Epidemiological and bacteriological profiles in children with burns

Ten-Year Analysis of Bacterial Colonisation and Outcomes of Major Burn Patients with a Focus on Pseudomonas aeruginosa

A retrospective descriptive study included patients admitted with severe burns over the course of 10 years (2008-2018). Across all patients, there were 39 different species of bacteria, with 23 species being Gram-negative and 16 being Gram-positive bacteria, with also five different species of fungi cultured. Pseudomonas aeruginosa was the most commonly isolated organism, with 57.45% of patients having a positive culture. There was a significant difference in the number of P. aeruginosa isolated from patients that acquired their burns at work, in a garden, inside a vehicle, in a garage or in a public place. In patients that were positive for P. aeruginosa, the number of operations was higher (2.4) and the length of stay was significantly increased (80.1 days). Patients that suffered from substance abuse demonstrated significantly higher numbers of isolated P. aeruginosa (14.8%). Patients that suffered from both mental health illness and substance abuse demonstrated significantly higher numbers of P. aeruginosa isolated (18.5%). In the P. aeruginosa-negative group, there were significantly fewer patients that had been involved in a clothing fire. Furthermore, in the P. aeruginosa-negative patient cohort, the mortality rate was significantly higher (p = 0.002). Since the incidence of P. aeruginosa was also associated with a decreased mortality rate, it may be that patients admitted to hospital for shorter periods of time were less likely to be colonised with P. aeruginosa. This study demonstrates novel factors that may increase the incidence of P. aeruginosa isolated from burn patients.

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.

Infections in Patients with Major Burns: A Retrospective Study of a Burn Intensive Care Unit

OBJECTIVES

Burn related infections are challenging conditions to manage and can cause several complications entailing a complicated treatment. In this study infection in burn patients hospitalized in burn intensive care unit (ICU) of a tertiary care hospital is investigated.

MATERIAL AND METHODS

This retrospective study was conducted between 1 January 2018 and 31 December 2020 in burn ICU of a tertiary care hospital. Patients with an ICU stay less than 48 hours and survival less than 72 hours were not included in the study. The demographic and clinical data as well as referral status, the type of infections and the isolated microorganisms, antibiotics used for prophylaxis, outcomes and the mortality rate are evaluated retrospectively from patient files and the hospital registries.

RESULTS

A total of 311 patients were included in our study cohort with a mean age of 22.11±20.9 years. The burned total body surface area was 28.07±17.1 and abbreviated burn severity index was 5.76±2.3. There were 155 patients with 283 infections and the infection rate was 45.8 per 1000 patient days. The most commonly isolated microorganisms were Candida species in blood-stream and urinary tract infections, Pseudomonas aeruginosa in burn wound infections. Most of the deaths (86.7%) occurred in patients with infections.

CONCLUSIONS

In major burns strict adherence to isolation procedures, avoiding delays in referrals, early excision and early wound closure are important measures to reduce infections. Each burn center should develop appropriate antibiotic strategies due to their culture results and prophylaxis with broad spectrum antibiotics should be avoided.

Pediatric Burn Infection

Background: Severe burns lead to a profound hypermetabolic, hypercatabolic, hyper-inflammatory state. Pediatric burn patients are at significantly increased risk for infection and sepsis secondary to loss of the skin barrier and subsequent immunosuppression. Infection is the most common cause of morbidity and death in pediatric burn patients, and the mortality rate from sepsis remains high. Methods: Review of pertinent English-language literature pertaining to infection among pediatric burn patients. Results: Established risk factors for infection in pediatric burn patients are the depth of injury, presence of inhalation injury, indwelling devices, and total body surface area burned. Total body surface area remains one of the most important risk factors for the development of infectious complications, and mortality risks increase significantly if the burn size is >40%. The predominant colonization of burn wound starts with gram-positive organisms, which are replaced later by gram-negative organisms. Most cases of sepsis in burn patients originate from infected burn wounds. Treatment options include topical and systemic antimicrobial drugs, but surgical intervention often is the most definitive treatment. Excision of burn eschar to remove the source of potential infection is a key component of the treatment as well as prevention of infection. Conclusion: Key principles in improving outcomes for septic pediatric burn patients is early recognition, resuscitation, and adherence to management strategies such as prompt antimicrobial drug administration and source control.

Epidemiology of burn-related infections in the largest burn unit in Saudi Arabia

OBJECTIVES

To first describe the epidemiological data of burns, including burn types and burn-related infections, in adult and pediatric patients. Second, to determine the effect of Methicillin-Resistant Staphylococcus aureus (MRSA) on length of hospital stay and, third, to determine if the microbiological profile differs in patients with severe and non-severe burns. Methods: This is a retrospective chart review in which medical records of all burn patients admitted to Al-Noor Specialist Hospital, Makkah, Kingdom of Saudi Arabia between January 2016 and January 2017 were reviewed for demographic, microbiological, and burn data using a data-collection sheet. No randomization was necessary as all patients were included. Descriptive and inferential statistics were performed on the collected data. Results: Of 250 patients, 53.6% were pediatric patients and 68.4% were male patients. The most common organism in blood and wound cultures of minor burns was Staphylococcus aureus. Methicillin-resistant Staphylococcus aureus (MRSA) frequency was 82.5%. Length of stay increased in patients with infected burn injuries. Conclusion: The pediatric population had a high frequency of burn injuries, representing an incentive for more focused educational prevention programs in that group. Additionally, burn infections carry significant morbidity, and are associated with longer hospital stay. These data can help implement various prevention programs.

Infections in Pediatric Burn Patients: An Analysis of One Hundred Eighty-One Patients

Background: Infectious complications are one of the most life-threatening complications and result in substantial mortality and morbidity in children who have been burned. The goal of the study is to assess the risk factors for sepsis in pediatric burn patients in a referral hospital. Methods: This study was performed at the Pediatric Burn Unit of Ankara Child Health and Diseases Hematology Oncology Training and Research Hospital during the period between January 2014 and June 2017. The patients were evaluated for age, sex, burn etiology, burned body surface area (BSA), the presence of inhalation injury, sepsis, positive cultures, the micro-organisms cultured samples, and septic focus. Results: A total of 181 patients were included in the study. The most common cause of burns was scalds in 120 patients (66.3%). Forty-one patients (22.7%) developed health-care-associated infection and sepsis. Gram-negative micro-organisms were isolated in 40 (97.6%) patients (Acinetobacter spp., Pseudomonas aeruginosa, Klebsiella pneumonia) with sepsis. Carbapenem resistance was detected in 31 (93.8%) of 40 patients. Mortality was observed in 11 patients (6.1%) in the group with sepsis. Burn surface area, burn depth, C-reactive protein (CRP) values, mortality, Garcés index, and Baux index were higher in the group with sepsis (p < 0.05). Multiple regression analysis revealed that mechanism of injury (flame), burned BSA ≥25%, C-reactive protein ≥6 mg/dL (area under the curve [AUC]: 0.76 p < 0.001 and AUC: 0.90, p < 0.001, respectively) at admission were independent parameters for development of sepsis in pediatric burn patients. Conclusion: Multi-drug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii were important agents of blood stream infection in burned children. Burned BSA ≥25% and CRP ≥6 mg/dL were risk factors for developing sepsis in pediatric burn patients.

Progress Toward the Elusive Pseudomonas aeruginosa Vaccine

Background: The gram-negative bacterial pathogen Pseudomonas aeruginosa causes a wide range of infections, mostly in hospitalized and immunocompromised patients, those with burns, surgical wounds, or combat-related wounds, and in people with cystic fibrosis. The increasing antibiotic resistance of P. aeruginosa confers a pressing need for vaccines, yet there are no P. aeruginosa vaccines approved for human use, and recent promising candidates have failed in large clinical trials. Discussion: In this review, we summarize recent clinical trials and pre-clinical studies of P. aeruginosa vaccines and provide a suggested framework for the makeup of a future successful vaccine. Murine models of infection suggest that antibodies, specifically opsonophagocytic killing antibodies (OPK), antitoxin antibodies, and anti-attachment antibodies, combined with T cell immunity, specifically T_H17 responses, are needed for broad and potent protection against P. aeruginosa infection. A better understanding of the human immune response to P. aeruginosa infections, and to vaccine candidates, will eventually pave the way to a successful vaccine for this wily pathogen.

Predicting and managing sepsis in burn patients: current perspectives

Modern burn care has led to unprecedented survival rates in burn patients whose injuries were fatal a few decades ago. Along with improved survival, new challenges have emerged in the management of burn patients. Infections top the list of the most common complication after burns, and sepsis is the leading cause of death in both adult and pediatric burn patients. The diagnosis and management of sepsis in burns is complex as a tremendous hypermetabolic response secondary to burn injury can be superimposed on systemic infection, leading to organ dysfunction. The management of a septic burn patient represents a challenging scenario that is commonly encountered by providers caring for burn patients despite preventive efforts. Here, we discuss the current perspectives in the diagnosis and treatment of sepsis and septic shock in burn patients.

Epidemiology of Staphylococcus aureus in a burn unit of a tertiary care center in Ghana

BACKGROUND

In developing countries, hospitalized burn victims are at high risk of nosocomial infections caused by Staphylococcus aureus. Risk factors include poor infection control practices, prolonged hospitalisation and limited capacity for laboratory microbiological analyses. These problems are compounded by widespread use of antibiotics that drives the spread of multi-drug resistant bacteria.

METHODS

During the study period (November 2014-June 2015), nasal and invasive S. aureus isolates were collected consecutively from patients and healthcare workers (HCWs) within the burn unit of the Reconstructive Plastic Surgery and Burn Center of Korle Bu Teaching Hospital in Ghana. Antibiotic prescription, antibiotic susceptibility and bacterial typing were used to assess antibiotic pressure, antibiotic resistance, and possible transmission events among patients and HCWs.

RESULTS

Eighty S. aureus isolates were obtained from 37 of the 62 included burn patients and 13 of the 29 HCWs. At admission, 50% of patients carried or were infected with S. aureus including methicillin resistant S. aureus (MRSA). Antibiotic use per 100 days of hospitalization was high (91.2 days), indicating high selective pressure for resistant pathogens. MRSA isolates obtained from 11 patients and one HCW belonged to the same spa-type t928 and multi-locus sequence type 250, implying possible transmission events. A mortality rate of 24% was recorded over the time of admission in the burn unit.

CONCLUSION

This study revealed a high potential for MRSA outbreaks and emergence of resistant pathogens amongst burn patients due to lack of patient screening and extended empirical use of antibiotics. Our observations underscore the need to implement a system of antibiotic stewardship and infection prevention where microbiological diagnostics results are made available to physicians for timely and appropriate patient treatment.

Calcium induces tobramycin resistance in Pseudomonas aeruginosa by regulating RND efflux pumps

Pseudomonas aeruginosa is an opportunistic multidrug resistant pathogen causing severe chronic infections. Our previous studies showed that elevated calcium (Ca²⁺) enhances production of several virulence factors and plant infectivity of the pathogen. Here we show that Ca²⁺ increases resistance of P. aeruginosa PAO1 to tobramycin, antibiotic commonly used to treat Pseudomonas infections. LC-MS/MS-based comparative analysis of the membrane proteomes of P aeruginosa grown at elevated versus not added Ca²⁺, determined that the abundances of two RND (resistance-nodulation-cell division) efflux pumps, MexAB-OprM and MexVW-OprM, were increased in the presence of elevated Ca²⁺. Analysis of twelve transposon mutants with disrupted RND efflux pumps showed that six of them (mexB, muxC, mexY, mexJ, czcB, and mexE) contribute to Ca²⁺-induced tobramycin resistance. Transcriptional analyses by promoter activity and RT-qPCR showed that the expression of mexAB, muxABC, mexXY, mexJK, czcCBA, and mexVW is increased by elevated Ca²⁺. Disruption of mexJ, mexC, mexI, and triA significantly decreased Ca²⁺-induced plant infectivity of the pathogen. Earlier, our group showed that PAO1 maintains intracellular Ca²⁺ (Ca²⁺_in) homeostasis, which mediates Ca²⁺ regulation of P. aeruginosa virulence, and identified four putative Ca²⁺ transporters involved in this process (Guragain et al., 2013). Here we show that three of these transporters (PA2435, PA2092, PA4614) play role in Ca²⁺-induced tobramycin resistance and one of them (PA2435) contributes to Ca²⁺ regulation of mexAB-oprM promoter activity. Furthermore, mexJ, czcB, and mexE contribute to the maintenance of Ca²⁺_in homeostasis. This provides the first evidence that Ca²⁺_in homeostasis mediates Ca²⁺ regulation of RND transport systems, which contribute to Ca²⁺-enhanced tobramycin resistance and plant infectivity in P. aeruginosa.

Burn-associated bloodstream infections in pediatric burn patients: Time distribution of etiologic agents

BACKGROUND

Infections are the leading cause of morbidity and mortality in patients with burns in burn units. Bloodstream infections (BSIs) in patients with burns may result from burn wound infection, use of invasive devices such as central venous catheters, and translocation of the gastrointestinal flora.

OBJECTIVE

In this study, we investigated the distribution and antimicrobial drug resistance of causative pathogens in children with burns and the durational changes of microorganisms in the distribution of BSIs in children.

METHODS

This study was conducted at the Pediatric Burn Unit (PBU) of Dr. Behçet Uz Children Research and Training Hospital during the period of November 2008-April 2015. The study subjects were all the patients admitted to the PBU, in whom microorganisms were isolated at least from one of the cultures, including blood and catheter cultures.

RESULTS

Gram-positive bacteria were the most common causative agents of BSI in patients with burns (66.4%), followed by gram-negative bacteria (22.1%) and fungi (11.5%). The median duration of development of BSIs caused by gram-positive bacteria from the time of burn was 5 days (ranging from 2 to 54 days of burn), which was significantly shorter than that of BSIs caused by gram-negative bacteria (12 days) and fungal pathogens (13 days).

CONCLUSION

The etiologic agents of BSIs in children may differ from those in adults. Gram-negative drug-resistant bacteria such as multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii were important agents of BSI in patients with burns, especially in the long term; however, gram-positive bacteria should also be considered while deciding the antimicrobial therapy, especially in the early periods of burn.