Candidemia in major burns patients

Decoding the role of oxidative stress resistance and alternative carbon substrate assimilation in the mature biofilm growth mode of Candida glabrata

BACKGROUND

Biofilm formation is viewed as a vital mechanism in C. glabrata pathogenesis. Although, it plays a significant role in virulence but transcriptomic architecture and metabolic pathways governing the biofilm growth mode of C. glabrata remain elusive. The present study intended to investigate the genes implicated in biofilm growth phase of C. glabrata through global transcriptomic approach.

RESULTS

Functional analysis of Differentially expressed genes (DEGs) using gene ontology and pathways analysis revealed that upregulated genes are involved in the glyoxylate cycle, carbon-carbon lyase activity, pre-autophagosomal structure membrane and vacuolar parts whereas, down- regulated genes appear to be associated with glycolysis, ribonucleoside biosynthetic process, ribosomal and translation process in the biofilm growth condition. The RNA-Seq expression of eight selected DEGs (CgICL1, CgMLS1, CgPEP1, and CgNTH1, CgERG9, CgERG11, CgTEF3, and CgCOF1) was performed with quantitative real-time PCR (RT-qPCR). The gene expression profile of selected DEGs with RT-qPCR displayed a similar pattern of expression as observed in RNA-Seq. Phenotype screening of mutant strains generated for genes CgPCK1 and CgPEP1, showed that Cgpck1∆ failed to grow on alternative carbon substrate (Glycerol, Ethanol, Oleic acid) and similarly, Cgpep1∆ unable to grow on YPD medium supplemented with hydrogen peroxide. Our results suggest that in the absence of glucose, C. glabrata assimilate glycerol, oleic acid and generate acetyl coenzyme-A (acetyl-CoA) which is a central and connecting metabolite between catabolic and anabolic pathways (glyoxylate and gluconeogenesis) to produce glucose and fulfil energy requirements.

CONCLUSIONS

The study was executed using various approaches (transcriptomics, functional genomics and gene deletion) and it revealed that metabolic plasticity of C. glabrata (NCCPF-100,037) in biofilm stage modulates its virulence and survival ability to counter the stress and may promote its transition from commensal to opportunistic pathogen. The observations deduced from the present study along with future work on characterization of the proteins involved in this intricate process may prove to be beneficial for designing novel antifungal strategies.

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.

Invasive Candidiasis in Hospitalized Patients with Major Burns

Background: Invasive candidiasis (IC) is a major cause of morbidities and mortality in patients hospitalized with major burns. This study investigated the incidence of IC in this specific population and analyzed the possible risk factors. Materials and Methods: We retrospectively analyzed data from the National Health Insurance Research Database (NHIRD) of Taiwan. We identified 3582 patients hospitalized with major burns on over 20% of their total body surface area (TBSA) during 2000–2013; we further analyzed possible risk factors. Result: IC was diagnosed in 452 hospitalized patients (12.6%) with major burns. In the multivariate analysis, patients older than 50 years (adjusted odds ratio (OR) = 1.96, 95% confidence interval (CI) 1.36–2.82), those of female sex (adjusted OR = 1.33, 95% CI 1.03–1.72), those with burns on the head (adjusted OR = 1.33, 95% CI 1.02–1.73), and those with burns over a greater TBSA had higher risks of IC. Conclusion: Treating IC is crucial in healthcare for major burns. Our study suggests that several risk factors are associated with IC in patients hospitalized with major burns, providing reliable reference value for clinical decisions.

Antifungal Resistance in Clinical Isolates of Candida glabrata in Ibero-America

In different regions worldwide, there exists an intra-and inter-regional variability in the rates of resistance to antifungal agents in Candida glabrata, highlighting the importance of understanding the epidemiology and antifungal susceptibility profiles of C. glabrata in each region. However, in some regions, such as Ibero-America, limited data are available in this context. Therefore, in the present study, a systematic review was conducted to determine the antifungal resistance in C. glabrata in Ibero-America over the last five years. A literature search for articles published between January 2015 and December 2020 was conducted without language restrictions, using the PubMed, Embase, Cochrane Library, and LILACS databases. The search terms that were used were "Candida glabrata" AND "antifungal resistance" AND "Country", and 22 publications were retrieved from different countries. The use of azoles (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, ketoconazole, and miconazole) varied between 4.0% and 100%, and that of echinocandins (micafungin, caspofungin, and anidulafungin) between 1.1% and 10.0%. The limited information on this subject in the region of Ibero-America emphasizes the need to identify the pathogens at the species level and perform antifungal susceptibility tests that may lead to the appropriate use of these drugs and the optimal doses in order to avoid the development of antifungal resistance or multi-resistance.

Prevalence, species distribution, and risk factors of fungal colonization and infection in patients at a burn intensive care unit in Vietnam

Background and Purpose :

Burn patients are at a higher risk of infections caused by different organisms. This study aimed to address the prevalence, causative species, and factors related to fungal colonization or infection in patients with acute severe injuries admitted to the intensive care unit (ICU) of a burn hospital in northern Vietnam.

Materials and Methods:

This prospective study was conducted on 400 patients in a burn ICU between 2017 and 2019. Clinical samples were weekly collected and screened for fungi, and relevant clinical information was obtained from medical records.

Results:

According to the results, 90% of the patients were colonized with fungi. Out of this group, 12.75% of the cases had invasive fungal infection (IFI). Eleven yeasts and six mold species were isolated from the patients, with the most common species being Candida tropicalis (45.56%) and C. albicans (41.94%). Among the eleven species causing fungal wound infection (FWI), the most common agents were Candida (66.7% of FWI patients) and Aspergillus (38.5%) species. Three Candida species isolated from blood were C. tropicalis (66.7%), C. albicans (20.0%), and C. parapsilosis (14.3%). No factors were found to expose the patients to a higher risk of fungal colonization. However, hyperglycemia, prolonged ICU stay, and heavy Candida species colonization were found to be independently predictive of IFI.

Conclusion:

Burn patients are at the risk of fungal infection with Candida species (especially C. tropicalis) and Aspergillus as the most frequently responsible agents. Continuous surveillance of fungi and appropriate management of pathophysiological consequences are essential to prevent fungal infection in burn patients.

Candidemia in pediatric burn patients: Risk factors and outcomes in a retrospective cohort study

Background and Purpose :

Despite advances in burn care and management, infections are still a major contributor to morbidity and mortality rates in patients with burn injuries. Regarding this, the present study was conducted to investigate the prevalence and importance of candidemia in pediatric burn patients.

Materials and Methods:

Blood samples were collected from the patients and cultured in an automated blood culture system. Candida species were identified using specific culture media. The relationship between candidemia and possible risk factors was evaluated and compared to a control group.

Results:

A total of 71 patients with the mean age of 4.52±3.63 years were included in the study. Blood cultures showed candidemia in 19 (27%) patients. Based on the results, C. albicans was the most common fungus among patients with and without candidemia. The results of statistical analysis also showed that candidemia was significantly correlated with total body surface area (TBSA), mechanical ventilation, duration of total parenteral nutrition, length of intensive care unit (ICU) stay, presence of neutropenia, and R-Baux score (all P≤0.001). In this regard, TBSA, length of ICU stay, R-Baux score, and Candida score were identified as the determinant factors for mortality due to candidemia.

Conclusion:

Candidemia increases the mortality and morbidity rates associated with burn injuries. Prompt diagnostic and prevention measures can reduce the unfortunate outcomes via controlling the possible risk factors.

Infections in patients with burn injuries receiving extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) has only recently been described in patients with burn injuries. We report the incidence and type of infections in critically ill burn and non-burn patients receiving ECMO.

METHODS

A retrospective chart review was performed on all patients at Brooke Army Medical Center who received ECMO between September 2012 and May 2018.

RESULTS

78 patients underwent ECMO. Approximately half were men with a median age of 34 years with a median time on ECMO of 237 h (IQR 121-391). Compared to patients without burns (n = 58), patients with burns (n = 20) had no difference in time on ECMO, but had more overall infections (86 vs. 31 per 1000 days, p = 0.0002), respiratory infections (40 vs. 15 per 1000 days, p = 0.01), skin and soft tissue infections (21 vs. 5 per 1000 days, p = 0.02) and fungal infections (35% vs 10%, p = 0.02). Twenty percent of bacterial burn infections were due to drug resistant organisms.

CONCLUSION

This is the first study to describe the incidence of infection in burn injury patients who are undergoing ECMO. We observed an increase in infections in burn patients on ECMO compared to non-burn patients. ECMO remains a viable option for critically ill patients with burn injuries.

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.

Candidemia in major burn patients and its possible risk factors: A 6-year period retrospective study at a burn ICU

OBJECTIVE

The aims of this study were to evaluate the epidemiological and clinical characteristics of candidemia in a typical burn ICU, and to determine the risk factors associated with candidemia among major burn patients.

METHOD

This retrospective observational study of candidemia from 2012 to 2017 in a burn ICU was conducted in the Department of Burn, Southwest hospital, Chongqing, China.

RESULTS

The study included 410 major burn patients (≥40% total body surface area), 39 (9.51%) of which were diagnosed with candidemia. The annual incidences of candidemia varied from 6.06% to 17.54%, and increased gradually in the 6 years. Candida parapsilosis was the dominant pathogen (28.21% strains). The overall resistance rate of Candida spp. to fluconazole was 35.89%. Candidemia cases most frequently occurred in the 2nd (30.77%) and 3rd (23.08%) weeks after burn, and intravascular catheters were the most common sources of bloodstream Candida infections (31.58%). The crude mortality of candidemia was 23.08%, and the mortality attributable to candidemia was 14.99%. Risk factors of candidemia included inhalation injury, renal dysfunction with replacement therapy, severe gastrointestinal complications, T-cell lymphopenia and prior Candida colonization.

CONCLUSION

Candidemia has a high incidence and mortality in major burn patients. The changes in etiology and drug sensitivity may make new challenges for the management of candidemia in burn ICUs.

Outcome and potentially modifiable risk factors for candidemia in critically ill burns patients: A matched cohort study

BACKGROUND

Patients with extensive burns are at risk of developing candidemia.

OBJECTIVES

To identify potentially modifiable risk factors and outcomes of candidemia in critically ill burns patients.

PATIENTS AND METHODS

Retrospective matched cohort study including adult burns patients. Patients who developed candidemia were matched with burns patients with Candida spp colonisation and sepsis or septic shock without candidemia in a ratio of 1:3 (same severity scores and colonisation index). Univariate and multiple regression analyses were performed.

RESULTS

Of 130 severely burned patients with Candida spp colonisation and at least one episode of sepsis or septic shock, 14 were diagnosed with candidemia. In the candidemia group, patients had a median (IQR) total burns surface area (TBSA) of 57 (38-68)%, SAPSII of 43 (36-58) and ABSI of 11 (8-13). Multiple regression analysis showed that only duration of prior antibiotic therapy was independently associated with candidemia. ICU mortality was higher in the candidemia group (71% vs 35% [P = 0.02]). The log-rank test for 28-day mortality comparing patients with candidemia treated with an empirical strategy vs a curative strategy did not reach significance (P = 0.056).

CONCLUSIONS

Burns patients having received recent antibiotherapy have a higher risk of candidemia. Antifungal strategies did not influence outcome in this series.

Candida parapsilosis isolates from burn wounds can penetrate an acellular dermal matrix

We isolated and identified yeasts from burn wounds and evaluated the ability of Candida parapsilosis isolates from burn wounds to penetrate an acellular dermal matrix (ADM). A prospective study was conducted with patients from the burn treatment center of North Paraná University Hospital in Londrina, Brazil from February 2015 to January 2016. Yeast cultures were obtained from the tissue of burn wounds that had been debrided and cleansed with 2% chlorhexidine. After identification and confirmation of the purity of the culture, the yeasts were placed on ADM fragments and incubated for three or seven days. During the study period, 273 patients were treated, and 36 of these patients fulfilled the inclusion criteria and provided samples for culture. Yeasts were isolated in 19.44% (n = 7) of the cultures, and the following species were identified: C. parapsilosis (57.1%), C. albicans (28.6%), and C. glabrata (14.3%). C. parapsilosis, the most frequent species, was chosen for the ADM tests. We demonstrated active penetration of the ADM by the yeast isolates from burn wounds. C. parapsilosis grew on ADM and penetrated the matrix, indicating that this yeast, which is common in skin and cutaneous wounds, has the potential to colonize and pass through ADM, a medical device that is frequently used to dress and regenerate burn wounds.