for the burned population. We performed a query of burned patients in a large established database to understand differences in antibiotic use related to patient-specific factors.

METHODS

Burned patients with systemic antibiotics given within 7 days of injury were identified on the TriNetX database. The patient population was stratified by age, 1-year time intervals of antibiotic prescription from 2004 to 2019, time of antibiotic prescription in 1-day intervals after injury, and % TBSA burned in 10% intervals ranging from < 10% to > 90%. Data were analyzed using χ2 with p < 0.05 considered significant. Pearson coefficients (r2) values were used to correlate differences in antibiotic prescription between age groups and to changes over time.

RESULTS

Stratification by age revealed higher use of antibiotics in older burned patients compared to younger patients. Surprisingly, 87.6% of burn patients of those who received antibiotic therapy was on the day of injury. Penicillins and beta-lactam antimicrobials were used most often at a frequency of 64%. No statistically significant differences in rates of antibiotic therapy were observed in burned patients when stratified by %TBSA burned.

CONCLUSIONS

The study elucidates current patterns of antibiotic use in burn care in the United States, allowing for improved understanding of both past and present patterns of antibiotic prescription.

Efficacy of a Mexican folk remedy containing cuachalalate (Amphipterygium adstringens (Schltdl.) Schiede ex Standl) for the treatment of burn wounds infected with Pseudomonas aeruginosa

ETHNOPHARMACOLOGICAL RELEVANCE

Cuachalalate (Amphipterygium adstringens) stem bark has been used to heal wounds and counteract microbial infections since pre-Hispanic times. However, its effect in treating infected burns remains unclear.

STUDY OBJECTIVES

To determine the antipathogenic capacity of a folk remedy (FR) containing cuachalalate stem bark to treat lesions caused by thermal damage and bacterial infection.

MATERIALS AND METHODS

The antipathogenic capacity of the hexanic extract (HE) and FR was evaluated in a burned mouse model infected with Pseudomonas aeruginosa. Second to third-degree burns were induced with 95 °C water in CD1 mice in similar ratios of males to females. The mice were randomly grouped into non-inoculated (Group 1) and P. aeruginosa inoculated. The latter were divided into untreated infection (Group 2) and infection topically treated with HE (Group 3), silver sulfadiazine (Group 4), and tween 80 (Group 5). In the case of FR, the lesions were washed with an aqueous extract (AE) and applied powdered stem bark (Group 6). Animal survival, establishment of the bacteria in the lesions, and systemic dispersion were determined. In addition, histopathological analysis was performed. The chemical composition of the AE was analyzed through molecular networking analysis, and the antivirulence capacity was determined through the inhibition of pyocyanin production and caseinolytic activity.

RESULTS

Only the FR showed antipathogenic activity and increased animal survival by 50% by reducing the systemic dispersion of P. aeruginosa. In addition, it stimulated the formation of granulation tissue and the generation of new blood vessels. The AE did not show bactericidal activity but reduced bacterial virulence, and glycosylated flavonoids and catechins were identified as its main constituents.

CONCLUSIONS

The results of this study contribute to validating the effectiveness of a popular remedy containing cuachalalate stem bark for treating burns infected with P. aeruginosa.

Whole-transcriptome analysis reveals mechanisms underlying antibacterial activity and biofilm inhibition by a malic acid combination (MAC) in Pseudomonas aeruginosa

Background

Pseudomonas aeruginosa is a highly prevalent bacterial species known for its ability to cause various infections and its remarkable adaptability and biofilm-forming capabilities. In earlier work, we conducted research involving the screening of 33 metabolites obtained from a commercial source against two prevalent bacterial strains, Escherichia coli and Staphylococcus aureus. Through screening assays, we discovered a novel malic acid combination (MAC) consisting of malic acid, citric acid, glycine, and hippuric acid, which displayed significant inhibitory effects. However, the precise underlying mechanism and the potential impact of the MAC on bacterial biofilm formation remain unknown and warrant further investigation.

Methods

To determine the antibacterial effectiveness of the MAC against Pseudomonas aeruginosa, we conducted minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques were employed to observe bacterial morphology and biofilm formation. We further performed a biofilm inhibition assay to assess the effect of the MAC on biofilm formation. Whole-transcriptome sequencing and bioinformatics analysis were employed to elucidate the antibacterial mechanism of the MAC. Additionally, the expression levels of differentially expressed genes were validated using the real-time PCR approach.

Results

Our findings demonstrated the antibacterial activity of the MAC against P. aeruginosa. SEM analysis revealed that the MAC can induce morphological changes in bacterial cells. The biofilm assay showed that the MAC could reduce biofilm formation. Whole-transcriptome analysis revealed 1093 differentially expressed genes consisting of 659 upregulated genes and 434 downregulated genes, in response to the MAC treatment. Mechanistically, the MAC inhibited P. aeruginosa growth by targeting metabolic processes, secretion system, signal transduction, and cell membrane functions, thereby potentially compromising the survival of this human pathogen. This study provides valuable insights into the antibacterial and antibiofilm activities of the MAC, a synergistic and cost-effective malic acid combination, which holds promise as a potential therapeutic drug cocktail for treating human infectious diseases in the future.

Evaluation of silver sulfadiazine 1%-cerium nitrate 2.2% cream efficacy and safety in moderate to severe burn patients: a single-blind randomized clinical trial

BACKGROUND

Burn injury is a major global health crisis. Topical antimicrobials such as silver sulfadiazine (SSD) are commonly used for superficial burn wounds. SSD has a broad-spectrum antimicrobial activity and also anti-inflammatory property, but also suffers from some limitations. Therefore, some studies suggest to add cerium nitrate (CN) to SSD, as an immunomodulatory and tanning agent with antitoxic properties, but its effect on patients' mortality, length of hospital stay, and bacterial colonization is contraversial.

OBJECTIVES

In this research, we evaluated the efficacy and safety of SSD 1%+CN 2.2% cream in patients with moderate to severe burn.

MATERIAL AND METHODS

Twenty-two patients who fulfilled the inclusion criteria randomly were assigned to the intervention (n=7) or control (n=15) group and received SSD 1%+CN 2.2% or SSD cream 1% respectively, once daily until the complete re-epithelization or prepration of the burned skin for grafting. Intesity of pain, re-epithelialization time, required interventions, laboratory and clinical findings and final outcome were recorded.

RESULTS

There was no significant difference in re-epithelialization time between the treatment and control groups (P>0.05). The same findings were reported about the required interventions and laboratory and clinical parameters. However, the final outcome and the pain score on third day were significantly better in the treatment group (P=0.017). On the other hand, all patients in the treatment group needed graft surgery.

CONCLUSION

Use of SSD 1%+CN 2.2% cream did not significantly improve re-epithelization time or infection occurrence and patients' pain, but also increased graft surgery rate in comparison with SDD 1% cream in moderate to severe burns.

Cerium Nitrate Stiffens In Vitro Skin Models and Reduces Pseudomonas aeruginosa Pathogenicity and Penetration Through Skin Models

Objective: Cerium nitrate (CeN) plus silver sulfadiazine (SSD) cream has been used for 40-plus years to manage burns. CeN produces a hardened eschar believed to resist bacterial colonization/infection. To evaluate this potential mechanism, we treated in vitro skin models or Pseudomonas aeruginosa with CeN and measured mechanical properties of the models and bacterial virulence, respectively. Approach: We treated three-dimensional-collagen matrix and ex-vivo-burned porcine skin with CeN and evaluated stiffness and P. aeruginosa penetration. In addition, we treated P. aeruginosa with CeN and evaluated the bacteria's motility, skin model penetration, susceptibility to be phagocytized by the human monocytic cell line THP-1, and ability to stimulate this cell line to produce cytokines. Results: CeN treatment of skin models stiffened them and made them resistant to P. aeruginosa penetration. Inversely, CeN treatment of P. aeruginosa reduced their motility, penetration through skin models (ex-vivo-burned porcine skin), and ability to stimulate cytokine production (tumor necrosis factor-α [TNF-α] and interleukin 8 [IL-8]) by THP-1 cells. In addition, CeN-treated Pseudomonas was more readily phagocytized by THP-1 cells. Finally, P. aeruginosa inoculated on CeN-treated ex-vivo-burned porcine skin was more susceptible to killing by a silver dressing. Innovation: In vitro skin models offer a platform for screening drugs that interfere with bacterial penetration into wounded tissue. Conclusion: CeN treatment reduced P. aeruginosa virulence, altered the mechanical properties of ex-vivo-burned porcine skin and collagen matrix, retarded penetration of P. aeruginosa through the skin models, and resulted in increased vulnerability of P. aeruginosa to killing by antimicrobial wound dressings. These data support the use of CeN in burn management.

Bacterial Pyocyanin Inducible Keratin 6A Accelerates Closure of Epithelial Defect under Conditions of Mitochondrial Dysfunction

Repair of epithelial defect is complicated by infection and related metabolites. Pyocyanin (PYO) is one such metabolite that is secreted during Pseudomonas aeruginosa infection. Keratinocyte (KC) migration is required for the closure of skin epithelial defects. This work sought to understand PYO-KC interaction and its significance in tissue repair. Stable Isotope Labeling by Amino acids in Cell culture proteomics identified mitochondrial dysfunction as the top pathway responsive to PYO exposure in human KCs. Consistently, functional studies showed mitochondrial stress, depletion of reducing equivalents, and adenosine triphosphate. Strikingly, despite all stated earlier, PYO markedly accelerated KC migration. Investigation of underlying mechanisms revealed, to our knowledge, a previously unreported function of keratin 6A in KCs. Keratin 6A was PYO inducible and accelerated closure of epithelial defect. Acceleration of closure was associated with poor quality healing, including compromised expression of apical junction proteins. This work recognizes keratin 6A for its role in enhancing KC migration under conditions of threat posed by PYO. Qualitatively deficient junctional proteins under conditions of defensive acceleration of KC migration explain why an infected wound close with deficient skin barrier function as previously reported.

Interkingdom interactions between Pseudomonas aeruginosa and Candida albicans affect clinical outcomes and antimicrobial responses

Infections that involve interkingdom microbial communities, such as those between bacteria and yeast pathogens, are difficult to treat, associated with worse patient outcomes, and may be a source of antimicrobial resistance. In this review, we address co-occurrence and co-infections of Candida albicans and Pseudomonas aeruginosa, two pathogens that occupy multiple infection niches in the human body, especially in immunocompromised patients. The interaction between the pathogen species influences microbe-host interactions, the effectiveness of antimicrobials and even infection outcomes, and may thus require adapted treatment strategies. However, the molecular details of bacteria-fungal interactions both inside and outside the infection sites, are insufficiently characterised. We argue that comprehensively understanding the P. aeruginosa-C. albicans interaction network through integrated systems biology approaches will capture the highly dynamic and complex nature of these polymicrobial infections and lead to a more comprehensive understanding of clinical observations such as reshaped immune defences and low antimicrobial treatment efficacy.

Invasive Non-Candida Fungal Infections in Acute Burns-A 13-Year Review of a Single Institution and Review of the Literature

The past decade has demonstrated increased burn wound infections with atypical invasive fungal organisms. The range of previously regiospecific organisms has expanded, and plant pathogens are increasingly represented. Our institution sought to examine changes in severe fungal non-Candida infections in our patients, via retrospective review of patients admitted to our burn center from 2008 to 2021. We identified 37 patients with atypical invasive fungal infections. Non-Candida genera included Aspergillus (23), Fusarium (8), Mucor (6), and 13 cases of 11 different species, including the second-ever human case of Petriella setifera. Three fungi were resistant to at least one antifungal. Concomitant infections included Candida (19), Staphylococcus and Streptococcus (14), Enterococcus and Enterobacter (13), Pseudomonas (9), and 14 additional genera. Complete data was available for 18 patients, who had a median of 3.0 (IQR 8.5, range 0-15) additional bacteria required a median of 1 (IQR 7, range 0-14) systemic antibacterials and 2 (IQR 2.5, range 0-4) systemic antifungals. One case of total-drug-resistant Pseudomonas aeruginosa required bacteriophage treatment. One case of Treponema pallidum was found in infected burn wound tissue. Every patient required Infectious Disease consultation. Eight patients became bacteremic and one developed Candida fermentatifungemia. There were five patient deaths (13.8%), all due to overwhelming polymicrobial infection. Burn patients with atypical invasive fungal infections can have severe concomitant polymicrobial infections and multidrug resistance with fatal results. Early Infectious Disease consultation and aggressive treatment is critical. Further characterization of these patients may provide better understanding of risk factors and ideal treatmentpatterns.

Nosocomial Infection Among Burn Patients Admitted to a Tertiary Care Hospital of Bangladesh: A Cross-Sectional Study

Nosocomial infection is a major challenge for the appropriate management of burns. The present study aimed to investigate incidence, risk factors, and causative organisms of nosocomial infection in burn patients of Khulna, Bangladesh. This cross-sectional study was conducted among patients admitted to the Burn and Plastic Surgery Department of Khulna Medical College Hospital (KMCH) from January to December 2020. Relevant data were collected from the patients' hospital records. Samples of wound swabs and blood were collected and cultured in the microbiology laboratory of KMCH. Logistic regression models were used to determine risk factors for infective complications in burn patients. All statistical analyses were carried out using SPSS version 26.0. A total of 100 burn patients were included. Mean age was 29.2 years with a male-female ratio of 1.3:1. Flame burns were most prevalent among the patients (41%), followed by scald (23%) and electric burns (15%). Almost 40% patients had full thickness burn. The incidence of nosocomial infection was 42% (wound infection 33% and septicemia 9%). Total body surface area of burn >40% (OR 7.56, 95% CI 2.89-19.81), full thickness burn (OR 34.40, 95% CI 3.25-97.14) and prolonged hospital stay (aOR 1.31, 95% CI 1.15-1.51) were significant risk factors for nosocomial infection. Staphylococcus aureus was the most commonly isolated organism (45%), followed by Streptococcus (24%), Pseudomonas aeruginosa (19%) and Escherichia coli (12%). As the epidemiology of nosocomial infection is not the same in different health facilities, a facility-based comprehensive burn management protocol considering the local epidemiology and causative organisms of burn wound infection is crucial for the prevention and management of nosocomial infections in burn patients.

Tazobactam/ceftolozane and tobramycin combination therapy in extensively drug-resistant Pseudomonas aeruginosa infections in severe burn injury: a case report

BACKGROUND

Combination therapy with tazobactam/ceftolozane (TAZ/CTLZ) and high-dose aminoglycosides has been reported to be efficacious in extensively drug-resistant (XDR)-Pseudomonas aeruginosa infection. However, there are no reports of efficacy in XDR-P. aeruginosa infection for combination therapy with low-dose aminoglycosides and TAZ/CTLZ. Herein, we describe a rare case of severe burn injury patients with persistent bacteremia due to XDR-P. aeruginosa, which was successfully treated with TAZ/CTLZ and low-dose tobramycin (TOB).

CASE PRESENTATION

A 31-year-old man was admitted to the intensive care unit with severe burn injury involving 52% of the total body surface area and a prognostic burn index of 79.5. The patient had recurrent bacterial infections since admission, and blood cultures collected on the 37th day of admission revealed the presence of P. aeruginosa strains that were resistant to all β-lactams and amikacin (AMK). The results of the antimicrobial synergistic study showed no synergistic effect of low-dose meropenem (MEPM) and AMK combination therapy. The patient had acute renal failure, and it was difficult to increase the dose of MEPM and AMK, respectively. Thus, we initiated TAZ/CTLZ 1.5 g/8 h instead of the AMK and MEPM combination therapy on the 43rd day of hospitalization. Low-dose TAZ/CTLZ was continued because of prolonged renal dysfunction and resulted in a transient clinical improvement. However, the dosage of TAZ/CTLZ could be increased as the renal function improved, but despite an increased TAZ/CTLZ dose, bacteremia persisted, and the blood cultures remained positive. Thus, TOB was added to TAZ/CTLZ at low doses for synergistic effect against Gram-negative bacteria. Blood cultures collected after initiation of combination therapy with TAZ/CTLZ and low-dose TOB were negative on two consecutive follow-up evaluations. Thereafter, although the patient had several episodes of fever and increased inflammatory response, blood cultures consistently tested negative, and all of the wounds healed. On the 93rd day, due to the good healing progress, the patient was transferred to another hospital.

CONCLUSIONS

TAZ/CTLZ and low-dose TOB combination therapy showed the potential for synergistic effects. Our present report suggests a novel synergistic treatment strategy for rare cases that are refractory to the treatment of infections, such as XDR-P. aeruginosa infection.

Common Resistance Patterns in the Burn Unit of a Tertiary Care Center: A Retrospective Observational Study

Background Nosocomial bacterial infections have been one of the major concerns in the healthcare system. Burn patients, specifically severe cases, are at a high risk of developing bacterial infections compared to others. The most frequent cultures among burn patients are Staphylococcus aureus, Pseudomonas aeruginosa,and Acinetobacter baumannii. There is a scarcity of local data showing the most common infections in burn patients. This research aimed to determine the most common organisms that cause infections in burn unit patients and the antibiotic sensitivity and resistance patterns in King Abdulaziz Medical City (KAMC) in Jeddah. Methodology In this cross-sectional study, data were collected from patients' files into a data collection sheet. All patients in the burn unit with a positive culture were included in the study using a convenient sampling technique from Best-Care, KAMC electronic medical records. Burn patients with negative culture results and patients who were admitted to the plastic surgery ward for reasons other than burns were excluded. For sample size calculation, convenience sampling of 109 patient medical charts, over the study period from June 2016 to November 2021, was selected for data extraction, analysis, and reporting. Results Pseudomonas aeruginosa was the leading cause of infection in burn patients comprising 33.9% of the cases. Enterobacter cloacae was the second most frequent cause of infection among burn patients (27.5%). Klebsiella pneumoniae was the third most frequent cause of infection (26.6%) while Acinetobacter baumannii was the fourth most frequent cause of infection in burn patients (22.9%). Conclusions Understanding the local epidemiology of bacterial infections will be crucial for the development of treatment guidelines designed to standardize initial antibiotic use, reduce hospital-acquired infections, and reduce drug resistance. More attention should be paid to gram-negative bacteria, specifically Pseudomonas aeruginosa and Enterobacter Cloacae.

Multidrug-Resistant Pathogens in Burn Wound, Prevention, Diagnosis, and Therapeutic Approaches (Conventional Antimicrobials and Nanoparticles)

Multidrug-resistant pathogens are one of the common causes of death in burn patients and have a high risk of nosocomial infections, especially pneumonia, urinary tract infections, and cellulitis. The role of prolonged hospitalization and empirical antibiotics administration in developing multidrug-resistant pathogens is undeniable. In the early days of admitting burn patients, Gram-positive bacteria were the dominant isolates with a more sensitive antibiotic pattern. However, the emergence of Gram-negative bacteria that are more resistant later occurs. Trustworthy guideline administration in burn wards is one of the strategies to prevent multidrug-resistant pathogens. Also, a multidisciplinary therapeutic approach is an effective way to avoid antibiotic resistance that involves infectious disease specialists, pharmacists, and burn surgeons. However, the emerging resistance to conventional antimicrobial approaches (such as systemic antibiotic exposure, traditional wound dressing, and topical antibiotic ointments) among burn patients has challenged the treatment of multidrug-resistant infections, and using nanoparticles is a suitable alternative. In this review article, we will discuss different aspects of multidrug-resistant pathogens in burn wounds, emphasizing the full role of these pathogens in burn wounds and discussing the application of nanotechnology in dealing with them. Also, some advances in various types of nanomaterials, including metallic nanoparticles, liposomes, hydrogels, carbon quantum dots, and solid lipid nanoparticles in burn wound healing, will be explained.

Swine Model of Biofilm Infection and Invisible Wounds

Biofilm infection is a major contributor to wound chronicity. The establishment of clinically relevant experimental wound biofilm infection requires the involvement of the host immune system. Iterative changes in the host and pathogen during the formation of such clinically relevant biofilm can only occur in vivo. The swine wound model is recognized for its advantages as a powerful pre-clinical model. There are several reported approaches for studying wound biofilms. In vitro and ex vivo systems are deficient in terms of the host immune response. Short-term in vivo studies involve acute responses and, thus, do not allow for biofilm maturation, as is known to occur clinically. The first long-term swine wound biofilm study was reported in 2014. The study recognized that biofilm-infected wounds may close as determined by planimetry, but the skin barrier function of the affected site may fail to be restored. Later, this observation was validated clinically. The concept of functional wound closure was thus born. Wounds closed but deficient in skin barrier function may be viewed as invisible wounds. In this work, we seek to report the methodological details necessary to reproduce the long-term swine model of biofilm-infected severe burn injury, which is clinically relevant and has translational value. This protocol provides detailed guidance on establishing an 8 week wound biofilm infection using P. aeruginosa (PA01). Eight full-thickness burn wounds were created symmetrically on the dorsum of domestic white pigs, which were inoculated with (PA01) at day 3 post-burn; subsequently, noninvasive assessments of the wound healing were conducted at different time points using laser speckle imaging (LSI), high-resolution ultrasound (HUSD), and transepidermal water loss (TEWL). The inoculated burn wounds were covered with a four-layer dressing. Biofilms, as established and confirmed structurally by SEM at day 7 post-inoculation, compromised the functional wound closure. Such an adverse outcome is subject to reversal in response to appropriate interventions.

Etiology and Multi-Drug Resistant Profile of Bacterial Infections in Severe Burn Patients, Romania 2018-2022

Infections in severe burns and their etiology are and will remain a big concern for the medical field. The multi-drug resistant strains of bacteria are a challenge of today's medicine. The aim of our study was to identify the etiological spectrum of bacterial infections in severe burn patients in Romania and their multi-drug resistant patterns. We performed a prospective study that included 202 adult patients admitted to the intensive care unit (ICU) of the Clinical Emergency Hospital of Plastic, Reconstructive Surgery and Burns, Bucharest, Romania (CEHPRSB), from 1 October 2018 to 1 April 2022, a period which includes the first 2 years of the outbreak of COVID-19. From each patient, wound swabs, endotracheal aspirates, blood for blood culture, and urine were collected. The most frequently isolated bacterium was Pseudomonas aeruginosa (39%), followed by Staphylococcus aureus (12%), Klebsiella spp. (11%), and Acinetobacter baumannii (9%). More than 90% of Pseudomonas aeruginosa and Acinetobacter baumannii were MDR, regardless of the clinical specimen from which they were isolated.

The Burn Wound

Skin serves as a protective barrier against infection, prevents excessive fluid and electrolyte losses, performs crucial thermoregulation, and provides tactile feedback of surroundings. The skin also plays an essential role in human perception of body image, personal appearance, and self-confidence. With these many diverse functions, understanding normal anatomic composition of skin is pivotal to evaluating the extent of its disruption from burn injury. This article discusses the pathophysiology, initial evaluation, subsequent progression, and healing of burn wounds. By delineating the various microcellular and macrocellular alterations of burn injury, this review also augments providers' capacity to deliver patient-centered, evidence-based burn care.

Use of Female External Urinary Catheters in a Burn Intensive Care Unit: Benefits and Challenges

BACKGROUND

Burn patients have a relatively high rate of indwelling Foley catheter use because of their need for complex fluid management and wound care. However, Foley catheter use is associated with risks, including urinary tract infection. For female patients, an external urinary catheter is an alternative.

OBJECTIVES

To evaluate the use of female external urinary catheters in a burn intensive care unit and to develop a standard protocol.

METHODS

This study involved female patients admitted to a burn intensive care unit from 2017 to 2020. An initiative to increase the use of female external urinary catheters was begun in 2019. A retrospective review of medical records was used to determine rates of indwelling and external catheter use and of catheter-associated urinary tract infection before and after implementation of the initiative.

RESULTS

Of 77 female burn patients admitted to the unit between 2019 and 2020, 56 (73%) required indwelling Foley catheterization, a significant decrease from 94% before the initiative (P = .002). The mean duration of indwelling Foley catheter use decreased significantly from 19.4 days to 10.47 days (P = .049). Female external urinary catheters were used in 21 patients (27%). No patients with female external urinary catheters contracted urinary tract infections, compared with 9 patients with indwelling Foley catheters.

CONCLUSION

The use of female external urinary catheters may help reduce the risk of urinary tract infection in female burn patients. Further research is needed to refine the protocol for use of these devices and determine their safety profile.

Clonal relatedness of carbapenem-resistant Acinetobacter baumannii: high prevalence of ST136pas in a burn center

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a global health crisis. This study aimed to determine the clonal relatedness of antibiotic-resistant A. baumannii isolates in hospitalized patients who suffered from burn wound infection.

METHODS

One hundred and six A. baumannii isolates from 562 patients with burn wound infections, were identified and examined for antimicrobial susceptibility. Detection and characterization of carbapenem-hydrolyzing class D OXA-type beta-lactamases (CHDLs) were performed by PCR assays. The clonal relatedness of A. baumannii isolates was determined by multilocus sequence typing (MLST) according to the Pasteur scheme, dual-sequence typing of bla_OXA-51-like and ampC genes, and RAPD-PCR method.

RESULTS

All isolates were carbapenem-resistant while susceptible to colistin, minocycline, doxycycline, and ampicillin-sulbactam. The intrinsic bla_OXA-51-like was detected in all isolates, and bla_OXA-23-like was identified in 92.5% of isolates. However, bla_OXA-143-like and bla_OXA-58-like genes were not detected among isolates. Four distinct bla_OXA-51-like alleles were determined as follows: bla_OXA-317 (67.0%), bla_OXA-90 (9.4%), bla_OXA-69 (17.0%), and bla_OXA-64 (6.6%) and four ampC (bla_ADC) allele types including ampC-25 (6.6%), ampC-39 (9.4%), ampC-1 (17.0%), and bla_ADC-88 (67.0%) were identified. MLST (Pasteur scheme) analysis revealed four ST types including ST136 (singleton), ST1 (CC1), ST25 (CC25), and ST78 (singleton) in 71, 18, 7, and 10 of A. baumannii strains, respectively. Five RAPD clusters including A (1.9%), B (26.4%), C (57.5%), D (7.5%), and E (1.9%) were characterized and 5 (4.7%) strains were found to be singletons.

CONCLUSION

The present study demonstrated that there was a high prevalence of bla_OXA-23-like producing CRAB in the clinical setting. The majority of isolates belonged to ST136 (singleton). However, bla_OXA-23-like producing multi-drug resistant international clones including ST1, and emerging lineages (e.g. ST25 and ST78) were also identified. Interestingly, in this study ST2 was not detected.

Antimicrobial PVA Hydrogels with Tunable Mechanical Properties and Antimicrobial Release Profiles

Hydrogels are broadly employed in wound healing applications due to their high water content and tissue-mimicking mechanical properties. Healing is hindered by infection in many types of wound, including Crohn's fistulas, tunneling wounds that form between different portions of the digestive system in Crohn's disease patients. Owing to the rise of drug-resistant infections, alternate approaches are required to treat wound infections beyond traditional antibiotics. To address this clinical need, we designed a water-responsive shape memory polymer (SMP) hydrogel, with natural antimicrobials in the form of phenolic acids (PAs), for potential use in wound filling and healing. The shape memory properties could allow for implantation in a low-profile shape, followed by expansion and would filling, while the PAs provide localized delivery of antimicrobials. Here, we developed a urethane-crosslinked poly(vinyl alcohol) hydrogel with cinnamic (CA), p-coumaric (PCA), and caffeic (Ca-A) acid chemically or physically incorporated at varied concentrations. We examined the effects of incorporated PAs on antimicrobial, mechanical, and shape memory properties, and on cell viability. Materials with physically incorporated PAs showed improved antibacterial properties with lower biofilm formation on hydrogel surfaces. Both modulus and elongation at break could be increased simultaneously in hydrogels after both forms of PA incorporation. Cellular response in terms of initial viability and growth over time varied based on PA structure and concentration. Shape memory properties were not negatively affected by PA incorporation. These PA-containing hydrogels with antimicrobial properties could provide a new option for wound filling, infection control, and healing. Furthermore, PA content and structure provide novel tools for tuning material properties independently of network chemistry, which could be harnessed in a range of materials systems and biomedical applications.

Cross-Border Antibiotic Resistance Patterns in Burn Patients

Background: Antimicrobial resistance (AMR) is a growing problem worldwide, with differences in regional resistance patterns partially driven by local variance in antibiotic stewardship. Trauma patients transferring from Mexico have more AMR than those injured in the United States; we hypothesized a similar pattern would be present for burn patients. Patients and Methods: The registry of an American Burn Association (ABA)-verified burn center was queried for all admissions for burn injury January 2015 through December 2019 with hospital length-of-stay (LOS) longer than seven days. Patients were divided into two groups based upon burn location: United States (USA) or Mexico (MEX). All bacterial infections were analyzed. Results: A total of 73 MEX and 826 USA patients were included. Patients had a similar mean age (40.4 years MEX vs. 42.2 USA) and gender distribution (69.6% male vs. 64.4%). The MEX patients had larger median percent total body surface area burned (%TBSA; 11.1% vs. 4.3%; p ≤ 0.001) and longer hospital LOS (18.0 vs. 13.0 days; p = 0.028). The MEX patients more often had respiratory infections (16.4% vs. 7.4%; p = 0.046), whereas rates of other infections were similar. The MEX patients had higher rates of any resistant organism (47.2% of organisms MEX vs. 28.1% USA; p = 0.013), and were more likely to have resistant infections on univariable analysis; however, on multivariable analysis country of burn was no longer significant. Conclusions: Antimicrobial resistance is more common in burn patients initially burned in Mexico than those burned in the United States, but location was not a predictor of resistance compared to other traditional burn-related factors. Continuing to monitor for AMR regardless of country of burn remains critical.

Infections in Burn Patients

Infections are the leading cause of mortality in burn patients who survive their initial resuscitation. Burn injury leads to immunosuppression and a dysregulated inflammatory response which can have a prolonged impact. Early surgical excision along with support of the multidisciplinary burn team has improved mortality in burn patients. The authors review diagnostic and therapeutic challenges as well as strategies for management of burn related infections.

Thermal Injuries Occurring to the Foot: A Review

Thermal injuries are one of the most common injuries in both civilian and combat scenarios. The importance of clinical determination of burn and frostbite injuries and treatment involves understanding the pathophysiology and mechanisms of these injuries while continually reviewing literature and studying new treatment modalities. This present review examines the (1) epidemiology, (2) etiology, (3) pathophysiology and classification, and (4) treatment of thermal injuries occurring to the foot. In addition to the paucity of new literature and studies on thermal injury, this is the first review, to the best of our knowledge, to examine the management of thermal injuries occurring to the foot.

Combined Silver Sulfadiazine Nanosuspension with Thermosensitive Hydrogel: An Effective Antibacterial Treatment for Wound Healing in an Animal Model

Introduction

Silver sulfadiazine (AgSD) is widely used in burn wound treatment due to its broad-spectrum antibacterial activity. However, its application in wound healing is greatly hindered by the low solubility of AgSD particles and their cellular cytotoxicity. Herein, we studied the safety and in vivo efficacy of nano-sized silver sulfadiazine loaded in poloxamer thermosensitive hydrogel (NS/Gel).

Methods

In NS/Gel, silver sulfadiazine was prepared into silver sulfadiazine nanosuspension (NS) to improve the solubility and enhance its antibacterial activity, whereas the poloxamer thermosensitive hydrogel was selected as a drug carrier of NS to achieve slow drug release and reduced cytotoxicity. The acute toxicity of silver sulfadiazine nanosuspension was first evaluated in healthy mice, and its median lethal dose (LD₅₀) was calculated by the modified Karber method. Furthermore, in vivo antibacterial effect and wound healing property of NS/Gel were evaluated on the infected deep second-degree burn wound mice model.

Results

The mortality ratio of mice was concentration-dependent, and the LD₅₀ for silver sulfadiazine nanosuspension was estimated to be 252.1 mg/kg (230.8 to 275.4 mg/kg, 95% confidence limit). The in vivo dosages used for burn wound treatment (40-50 mg/kg) were far below LD₅₀ (252.1 mg/kg). NS/Gel significantly accelerated wound healing in the deep second wound infection mice model, achieving > 85% wound contraction on day 14. Staphylococcus aureus in the wound region was eradicated after 7 days in NS/Gel group, while the bacterial colony count was still measurable in the control group. Histological analysis and cytokines measurement confirmed that the mice treated with NS/Gel exhibited well-organized epithelium and multiple keratinized cell layers compared to control groups with the modulated expression of IL-6, VEGF, and TGF-β.

Conclusion

The combination of silver sulfadiazine nanosuspension and thermo-responsive hydrogel has great potential in clinical burn wound treatment.

A Sustainable Solution to Skin Diseases: Ecofriendly Transdermal Patches

Skin is the largest epithelial surface of the human body, with a surface area of 2 m2 for the average adult human. Being an external organ, it is susceptible to more than 3000 potential skin diseases, including injury, inflammation, microbial and viral infections, and skin cancer. Due to its nature, it offers a large accessible site for administrating several medications against these diseases. The dermal and transdermal delivery of such medications are often ensured by utilizing dermal/transdermal patches or microneedles made of biocompatible and biodegradable materials. These tools provide controlled delivery of drugs to the site of action in a rapid and therapeutically effective manner with enhanced diffusivity and minimal side effects. Regrettably, they are usually fabricated using synthetic materials with possible harmful environmental effects. Manufacturing such tools using green synthesis routes and raw materials is hence essential for both ecological and economic sustainability. In this review, natural materials including chitosan/chitin, alginate, keratin, gelatin, cellulose, hyaluronic acid, pectin, and collagen utilized in designing ecofriendly patches will be explored. Their implementation in wound healing, skin cancer, inflammations, and infections will be discussed, and the significance of these studies will be evaluated with future perspectives.

Beneficial Effect of Wound Dressings Containing Silver and Silver Nanoparticles in Wound Healing-From Experimental Studies to Clinical Practice

Impaired wound healing affects hundreds of million people around the world; therefore, chronic wounds are a major problem not only for the patient, but also for already overloaded healthcare systems. Chronic wounds are always very susceptible to infections. Billions of dollars are spent to discover new antibiotics as quickly as possible; however, bacterial resistance against antibiotics is rising even faster. For this reason, a complete shift of the antibacterial treatment paradigm is necessary. The development of technology has allowed us to rediscover well-known agents presenting antimicrobial properties with a better outcome. In this context, silver nanoparticles are a promising candidate for use in such therapy. Silver has many useful properties that can be used in the treatment of chronic wounds, such as anti-bacterial, anti-inflammatory, and anti-oxidative properties. In the form of nanoparticles, silver agents can work even more effectively and can be more easily incorporated into various dressings. Silver-based dressings are already commercially available; however, innovative combinations are still being discovered and very promising results have been described. In this review article, the authors focused on describing experimental and clinical studies exploring dressings containing either silver or silver nanoparticles, the results of which have been published in recent years.

Pediatric First-Degree Burn Management With Honey and 1% Silver Sulfadiazine (Ag-SD): Comparison and Contrast

Background The cardinal area of managing fire wounds is guided by adequately evaluating the burn-induced lesion's profundity and size. Superficial second-degree burns are often treated through daily reinstating with fresh sterile bandaging with appropriate topical antimicrobials to allow rapid spontaneous epithelialization. Around the world, a wide variety of substances are used to treat these wounds, from honey to synthetic biological dressings. Objective This study intended to determine honey's therapeutic potential compared with 1% silver sulfadiazine (Ag-SD) in arsenal-caused contusion medicament fulfillment. Methods A total of 70 cases were evaluated in this research work after fulfilling the required selection criteria during the study period of January 2014 to December 2014 and January 2017 to December 2017. Purposive selection criteria were adopted in the study to select research patients. The patients in Group-1 (n = 35) relied on honey as medication, while patients in Group-2 (n = 35) relied on 1% Ag-SD. Results In Group-1, exudation (68.4%) and sloughing (82.9%) were substantially reduced by Days 3 and 5 of therapeutic intervention, respectively. However, in Group-2, a reduction of exudation (17.1%) and sloughing (22.9%) occurred after Days 3 and 5 of treatment, respectively. Completion of the epithelialization process was observed among Group-1 and Group-2 cases. It was detected after Days 7 and 10 of treatment at 36.3% and 77% (Group-1) and 27% and 67% (Group-2), respectively. Around 3 ml of 1% honey was required per body surface area per dressing in Group-1. On the other hand, in Group-2, 2 gm Ag-SD was needed per body surface area per dressing. Conclusion Patients treated with honey found better clinical outcomes in managing superficial partial-thickness burns.