Timeline of health care-associated infections and pathogens after burn injuries

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.

Assessing Pediatric Burn Wound Infection Using a Point-of-Care Fluorescence Imaging Device

Wound infection is the most common complication among pediatric burn patients. When not treated promptly, burn wound infection may lead to delayed healing, failure of skin grafts, or death. Standard burn wound assessment includes inspection for visual signs and symptoms of infection (VSSI) and microbial sampling. To aid in the assessment of burn wound infection, the MolecuLight, a point-of-care autofluorescence imaging device, was introduced at our pediatric burn program in 2020. The MolecuLight uses violet light to illuminate the wound bed, causing clinically relevant quantities of 29 different species of bacteria (>104 CFU/g) to fluoresce in real time. The objectives of this study were to evaluate the role of the MolecuLight in the management of pediatric burn wounds and determine if the findings from the MolecuLight corresponded to VSSI and/or microbial sampling. A retrospective review of patients 0-18 years who had burn wounds assessed with the MolecuLight between November 1, 2020 and June 8, 2023 was conducted. Data were extracted from the medical records of 178 eligible patients with 218 wounds imaged with the device. Fluorescence corresponded with VSSI in 81% of wounds and microbial findings in 82% of wounds. MolecuLight fluorescence, in combination with VSSI, improved sensitivity for detecting wound infections by 39% and decreased specificity by 19% compared to visual signs and symptoms in isolation. Incorporation of the MolecuLight in standard burn wound assessments can improve the detection of infections, which may promote improved wound healing outcomes and antimicrobial stewardship.

Bloodstream infections and multidrug resistant bacteria acquisition among burns patients in Australia and New Zealand: A registry-based study

INTRODUCTION

This study interrogates infection related data in the Burns Registry of Australia and New Zealand (BRANZ), to examine associations of multi-drug resistant organisms (MDROs) and blood stream infection (BSI).

METHODS

Data between July 2016 and June 2021 were analysed to determine prevalence, risk factors and outcomes associated with BSIs and MDROs: Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Pseudomonas spp. (CRP), and carbapenem-resistant Enterobacter (CRE). Data completeness and value for quality improvement activity were assessed.

RESULTS

We found a low incidence (3.4%) of the resistant organisms of interest, and no change over the study period. Fequency varied between services and increased with age and size of burn. MRSA was the commonest organism in all age groups. A positive BSI result occurred in 1.6% of patients (12.1% of cultures taken) at a median time of 10.2 days post injury. Free text identification of organisms was inconsistently documented.

CONCLUSIONS

The low rate and patterns of acquisition of MDROs of interest and BSIs is comparable with reports from countries with low incidence of massive burns. Wider adoption of a standardized laboratory reporting framework would help realise the potential of clinical quality registries to provide data which supports evidence based infection prevention initiatives.

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.

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.

High-Intensity Blue Light (450-460 nm) Phototherapy for Pseudomonas aeruginosa-Infected Wounds

Background: Nosocomial wound infection with Pseudomonas aeruginosa (PA) is a serious complication often responsible for the septic mortality of burn patients. Objective: High-intensity antimicrobial blue light (aBL) treatment may represent an alternative therapy for PA infections and will be investigated in this study. Methods: Antibacterial effects of a light-emitting diode array (450-460 nm; 300 mW/cm2; 15/30 min; 270/540 J/cm2) against PA were determined by suspension assay, biofilm assay, and a human skin wound model and compared with 15-min topically applied 3% citric acid (CA) and wound irrigation solution (Prontosan®; PRT). Results: aBL reduced the bacterial number [2.51-3.56 log10 colony-forming unit (CFU)/mL], whereas PRT or CA treatment achieved a 4.64 or 6.60 log10 CFU/mL reduction in suspension assays. aBL reduced biofilm formation by 60-66%. PRT or CA treatment showed reductions by 25% or 13%. Here, aBL reduced bacterial number in biofilms (1.30-1.64 log10 CFU), but to a lower extend than PRT (2.41 log10 CFU) or CA (2.48 log10 CFU). In the wound skin model, aBL (2.21-2.33 log10 CFU) showed a bacterial reduction of the same magnitude as PRT (2.26 log10 CFU) and CA (2.30 log10 CFU). Conclusions: aBL showed a significant antibacterial efficacy against PA and biofilm formation in a short time. However, a clinical application of aBL in wound therapy requires effective active skin cooling and eye protection, which in turn may limit clinical implementation.

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.

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.

Which Are the Best Regimens of Broad-Spectrum Beta-Lactam Antibiotics in Burn Patients? A Systematic Review of Evidence from Pharmacology Studies

BACKGROUND

Burn injury causes profound pathophysiological changes in the pharmacokinetic/pharmacodynamic (PK/PD) properties of antibiotics. Infections are among the principal complications after burn injuries, and broad-spectrum beta-lactams are the cornerstone of treatment. The aim of this study was to review the evidence for the best regimens of these antibiotics in the burn patient population.

METHODS

We performed a systematic review of evidence available on MEDLINE (from its inception to 2023) of pharmacology studies that focused on the use of 13 broad-spectrum beta-lactams in burn patients. We extracted and synthetized data on drug regimens and their ability to attain adequate PK/PD targets.

RESULTS

We selected 35 studies for analysis. Overall, studies showed that both high doses and the continuous infusion (CI) of broad-spectrum beta-lactams were needed to achieve internationally-recognized PK/PD targets, ideally with therapeutic drug monitoring guidance. The most extensive evidence concerned meropenem, but similar conclusions could be drawn about piperacillin-tazobactam, ceftazidime, cefepime, imipenem-clinastatin and aztreonam. Insufficient data were available about new beta-lactam-beta-lactamase inhibitor combinations, ceftaroline, ceftobiprole and cefiderocol.

CONCLUSIONS

Both high doses and CI of broad-spectrum beta-lactams are needed when treating burn patients due to the peculiar changes in the PK/PD of antibiotics in this population. Further studies are needed, particularly about newer antibiotics.

Evolution of Microbial Flora Colonizing Burn Wounds during Hospitalization in Uruguay

(1) Background: Infections are a main cause of morbidity and mortality among burn patients. The spectrum of microorganisms depends on the epidemiological context and treatment practices. We aimed to describe the evolution of microbial flora colonizing burn wounds among patients hospitalized during 15 or more days at the National Burn Center in 2015. (2) Methods: Demographic data, length of stay, total body surface area burn, and status at discharge were collected from electronic records and culture results from the laboratory database. (3) Results: Among 98 included patients, 87 were colonized. The mean length of stay was 39 days overall and 16 days in the ICU. Acinetobacter spp., Enterococcus spp., and Staphylococcus aureus predominated. Fifty-six patients harbored multidrug-resistant bacteria and had a significantly greater TBSA. The mean time to colonization was 6 days overall and 14 days for multidrug-resistant bacteria; it was significantly longer for methicillin-resistant S. aureus than for methicillin-susceptible S. aureus. (4) Conclusions: This is the first report describing the dynamics of microbial colonization of burn wounds in Uruguay. Similarities were found with reports elsewhere, but early colonization with yeasts and the absence of Streptococcus pyogenes were unique. Each burn center needs to monitor its microbial ecology to tailor their antimicrobial strategies effectively.

Risk Factors and Pathogens of Wound Infection in Burn Inpatients from East China

BACKGROUND

Infection is the predominant contributor to morbidity and mortality in burn patients, and burn wound infection (BWI) is the most common reason. The objective of this research was to analyze the incidence, factors and progression of BWI, in terms of events and bacteria.

METHODS

Clinical variables of all qualified patients admitted to burn wards were analyzed retrospectively in 2021 at a tertiary hospital in eastern China through univariate analysis and multivariate logistic regression. The Kaplan-Meier method was also used for plotting survival curves. Isolates and resistance data were evaluated to demonstrate the evolution of targeted antibiotics of strains from BWI.

RESULTS

A total of 580 (median age, 39.5 years (23-56 years); 372/580 (64.14%) male) patients were evaluated, 348 (60.0%) of whom experienced BWI. A variety of factors are associated with BWI. Multivariate logistic regression analysis showed that depth and area of burn and duration from burn to first hospitalization are independent risk factors for BWI. For BWI onset in these patients, 47.24% (274/580) occurred in the first week. The most frequently isolated causative organism was Staphylococcus aureus (15.7%) in patients with BWI. The duration of transition from Gram-positive strains (median 3 days, (2-7 days)) to Gram-negative (median 10 days, (4-17 days)) ones isolated from burn wound shrunk. Hospital length of stay was considered as a protective factor for BWI.

CONCLUSION

The precise assessment of factors affecting BWI in burn patients enhances prompt and suitable management. Swab cultures for surveillance could be utilized to monitor the microbiological status of burn patients.

Enterobacter cloacae infection characteristics and outcomes in battlefield trauma patients

Enterobacter cloacae is a Gram-negative rod with multidrug-resistant potential due to chromosomally-induced AmpC β-lactamase. We evaluated characteristics, antibiotic utilization, and outcomes associated with battlefield-related E. cloacae infections (2009-2014). Single initial and serial E. cloacae isolates (≥24 hours from initial isolate from any site) associated with a clinical infection were examined. Susceptibility profiles of initial isolates in the serial isolation group were contrasted against last isolate recovered. Characteristics of 112 patients with E. cloacae infections (63 [56%] with single initial isolation; 49 [44%] with serial isolation) were compared to 509 patients with bacterial infections not attributed to E. cloacae. E. cloacae patients sustained more blast trauma (78%) compared to non-E. cloacae infections patients (75%; p<0.001); however, injury severity scores were comparable (median of 34.5 and 33, respectively; p = 0.334). Patients with E. cloacae infections had greater shock indices (median 1.07 vs 0.92; p = 0.005) and required more initial blood products (15 vs. 14 units; p = 0.032) compared to patients with non-E. cloacae infections. Although E. cloacae patients had less intensive care unit admissions (80% vs. 90% with non-E. cloacae infection patients; p = 0.007), they did have more operating room visits (5 vs. 4; p = 0.001), longer duration of antibiotic therapy (43.5 vs. 34 days; p<0.001), and lengthier hospitalizations (57 vs. 44 days; p<0.001). Patients with serial E. cloacae had isolation of infecting isolates sooner than patients with single initial E. cloacae (median of 5 vs. 8 days post-injury; p = 0.046); however, outcomes were not significantly different between the groups. Statistically significant resistance to individual antibiotics did not develop between initial and last isolates in the serial isolation group. Despite current combat care and surgical prophylaxis guidelines recommending upfront provision of AmpC-inducing antibiotics, clinical outcomes did not differ nor did significant antibiotic resistance develop in patients who experienced serial isolation of E. cloacae versus single initial isolation.

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.

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.

Speeding up the Production of Clinical-Grade Skin Substitutes Using Off-the-shelf Decellularized Self-Assembled Dermal Matrices

Patients with deep and extensive wounds need urgent skin coverage to re-establish the cutaneous barrier that prevents life-threatening infections and dehydration. However, the current clinically-available skin substitutes intended for permanent coverage are limited in number, and a trade-off between production time and quality must be made. Here, we report the use of decellularized self-assembled dermal matrices to reduce by half the manufacturing process time of clinical-grade skin substitutes. These decellularized matrices can be stored for over 18 months and recellularized with patients' cells in order to generate skin substitutes that show outstanding histological and mechanical properties in vitro. Once grafted in mice, these substitutes persist over weeks with high graft take, few contraction events, and high stem cell content. These next-generation skin substitutes constitute a substantial advancement in the treatment of major burn patients, combining, for the first time, high functionality, rapid manufacturability and easy handling for surgeons and healthcare practitioners. Future clinical trials will be conducted to assess the advantages of these substitutes over existing treatments. STATEMENT OF SIGNIFICANCE: The number of patients in need for organ transplantation is ever-growing and there is a shortage in tissue and organ donors. In this study, we show for the first time that we can preserve decellularized self-assembled tissues and keep them in storage. Then, in only three weeks we can use them to produce bilayered skin substitutes that have properties very close to those of the native human skin. These findings therefore represent a major step forward in the field of tissue engineering and organ transplantation, paving the way toward a universal off-the-shelf biomaterial for tissue reconstruction and surgery that will be beneficial for many clinicians and patients.

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.

Infections complicating extracorporeal membrane oxygenation in patients with traumatic injuries

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) has increasing utility in adult patients with traumatic injuries. There is currently limited data on the pathogens complicating a trauma patient's ECMO course, making empiric antibiotic decisions difficult. This study aims to characterize the types of infection among patients with traumatic injuries on ECMO.

METHODS

A chart review was performed on all trauma patients at Brooke Army Medical Center receiving ECMO between February 2013 and July 2021. Charts were reviewed to identify pathogens by culture site as well as time to infection following cannulation.

RESULTS

Twenty-one trauma patients underwent ECMO during the study period. The majority of patients were men (90%) with a median age of 30 [IQR 27-38], and a median ECMO course of 9.8 days [IQR 3.9-14.1]. Motor vehicle crashes (81%) accounted for the majority of mechanisms of injury. Of the 24 infections, the majority were respiratory (n = 13, 58/1000 ECMO days) followed by skin and soft tissue (n = 6, 26/1000 ECMO days), blood stream (n = 4, 18/1000 ECMO days), and urinary tract (n = 1, 5/1000 ECMO days). Gram-negative bacteria were the most commonly isolated organism from all sites and at all time periods following cannulation. Multi-drug resistant organisms accounted for 35% (n = 9) of infections and were independent of time from cannulation.

DISCUSSION/CONCLUSION

This is the first study to describe infections in trauma patients requiring ECMO support. We observed majority Gram-negative infections regardless of culture site or time after cannulation. Thus, with infection in this population, empiric antibiotics should have broad spectrum coverage of Gram-negative organisms.

Infections in Pediatric Patients With Burn Injury: 6 Years of Experience

BACKGROUND

This study aimed to determine the frequency of bloodstream and wound infections and their possible risk factors in hospitalized children with burn injury.

METHODS

We performed this retrospective descriptive study from 2015 to 2021. The study subjects consisted of all the pediatric patients hospitalized in the burn unit, from whom microorganisms were isolated either from blood or wound culture samples.

RESULTS

We detected a total of 142 microorganisms from 97 blood culture samples and 45 wound culture samples. Among the 115 patients, 44 (38.3%) were females and 71 (61.7%) were males, with a median age of 21 months (interquartile range: 14-39 months). Gram-positive bacteria were the most common causative agents of bloodstream infections in patients with burns (54.6%), followed by Gram-negative bacteria (32.9%) and fungi (12.3%). Gram-negative bacteria were the most common causative agent of wound infections (86.7%). Prolonged hospitalization positively correlated with the extent of the burn surface area (P: 0.031), degree of burn (P: 0.001), use of central venous catheter (P: 0.028), and intensive care unit stay (P: 0.044). Independent risk factors for Gram-negative bacteremia and Gram-negative wound infections were the extent of the burn surface area (P: 0.018), degree of burn (P: 0.024) and intensive care unit stay (P: 0.023). The independent risk factor for fungemia was prolonged hospitalization (P: 0.026).

CONCLUSIONS

To reduce infections, minimizing invasive procedures using a multidisciplinary approach would be beneficial, especially in patients who have a large burn surface area and are expected to have a long hospital stay.

The Effect of Drug Abuse on Clinical Outcomes of Adult Burn Patients Admitted to a Burn Center in the North of Iran

Objective

Burn trauma is a life-threatening incident that may be accompanied by several risk factors that increase morbidity and mortality. Drug abuse is one of the lifestyle dangers on the rise globally and can have an impact on the outcomes of burn injuries. This study aimed to evaluate the effect of drug abuse on the clinical outcomes of adult burn patients who were admitted to a burn center in the North of Iran.

Methods

This retrospective cross-sectional study included adult burn patients who were referred to Velayat Hospital, between March 1, 2021, and March 20, 2022. The hospital information system (HIS) was used to select patients with a history of drug use and then were compared with burn victims who had never used drugs before. In both groups, demographic information, the cause of the burn, the comorbid diseases, total body surface area, length of stay, and outcomes were collected and recorded for both groups.

Results

This study included 114 inpatients, 90 of whom (78.95%) were men. The mean age of the patients was 43±15 years. The mean length of hospitalization in the drug-user group was significantly higher than in the non-drug abuse group (p=0.004). The drug abuse group had significantly higher rates of comorbid diseases (p=0.021), inhalation injury (p<0.001), mortality (p=0.002), and pneumonia (p<0.001). However, there were no statistically significant differences in the Infection and Sir's rates (p=0.583) between the groups.

Conclusion

Drug abuse is a risk factor in adult burn patients, which can affect the length of stay and burn-related morbidities.

Patterns of multidrug resistant organism acquisition in an adult specialist burns service: a retrospective review

Background

Multidrug resistant organisms (MDROs) occur more commonly in burns patients than in other hospital patients and are an increasingly frequent cause of burn-related mortality. We examined the incidence, trends and risk factors for MDRO acquisition in a specialist burns service housed in an open general surgical ward, and general intensive care unit.

Methods

We performed a retrospective study of adult patients admitted with an acute burn injury to our specialist statewide tertiary burns service between July 2014 and October 2020. We linked patient demographics, injury, treatment, and outcome details from our prospective burns service registry to microbiology and antimicrobial prescribing data. The outcome of interest was first MDRO detection, stratified into the following groups of interest: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), two groups of Pseudomonas (carbapenem resistant, and piperacillin-tazobactam or cefepime resistant), carbapenem-resistant Acinetobacter species, Stenotrophomonas maltophilia, carbapenem-resistant Enterobacteriaceae (CRE), and extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE). We used a Cox proportional hazards model to evaluate the association between antibiotic exposure and MDRO acquisition.

Results

There were 2,036 acute admissions, of which 230 (11.3%) had at least one MDRO isolated from clinical specimens, most frequently wound swabs. While acquisition rates of individual MDRO groups varied over the study period, acquisition rate of any MDRO was reasonably stable over time. Carbapenem-resistant Pseudomonas was acquired at the highest rate over the study period (3.5/1000 patient days). The 12.8% (29/226) of MDROs isolated within 48 h were predominantly MRSA and Stenotrophomonas. Median (IQR) time from admission to MDRO detection was 10.9 (5.6–20.5) days, ranging from 9.8 (2.7–24.2) for MRSA to 23.6 (15.7–36.0) for carbapenem-resistant P. aeruginosa. Patients with MDROs were older, had more extensive burns, longer length of stay, and were more likely to have operative burn management. We were unable to detect a relationship between antibiotic exposure and emergence of MDROs.

Conclusions

MDROs are a common and consistent presence in our burns unit. The pattern of acquisition suggests various causes, including introduction from the community and nosocomial spread. More regular surveillance of incidence and targeted interventions may decrease their prevalence, and limit the development of invasive infection.

Predicting Risk of Multidrug-Resistant Enterobacterales Infections Among People With HIV

Background

Medically vulnerable individuals are at increased risk of acquiring multidrug-resistant Enterobacterales (MDR-E) infections. People with HIV (PWH) experience a greater burden of comorbidities and may be more susceptible to MDR-E due to HIV-specific factors.

Methods

We performed an observational study of PWH participating in an HIV clinical cohort and engaged in care at a tertiary care center in the Southeastern United States from 2000 to 2018. We evaluated demographic and clinical predictors of MDR-E by estimating prevalence ratios (PRs) and employing machine learning classification algorithms. In addition, we created a predictive model to estimate risk of MDR-E among PWH using a machine learning approach.

Results

Among 4734 study participants, MDR-E was isolated from 1.6% (95% CI, 1.2%-2.1%). In unadjusted analyses, MDR-E was strongly associated with nadir CD4 cell count ≤200 cells/mm³ (PR, 4.0; 95% CI, 2.3-7.4), history of an AIDS-defining clinical condition (PR, 3.7; 95% CI, 2.3-6.2), and hospital admission in the prior 12 months (PR, 5.0; 95% CI, 3.2-7.9). With all variables included in machine learning algorithms, the most important clinical predictors of MDR-E were hospitalization, history of renal disease, history of an AIDS-defining clinical condition, CD4 cell count nadir ≤200 cells/mm³, and current CD4 cell count 201-500 cells/mm³. Female gender was the most important demographic predictor.

Conclusions

PWH are at risk for MDR-E infection due to HIV-specific factors, in addition to established risk factors. Early HIV diagnosis, linkage to care, and antiretroviral therapy to prevent immunosuppression, comorbidities, and coinfections protect against antimicrobial-resistant bacterial infections.

Multidrug-Resistant Gram-Negative Bacteria in Burn Patients

Patients with burn injuries are at high risk for infectious complications, and infections are the most common cause of death after the first 72 h of hospitalization. Hospital-acquired infections caused by multidrug resistant (MDR) Gram-negative bacteria (GNB) in this population are concerning. Here, we evaluated carriage with MDR GNB in patients in a large tertiary-care burn intensive care unit. Twenty-nine patients in the burn unit were screened for intestinal carriage. Samples were cultured on selective media. Median time from admission to the burn unit to first sample collection was 9 days (IQR 5 - 17 days). In 21 (72%) patients, MDR GNB were recovered; the most common bacterial species isolated was Pseudomonas aeruginosa, which was found in 11/29 (38%) of patients. Two of these patients later developed bloodstream infections with P. aeruginosa. Transmission of KPC-31-producing ST22 Citrobacter freundii was detected. Samples from two patients grew genetically similar C. freundii isolates that were resistant to ceftazidime-avibactam. On analysis of whole-genome sequencing, blaKPC-31 was part of a Tn4401b transposon that was present on two different plasmids in each C. freundii isolate. Plasmid curing experiments showed that removal of both copies of blaKPC-31 was required to restore susceptibility to ceftazidime-avibactam. In summary, MDR GNB colonization is common in burn patients and patient-to-patient transmission of highly resistant GNB occurs. These results emphasize the ongoing need for infection prevention and antimicrobial stewardship efforts in this highly vulnerable population.

Multiplexed Human Gene Expression Analysis Reveals a Central Role of the TLR/mTOR/PPARγ and NFkB Axes in Burn and Inhalation Injury-Induced Changes in Systemic Immunometabolism and Long-Term Patient Outcomes

Burn patients are subject to significant acute immune and metabolic dysfunction. Concomitant inhalation injury increases mortality by 20%. In order to identify specific immune and metabolic signaling pathways in burn (B), inhalation (I), and combined burn-inhalation (BI) injury, unbiased nanoString multiplex technology was used to investigate gene expression within peripheral blood mononuclear cells (PBMCs) from burn patients, with and without inhalation injury. PBMCs were collected from 36 injured patients and 12 healthy, non-burned controls within 72 h of injury. mRNA was isolated and hybridized with probes for 1342 genes related to general immunology and cellular metabolism. From these specific gene patterns, specific cellular perturbations and signaling pathways were inferred using robust bioinformatic tools. In both B and BI injuries, elements of mTOR, PPARγ, TLR, and NF-kB signaling pathways were significantly altered within PBMC after injury compared to PBMC from the healthy control group. Using linear regression modeling, (1) DEPTOR, LAMTOR5, PPARγ, and RPTOR significantly correlated with patient BMI; (2) RPTOR significantly correlated with patient length of stay, and (3) MRC1 significantly correlated with the eventual risk of patient mortality. Identification of mediators of this immunometabolic response that can act as biomarkers and/or therapeutic targets could ultimately aid the management of burn patients.

Preparation of Silver Ion Antimicrobial Dressings and Prevention and Treatment of Central Venous Catheter-Related Infection on Burn Wounds of Critically Burned Patients

To further understand the characteristics of Ag+ antimicrobial dressings and its application value in the prevention and treatment of infections in burn patients, in the study, the Ag+ gel dressings were prepared and their physical and chemical characteristics were analyzed, and relationship between the gel dressing and central venous catheter (CVC)-related infections was further explored. The results showed that silver nitrate was made into nano silver particles, and its structure was clearly visible under microscope, and nano silver was further applied to preparation of Ag+ antibacterial dressings. Fibrocytes were clearly visible in Ag+ gel dressing and arranged uniformly, which indicated that Ag+ gel dressing had good compatibility with biological materials and had no obvious toxicity. Further clinical trials showed that Ag+ gel dressing can effectively reduce CVC-related infections. From 1 to 4 weeks of the experiment, the bacterial infection rate in burn wounds and blood of the treatment group (TG), which applied Ag+ gel dressing, was lower than the control group (P < 0.05). During the treatment, the burn healing rate of the TG was also greatly higher than the control group (P < 0.05). In addition, the burn wound exudate in the TG was greatly less than the control group (P < 0.05). In summary, the Ag+ gel dressing prepared has good biological and physical and chemical properties, which have bright prospects in the prevention and treatment of burn wounds and CVC-related infections. This study provides an experimental basis for clinical application of Ag+ gel dressing.

Resistance in Enterobacterales is higher among people with HIV

BACKGROUND

Multidrug-resistant Enterobacterales (MDR-E) are important pathogens. People with human immunodeficiency virus (HIV) may be at greater risk for MDR-E infection given relatively high antibiotic exposure and burden of comorbidities.

METHODS

Analyses were conducted using data collected on 36,521 patients in a healthcare system in North Carolina, who had at least 1 clinical culture with growth of an Enterobacterales species from 2000-2018; 440 were people with HIV infection (PWH). We used generalized linear models to estimate prevalence ratios and differences contrasting patients with and without HIV for resistance to individual antibiotic classes, as well as MDR-E. We assessed trends in prevalence over time by calculating the 5-year moving average and fitting restricted cubic spline models.

RESULTS

The overall prevalence of MDR-E was higher among PWH (21.5% [95% CI: 18.2%-25.1%]) versus patients without HIV (16.5% [95% CI: 16.2%-16.9%], with an adjusted prevalence ratio of 1.38 (95% CI: 1.14-1.65). PWH had higher rates of antimicrobial resistance than patients without HIV for all antibiotic classes analyzed, including penicillins, penicillin/beta-lactamase inhibitor combinations, and sulfonamides. MDR-E prevalence was 3 to 10 percentage points higher among PWH than patients without HIV throughout the study period based on the 5-year moving average.

CONCLUSION

In a large clinical study population in the southeastern US from 2000-2018, the prevalence of antibacterial resistance among Enterobacterales was consistently higher among PWH than patients without HIV. These data highlight the importance of identifying and mitigating the factors contributing to antimicrobial resistance in PWH, given the potential clinical consequences of these resistant pathogens.

Burn Injury Induces Proinflammatory Plasma Extracellular Vesicles That Associate with Length of Hospital Stay in Women: CRP and SAA1 as Potential Prognostic Indicators

Severe burn injury is a devastating form of trauma that results in persistent immune dysfunction with associated morbidity and mortality. The underlying drivers of this immune dysfunction remain elusive, and there are no prognostic markers to identify at-risk patients. Extracellular vesicles (EVs) are emerging as drivers of immune dysfunction as well as biomarkers. We investigated if EVs after burn injury promote macrophage activation and assessed if EV contents can predict length of hospital stay. EVs isolated early from mice that received a 20% total body surface area (TBSA) burn promoted proinflammatory responses in cultured splenic macrophages. Unbiased LC-MS/MS proteomic analysis of early EVs (<72 h post-injury) from mice and humans showed some similarities including enrichment of acute phase response proteins such as CRP and SAA1. Semi-unbiased assessment of early human burn patient EVs found alterations consistent with increased proinflammatory signaling and loss of inhibition of CRP expression. In a sample of 50 patients with large burn injury, EV SAA1 and CRP were correlated with TBSA injury in both sexes and were correlated with length of hospital stay in women. These findings suggest that EVs are drivers of immune responses after burn injury and their content may predict hospital course.

The Impact of Multidrug-Resistant Organisms Infection on Outcomes in Burn Injury Patients at Sanglah General Hospital, Bali

BACKGROUND: Research related to the impact of multidrug resistant organisms (MDRO) infection on clinical outcomes in burns is still limited. AIM: This study evaluated the effect of MDRO infection on morbidity and mortality of burn patients. METHODS: A single-center retrospective cohort study was conducted on burn patients admitted to the burn unit of Sanglah General Hospital, Bali, between 2018 and 2020. MDRO patients were described as those who had at least one positive MDRO culture. All other patients were included in the non-MDRO group. Measurement and analysis included mortality and five indicators of morbidity: length of stay, duration of antibiotic therapy, sepsis, pneumonia, and acute kidney injury (AKI). RESULTS: Significant associations of MDRO infection were found for duration of antibiotic therapy (0 vs. 7 days), sepsis (odds ratio [OR] 13.90 [95% Confidence interval (CI) 95% 2.88–67.10]), pneumonia (OR 12,67 [95% CI 3.26–49.23]), and mortality (OR 9.75 [95% CI 2.00–47.50]). No significant association was found for the length of stay and the incidence of AKI. Multivariate analysis found that MDRO infection increased risk of sepsis (OR 36.53 [95% CI 2.05–652.45], pneumonia (OR 10.75 [95% CI 1.87–61.86]) and mortality (OR 57.09 [95% CI 1.41–2318.87]). Multivariate analysis of MDRO infection with duration of antibiotic therapy found no independent variables that were significantly related. CONCLUSION: These research findings suggest that MDRO infections are associated with increasing length of antibiotic treatment, sepsis, pneumonia, and mortality in burn patients.

Chitosomes-In-Chitosan Hydrogel for Acute Skin Injuries: Prevention and Infection Control

Burns and other skin injuries are growing concerns as well as challenges in an era of antimicrobial resistance. Novel treatment options to improve the prevention and eradication of infectious skin biofilm-producing pathogens, while enhancing wound healing, are urgently needed for the timely treatment of infection-prone injuries. Treatment of acute skin injuries requires tailoring of formulation to assure both proper skin retention and the appropriate release of incorporated antimicrobials. The challenge remains to formulate antimicrobials with low water solubility, which often requires carriers as the primary vehicle, followed by a secondary skin-friendly vehicle. We focused on widely used chlorhexidine formulated in the chitosan-infused nanocarriers, chitosomes, incorporated into chitosan hydrogel for improved treatment of skin injuries. To prove our hypothesis, lipid nanocarriers and chitosan-comprising nanocarriers (≈250 nm) with membrane-active antimicrobial chlorhexidine were optimized and incorporated into chitosan hydrogel. The biological and antibacterial effects of both vesicles and a vesicles-in-hydrogel system were evaluated. The chitosomes-in-chitosan hydrogel formulation demonstrated promising physical properties and were proven safe. Additionally, the chitosan-based systems, both chitosomes and chitosan hydrogel, showed an improved antimicrobial effect against S. aureus and S. epidermidis compared to the formulations without chitosan. The novel formulation could serve as a foundation for infection prevention and bacterial eradication in acute wounds.

Association Between Alcohol, Substance Use, and Inpatient Burn Outcomes

The use of alcohol and illicit substances has been associated with impaired judgment and health, but the effect on inpatient outcomes after burn injury remains unsettled. Our objective was to evaluate the effect of alcohol and illicit substance use on our inpatient burn outcomes. Adult patients admitted with burn injury-including inhalation injury only-between January 1, 2014 and June 30, 2019 were eligible for inclusion. Alcohol use and illicit drug use were identified on admission. Outcomes of interest included requiring mechanical ventilation, admission to the intensive care unit, length of stay, and inpatient mortality. Multivariable linear and logistic regression models were used to estimate the effects of use on inpatient outcomes. A total of 3476 patients were included in our analyses; 8% (n = 284) tested positive for alcohol, 10% (n = 364) tested positive for cocaine, and 27% (n = 930) tested positive for marijuana and at admission. Two hundred and eighty adults (18% of all positive patients) tested positive for at least two substances. Patients who tested positive for alcohol had longer lengths of stay and were more likely to be admitted to the intensive care unit. Patients who tested positive for cocaine had longer overall and intensive care unit lengths of stay. No differences in inpatient outcomes were seen among patients who tested positive for marijuana. Neither alcohol nor illicit substance use appears to affect inpatient mortality after burns. Alcohol and cocaine use significantly increased overall length of stay. Marijuana use had no impact on inpatient outcomes.

Severe Altered Immune Status After Burn Injury Is Associated With Bacterial Infection and Septic Shock

Introduction: Burn injury is associated with a high risk of death. Whether a pattern of immune and inflammatory responses after burn is associated with outcome is unknown. The aim of this study was to explore the association between systemic immune and inflammatory responses and outcome in severely-ill burn patients.

Materials and Methods: Innate immunity, adaptive immunity, activation and stress and inflammation biomarkers were collected at admission and days 2, 7, 14, and 28 in severely-ill adult burn patients. Primary endpoint was mortality at day 90, secondary endpoint was secondary infections. Healthy donors (HD) served as controls. Multiple Factorial Analysis (MFA) was used to identify patterns of immune response.

Results: 50 patients were included. Age was 49.2 (44.2–54.2) years, total burn body surface area was 38.0% (32.7–43.3). Burn injury showed an upregulation of adaptive immunity and activation biomarkers and a down regulation of innate immunity and stress/inflammation biomarkers. High interleukin-10 (IL-10) at admission was associated with risk of death. However, no cluster of immune/inflammatory biomarkers at early timepoints was associated with mortality. HLA-DR molecules on monocytes at admission were associated with bacterial infections and septic shock. Later altered immune/inflammatory responses in patients who died may had been driven by the development of septic shock.

Conclusion: Burn injury induced an early and profound upregulation of adaptive immunity and activation biomarkers and a down regulation of innate immunity and stress/inflammation biomarkers. Immune and inflammatory responses were associated with bacterial infection and septic shock. Absence of immune recovery patterns was associated with poor prognosis.

Microbiome in the setting of burn patients: implications for infections and clinical outcomes

Burn damage can lead to a state of immune dysregulation that facilitates the development of infections in patients. The most deleterious impact of this dysfunction is the loss of the skin’s natural protective barrier. Furthermore, the risk of infection is exacerbated by protracted hospitalization, urinary catheters, endotracheal intubation, inhalation injury, arterial lines and central venous access, among other mainstays of burn care. Currently, infections comprise the leading cause of mortality after major burn injuries, which highlights the improvements observed over the last 50 years in the care provided to burn victims. The need to implement the empirical selection of antibiotic therapy to treat multidrug-resistant bacteria may concomitantly lead to an overall pervasiveness of difficult-to-treat pathogens in burn centres, as well as the propagation of antimicrobial resistance and the ultimate dysregulation of a healthy microbiome. While preliminary studies are examining the variability and evolution of human and mice microbiota, both during the early and late phase burn injury, one must consider that abnormal microbiome conditions could influence the systemic inflammatory response. A better understanding of the changes in the post-burn microbiome might be useful to interpret the provenance and subsequent development of infections, as well as to come up with inferences on the prognosis of burn patients. This review aims to summarise the current findings describing the microbiological changes in different organs and systems of burn patients and how these alterations affect the risks of infections, complications, and, ultimately, healing.

Difficult to Treat Infections in the Burn Patient

Background: Unusual infections can lead to complications in more severely burned patients and pose major challenges in treatment. Methods: The published literature of retrospective reviews and case series of the uncommon infections of osteomyelitis, polymicrobial bacteremia, recurrent bacteremia, endocarditis, central nervous system (CNS), and rare fungal infections in burned patients have been summarized and presented. Results: When compared with infections occurring in the non-burn population, these infections in burn patients are more likely to be because of gram-negative bacteria or fungi. Because of hyperdynamic physiology and changes in immunomodulatory response secondary to burns, the clinical presentation of these infections in a patient with major burns differs from that of the non-burn patient and may not be identified until the post-mortem examination. Some of these infections (osteomyelitis, endocarditis, CNS, rare fungal infections) may necessitate surgical intervention in addition to antimicrobial therapy to achieve cure. The presence of the burn and allograft can also present unique challenges for surgical management. Conclusions: These difficult and unusual infections in the severely burned patient necessitate an index of suspicion, appropriate diagnosis, identification and sensitivities of the putative pathogen, effective systemic antimicrobial therapy, and appropriate surgical intervention if recovery is to be achieved.

Multi-Drug-Resistant Organisms in Burn Infections

Background: Infection is the most frequent complication after severe burns and remains the predominant cause of death. Burn patients may require multiple courses of antibiotics, lengthy hospitalizations, and invasive procedures that place burn patients at especially high risk for infections with multi-drug-resistant organisms (MDROs). Methods: The published literature on MDROs in burn patients was reviewed to develop a strategy for managing these infections. Results: Within a burn unit meticulous infection prevention and control measures and effective antimicrobial stewardship can limit MDRO propagation and decrease the antibiotic pressure driving the selection of MDROs from less resistant strains. Several new antimicrobial agents have been developed offering potential therapeutic options, but familiarity with their benefits and limitations is required for safe utilization. Successful management of MDRO burn infections is supported by a multifactorial approach. Novel non-antibiotic therapeutics may help combat MDRO infections and outbreaks. Conclusions: Multi-drug-resistant organisms are being identified with increasing frequency in burn patients. Effective sensitivity testing is essential to identify MDROs and to direct appropriate antibiotic choices for patient treatment.

Burn Infection and Burn Sepsis

Background: Infection is the most common complication and cause of death in patients suffering burn injuries. These patients are susceptible to infection and burn wound sepsis secondary to the alterations in their physiology. Diagnosis and management of infections rely on physical examination, cultures, and the pathology of the burn wound. Method: We performed an electronic search for articles in the Google Scholar and PubMed databases using the search terms "burn sepsis," "burn infection," and "burn critical care." Results: Multiple factors increase burn patients' risk of invasive infection and sepsis, including underlying factors and co-morbidities, the percent total body surface area of the burn, delays in burn wound excision, and microbial virulence/bacterial count. Organisms causing burn wound infection differ, depending on the time since injury and its location; and diagnosis is multi-factorial. The most common pathogens remain Staphylococcus and Pseudomonas spp. Conclusion: Overall, the recognition of burn sepsis is based on clinical findings. Treatment consists of a combination of local dressings, early burn excision, and systemic antimicrobial therapy. The mortality rate has decreased significantly over the past 10 years, but continued efforts at timely management and infection prevention are essential.

Microbiology and clinical characteristics of industrial oil burns

INTRODUCTION

Infections complicating burns generally transition from Gram-positive to Gram-negatives over the first couple weeks, but this depends on multiple factors. The microbiology of infections complicating crude oil (CO) and hydraulic fracturing (FRAC) burns is unknown.

METHODS

We performed a retrospective study of patients with industrial thermal burns hospitalized >2 days with ≥1 day in the ICU between 4/2011-11/2016. Burns were oil-related (ORB; CO or FRAC) or non-oil related (NORB). Epidemiology and microbiology during the first 15 hospital days was compared.

RESULTS

149 patients were included, with 11 FRAC and 24 CO. CO burns were more severely burned than those with FRAC and NORB (p<0.05). Mortality was 17% and 18% for CO and FRAC burns compared to 3% in NORB (p<0.01). More cultures were obtained from ORB than NORB (p<0.05). ORB were associated with Stenotrophomonas maltophilia and FRAC associated with Serratia marcescens and Candida glabrata. Patients with FRAC, CO and NORB had a median of 13, 3.5, and 4 days to first positive culture respectively (p=0.03).

CONCLUSION

ORB were associated with more severe burns and unique microbiology. FRAC burns had longer to initial positive culture, potentially suggesting our current methodology is inadequate to diagnose infections associated with FRAC.

Incorporating Statistical Test and Machine Intelligence Into Strain Typing of Staphylococcus haemolyticus Based on Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

Staphylococcus haemolyticus is one of the most significant coagulase-negative staphylococci, and it often causes severe infections. Rapid strain typing of pathogenic S. haemolyticus is indispensable in modern public health infectious disease control, facilitating the identification of the origin of infections to prevent further infectious outbreak. Rapid identification enables the effective control of pathogenic infections, which is tremendously beneficial to critically ill patients. However, the existing strain typing methods, such as multi-locus sequencing, are of relatively high cost and comparatively time-consuming. A practical method for the rapid strain typing of pathogens, suitable for routine use in clinics and hospitals, is still not available. Matrix-assisted laser desorption ionization-time of flight mass spectrometry combined with machine learning approaches is a promising method to carry out rapid strain typing. In this study, we developed a statistical test-based method to determine the reference spectrum when dealing with alignment of mass spectra datasets, and constructed machine learning-based classifiers for categorizing different strains of S. haemolyticus. The area under the receiver operating characteristic curve and accuracy of multi-class predictions were 0.848 and 0.866, respectively. Additionally, we employed a variety of statistical tests and feature-selection strategies to identify the discriminative peaks that can substantially contribute to strain typing. This study not only incorporates statistical test-based methods to manage the alignment of mass spectra datasets but also provides a practical means to accomplish rapid strain typing of S. haemolyticus.

Management and prevention of drug resistant infections in burn patients

Introduction: Despite modern advances, the primary cause of death after burns remains infection and sepsis. A key factor in determining outcomes is colonization with multi-drug resistant (MDR) organisms. Infections secondary to MDR organisms are challenging due to lack of adequate antibiotic treatment, subsequently prolonging hospital stay and increasing risk of adverse outcomes. Areas covered: This review highlights the most frequent organisms colonizing burn wounds as well as the most common MDR bacterial infections. Additionally, we discuss different treatment modalities and MDR infection prevention strategies as their appropriate management would minimize morbidity and mortality in this population. We conducted a search for articles on PubMed, Web of Science, Embase, Cochrane, Scopus and UpToDate with applied search strategies including a combination of: "burns, 'thermal injury,' 'infections,' 'sepsis,' 'drug resistance,' and 'antimicrobials.' Expert opinion: Management and prevention of MDR infections in burns is an ongoing challenge. We highlight the importance of preventative over therapeutic strategies, which are easy to implement and cost-effective. Additionally, targeted, limited use of antimicrobials can be beneficial in burn patients. A promising future area of investigation within this field is post-trauma microbiome profiling. Currently, the best treatment strategy for MDR in burn patients is prevention.

Successful control of a methicillin-resistant Staphylococcus aureus outbreak in a burn intensive care unit by addition of universal decolonization with intranasal mupirocin to basic infection prevention measures

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is frequently implicated in health care-associated outbreaks in burn intensive care units, incurring substantial morbidity and mortality to these high-risk patients and excess costs to health care systems.

METHODS

MRSA health care-associated infections (HAIs) were noted before and after the implementation of basic infection prevention measures and the subsequent implementation of universal decolonization with intranasal mupirocin. Pulsed-field gel electrophoresis was used to determine the relatedness of clinical isolates. A case-control study was conducted to characterize the risk factors for MRSA HAIs.

RESULTS

Basic interventions failed to decrease the rate of MRSA HAIs, although compliance with these interventions was high throughout the study. MRSA HAIs decreased from 8.53 HAIs per 1,000 patient days before the implementation of intranasal mupirocin to 3.61 HAIs per 1,000 patient days after the implementation of intranasal mupirocin (P = .033). Pulsed-field gel electrophoresis disclosed 10 unique clones with no large clusters. The case-control study revealed a significant association between MRSA HAIs and lengths of stay, body surface area burned, intubation, pressor requirement, leukocytosis, lactic acidosis, development of pneumonia, MRSA colonization, and death.

CONCLUSIONS

Basic environmental and behavioral interventions fell short of controlling a low-count, sporadic, and multiclonal MRSA outbreak in the burn intensive care unit of a tertiary medical center. However, the added implementation of universal decolonization with intranasal mupirocin was effective. Burn victims with greater disease severity were at higher risk for MRSA HAIs.

One-hit wonder: Late after burn injury, granulocytes can clear one bacterial infection but cannot control a subsequent infection

OBJECTIVE

Burn injury induces an acute hyperactive immune response followed by a chronic immune dysregulation that leaves those afflicted susceptible to multiple secondary infections. Many murine models are able to recapitulate the acute immune response to burn injury, yet few models are able to recapitulate long-term immune suppression and thus chronic susceptibility to bacterial infections seen in burn patients. This has hindered the field, making evaluation of the mechanisms responsible for these susceptibilities difficult to study. Herein we describe a novel mouse model of burn injury that promotes chronic immune suppression allowing for susceptibility to primary and secondary infections and thus allows for the evaluation of associated mechanisms.

METHODS

C57Bl/6 mice receiving a full-thickness contact burn were infected with Pseudomonas aeruginosa 14 days (primary infection) and/or 17 days (secondary infection) after burn or sham injury. The survival, pulmonary and systemic bacterial load as well as frequency and function of innate immune cells (neutrophils and macrophages) were evaluated.

RESULTS

Following secondary infection, burn mice were less effective in clearance of bacteria compared to sham injured or burn mice following a primary infection. Following secondary infection both neutrophils and macrophages recruited to the airways exhibited reduced production of anti-bacterial reactive oxygen and nitrogen species and the pro-inflammatory cytokineIL-12 while macrophages demonstrated increased expression of the anti-inflammatory cytokine interleukin-10 compared to those from sham burned mice and/or burn mice receiving a primary infection. In addition the BALF from these mice contained significantly higher level so of the anti-inflammatory cytokine IL-4 compared to those from sham burned mice and/or burn mice receiving a primary infection.

CONCLUSIONS

Burn-mediated protection from infection is transient, with a secondary infection inducing immune protection to collapse. Repeated infection leads to increased neutrophil and macrophage numbers in the lungs late after burn injury, with diminished innate immune cell function and an increased anti-inflammatory cytokine environment.

Risk factors and distribution of MDROs among patients with healthcare associated burn wound infection

INTRODUCTION

Patients with burn wounds are more susceptible to develop healthcare associated (HA) infection. Bacterial isolates from HA burn wound infection vary from one place to the other and also differ in terms of antimicrobial susceptibility pattern. The aim of our study was to assess the incidence of HA burn wound infection, risk factors and to determine the microbiological profile and antimicrobial susceptibility pattern of isolated pathogens.

METHODS

This was a one-year retrospective descriptive study conducted between January 2017 and December 2017, in Al-Babtain Burn and Plastic Surgery center, Kuwait. The identification of bacterial isolates was conducted by conventional biochemical methods according to standard microbiological techniques and commercially available kits using analytical profile index procedure.

RESULTS

Total body surface area >35% affected and length of stay more than 14 days were statistically significant risk factors for HA burn infection (RR of 10.057 and 5.912, respectively). Analysis of microbiological profile of these positive cultures indicated that the most common isolated organism was Acinetobacter baumannii followed by Klebsiella pneumoniae. Multidrug resistant organisms composed 65.85% of the positive isolates. Vancomycin, tigecycline, teicoplanin and linezolid showed 100% effectiveness for all Gram positive isolates. For Gram negative organisms, imipenem and meropenem showed 38.71% and 41.93% efficacy, respectively.

CONCLUSION

Identification of antimicrobial susceptibility patterns helps to tailor the required antibiotic policy to minimize the acquired infections among these vulnerable patients.

Infection control in german-speaking burn centres: results of an online survey

To systematically evaluate which infection control measures are in place in burn units, we conducted an online survey among 43 German-speaking burn units. The 29 units that responded and agreed to publication represented more than 125 patient beds. All units were located in advanced care hospitals. A total of 14 units provided single rooms only, and 22 units had a nurse-to-patient ratio of at least 1:2. Infection control practices included pre-emptive barrier precautions (29 units), the use of sterile filters for tap water supply (29 units), and an antibiotic stewardship program (24 units). Microbial screening of the patients on admission (23 units), regular prevalence screening (26 units) and surveillance of nosocomial infections (21 units) were also widely used. The high reply rate to the survey indicates the special relevance of infection control for burn units. Our survey shows that great efforts and several measures are being undertaken to address infection control challenges in burn patient care, but it also underlines the need for increased interdisciplinary infection control and antibiotic stewardship activities.

Clinical features, outcomes, and molecular characteristics of an outbreak of Staphylococcus haemolyticus infection, among a mass-burn casualty patient group, in a tertiary center in northern Taiwan

BACKGROUND/PURPOSE

We reported an outbreak of Staphylococcus haemolyticus (SH) infection in a group of young patients (mean age 21.6) simultaneously hospitalized due to a mass-burn incident. This study analyzed the clinical features of these patients and the microbiological characteristics of the outbreak.

METHODS

All 50 patients hospitalized for burns were enrolled, and their clinical differences were analyzed based on culture results. A drug sensitivity test and pulsed-field gel electrophoresis (PFGE) were conducted to analyze the microbiological difference between SH isolates from the mass-burn casualty patients (the study group) and SH isolates from other patients hospitalized during the same period (the control group) with the intention of identifying the strain of SH outbreak.

RESULTS

Patients with isolated SH (N = 36) had a significantly higher disease severity (higher revised Baux score, APACHE II score, and concurrent bacteremia rate), and a significantly poorer clinical outcome (longer ICU and hospital stay, and longer MV usage). Significant differences in the phenotype (antibiotics drug sensitivity test) and genotype (PFGE typing) were observed between the study and control groups. The dominant PFGE type C identified among the study group was related to poorer outcomes in a subgroup analysis.

CONCLUSION

A dominant PFGE type of SH infection was found in these mass-burn casualty patients. Pathogenesis or virulence factors may have contributed to our results. Further study of isolated SH should be conducted.