Invasive candidiasis in critical care: challenges and future directions

Humanized Candida and NanoBiT Assays Expedite Discovery of Bdf1 Bromodomain Inhibitors With Antifungal Potential

The fungal Bromodomain and Extra-Terminal (BET) protein Bdf1 is a potential antifungal target against invasive fungal infections. However, the need to selectively inhibit both Bdf1 bromodomains (BDs) over human orthologs and the lack of molecular tools to assess on-target antifungal efficacy hamper efforts to develop Bdf1 BD inhibitors as antifungal therapeutics. This study reports a phenyltriazine compound that inhibits both Bdf1 BDs from the human fungal pathogen Candida glabrata with selectivity over the orthologous BDs from the human BET protein Brd4. On-target antifungal activity is established by devising two yeast-based inhibition assays: a growth assay using humanized Candida strains in which the Bdf1 BDs are replaced by their Brd4 counterparts, and a NanoBiT assay that evaluates the BD-mediated association of Bdf1 with chromatin. These assays additionally enable the discovery that BET inhibitor I-BET726 targets both Bdf1 BDs, inhibits the growth of a broad spectrum of Candida species, including antifungal-resistant clinical isolates, and displays efficacy in an invertebrate animal model of infection. These collective findings highlight the promising potential of Bdf1 BD inhibitors as an innovative class of antifungal therapeutics and the pivotal role of yeast-based assay development toward achieving this end.

Discovery of new fungal jumonji H3K27 demethylase inhibitors for the treatment of Cryptococcus neoformans and Candida auris infections

Invasive fungal infections have become a serious public health problem. To tackle the challenges of limited efficacy in antifungal therapy and severe drug resistance, antifungal drugs with new mechanisms of action are urgently needed. Our previous study identified JIB-04 to be an inhibitor of fungal histone demethylase (HDM). To promote target validation and inhibitor design, herein a series of new JIB-04 derivatives were designed and synthesized. After the establishment of structure-activity relationship, compound A4 was identified to possess potent antifungal activity against Cryptococcus neoformans and Candida auris. Compared to lead compound JIB-04, compound A4 was a more potent HDM inhibitor and exhibited better water solubility, virulence factors inhibitory activity and in vivo antifungal potency. Collectively, this study further confirmed that fungal HDMs were potential antifungal targets and compound A4 was a promising antifungal lead compound.

Establishment and Validation of a Machine-Learning Prediction Nomogram Based on Lymphocyte Subtyping for Intra-Abdominal Candidiasis in Septic Patients

This study aimed to develop and validate a nomogram based on lymphocyte subtyping and clinical factors for the early and rapid prediction of Intra-abdominal candidiasis (IAC) in septic patients. A prospective cohort study of 633 consecutive patients diagnosed with sepsis and intra-abdominal infection (IAI) was performed. We assessed the clinical characteristics and lymphocyte subsets at the onset of IAI. A machine-learning random forest model was used to select important variables, and multivariate logistic regression was used to analyze the factors influencing IAC. A nomogram model was constructed, and the discrimination, calibration, and clinical effectiveness of the model were verified. High-dose corticosteroids receipt, the CD4+T/CD8+ T ratio, total parenteral nutrition, gastrointestinal perforation, (1,3)-β-D-glucan (BDG) positivity and broad-spectrum antibiotics receipt were independent predictors of IAC. Using the above parameters to establish a nomogram, the area under the curve (AUC) values of the nomogram in the derivation and validation cohorts were 0.822 (95% CI 0.777-0.868) and 0.808 (95% CI 0.739-0.876), respectively. The AUC in the derivation cohort was greater than the Candida score [0.822 (95% CI 0.777-0.868) vs. 0.521 (95% CI 0.478-0.563), p < 0.001]. The calibration curve showed good predictive values and observed values of the nomogram; the Decision Curve Analysis (DCA) results showed that the nomogram had high clinical value. In conclusion, we established a nomogram based on the CD4+/CD8+ T-cell ratio and clinical risk factors that can help clinical physicians quickly rule out IAC or identify patients at greater risk for IAC at the onset of infection.

Candidemia chronicles: Retrospective analysis of candidemia epidemiology, species distribution, and antifungal susceptibility patterns in Bahrain

BACKGROUND

Invasive fungal infections, particularly candidemia, pose significant clinical challenges globally. Understanding local epidemiology, species distribution, and antifungal susceptibility patterns is crucial for effective management despite regional variations.

AIM

To investigate the epidemiology, species distribution, antifungal susceptibility patterns, and associated risk factors of candidemia among patients in Bahrain from 2021 to 2023.

METHODS

This retrospective study analyzed demographic data, Candida species distribution, antifungal susceptibility profiles, and risk factors among candidemia patients treated at a tertiary care hospital in Bahrain over three years. Data was collected from medical records and analyzed using descriptive statistics.

RESULTS

A total of 430 candidemia cases were identified. The mean age of patients was 65.7 years, with a mortality rate of 85.5%. Candida albicans (C. albicans) was the most common species, followed by Candida parapsilosis, Candida tropicalis (C. tropicalis), and emerging multidrug-resistant Candida auris (C. auris). Antifungal susceptibility varied across species, with declining susceptibility to azoles observed, particularly among C. albicans and C. tropicalis. Major risk factors included central venous catheters, broad-spectrum antibiotics, and surgical procedures.

CONCLUSION

This study highlights the substantial burden of candidemia among older adults in Bahrain, characterized by diverse Candida species. It also concerns levels of antifungal resistance, notably in C. auris. The findings underscore the importance of local epidemiological surveillance and tailored treatment strategies to improve outcomes and mitigate the spread of multidrug-resistant Candida species. Future research should focus on molecular resistance mechanisms and optimizing therapeutic approaches to address this growing public health concern.

Candida albicans Horizontal Transmission in COVID-19 Patients Hospitalized in Intensive Care Unit

BACKGROUND

Invasive candidiasis is a predominant mycosis in hospitalized patients, and Candida albicans is the species most often responsible for this infection. Most candidiasis cases originate from endogenous mycobiota; therefore, Candida strains can easily be transferred among hospital patients and personnel. The aim of this study was to assess the possible horizontal transmission of C. albicans in patients with severe COVID-19 infection requiring hospitalization in the intensive care unit.

METHODS

In total, 59 C. albicans strains from 36 patients were collected from blood and lower-respiratory samples. The strains were genotyped using the RAPD method with the OPA-18 primer (5'-AGCTGACCGT-3'). Antifungal susceptibility testing was performed for amphotericin B (AMB), fluconazole (FCZ), voriconazole (VCZ), and anidulafungin (ANF) using the EUCAST method.

RESULTS

C. albicans strains were separated into 13 different groups according to their RAPD pattern. Two predominant clonal clusters of 17 strains isolated from 12 patients and 12 strains from 7 patients were identified, followed by clusters with 6, 4, and 8 strains isolated from 5, 4, and 3 patients, respectively. C. albicans strains were sensitive to AMB, FCZ, VCZ, and ANF, and antifungal susceptibility profiles were similar in all genetic clusters.

CONCLUSIONS

Our study indicates that C. albicans strains can spread horizontally. The routes of transmission for strains in the ward have not been explained due to there being insufficient data. The transmission could have been caused by the unintentional spread of pathogens by medical personnel.

Antifungal activities of Equol against Candida albicans in vitro and in vivo

Candida albicans is an opportunistic fungal pathogen that can cause systemic infections in immunocompromised individuals. Morphological transition and biofilm formation are major virulence factors of C. albicans. Moreover, biofilm enhances resistance to antifungal agents. Therefore, it is urgent to identify new and effective compounds to target the biofilm of C. albicans. In the present study, the antifungal activities of equol against C. albicans were investigated. In vitro, the microdilution analysis and spot assay result showed that equol exhibited potent inhibitory activities against C. albicans. Further investigations confirmed that the antifungal effects of equol involved interference with the transition from yeast to hypha and biofilm formation of C. albicans. In addition, transcriptome sequencing and reverse transcription-quantitative PCR (qRT-PCR) analysis showed that equol significantly downregulated the expression of several genes in the Ras1-cAMP-PKA pathway related to hyphae and biofilm formation and significantly upregulated the expression of the negative transcriptional repressors RFG1 and TUP1. Moreover, equol effectively reduced the production of cAMP, a key messenger in the Ras1-cAMP-PKA pathway, while supplementation with cAMP partly rescued the equol-induced defects in hyphal development. Furthermore, in a mouse model of systemic candidiasis (SC), equol treatment significantly decreased the fungal burden (liver, kidneys, and lung) in mice and local tissue damage, while enhancing the production of interleukin-10 (IL-10). Together, these findings confirm that equol is a potentially effective agent for treatment of SC.

Evaluation of colonization index and (1,3)- ß- D glucan as diagnostic tools of invasive candidiasis in a pediatric Intensive Care Unit

PURPOSE

The study aimed to evaluate the corrected colonization index (CCI) and (1, 3)-ß-D Glucan (BDG) in diagnosis of Invasive Candidiasis (IC) in critically ill pediatric patients.

METHODS

A prospective observational study in a tertiary care (PICU) were surveyed for Candida colonization and CCI was calculated. For cases with suspicious clinical presentation, samples were cultured, and double(1,3) ß-D- glucan (BDG) performed.

RESULTS

According to the European Organization for Research and Treatment of Cancer EORTC case definition for critically ill non-neutropenic patients, only 7.14 % (9/188) were diagnosed as IC (4 proven and 5 probable cases). The combined use of CCI with BDG proved to have excellent discriminative power AUC= 0.946, improved sensitivity 87.5 % and specificity 85.71 %.

CONCLUSION

The key in diagnosis of IC relies in compiling proofs from the clinical context, high CCI (≥ 0.4) and BDG.

Treatment of Invasive Pulmonary Aspergillosis and Preventive and Empirical Therapy for Invasive Candidiasis in Adult Pulmonary and Critical Care Patients. An Official American Thoracic Society Clinical Practice Guideline

BACKGROUND

The incidence of invasive fungal infections is increasing in immune-competent and immune-compromised patients. An examination of the recent literature related to the treatment of fungal infections was performed to address two clinical questions. First, in patients with proven or probable invasive pulmonary aspergillosis, should combination therapy with a mold-active triazole plus echinocandin be administered vs. mold-active triazole monotherapy? Second, in critically ill patients at risk for invasive candidiasis who are non-neutropenic and are not transplant recipients, should systemic antifungal agents be administered either as prophylaxis or as empiric therapy?

METHODS

A multidisciplinary panel reviewed the available data concerning the two questions. The evidence was evaluated, and recommendations were generated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

A conditional recommendation was made for patients with proven or probable invasive pulmonary aspergillosis to receive either initial combination therapy with a mold-active triazole plus an echinocandin or initial mold-active triazole monotherapy based on low-quality evidence. Further, a conditional weak recommendation was made against routine administration of prophylactic or empiric antifungal agents targeting Candida species for critically ill patients without neutropenia or a history of transplant based on low-quality evidence.

CONCLUSIONS

The recommendations presented in these Guidelines are the result of an analysis of currently available evidence. Additional research and new clinical data will prompt an update in the future.

Combining Fluconazole with Benzo[a]phenoxazine Derivatives as a Promising Strategy Against Fluconazole-Resistant Candida Species

The rise in non-albicans Candida species, exhibiting unpredictable antifungal resistance, complicates treatment and contributes to the growing threat of invasive, life-threatening infections. This study evaluates the antifungal activity of four benzo[a]phenoxazine derivatives (C34, C35, A42, and A44) against 14 Candida strains following EUCAST standards. Fluconazole interactions are analysed through fractional inhibitory concentration index (FICI) calculation and response surface analysis based on the Bliss model. Macrophage-like J774A.1 cells are used to assess Candida killing in the presence of synergistic compounds. The MIC values against the different strains vary, with C34 showing the strongest activity, followed by C35, while A42 has the highest MIC values, indicating lower efficacy. However, A42 demonstrates the best synergy with fluconazole against fluconazole-resistant Candida strains. Cytotoxicity assays reveal that the chloropropyl group present in C35 and A42 enhances cytocompatibility. Co-culture with macrophages shows significant yeast killing for C. albicans and C. auris when fluconazole and A42 are combined, requiring concentrations 4 and 16 times lower than their MIC values, enhancing antifungal activity. Given fluconazole's fungistatic nature and the emergence of drug-resistant strains, benzo[a]phenoxazine derivatives' ability to enhance fluconazole's efficacy present a promising strategy to address antifungal resistance in critical pathogens. These findings align with global research priorities, offering new potential avenues for developing more effective antifungal therapies.

Rezafungin versus caspofungin for patients with candidaemia or invasive candidiasis in the intensive care unit: pooled analyses of the ReSTORE and STRIVE randomised trials

BACKGROUND

Rezafungin is an echinocandin approved in the US and EU to treat candidaemia and/or invasive candidiasis. This post-hoc, pooled analysis of the Phase 2 STRIVE and Phase 3 ReSTORE trials assessed rezafungin versus caspofungin in patients with candidaemia and/or invasive candidiasis (IC) in the intensive care unit (ICU) at randomisation.

METHODS

STRIVE and ReSTORE were randomised double-blind trials in adults with systemic signs and mycological confirmation of candidaemia and/or IC in blood or a normally sterile site ≤ 96 h before randomisation. Data were pooled for patients in the ICU at randomisation who received intravenous rezafungin (400 mg loading dose then 200 mg once weekly) or caspofungin (70 mg loading dose then 50 mg once daily) for ≤ 4 weeks. Outcomes were Day 30 all-cause mortality (primary outcome), Day 5 and 14 mycological eradication, time to negative blood culture, mortality attributable to candidaemia/invasive candidiasis, safety, and pharmacokinetics.

RESULTS

Of 294 patients in STRIVE/ReSTORE, 113 were in the ICU at randomisation (rezafungin n = 46; caspofungin n = 67). At baseline, ~ 30% of patients in each group had impaired renal function and/or an Acute Physiologic Assessment and Chronic Health Evaluation II score ≥ 20. One patient (in the caspofungin group) was neutropenic at baseline. Day 30 all-cause mortality was 34.8% for rezafungin versus 25.4% for caspofungin. Day 5 and 14 mycological eradication was 78.3% and 71.7% for rezafungin versus 59.7% and 65.7% for caspofungin, respectively. Median time to negative blood culture was 18 (interquartile range, 12.6-43.0) versus 38 (interquartile range, 15.9-211.3) h for rezafungin versus caspofungin (stratified log-rank P = 0.001; nominal, not adjusted for multiplicity). Candidaemia/IC-attributable deaths occurred in two rezafungin patients versus one caspofungin patient. Safety profiles were similar between groups. Overall, 17.4% (rezafungin) versus 29.9% (caspofungin) of patients discontinued due to treatment-emergent adverse events. Rezafungin exposure following the initial 400-mg dose was comparable between patients in the ICU at randomisation (n = 50) and non-ICU patients (n = 117).

CONCLUSIONS

Rezafungin was well tolerated and efficacious in critically ill, mainly non-neutropenic patients with candidaemia and/or IC. This analysis provides additional insights into the efficacy and safety of rezafungin in the ICU population.

Isolation of Candida Species Is Associated with Comorbidities, Prolonged Mechanical Ventilation, and Treatment Outcomes in Surgical ICU Patients, a Cross-Sectional Study

The isolation of Candida may be related to comorbidity, prolonged mechanical ventilation, and survival during intensive care unit (ICU) stay, especially with non-albicans Candida (NAC). To examine the frequency of Candida isolation, associated comorbidities and outcomes in the surgical ICU in Osijek University Hospital, Croatia, the data from the electronic database from May 2016 to 30 June 2023 were analyzed. In a cross-sectional study examining 15,790 microbiological samples, different strains of Candida were observed in 581 samples from 236 patients. The control group (N = 261) was 130 consecutive patients from March to May 2019 and 131 in the same months in 2020 (pre- and post-COVID-19). Comorbidities, duration of mechanical ventilation, and survival were compared. Patients with isolated Candida were more often non-elective and had significantly more heart, kidney, and liver diseases and sepsis than the control group (p < 0.001). The duration of mechanical ventilation was 9.2 [2.2-9.24], 96 [24-146], 160 [19.5-343], and 224 [73.5-510] hours in the controls, in patients with Candida albicans, in patients with NAC, and in patients with ≥2 Candida species isolated, respectively. The mortality was significantly higher (42%) in patients with isolated Candida than in the control group (19%, p < 0.001). In a multivariate analysis adjusted for patients' age, the Simplified Acute Physiology Score II, days of ICU, and type of admission, only sepsis on admission was an independent predictor of mortality (odds ratio = 2.27).

Invasive Fungal Infections in Immunocompromised Conditions: Emphasis on COVID-19

The COVID-19 pandemic caused death of 6 million lives globally, primarily from respiratory failure, but also a significant number from invasive fungal co-infections in these patients, owing to the immune dysfunction in hospitalized patients. Such complications occurred more often in critically ill, hospitalized patients particularly those admitted in intensive care units and were reported as the major reason associated with a high mortality rate worldwide. Fungal pathogens most commonly associated with COVID-19 patients comprise members of the Mucorales (such as Rhizopus, Mucor, and Lichtheimia), as well as genera Aspergillus and Candida. In India, the prevalence rate of mucormycosis is relatively high than aspergillosis and candidiasis, and the predisposing risk factors associated with such infections included uncontrolled diabetes, underlying lung disease, leukopenia, neutropenia, malignancies and prolonged steroid therapy. However, co-infection with other fungi, including Alternaria and Scedosporium was also sporadically reported. These devastating invasive fungal infections are associated with differential mortality (high-low) and morbidity rates even after active management. The diagnosis of such infections is often challenging due to lack of sensitivity in contemporary diagnostic methods and poses an enormous challenge to healthcare experts. Thus, the role of early and accurate diagnosis, and management of such fungal infections, is vital in preventing life-threatening situations. Hence, this review focusses primarily on the epidemiology, predisposing risk factors, host environment, diagnosis and treatment of the most common medically important invasive fungal infections in immunocompromised conditions associated with COVID-19.

Antifungal susceptibility, molecular epidemiology, and clinical risk factors of Candida glabrata in intensive care unit in a Chinese Tertiary Hospital

Background

The increasing incidence and high mortality rate of Candida glabrata infection in ICU patients is an important issue. Therefore, it is imperative to investigate the antifungal susceptibility profiles and epidemiological characteristics in local regions.

Methods

Herein, antifungal susceptibility testing was conducted to determine the minimum inhibitory concentrations (MICs) of eight antifungal drugs. Multilocus sequence typing (MLST) was used to study the strain genotype, geographical distribution, and susceptibility to antifungal agents among C. glabrata isolates. The mechanism of echinocandin resistance was explored by sequencing the FKS1 and FKS2 genes (encoding 1,3-β-D-glucan synthases) of echinocandin-resistant C. glabrata strains. Moreover, we further investigated the clinical manifestations and the various risk factors of patients infected with C. glabrata in the ICU.

Results

We selected 234 C. glabrata isolates from 234 patients in the ICU randomly for the follow-up study. Cross-resistance was found among the ICU C. glabrata isolates. Analysis using MLST showed that the genetic diversity among the C. glabrata isolates was low. Furthermore, sequence type showed no correlation with the antifungal resistance profiles, but was associated with geographical distribution. We also revealed novel mutations in FKS1 (S629P) and FKS2 (W1497stop) that mediated high-level echinocandin resistance (MIC >8 µg/mL). More than 14 days' stay in ICU (P=0.007), Acute Physiology and Chronic Health Evaluation II (APACHE-II) score (P=0.024), prior antifungal exposure (P=0.039) and lung disease (P=0.036) were significantly associated with antifungal resistant/non-wild-type C. glabrata infection.

Conclusion

Our study shed light on the antifungal susceptibility, molecular epidemiology, and clinical risk factors of C. glabrata in the ICU of a Chinese Tertiary Hospital. Importantly, we revealed the molecular mechanism of echinocandin resistance. These results highlight the significance of continued surveillance in ICUs and provide data support for the treatment of C. glabrata in clinics.

Prevalence and prognostic relevance of invasive fungal disease during veno-arterial ECMO: A retrospective single-center study

PURPOSE

To assess the prevalence and relevance of invasive fungal disease (IFD) during veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO).

METHODS

Retrospective analysis from January 2013 to November 2023 of adult V-A ECMO cases at a German University Hospital. Parameters relating to IFD, demographics, length of stay (LoS), days on ECMO and mechanical ventilation, prognostic scores and survival were assessed. Multivariable logistic regression analyses with IFD and death as dependent variables were performed. Outcome was assessed after propensity score matching IFD-patients to non-IFD-controls.

RESULTS

421 patients received V-A ECMO. 392 patients with full electronic datasets were included. The prevalence of IFD, invasive candidiasis and probable invasive pulmonary aspergillosis was 4.6%, 3.8% and 1.0%. Severity of acute disease, pre-existing moderate-to-severe renal disease and continuous kidney replacement therapy were predictive of IFD. In-hospital mortality (94% (17/18) compared to 67% (252/374) in non-IFD patients (p = 0.0156)) was predicted by female sex, SOFA score at admission, SAVE score and IFD (for IFD: OR: 8.31; CI: 1.60-153.18; p: 0.044). There was no difference in outcome after matching IFD-cases to non-IFD-controls.

CONCLUSIONS

IFD are detected in about one in 20 patients on V-A ECMO, indicating mortality >90%. However, IFD do not contribute to prognosis in this population.

Enhancement of ROS Production by Catechin Is a Primary Effect of Increased Azole Efficacy in Nakaseomyces glabratus (Candida glabrata) Cells Lacking the ERG6 Gene

Fungal infections have become an important public health problem. Currently, there are only three available classes of antifungals for the treatment of invasive infections. Two of them, azoles and polyenes, target the synthesis of ergosterol or bind to sterols. A promising strategy to improve current therapies is the use of natural compounds in combinational therapies with the existing antifungals. In this work, we analyzed the changes in the susceptibility of the mutant strain of Nakaseomyces glabratus (Candida glabrata) lacking the ERG6 gene (encoding the sterol C-24 methyltransferase in ergosterol biosynthesis) in the presence of catechin and antifungal azoles. The reduced content of ergosterol in the Cgerg6Δ mutant resulted in the increased tolerance of the mutant cells to both azoles and polyenes. The combination of catechin with fluconazole or miconazole led to the growth inhibition of the azole-resistant Cgerg6Δ mutant strain. In the presence of catechin and miconazole, the Cgerg6Δ mutant fails to properly activate the expression of genes encoding the transcription factors CgYap1p and CgMsn4p, as well as the gene expression of CgCTA1, which are involved in oxidative stress response and lead to the intracellular accumulation of ROS. Finally, we show that catechin administration reduces mortality in a Galleria mellonella model infected with C. glabrata. Our work thus supports the use of catechin in combination therapies for fungal infections and shows that the CgERG6 gene could be a potential new drug target.

A Cluster of Diutina catenulata Funguria in Patients with Coronavirus Disease 2019 (COVID-19) Hospitalized in a Tertiary Reference Hospital from Rio de Janeiro, Brazil

During the COVID-19 pandemic, fungal infections, especially pulmonary aspergillosis, mucormycosis, and invasive candidiasis, have emerged as a significant health concern. Beyond Candida albicans, the most common cause of invasive candidiasis, other rare ascomycetous yeast species have been described in tertiary care units, potentially posing a broader health threat. We have isolated, from September 2020 to June 2021, nine Diutina catenulata strains from urine samples of six patients. This was intriguing as this fungus had not been previously identified in our institution, nor after June 2021. Therefore, we decided to outline the clinical features of the patients with this rare pathogen, to describe phenotypic characteristics, including antifungal susceptibility profiles, of this yeast species and to identify the genetic makeup through whole-genome sequencing analysis to evaluate if this was a cluster of genetically similar D. catenulata isolates in our institution. The strains were identified through MALDI-TOF MS analyses and Sanger sequencing of two rDNA regions. All patients yielding D. catenulata from urine samples needed ventilator support and used urinary catheters during hospitalization for treatment of COVID-19. None of them had received COVID-19 vaccines. Morphological and biochemical profiles of the nine strains were largely consistent, although fluconazole susceptibility varied, ranging from 4 to 32 μg/mL. Phylogenomic analysis revealed minimal genetic variation among the isolates, with low intrapopulation variation, supported by the identification of only 84 SNPs across all strains. Therefore, we propose that the yeast strains isolated were part of a cluster of D. catenulata funguria in the context of COVID-19.

Infection Prevention and Control Strategies According to the Type of Multidrug-Resistant Bacteria and Candida auris in Intensive Care Units: A Pragmatic Resume including Pathogens R0 and a Cost-Effectiveness Analysis

Multidrug-resistant organism (MDRO) outbreaks have been steadily increasing in intensive care units (ICUs). Still, healthcare institutions and workers (HCWs) have not reached unanimity on how and when to implement infection prevention and control (IPC) strategies. We aimed to provide a pragmatic physician practice-oriented resume of strategies towards different MDRO outbreaks in ICUs. We performed a narrative review on IPC in ICUs, investigating patient-to-staff ratios; education, isolation, decolonization, screening, and hygiene practices; outbreak reporting; cost-effectiveness; reproduction numbers (R0); and future perspectives. The most effective IPC strategy remains unknown. Most studies focus on a specific pathogen or disease, making the clinician lose sight of the big picture. IPC strategies have proven their cost-effectiveness regardless of typology, country, and pathogen. A standardized, universal, pragmatic protocol for HCW education should be elaborated. Likewise, the elaboration of a rapid outbreak recognition tool (i.e., an easy-to-use mathematical model) would improve early diagnosis and prevent spreading. Further studies are needed to express views in favor or against MDRO decolonization. New promising strategies are emerging and need to be tested in the field. The lack of IPC strategy application has made and still makes ICUs major MDRO reservoirs in the community. In a not-too-distant future, genetic engineering and phage therapies could represent a plot twist in MDRO IPC strategies.

The impact of the fluconazole trailing effect on the persistence of Candida albicans bloodstream infection when treated with fluconazole

OBJECTIVES

The trailing effect of Candida species is a phenomenon characterized by reduced but persistent growth at antifungal concentrations above the MIC. We assessed the impact of trailing growth on the persistence of Candida albicans candidemia in patients receiving fluconazole (FLC) therapy.

METHODS

We retrospectively investigated candidemia isolates at three hospitals in southern Taiwan between 2013 and 2020. Patients treated with FLC for FLC-susceptible C. albicans candidemia were enrolled. The degree of trailing was determined as the average growth above the MIC divided by the measured growth at the lowest drug concentration using the EUCAST method and classified into four categories: residual (0.1-5%), slight (6-10%), moderate (11-15%), and heavy trailers (>15%).

RESULTS

Among isolates from 190 patients, the proportions of heavy trailers at 24 hours, 48 hours, and 72 hours were 63.7% (121/190), 63.2% (120/190), and 74.7% (142/190), respectively. Persistent candidemia was observed in 17 (8.9 %) patients. The proportion of persistent C. albicans candidemia in heavy trailing isolates at 48 hours was higher than in isolates without heavy trailing (13.3% [16/120] vs. 1.4% [1/70], p = 0.007). A multivariate analysis showed that immunosuppression (OR = 7.92; 95% CI: 2.38-26.39, p = 0.001), hospitalization days after the index date of C. albicans identification (OR = 1.03; 95% CI: 1.01-1.05, p = 0.011), and heavy trailing isolates at 48 hours (OR = 10.04; 95% CI: 1.27-79.88, p = 0.029) were independent factors for persistent candidemia.

DISCUSSION

The current study revealed that heavy trailing in C. albicans isolates is associated with persistent candidemia in patients receiving FLC treatment.

Unmasking the Antifungal Activity of Anacardium occidentale Leaf Extract against Candida albicans

Invasive fungal disease causes high morbidity and mortality among immunocompromised patients. Resistance to conventional antifungal drugs and the toxicity associated with high doses highlight the need for effective antifungal therapies. In this study, the antifungal potential of the ethanolic extract of Anacardium occidentale (Cashew Leaf) leaves were evaluated against Candida albicans and C. auris. The antifungal activity was tested by the broth microdilution method and growth kinetic test. To further explore its antifungal action mode, spectrofluorophotometry, confocal microscopy and scanning and transmission electron microscopy were performed. Additionally, heterozygous knockout strains associated with resistance to oxidative stress were included in the study. We found that A. occidentale could inhibit the proliferation and growth of C. albicans at concentrations of 62.5 and 125 μg/mL. The doubling time was also drastically affected, going from 2.8 h to 22.5 h, which was also observed in C. auris. The extract induced the accumulation of intracellular reactive oxygen species (ROS), resulting in endoplasmic reticulum stress and mitochondrial dysfunction, while it did not show cytotoxicity or hemolytic activity at the concentrations evaluated. Our work preliminarily elucidated the potential mechanisms of A. occidentale against C. albicans on a cellular level, and might provide a promising option for the design of a new treatment for invasive candidiasis.

In Vitro Activitiy of Rezafungin in Comparison with Anidulafungin and Caspofungin against Invasive Fungal Isolates (2017 to 2022) in China

The efficacy of different echinocandins is assessed by evaluating the in vitro activity of a novel antifungal, rezafungin, against invasive fungal isolates in comparison with anidulafungin and caspofungin. Using the broth microdilution (BMD) method, the susceptibility of 1000 clinical Candida isolates (including 400 C. albicans, 200 C. glabrata, 200 C. parapsilosis, 150 C. tropicalis and 50 C. krusei) and 150 Aspergillus isolates (100 A. fumigatus and 50 A. flavus) from the Eastern China Invasive Fungi Infection Group (ECIFIG) was tested for the antifungals including anidulafungin, rezafungin, caspofungin and fluconazole. The echinocandins showed strong activity against C. albicans that was maintained against fluconazole-resistant isolates. The GM MIC (geometric mean minimum inhibitory concentration) value of rezafungin was found to be comparable to that of anidulafungin or caspofungin against the five tested common Candida species. C. tropicalis exhibited higher resistance rates (about 8.67-40.67% in different antifungals) than the other four Candida species. Through the sequencing of FKS genes, we searched for mutations in echinocandin-resistant C. tropicalis isolates and found that all displayed alterations in FKS1 S654P. The determined MEC (minimal effective concentration) values against A. fumigatus and A. flavus for rezafungin (0.116 μg/mL, 0.110 μg/mL) are comparable to those of caspofungin (0.122 μg/mL, 0.142 μg/mL) but higher than for anidulafungin (0.064 μg/mL, 0.059 μg/mL). Thus, the in vitro activity of rezafungin appears comparable to anidulafungin and caspofungin against most common Candida and Aspergillus species. Rezafungin showed higher susceptibility rates against C. glabrata. Rezafungin indicates its potent activity for potential clinical application.

In vitro efficacy of essential oils against various Candida species

Candida species are responsible for the most common fungal infections worldwide. We studied the in vitro antifungal activity of a large panel of essential oils (EOs) against various Candida species. The EOs activity against Candida spp. was tested using a gradient microdilution assay ranging from 4% to 0.008% (v/v). After a preliminary screening including 31 EOs, seven selected EOs were tested against 13 clinical isolates and four reference strains belonging to six Candida species. Cinnamomum zeylanicum and Cymbopogon giganteus EOs exhibited the best antifungal activity against all clinical and reference strains, with MIC ranges of 0.015%-0.25% (v/v). EOs from Litsea citrata, Backhousia citriodora and Ocimum sanctum presented MIC ranges of 0.03%-0.5% (v/v). The antifungal efficacy of EOs was independent of the susceptibility of Candida strains to usual antifungal agents. These EOs could have a promising antifungal action.

Identifying the risk factors of ICU-acquired fungal infections: clinical evidence from using machine learning

Background

Fungal infections are associated with high morbidity and mortality in the intensive care unit (ICU), but their diagnosis is difficult. In this study, machine learning was applied to design and define the predictive model of ICU-acquired fungi (ICU-AF) in the early stage of fungal infections using Random Forest.

Objectives

This study aimed to provide evidence for the early warning and management of fungal infections.

Methods

We analyzed the data of patients with culture-positive fungi during their admission to seven ICUs of the First Affiliated Hospital of Chongqing Medical University from January 1, 2015, to December 31, 2019. Patients whose first culture was positive for fungi longer than 48 h after ICU admission were included in the ICU-AF cohort. A predictive model of ICU-AF was obtained using the Least Absolute Shrinkage and Selection Operator and machine learning, and the relationship between the features within the model and the disease severity and mortality of patients was analyzed. Finally, the relationships between the ICU-AF model, antifungal therapy and empirical antifungal therapy were analyzed.

Results

A total of 1,434 cases were included finally. We used lasso dimensionality reduction for all features and selected six features with importance ≥0.05 in the optimal model, namely, times of arterial catheter, enteral nutrition, corticosteroids, broadspectrum antibiotics, urinary catheter, and invasive mechanical ventilation. The area under the curve of the model for predicting ICU-AF was 0.981 in the test set, with a sensitivity of 0.960 and specificity of 0.990. The times of arterial catheter (p = 0.011, OR = 1.057, 95% CI = 1.053-1.104) and invasive mechanical ventilation (p = 0.007, OR = 1.056, 95%CI = 1.015-1.098) were independent risk factors for antifungal therapy in ICU-AF. The times of arterial catheter (p = 0.004, OR = 1.098, 95%CI = 0.855-0.970) were an independent risk factor for empirical antifungal therapy.

Conclusion

The most important risk factors for ICU-AF are the six time-related features of clinical parameters (arterial catheter, enteral nutrition, corticosteroids, broadspectrum antibiotics, urinary catheter, and invasive mechanical ventilation), which provide early warning for the occurrence of fungal infection. Furthermore, this model can help ICU physicians to assess whether empiric antifungal therapy should be administered to ICU patients who are susceptible to fungal infections.

Secreted Aspartic Proteinases: Key Factors in Candida Infections and Host-Pathogen Interactions

Extracellular proteases are key factors contributing to the virulence of pathogenic fungi from the genus Candida. Their proteolytic activities are crucial for extracting nutrients from the external environment, degrading host defenses, and destabilizing the internal balance of the human organism. Currently, the enzymes most frequently described in this context are secreted aspartic proteases (Saps). This review comprehensively explores the multifaceted roles of Saps, highlighting their importance in biofilm formation, tissue invasion through the degradation of extracellular matrix proteins and components of the coagulation cascade, modulation of host immune responses via impairment of neutrophil and monocyte/macrophage functions, and their contribution to antifungal resistance. Additionally, the diagnostic challenges associated with Candida infections and the potential of Saps as biomarkers were discussed. Furthermore, we examined the prospects of developing vaccines based on Saps and the use of protease inhibitors as adjunctive therapies for candidiasis. Given the complex biology of Saps and their central role in Candida pathogenicity, a multidisciplinary approach may pave the way for innovative diagnostic strategies and open new opportunities for innovative clinical interventions against candidiasis.

Synthesis of bio-stabilized silver nanoparticles using Roccella montagnei, their anticandidal capacities & potential to inhibit the virulence factors in fluconazole-resistant Candida albicans

Candida species is the causative agent in approximately 80% of invasive mycoses and drug-resistant Candida albicans is among the four strains of 'critical priority group' framed by WHO. Lichens are endowed with some rare phytochemicals and a plethora of therapeutics viz. antifungal capacities of Roccella montagnei. Biosynthesis of silver nanoparticles (AgNPs) using lichen could offer an eco-friendly, and cost-effective alternative against emerging 'microbial resistance.' Therefore, the objective was to biosynthesize silver nanoparticles (Rm-AgNPs) using a Hydro-alcoholic (1:1) extract of R. montagnei to develop a potent anticandidal agent against Fluconazole-resistant C. albicans NBC099. UV-Spectroscopy identified AgNPs specific-peak of Rm-AgNPs at 420-440 nm and FTIR revealed the presence of amines, alcohol, aromatic compounds, and acids. SEM and TEM analysis indicated that Rm-AgNPs are spherical shaped with a size range of 10-50 nm. Zetasizer analysis indicated that particles are highly stable and have a mean hydrodynamic diameter of 116 nm with a zeta potential charge of - 41 mV. XRD analysis suggested face centered cubic crystal lattice structure. Results indicated that Rm-AgNPs strongly inhibited the growth of NBC099 at a minimum inhibitory concentration (IC50) of ≤ 15 µg. C. albicans culture treated with Rm-AgNPs at concentrations below IC50, down-regulates the production of different virulence factors in NBC099, viz. hyphal formation (> 85%), biofilms production (> 80%), phospholipase, esterase, proteinase activity. The apoptosis assay demonstrated the Rm-AgNPs induced apoptosis in NBC099 cells via oxidative stress. Interestingly, Rm-AgNPs showed negligible cytotoxicity (< 6%) in murine RAW 246.7 macrophage cells at a concentration above 15 µg/mL. Therefore, Rm-AgNPs have been offered as an anti-candida alternative that can be utilized to improve the efficacy of already available medications.

Invasive candidiasis

Invasive candidiasis is an important fungal disease caused by Candida albicans and, increasingly, non-albicans Candida pathogens. Invasive Candida infections originate most frequently from endogenous human reservoirs and are triggered by impaired host defences. Signs and symptoms of invasive candidiasis are non-specific; candidaemia is the most diagnosed manifestation, with disseminated candidiasis affecting single or multiple organs. Diagnosis poses many challenges, and conventional culture techniques are frequently supplemented by non-culture-based assays. The attributable mortality from candidaemia and disseminated infections is ~30%. Fluconazole resistance is a concern for Nakaseomyces glabratus, Candida parapsilosis, and Candida auris and less so in Candida tropicalis infection; acquired echinocandin resistance remains uncommon. The epidemiology of invasive candidiasis varies in different geographical areas and within various patient populations. Risk factors include intensive care unit stay, central venous catheter use, broad-spectrum antibiotics use, abdominal surgery and immune suppression. Early antifungal treatment and central venous catheter removal form the cornerstones to decrease mortality. The landscape of novel therapeutics is growing; however, the application of new drugs requires careful selection of eligible patients as the spectrum of activity is limited to a few fungal species. Unanswered questions and knowledge gaps define future research priorities and a personalized approach to diagnosis and treatment of invasive candidiasis is of paramount importance.

Promising immunotherapeutic targets for treating candidiasis

In the last twenty years, there has been a significant increase in invasive fungal infections, which has corresponded with the expanding population of individuals with compromised immune systems. As a result, the mortality rate linked to these infections remains unacceptably high. The currently available antifungal drugs, such as azoles, polyenes, and echinocandins, face limitations in terms of their diversity, the escalating resistance of fungi and the occurrence of significant adverse effects. Consequently, there is an urgent need to develop new antifungal medications. Vaccines and antibodies present a promising avenue for addressing fungal infections due to their targeted antifungal properties and ability to modulate the immune response. This review investigates the structure and function of cell wall proteins, secreted proteins, and functional proteins within C. albicans. Furthermore, it seeks to analyze the current advancements and challenges in macromolecular drugs to identify new targets for the effective management of candidiasis.

Spectrum and management of rare Candida/yeast infections in Kuwait in the Middle East

Invasive fungal infections (IFIs) are associated with high mortality rates and mostly affect patients with compromised immunity. The incidence of IFIs is increasing worldwide with the expanding population of susceptible patients. Candida and other yeast infections represent a major component of IFIs. Rare Candida/yeast infections have also increased in recent years and pose considerable diagnostic and management challenges as they are not easily recognized by routine phenotypic characteristic-based diagnostic methods and/or by the automated yeast identification systems. Rare Candida/yeasts also exhibit reduced susceptibility to antifungal drugs making proper management of invasive infections challenging. Here, we review the diagnosis and management of 60 cases of rare Candida/yeast IFIs described so far in Kuwait, an Arabian Gulf country in the Middle East. Interestingly, majority (34 of 60, 56.7%) of these rare Candida/yeast invasive infections occurred among neonates or premature, very-low-birth-weight neonates, usually following prior bacteremia episodes. The clinical details, treatment given, and outcome were available for 28 of 34 neonates. The crude mortality rate among these neonates was 32.2% as 19 of 28 (67.8%) survived the infection and were discharged in healthy condition, likely due to accurate diagnosis and frequent use of combination therapy. Physicians treating patients with extended stay under intensive care, on mechanical ventilation, receiving broad spectrum antibiotics and with gastrointestinal surgery/complications should proactively investigate IFIs. Timely diagnosis and early antifungal treatment are essential to decrease mortality. Understanding the epidemiology and spectrum of rare Candida/yeast invasive infections in different geographical regions, their susceptibility profiles and management will help to devise novel diagnostic and treatment approaches and formulate guidelines for improved patient outcome.

Epidemiology and antifungal susceptibility of fungal infections from 2018 to 2021 in Shandong, eastern China: A report from the SPARSS program

PURPOSE

We analyzed the pathogenic fungal epidemiology and antifungal susceptibility from 2018 to 2021 in Shandong Province, China, to provide the basis for empiric antifungal therapy.

METHODS

Fungal isolates were collected from 54 hospitals in Shandong province from 2018 to 2021 through the Shandong Province Pediatric bacterial & fungal Antimicrobial Resistance Surveillance System (SPARSS), WHONET v5.6 and SPSS software v20.0 were used for statistical analysis.

RESULTS

A total of 15,348 strains of fungi were collected, with Candida accounting for 78.25 %, followed by Aspergillus at 15.45 %, and other species at 6.27 %. Candida albicans was the predominant Candida species, but more than half of the Candida isolates were non-albicans species, with C. tropicalis being the most dominant (22.74 %), followed by C. glabrata (17.50 %) and C. parapsilosis (11.02 %). The composition of fungi varied significantly among different age groups. Children had a higher proportion of C. albicans (47.30 %) compared to non-children (32.06 %). The non-wild-type phenotype rate of Candida for Amphotericin B was less than 3 %, while Cryptococcus neoformans was 16.67 %. In addition, less than 6 % of C. albicans and C. parapsilosis were resistant to fluconazole and voriconazole, and 96.30 % of C. glabrata were SDD to fluconazole. We also found that 80.56 % of C. glabrata and 83.70 % of C. krusei were voriconazole WT/susceptibility phenotype. However, the susceptibility rates of C. tropicalis to fluconazole/voriconazole decreased from 70.40 %/46.40 % in 2018 to 62.30 %/35.20 % in 2021. The comprehensive susceptibility rate to fluconazole of C. albicans, C. tropicalis, C. parapsilosis and C. glabrata isolated from the blood has decreased from 69.36 % to 56.62 %.

CONCLUSIONS

The study reveals that the composition and antifungal susceptibility of pathogenic fungi in Shandong Province differ from other regions. Moreover, the resistance to azoles is more severe, especially in C. tropicalis. These findings indicate the need for region-specific antifungal treatment strategies to combat fungal infections effectively.

A Narrative Review of Invasive Candidiasis in the Intensive Care Unit

Candida species is the most common cause of invasive fungal infection in the critically ill population admitted to the intensive care unit (ICU). Numerous risk factors for developing invasive candidiasis (IC) have been identified, and some, like the breach of protective barriers, abound within the ICU. Given that IC carries a significant mortality, morbidity, and healthcare cost burden, early diagnosis and treatment have become an essential topic of discussion. Several expert panels and task forces have been established to provide clear guidance on the management of IC. Unfortunately, IC remains a diagnostic and therapeutic challenge attributable to the changing fungal ecology of Candida species and the emergence of multidrug-resistant strains. This narrative review will focus on the following: (1) the incidence, outcomes, and changing epidemiology of IC globally; (2) the risk factors for developing IC; (3) IC risk stratification tools and their appropriate use; (4) diagnosis of IC; and (5) therapeutic agents and regimens.

Association between selective digestive decontamination and decreased rate of acquired candidemia in mechanically ventilated ICU patients: a multicenter nationwide study

BACKGROUND

Candidemia is a high-risk complication among intensive care unit (ICU) patients. While selective digestive decontamination (SDD) has been shown to be effective in preventing ICU-acquired bacterial secondary infection, its effects on ICU-acquired candidemia (ICAC) remain poorly explored. Therefore, we sought to assess the effects of SDD on ICAC.

METHOD

Using the REA-REZO network, we included adult patients receiving mechanical ventilation for at least 48 h from January 2017 to January 2023. Non-parsimonious propensity score matching with a 1:1 ratio was performed to investigate the association between SDD and the rate of ICAC.

RESULTS

A total of 94 437 patients receiving at least 48 h of mechanical ventilation were included throughout the study period. Of those, 3 001 were treated with SDD and 651 patients developed ICAC. The propensity score matching included 2 931 patients in the SDD group and in the standard care group. In the matched cohort analysis as well as in the overall population, the rate of ICAC was lower in patients receiving SDD (0.8% versus 0.3%; p = 0.012 and 0.7% versus 0.3%; p = 0.006, respectively). Patients with ICAC had higher mortality rate (48.4% versus 29.8%; p < 0.001). Finally, mortality rates as well as ICU length of stay in the matched populations did not differ according to SDD (31.0% versus 31.1%; p = 0.910 and 9 days [5-18] versus 9 days [5-17]; p = 0.513, respectively).

CONCLUSION

In this study with a low prevalence of ICAC, SDD was associated with a lower rate of ICAC that did not translate to higher survival.

Discovery of Novel 8-Hydroxyquinoline Derivatives with Potent In Vitro and In Vivo Antifungal Activity

Fungal pathogens can cause life-threatening infections, yet current antifungals are inadequate at treating many of these, highlighting the importance of novel drug discovery. Here, we report hit compound L14, a novel 8-hydroxyquinoline derivative with potent and broad-spectrum antifungal activity. In vitro experiments exhibited that L14 had better activity and lower cytotoxicity than that of clioquinol and showed synergy in combination with fluconazole (FLC). In a Candida albicans-infected murine model, L14 at 2 mg/kg showed better in vivo efficacy than clioquinol at reducing fungal burden and extending the survival of C. albicans-infected mice. In addition, L14 alone or in combination with FLC had significant inhibitory activity against hypha and biofilm formation. Overall, our data indicated that 8-hydroxyquinoline derivative L14 has favorable pharmacokinetics and acceptable safety profiles and could be further investigated as a promising antifungal hit compound.

Combination of serum and peritoneal 1.3-beta-D-glucan can rule out intra-abdominal candidiasis in surgical critically ill patients: a multicenter prospective study

BACKGROUND

Intra-abdominal candidiasis (IAC) is difficult to predict in critically ill patients with intra-abdominal infection, leading to the overuse of antifungal treatments. Serum and peritoneal 1.3-beta-D-glucan (sBDG and pBDG) have been proposed to confirm or invalidate the diagnosis of IAC, but clinical studies have reported inconsistent results, notably because of heterogeneous populations with a low IAC prevalence. This study aimed to identify a high-risk IAC population and evaluate pBDG and sBDG in diagnosing IAC.

METHODS

This prospective multicenter noninterventional French study included consecutive critically ill patients undergoing abdominal surgery for abdominal sepsis. The primary objective was to establish the IAC prevalence. The secondary objective was to explore whether sBDG and pBDG could be used to diagnose IAC. Wako® beta-glucan test (WT, Fujifilm Wako Chemicals Europe, Neuss, Germany) was used for pBDG measurements. WT and Fungitell® beta-D-glucan assay (FA, Associate of Cape Cod, East Falmouth, USA) were used for sBDG measurements.

RESULTS

Between 1 January 2020 and 31 December 2022, 199 patients were included. Patients were predominantly male (63%), with a median age of 66 [54-72] years. The IAC prevalence was 44% (87/199). The main IAC type was secondary peritonitis. Septic shock occurred in 63% of cases. After multivariate analysis, a nosocomial origin was associated with more IAC cases (P = 0.0399). The median pBDG level was significantly elevated in IAC (448 [107.5-1578.0] pg/ml) compared to non-IAC patients (133 [16.0-831.0] pg/ml), P = 0.0021. For a pBDG threshold of 45 pg/ml, the negative predictive value in assessing IAC was 82.3%. The median sBDG level with WT (n = 42) at day 1 was higher in IAC (5 [3.0-9.0] pg/ml) than in non-IAC patients (3 [3.0-3.0] pg/ml), P = 0.012. Similarly, median sBDG level with FA (n = 140) at day 1 was higher in IAC (104 [38.0-211.0] pg/ml) than in non-IAC patients (50 [23.0-141.0] pg/ml), P = 0.009. Combining a peritonitis score < 3, sBDG < 3.3 pg/ml (WT) and pBDG < 45 pg/ml (WT) yielded a negative predictive value of 100%.

CONCLUSION

In critically ill patients with intra-abdominal infection requiring surgery, the IAC prevalence was 44%. Combining low sBDG and pBDG with a low peritonitis score effectively excluded IAC and could limit unnecessary antifungal agent exposure.

TRIAL REGISTRATION

The study was registered with ClinicalTrials.gov (ID number 03997929, first registered on June 24, 2019).

Severe Candida infections in critically ill patients with COVID-19

The frequency of co-infections with bacterial or fungal pathogens has constantly increased among critically ill patients with coronavirus disease 2019 (COVID-19) during the pandemic. Candidemia was the most frequently reported invasive fungal co-infection. The onset of candidemia in COVID-19 patients was often delayed compared to non-COVID-19 patients. Additionally, Candida invasive infections in COVID-19 patients were more often linked to invasive procedures (e.g., invasive mechanical ventilation or renal replacement therapy) during the intensive care stay and the severity of illness rather than more "classic" risk factors present in patients without COVID-19 (e.g., underlying diseases and prior hospitalization). Moreover, apart from the increased incidence of candidemia during the pandemic, a worrying rise in fluconazole-resistant strains was reported, including a rise in the multidrug-resistant Candida auris. Regarding outcomes, the development of invasive Candida co-infection had a negative impact, increasing morbidity and mortality compared to non-co-infected COVID-19 patients. In this narrative review, we present and critically discuss information on the diagnosis and management of invasive fungal infections caused by Candida spp. in critically ill COVID-19 patients.

Evaluation of the Antifungal Effect of Rhus verniciflua Stokes Extract for Oral Application Potential

Background and Objectives: This study confirms the possibility of using Rhus verniciflua Stokes (RVS) extract as a natural treatment for oral candidiasis. Materials and Methods: RVS was extracted with 70% ethanol to examine the antioxidant activity through polyphenol, flavonoid content, and DPPH (1,1-diphenyl-2-picrylhydrazyl). To evaluate the antifungal effect against Candida albicans (C. albicans; KCTC 7965/ATCC 10231) and evaluate the stability of RVS, a water-soluble tetrazolium salt (WST-1) assay was performed in human keratinocytes (HaCaT). Results: The findings revealed that RVS extract has fairly high antioxidant activity. The clear zones of the RVS extract against C. albicans increased in diameter due to the inhibition of fungal growth at higher concentrations. Treatment with the 1.25 mg/mL RVS extract had a more than 99% antifungal effect against C. albicans, and the 20 mg/mL RVS extract had a 100% antifungal effect. The WST-1 assay showed that the RVS extract induced low cell viability in the HaCaT cells, which inhibited their proliferation, and the RVS extract is also toxic to normal cells. Conclusions: Although the RVS extract with high antioxidant activity showed clear antifungal activity against C. albicans, it exhibited a low survival rate. Therefore, the development of a safe natural antibiotic is necessary.

Molecular fingerprinting by multi-locus sequence typing identifies microevolution and nosocomial transmission of Candida glabrata in Kuwait

Backgrounds

Candida glabrata is a frequently isolated non-albicans Candida species and invasive C. glabrata infections in older patients are associated with high mortality rates. Opportunistic Candida infections in critically ill patients may be either endogenous or nosocomial in origin and this distinction is critical for effective intervention strategies. This study performed multi-locus sequence typing (MLST) to study genotypic relatedness among clinical C. glabrata isolates in Kuwait.

Methods

Candida glabrata isolates (n = 91) cultured from 91 patients were analyzed by MLST. Repeat isolates (n = 16) from 9 patients were also used. Antifungal susceptibility testing for fluconazole, voriconazole, caspofungin and amphotericin B (AMB) was determined by Etest. Genetic relatedness was determined by constructing phylogenetic tree and minimum spanning tree by using BioNumerics software.

Results

Resistance to fluconazole, voriconazole and AMB was detected in 7, 2 and 10 C. glabrata isolates, respectively. MLST identified 28 sequence types (STs), including 12 new STs. ST46 (n = 33), ST3 (n = 8), ST7 (n = 6) and ST55 (n = 6) were prevalent in ≥4 hospitals. Repeat isolates obtained from same or different site yielded identical ST. No association of ST46 with source of isolation or resistance to antifungals was apparent. Microevolution and cross-transmission of infection was indicated in two hospitals that yielded majority (57 of 91, 67%) of C. glabrata.

Conclusion

Our data suggest that C. glabrata undergoes microevolution in hospital environment and can be nosocomially transmitted to other susceptible patients. Thus, proper infection control practices during routine procedures on C. glabrata-infected patients may prevent transmission of this pathogen to other hospitalized patients.

An Overview on Candida auris in Healthcare Settings

Candida auris has become a major concern in critical care medicine due to the increasing number of immunocompromised patients and candidiasis is the most frequent cause of fungal infections. C. auris and other fungal pathogens are responsible for at least 13 million infections and 1.5 million deaths globally per year. In immunocompromised patients, infections can quickly become severe, causing wound infections, otitis and candidemia, resulting in high morbidity and mortality. The clinical presentation of C. auris is often non-specific and similar to other types of systemic infections; in addition, it is harder to identify from cultures than other, more common types of Candida spp. Some infections are particularly difficult to treat due to multi-resistance to several antifungal agents, including fluconazole (and other azoles), amphotericin B and echinocandins. This entails treatment with more drugs and at higher doses. Even after treatment for invasive infections, patients generally remain colonized for long periods, so all infection control measures must be followed during and after treatment of the C. auris infection. Screening patients for C. auris colonization enables facilities to identify individuals with C. auris colonization and to implement infection prevention and control measures. This pathogenic fungus shows an innate resilience, enabling survival and persistence in healthcare environment and the ability to rapidly colonize the patient's skin and be easily transmitted within the healthcare setting, thus leading to a serious and prolonged outbreak.

Ssa1-targeted antibody prevents host invasion by Candida albicans

INTRODUCTION

Candida albicans is a commensal fungus that colonizes most healthy individuals' skin and mucosal surfaces but can also cause life-threatening invasive infections, particularly in immunocompromised patients. Despite antifungal treatment availability, drug resistance is increasing, and mortality rates remain unacceptably high. Heat shock protein Ssa1, a conserved member of the Hsp70 family in yeast, is a novel invasin that binds to host cell cadherins, induces host cell endocytosis, and enables C. albicans to cause maximal damage to host cells and induces disseminated and oropharyngeal disease.

RESULT

Here we discovered a mouse monoclonal antibody (mAb 13F4) that targeting C. albicans Ssa1 with high affinity (EC50 = 39.78 ng/mL). mAb 13F4 prevented C. albicans from adhering to and invading human epithelial cells, displayed antifungal activity, and synergized with fluconazole in proof of concept in vivo studies. mAb 13F4 significantly prolonged the survival rate of the hematogenous disseminated candidiasis mice to 75%. We constructed a mAb 13F4 three-dimensional structure using homology modeling methods and found that the antigen-binding fragment (Fab) interacts with the Ssa1 N-terminus.

DISCUSSION

These results suggest that blocking Ssa1 cell surface function may effectively control invasive C. albicans infections and provide a potential new treatment strategy for invasive fungal infections.

COVID-19 Is an Independent Risk Factor for Detrimental Invasive Fungal Disease in Patients on Veno-Venous Extracorporeal Membrane Oxygenation: A Retrospective Study

Invasive fungal disease (IFD) is associated with the mortality of patients on extracorporeal membrane oxygenation (ECMO). Several risk factors for IFD have been identified in patients with or without ECMO. Here, we assessed the relevance of coronavirus disease (COVID-19) for the occurrence of IFD in patients on veno-venous (V-V) ECMO for respiratory failure. In a retrospective analysis of all ECMO cases between January 2013 and December 2022 (2020-2022 for COVID-19 patients), active COVID-19 and the type, timing and duration of IFD were investigated. Demographics, hospital, ICU length of stay (LoS), duration of ECMO, days on invasive mechanical ventilation, prognostic scores (Respiratory ECMO Survival Prediction (RESP) score, Charlson Comorbidity Index (CCI), Therapeutic Intervention Scoring System (TISS)-10, Sequential Organ Failure Assessment (SOFA) score and Simplified Acute Physiology Score (SAPS)-II) and length of survival were assessed. The association of COVID-19 with IFD was investigated using propensity score matching and uni- and multivariable logistic regression analyses. We identified 814 patients supported with ECMO, and 452 patients were included in further analyses. The incidence of IFD was 4.8% and 11.0% in patients without and with COVID-19, respectively. COVID-19 status represented an independent risk factor for IFD (OR 4.30; CI 1.72-10.85; p: 0.002; multivariable regression analysis). In patients with COVID-19, 84.6% of IFD was candidemia and 15.4% represented invasive aspergillosis (IA). All of these patients died. In patients on V-V ECMO, we report that COVID-19 is an independent risk factor for IFD, which is associated with a detrimental prognosis. Further studies are needed to investigate strategies of antifungal therapy or prophylaxis in these patients.

Invasive Candida infection: epidemiology, clinical and therapeutic aspects of an evolving disease and the role of rezafungin

INTRODUCTION

Invasive Candida Infections (ICIs) have undergone a series of significant epidemiological, pathophysiological, and clinical changes during the last decades, with a shift toward non-albicans species, an increase in the rate of exogenous infections and clinical manifestations ranging from candidemia to an array of highly invasive and life-threatening clinical syndromes. The long-acting echinocandin rezafungin exhibits potent in-vitro activity against most wild-type and azole-resistant Candida spp. including C.auris.

AREAS COVERED

The following topics regarding candidemia only and ICIs were reviewed and addressed: i) pathogenesis; ii) epidemiology and temporal evolution of Candida species; iii) clinical approach; iv) potential role of the novel long-acting rezafungin in the treatment of ICIs.

EXPERT OPINION

Authors' expert opinion focused on considering the potential role of rezafungin in the evolving context of ICIs. Rezafungin, which combines a potent in-vitro activity against Candida species, including azole-resistant strains and C.auris, with a low likelihood of drug-drug interactions and a good safety profile, may revolutionize the treatment of candidemia/ICI. Indeed, it may shorten the length of hospital stays when clinical conditions allow and extend outpatient access to treatment of invasive candidiasis, especially when prolonged treatment duration is expected.

Overcoming clinical challenges in the management of invasive fungal infections in low- and middle-income countries (LMIC)

INTRODUCTION

The management of invasive fungal infections (IFIs) in low- and middle-income countries (LMIC) is a serious challenge due to limited epidemiology studies, sub-optimal laboratory facilities, gap in antifungal management training and resources. Limited studies highlighted distinctive epidemiology of IFIs in those countries, and difficulty in distinguishing from closely related infections. To overcome the gaps for appropriate management of IFIs, innovative approaches are required.

AREAS COVERED

Extensive literature search and discussion with experts have helped us to summarize the epidemiology, diagnostic and management difficulties in managing IFIs in LMIC, and recommend certain solutions to overcome the challenges.

EXPERT OPINION

The strategies to overcome the challenges in diagnosis may include local epidemiology study, training of healthcare workers, association of fungal infections with already existing budgeted national programs, development and incorporation of point-of-care test (POCT) for prompt diagnosis, simplifying clinical diagnostic criteria suitable for LMIC, judicious use of available expertise, and diagnostic stewardship. For management strategies judicious use of antifungal, partnering with industry for inexpensive antifungal agents, development of LMIC specific guidelines for cost-effective management of IFIs and fungal outbreaks, improvement of infection control practices, advocacy for implementation of WHO recommended antifungal use, and integration of IFIs with public health.

Invasive candidiasis: current clinical challenges and unmet needs in adult populations

Invasive candidiasis (IC) is a serious infection caused by several Candida species, and the most common fungal disease in hospitals in high-income countries. Despite overall improvements in health systems and ICU care in the last few decades, as well as the development of different antifungals and microbiological techniques, mortality rates in IC have not substantially improved. The aim of this review is to summarize the main issues underlying the management of adults affected by IC, focusing on specific forms of the infection: IC developed by ICU patients, IC observed in haematological patients, breakthrough candidaemia, sanctuary site candidiasis, intra-abdominal infections and other challenging infections. Several key challenges need to be tackled to improve the clinical management and outcomes of IC patients. These include the lack of global epidemiological data for IC, the limitations of the diagnostic tests and risk scoring tools currently available, the absence of standardized effectiveness outcomes and long-term data for IC, the timing for the initiation of antifungal therapy and the limited recommendations on the optimal step-down therapy from echinocandins to azoles or the total duration of therapy. The availability of new compounds may overcome some of the challenges identified and increase the existing options for management of chronic Candida infections and ambulant patient treatments. However, early identification of patients that require antifungal therapy and treatment of sanctuary site infections remain a challenge and will require further innovations.

Sequence Variation of Candida albicans Sap2 Enhances Fungal Pathogenicity via Complement Evasion and Macrophage M2-Like Phenotype Induction

Candida albicans (C. albicans) is an opportunistic pathogen increasingly causing candidiasis worldwide. This study aims to investigate the pattern of systemic immune responses triggered by C. albicans with disease associated variation of Sap2, identifying the novel evasion strategies utilized by clinical isolates. Specifically, a variation in clinical isolates is identified at nucleotide position 817 (G to T). This homozygous variation causes the 273rd amino acid exchange from valine to leucine, close to the proteolytic activation center of Sap2. The mutant (Sap2-273L) generated from SC5314 (Sap2-273V) background carrying the V273L variation within Sap2 displays higher pathogenicity. In comparison to mice infected with Sap2-273V strain, mice infected with Sap2-273L exhibit less complement activation indicated by less serum C3a generation and weaker C3b deposition in the kidney. This inhibitory effect is mainly achieved by Sap2_273L -mediated stronger degradation of C3 and C3b. Furthermore, mice infected with Sap2-273L strain exhibit more macrophage phenotype switching from M0 to M2-like and more TGF-β release which further influences T cell responses, generating an immunosuppressed cellular microenvironment characterized by more Tregs and exhausted T cell formation. In summary, the disease-associated sequence variation of Sap2 enhances pathogenicity by complement evasion and M2-like phenotype switching, promoting a more efficient immunosuppressed microenvironment.

The challenges of the genome-based identification of antifungal resistance in the clinical routine

The increasing number of chronic and life-threatening infections caused by antimicrobial resistant fungal isolates is of critical concern. Low DNA sequencing cost may facilitate the identification of the genomic profile leading to resistance, the resistome, to rationally optimize the design of antifungal therapies. However, compared to bacteria, initiatives for resistome detection in eukaryotic pathogens are underdeveloped. Firstly, reported mutations in antifungal targets leading to reduced susceptibility must be extensively collected from the literature to generate comprehensive databases. This information should be complemented with specific laboratory screenings to detect the highest number possible of relevant genetic changes in primary targets and associations between resistance and other genomic markers. Strikingly, some drug resistant strains experience high-level genetic changes such as ploidy variation as much as duplications and reorganizations of specific chromosomes. Such variations involve allelic dominance, gene dosage increments and target expression regime effects that should be explicitly parameterized in antifungal resistome prediction algorithms. Clinical data indicate that predictors need to consider the precise pathogen species and drug levels of detail, instead of just genus and drug class. The concomitant needs for mutation accuracy and assembly quality assurance suggest hybrid sequencing approaches involving third-generation methods will be utilized. Moreover, fatal fast infections, like fungemia and meningitis, will further require both sequencing and analysis facilities are available in-house. Altogether, the complex nature of antifungal resistance demands extensive sequencing, data acquisition and processing, bioinformatic analysis pipelines, and standard protocols to be accomplished prior to genome-based protocols are applied in the clinical setting.

Molecular Investigation of the Fatal Bloodstream Candida orthopsilosis Infection Case following Gastrectomy

Candida orthopsilosis represents a closely related cryptic genospecies of Candida parapsilosis complex-misidentified in routine diagnostic assays. This is emerging in settings where central venous catheters, invasive medical interventions, and echinocandin treatments are most likely to be used. A 59-year-old, non-neutropenic male patient, was admitted to an intensive care unit (ICU) due to respiratory distress syndrome, following a partial gastrectomy. As a result of duodenal stump leakage, re-laparotomy was required, abdominal drains were provided and central line catheters were exchanged. Multiple isolates of Candida orthopsilosis drawn from consecutive blood cultures were identified, despite ongoing echinocandin therapy and confirmed in vitro echinocandins susceptibility of the isolated strain. Species identification was verified via ITS region sequencing. Herein, we report the well-documented—per clinical data and relevant laboratory diagnosis—first case of a bloodstream infection caused by Candida orthopsilosis in Poland.

A scoring system based on novel biomarkers and clinical risk factors to predict invasive candidiasis in immunocompetent critically ill patients

Background

Delayed diagnosis further increases the mortality of invasive candidiasis (IC) in intensive care unit (ICU) patients. This study aimed to develop and validate a score based on novel serological biomarkers and clinical risk factors for predicting IC in immunocompetent ICU patients.

Methods

We retrospectively collected clinical data and novel serological markers on admission to ICU. Multivariate logistic regression was used to identify the risk factors associated with IC, which were adopted to establish a scoring system.

Results

Patients with IC had a higher C-reactive protein-to-albumin ratio (CAR) and neutrophil-to-lymphocyte ratio (NLR) and lower prognostic nutritional index than those without IC. The NLR, CAR, sepsis, total parenteral nutrition, 1,3-β-D-glucan (BDG)-positivity, and Sequential Organ Failure Assessment score were identified as independent risk factors for IC by multivariate logistic regression analysis and entered into the final scoring system. The area under receiver operating characteristic curve of the score were 0.883 and 0.892, respectively, in the development and validation cohort, higher than Candida score (0.883 vs.0.730, p &lt; 0.001).

Conclusion

We established a parsimonious score based on NLR, CAR, BDG-positivity, and clinical risk factors, which can accurately identify IC in ICU patients to give treatment on time and reduce mortality.

Predictive factors and prognostic value of candiduria in critically-ill patients with solid and hematological malignancies

PURPOSE

To investigate the epidemiology of candiduria in critically-ill patients with solid/hematological malignancies and to assess its predictive factors and prognostic value.

METHODS

All adult patients with confirmed solid/hematological malignancy admitted in the intensive care units (ICUs) for more than 48 h were retrospectively included. Urine cultures were sampled on admission and then whenever signs of sepsis were identified. Two groups were compared: (candiduria (+)) and (candiduria (-)).

RESULTS

One-hundred-seventy-three patients were included. Solid cancer was the underlying oncological disease for 147 patients (85%) while 26 patients (15%) had hematological malignancies. Twenty-nine patients (16.8%) were diagnosed with candiduria, and 31 urinary samples grew Candida spp. Candida spp represented 55.8% of the total urinary isolates. Fourteen isolates (45.2%) of Candida albicans were identified. Among the 17 non-albicans isolates, Candida tropicalis was the most predominant (41.9%). Six patients (3.5%) had candidemia with no significant difference between candiduria(+) and candiduria(-) groups (respectively, 6.9% and 2.8%; p = 0.264). In multivariate analysis, previous exposure to quinolones (OR = 3.8, CI95% [1.4-8.3]; p = 0.008), mechanical ventilation (OR = 4.1, CI95% [1.1-14.7]; p = 0.034) and renal replacement therapy (OR = 3.5, 95%CI [1.2-9.7]; p = 0.017) were identified as independent factors predicting candiduria. Candiduria was associated with significantly higher ICU-mortality after adjusting for SAPSII score on admission (OR = 2.9 CI95% [1.3-6.8]; p = 0.009).

CONCLUSION

Candiduria is common in cancer critically-ill patients. We reported an increased rate of non-albicans species, over albicans species. Patients with candiduria had higher ICU mortality, probably related to higher frailty and clinical severity.