Invasive aspergillosis: epidemiology, diagnosis and management in immunocompromised patients

Machine Learning Methods Based on Chest CT for Predicting the Risk of COVID-19-Associated Pulmonary Aspergillosis

RATIONALE AND OBJECTIVES

To develop and validate a machine learning model based on chest CT and clinical risk factors to predict secondary aspergillus infection in hospitalized COVID-19 patients.

MATERIALS AND METHODS

This retrospective study included 291 COVID-19 patients with complete clinical data between December 2022 and March 2024, and some (n=82) of them developed secondary aspergillus infection after admission. Patients were divided into training (n=162), internal validation (n=69) and external validation (n=60) cohorts. The least absolute shrinkage and selection operator regression was applied to select the most significant image features extracted from chest CT. Univariate and multivariate logistic regression analyses were performed to develop a multifactorial model, which integrated chest CT with clinical risk factors, to predict secondary aspergillus infection in hospitalized COVID-19 patients. The performance of the constructed models was assessed with the receiver operating characteristic curve and the area under the curve (AUC). The clinical application value of the models was comprehensively evaluated using decision curve analysis (DCA).

RESULTS

Eleven radiomics features and seven clinical risk factors were selected to develop prediction models. The multifactorial model demonstrated a favorable predictive performance with the highest AUC values of 0.98 (95% CI, 0.96-1.00) in the training cohort, 0.98 (95% CI, 0.96-1.00) in the internal validation cohort, and 0.87 (95% CI, 0.75-0.99) in the external validation cohort, which was significantly superior to the models relied solely on chest CT or clinical risk factors. The calibration curves from Hosmer-Lemeshow tests showed that there were no significant differences in the training cohort (p=0.359) and internal validation cohort (p=0.941), suggesting the good performance of the multifactorial model. DCA indicated that the multifactorial model exhibited better performance than others.

CONCLUSION

The multifactorial model can serve as a reliable tool for predicting the risk of COVID-19-associated pulmonary aspergillosis.

Pulmonary infection by Lophomonas spp. and Aspergillus spp. in a B-cell acute lymphocytic leukemia patient from Chile

The flagellated protozoan Lophomonas spp. is a commensal microorganism found in the intestinal tracts of cockroaches, termites, mites, and certain birds. It is the causative agent of a rare infection in humans called lophomoniasis, primarily affecting the lungs and mainly immunocompromised individuals. This parasitosis is transmitted to humans by air or through ingestion of the cystic forms of the parasite. We describe the case of a 50-year-old patient treated at a tertiary hospital in southern Chile with a history of B-cell acute lymphocytic leukemia. Radiological findings, along with increased levels of inflammatory parameters and galactomannan antigen in serum and Bronchoaveolar Lavage (BAL) raised the suspicion of a pulmonary infection. Microscopic study of BAL revealed oval to pyriform cells with mobile flagella at the anterior end, which were identified as Lophomonas spp. trophozoites, which based on EORTC/MSG criteria were associated with diagnosis of a probable pulmonary aspergillosis. Lophomoniasis was treated with metronidazole (500 mg IV every 8 h) for 14 days and pulmonary aspergillosis required a combination of fluconazole, voriconazole, anidulafungin, liposomal amphotericin B and isavuconazole. The patient responded favorably and was discharged after 95 days of hospitalization. This case highlights the importance of recognizing lophomoniasis as a parasitic infection in respiratory samples from immunocompromised patients who present pulmonary symptoms, especially those who do not respond satisfactorily to conventional antimicrobial treatments. Further research is needed to understand the various sources of Lophomonas spp. infection and develop infection prevention strategies particularly for high-risk patients.

Neutrophil phenotype, effector functions, and microbicidal activity in patients with SARS-CoV-2-associated ARDS

Critically ill patients admitted to the intensive care unit (ICU) for SARS-CoV-2-induced acute respiratory distress syndrome (ARDS) are at increased risk of bacterial and fungal secondary pulmonary infections due to acquired immune dysfunction. Given that the activity of neutrophils has not been described in these patients, we aimed to investigate the function of neutrophils at ICU admission and on day 7 (D7) postadmission. Neutrophil maturation and several functional indicators were investigated. We detected a significant decrease in reactive oxygen species production at D7, but we did not observe any other significant alterations in neutrophil function. Furthermore, bronchoalveolar lavage obtained from patients displayed no inhibitory effect on the function of neutrophils from healthy donors. These findings indicate that patients admitted to the ICU for SARS-CoV-2-induced ARDS do not acquire neutrophil dysfunction within the first week of their stay, which suggests that nosocomial infections among these patients are not due to acquired neutrophil dysfunctions.

Emergence of infectious diseases and role of advanced nanomaterials in point-of-care diagnostics: a review

Infectious outbreaks are the foremost global public health concern, challenging the current healthcare system, which claims millions of lives annually. The most crucial way to control an infectious outbreak is by early detection through point-of-care (POC) diagnostics. POC diagnostics are highly advantageous owing to the prompt diagnosis, which is economical, simple and highly efficient with remote access capabilities. In particular, utilization of nanomaterials to architect POC devices has enabled highly integrated and portable (compact) devices with enhanced efficiency. As such, this review will detail the factors influencing the emergence of infectious diseases and methods for fast and accurate detection, thus elucidating the underlying factors of these infections. Furthermore, it comprehensively highlights the importance of different nanomaterials in POCs to detect nucleic acid, whole pathogens, proteins and antibody detection systems. Finally, we summarize findings reported on nanomaterials based on advanced POCs such as lab-on-chip, lab-on-disc-devices, point-of-action and hospital-on-chip. To this end, we discuss the challenges, potential solutions, prospects of integrating internet-of-things, artificial intelligence, 5G communications and data clouding to achieve intelligent POCs.

Cerebrospinal fluid galactomannan detection for the diagnosis of central nervous system aspergillosis: a diagnostic test accuracy systematic review and meta-analysis

BACKGROUND

Cerebrospinal fluid (CSF) galactomannan is an adjunctive test for central nervous system (CNS) aspergillosis diagnosis with unclear diagnostic test characteristics.

OBJECTIVES

To evaluate the diagnostic test characteristics of CSF galactomannan in CNS aspergillosis.

METHODS

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, Web of Science, and Scopus, from inception to 24 February 2023.

STUDY ELIGIBILITY CRITERIA

Prospective and retrospective studies with 1-group and 2-group designs using any galactomannan assay on CSF to diagnose CNS aspergillosis.

PARTICIPANTS

Adult and/or paediatric patients with CNS aspergillosis.

TEST(S)

Galactomannan testing on CSF specimens.

REFERENCE STANDARD

European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) diagnostic criteria, or equivalent.

ASSESSMENT OF RISK OF BIAS

QUADAS-2 assessment in duplicate.

METHODS OF DATA SYNTHESIS

Bivariate restricted maximum likelihood estimation random-effects meta-analysis, summarized using forest and summary receiver operating characteristic plots; bivariate meta-regression models to investigate heterogeneity; and subgroup and sensitivity analyses to explore subgroup effects and methodologic choices (PROSPERO registration: CRD42022296331; funding: none).

RESULTS

We included eight studies (n = 342 participants). The summary estimates of CSF galactomannan sensitivity and specificity were 69.0% (95% CI, 57.2-78.7%) and 94.4% (95% CI, 82.8-98.3%), respectively. Using meta-regression, galactomannan cut-off (p = 0.38), EORTC/MSGERC criteria version (p = 0.48), or whether the reference standard was defined as both proven and probable or only proven aspergillosis (p = 0.48) did not explain observed heterogeneity. No subgroup effects were demonstrated by analysing the EORTC/MSGERC criteria reference standard used (e.g. 2002 vs. 2008 definitions) or whether paediatric patients were included. Diagnostic sensitivity was improved using a galactomannan cut-off of 1.0, and by excluding high risk of bias and 1-group design studies.

DISCUSSION

CSF galactomannan is a highly specific but insensitive test for use as a component of CNS aspergillosis diagnosis. Few included studies, no prospective studies, and a high risk of bias are study limitations.

Candidate-Probiotic Lactobacilli and Their Postbiotics as Health-Benefit Promoters

Lactobacillus species are widely recognized for their probiotic potential, focusing on their mechanisms of health benefits and protection. Here we conducted an in vitro investigation of the probiotic potential with a role in microbiome homeostasis of four strains: Lactiplantibacillus plantarum L6 and F53, Ligilactobacillus salivarius 1, and Lactobacillus helveticus 611. A broad spectrum of antibacterial and antifungal activity was determined. The strain-specific inhibition of Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and saprophytic/toxigenic fungi makes them promising as protective cultures. DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) measurements showed that tested samples had strain-specific capacity for scavenging of radicals. The molecular base for the antioxidant potential of two lyophilized forms of active strains was investigated by electron paramagnetic resonance spectroscopy. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, with fractions of the most active postbiotics obtained by SEC-FPLC (fast protein liquid chromatography) analysis, showed a wide variety of effects on the growth of a K562 myeloid leukemia cell line. The IC50 (half-maximal inhibitory concentration) of L. salivarius 1 was determined to be 46.15 mg/mL. The proven in vitro functionality of the selected lactobacilli make them suitable for development of target probiotics with specific beneficial effects expected in vivo. Further investigations on produced postbiotics and safety have to be completed before they can be considered as scientifically proven probiotic strains.

Optimizing Antifungal Treatment Strategies to Prevent Invasive Pulmonary Aspergillosis Infection-Related Deaths in Intensive Care Unit Patients: The Need for Standardization of Research Definitions

The clinical spectrum of invasive pulmonary aspergillosis (IPA) has expanded in recent decades. A large group of patients admitted to intensive care units (ICU) is indeed susceptible to the development of IPA. Although timely diagnosis and antifungal therapy of IPA in this expanding population is crucial to prevent IPA-related deaths, the magnitude of the favorable prognostic impact of antifungal therapy is difficult to measure precisely. In our opinion, the development of standardized research definitions could have favorable implications for further improving our ability both to measure the favorable effect of antifungal treatment and to prevent IPA-related death in ICU patients.

Contribution of Particulates to Airborne Disease Transmission and Severity: A Review

The emergence of coronavirus disease 2019 (COVID-19) has catalyzed great interest in the spread of airborne pathogens. Airborne infectious diseases are classified into viral, bacterial, and fungal infections. Environmental factors can elevate their transmission and lethality. Air pollution has been reported as the leading environmental cause of disease and premature death worldwide. Notably, ambient particulates of various components and sizes are harmful pollutants. There are two prominent health effects of particles in the atmosphere: (1) particulate matter (PM) penetrates the respiratory tract and adversely affects health, such as heart and respiratory diseases; and (2) bioaerosols of particles act as a medium for the spread of pathogens in the air. Particulates contribute to the occurrence of infectious diseases by increasing vulnerability to infection through inhalation and spreading disease through interactions with airborne pathogens. Here, we focus on the synergistic effects of airborne particulates on infectious disease. We outline the concepts and characteristics of bioaerosols, from their generation to transformation and circulation on Earth. Considering that microorganisms coexist with other particulates as bioaerosols, we investigate studies examining respiratory infections associated with airborne PM. Furthermore, we discuss four factors (meteorological, biological, physical, and chemical) that may impact the influence of PM on the survival of contagious pathogens in the atmosphere. Our review highlights the significant role of particulates in supporting the transmission of infectious aerosols and emphasizes the need for further research in this area.

Invasive Fungal Diseases in Adult Patients in Intensive Care Unit (FUNDICU): 2024 consensus definitions from ESGCIP, EFISG, ESICM, ECMM, MSGERC, ISAC, and ISHAM

PURPOSE

The aim of this document was to develop standardized research definitions of invasive fungal diseases (IFD) in non-neutropenic, adult patients without classical host factors for IFD, admitted to intensive care units (ICUs).

METHODS

After a systematic assessment of the diagnostic performance for IFD in the target population of already existing definitions and laboratory tests, consensus definitions were developed by a panel of experts using the RAND/UCLA appropriateness method.

RESULTS

Standardized research definitions were developed for proven invasive candidiasis, probable deep-seated candidiasis, proven invasive aspergillosis, probable invasive pulmonary aspergillosis, and probable tracheobronchial aspergillosis. The limited evidence on the performance of existing definitions and laboratory tests for the diagnosis of IFD other than candidiasis and aspergillosis precluded the development of dedicated definitions, at least pending further data. The standardized definitions provided in the present document are aimed to speed-up the design, and increase the feasibility, of future comparative research studies.

Characteristics and risk factors for invasive fungal infection in hospitalized patients with acute-on-chronic hepatitis B liver failure: a retrospective cohort study from 2010 to 2023

Background and aim

The global burden of invasive fungal infections (IFIs) is emerging in immunologic deficiency status from various disease. Patients with acute-on-chronic hepatitis B liver failure (ACHBLF) are prone to IFI and their conditions are commonly exacerbated by IFI. However, little is known about the characteristics and risk factors for IFI in hospitalized ACHBLF patients.

Methods

A total of 243 hospitalized ACHBLF patients were retrospectively enrolled from January 2010 to July 2023. We performed restricted cubic spline analysis to determine the non-linear associations between independent variables and IFI. The risk factors for IFI were identified using logistic regression and the extreme gradient boosting (XGBoost) algorithm. The effect values of the risk factors were determined by the SHapley Additive exPlanations (SHAP) method.

Results

There were 24 ACHBLF patients (9.84%) who developed IFI on average 17.5 (13.50, 23.00) days after admission. The serum creatinine level showed a non-linear association with the possibility of IFI. Multiple logistic regression revealed that length of hospitalization (OR = 1.05, 95% CI: 1.02-1.08, P = 0.002) and neutrophilic granulocyte percentage (OR = 1.04, 95% CI: 1.00-1.09, P = 0.042) were independent risk factors for IFI. The XGBoost algorithm showed that the use of antibiotics (SHAP value = 0.446), length of hospitalization (SHAP value = 0.406) and log (qHBV DNA) (SHAP value = 0.206) were the top three independent risk factors for IFI. Furthermore, interaction analysis revealed no multiplicative effects between the use of antibiotics and the use of glucocorticoids (P = 0.990).

Conclusion

IFI is a rare complication that leads to high mortality in hospitalized ACHBLF patients, and a high neutrophilic granulocyte percentage and length of hospitalization are independent risk factors for the occurrence of IFI.

SAR study of N'-(Salicylidene)heteroarenecarbohydrazides as promising antifungal agents

Clinically available antifungal drugs have therapeutic limitations due to toxicity, narrow spectrum of activity, and intrinsic or acquired drug resistance. Thus, there is an urgent need for new broad-spectrum antifungal agents with low toxicity and a novel mechanism of action. In this context, we have successfully identified several highly promising lead compounds, i.e., aromatic N'-(salicylidene)carbohydrazides, exhibiting excellent antifungal activities against Cryptococcus neoformans, Candida albicans, Aspergillus fumigatus and several other fungi both in vitro and in vivo. Building upon these highly promising results, 71 novel N'-(salicylidene)heteroarenecarbohydrazides 5 were designed, synthesized and their antifungal activities examined against fungi. Based on the SAR study, four highly promising lead compounds, i.e., 5.6a, 5.6b, 5.7b and 5.13a were identified, which exhibited excellent potency against C. neoformans, C. albicans and A. fumigatus, and displayed impressive time-kill profiles against C. neoformans with exceptionally high selectivity indices (SI ≥ 500). These four lead compounds also showed synergy with clinical antifungal drugs, fluconazole, caspofungin (CS) and amphotericin B against C. neoformans. For the SAR study, we also employed quantitative structure-activity relationship (QSAR) analysis by taking advantage of the accumulated data on a large number of aromatic and heteroaromatic N'-(salicylidene)carbohydrazides, which successfully led to rational design and selection of promising compounds for chemical synthesis and biological evaluation.

Incidence and inhospital outcomes of coronavirus disease 2019-associated pulmonary aspergillosis in the United States

OBJECTIVE

The aim of this study was to estimate the predictors, associations, and outcomes of COVID-19-associated pulmonary disease (CAPA) in the United States.

STUDY DESIGN AND METHODS

This retrospective cohort study was performed by using the National Inpatient Sample Database 2020 to identify coronavirus disease 2019 (COVID-19) and CAPA hospitalizations. Baseline variables and outcomes were compared between COVID-19 hospitalizations without aspergillosis and those with aspergillosis. These variables were then used to perform an adjusted analysis for obtaining predictors and factors associated with CAPA and its inhospital mortality.

RESULTS

Of the 1,020,880 hospitalizations identified with the principal diagnosis of COVID-19, CAPA was identified in 1510 (0.1%) hospitalizations. The CAPA cohort consisted of a higher proportion of males (58%) as well as racial and ethnic minorities (Hispanics, Blacks, and others [including Asian or Pacific islanders, native Americans]). Inhospital mortality was significantly higher (47.35% vs. 10.87%, P < 0.001), the average length of stay was longer (27.61 vs. 7.29 days, P < 0.001), and the mean cost per hospitalization was higher ($121,560 vs. $18,423, P < 0.001) in the CAPA group compared to COVID-19 without aspergillosis. History of solid organ transplant, chronic obstructive pulmonary disease, and venous thromboembolism were associated with higher odds of CAPA among other factors. The use of invasive mechanical ventilation (adjusted odds ratio [aOR] 6.24, P < 0.001), acute kidney injury (aOR 2.02, P = 0.028), and septic shock (aOR 2.07, P = 0.018) were associated with higher inhospital mortality in the CAPA cohort.

CONCLUSION

While CAPA is an infrequent complication during hospitalizations for COVID-19, it significantly increases all-cause mortality, prolongs hospital stays, and leads to higher hospital expenses compared to COVID-19 cases without aspergillosis.

Diagnostic Utility of Galactomannan Enzyme Immunoassay in Invasive Aspergillosis in Pediatric patients with Hematological Malignancy

OBJECTIVE

This study aims to determine the diagnostic utility of galactomannan enzyme immunoassay (GM EIA) in invasive aspergillosis (IA) in children with hematological malignancy (high risk population) in terms of sensitivity, specificity, negative predictive value (NPV) and positive predictive values (PPV) at various cut offs while validating the revised EORTC/MSG 2019 criteria in order to obtain the best cut-off.

MATERIAL AND METHODS

For 100 pediatric patients, serum and respiratory samples were collected. Clinical, mycological workup (potassium-hydroxide mount, fungal culture) and GM EIA was done to classify proven, probable, and possible IA as per EORTC-MSG guidelines,2019. Sensitivity, specificity, PPV and NPV were calculated of GM indices at cut-off 0.5, 0.7 and 1, and validated with revised EORTC -MSG, 2019.

RESULTS

Of 100 patients enrolled, 75 were diagnosed with ALL, 14 with AML, two with Hodgkin's, three had non-Hodgkin lymphoma, and six had undifferentiated leukemia. With routine mycological findings, 51 were classified as probable IA, 11 as possible IA, and 38 as no IA. Aspergillus flavus was the most prevalent on culture (56.9%, 29/51) followed by A. fumigatus (29%, 15/51) A. niger (7.8%, 4/51), A. terreus (3.9%, 2/51) and A. nidulans (2%, 1/51). GM EIA demonstrated sensitivity 82.3%, specificity 97.4%, PPV 98.1%, and NPV 77.1% at cut-off 0.67 when comparing probable/possible IA v/s no IA groups. The GM EIA had the best sensitivity (82.4%), specificity (81.8%), PPV (95.5%), and NPV (50%) at cut off 0.78 when the probable IA group was compared to the possible IA. Seven patients succumbed of whom 5 had GMI ≥ 2.

CONCLUSION

This study deduces the optimal cut-off for serum GM EIA to be 0.67 obtained by ROC analysis when comparing possible and probable IA versus no IA and reinforces the definition of probable category of EORTC-MSG criteria, 2019. At 0.5 ODI the sensitivity (87.1%) and NPV (80.5%) are high, thus making it the most suitable cut-off for detecting true positive and ruling out IA respectively, in pediatric patients with hematological malignancy. GM EIA when performed adjunctive to clinico-radiological findings can prove to be screening, diagnostic and prognostic test for IA in pediatric hematological malignancy patients.

Submandibular gland abscess in a kidney transplant recipient: a diagnostic and therapeutic enigma

A renal allograft transplant recipient presented to our emergency department with pus discharging right-sided cheek swelling. She had the same presentation 1 year after kidney transplant surgery. The abscess was incised and drained, and a sample was sent for culture and sensitivity. The culture initially grew Aspergillus fumigatus for which she was started on itraconazole. While the patient was on antifungal therapy, immunohistochemistry revealed diffuse large B-cell lymphoma to be the primary disease, and rituximab chemotherapy was initiated. The patient is being followed up and is currently in remission.We are reporting this rare case to raise awareness so that clinicians consider the possibility of post-transplant lymphoproliferative disorder when they see a similar presentation.

Effect of 5-Aminolevulinic Acid Photodynamic Therapy on Aspergillus fumigatus Biofilms in Vitro

Aspergillus fumigatus biofilm development results in enhanced pathogenicity and treatment resistance. Most contemporary antibiotics, however, are unable to eliminate biofilms. In recent years, with the application of new photosensitizers and the development of treatment, ALA-PDT (5-aminolevulinic acid photodynamic treatment) has achieved remarkable curative effect in the treatment of fungal infectious diseases; however, no research has been conducted on ALA-PDT against A. fumigatus. This study investigated the inhibitory effect of ALA-PDT at various 5-aminolevulinic acid concentrations and light doses on A. fumigatus planktonic and biofilms in vitro. We found that ALA-PDT may successfully inhibit the development of A. fumigatus biofilm and disintegrate mature biofilm. After ALA-PDT treatment, the adherence rate and vitality dramatically decreased, and the biofilm's structure was severely compromised. Our findings show for the first time that ALA-PDT may be used to prevent the formation of A. fumigatus biofilm and disturb the structure of mature biofilm, and that it could be employed as a therapeutic therapy for A. fumigatus superficial infection.

Probiotics and their postbiotics for the control of opportunistic fungal pathogens: A review

During past twenty years the opportunistic fungal infections have been emerging, causing morbidity and mortality. The fungi belonging to Aspergillus, Mucor, Rhizopus, Candida, Fusarium, Penicillium, Dermatophytes and others cause severe opportunistic fungal infections. Among these Aspergillus and Candida spp cause majority of the diseases. The continuum of fungal infections will prolong to progress in the surroundings of the growing inhabitants of immunocompromised individuals. Presently many chemical-based drugs were used as prophylactic and therapeutic agents. Prolonged usage of antibiotics may lead to some severe effect on the human health. Also, one of the major threats is that the fungal pathogens are becoming the drug resistant. There are many physical, chemical, and mechanical methods to prevent the contamination or to control the disease. Owing to the limitations that are observed in such methods, biological methods are gaining more interest because of the use of natural products which have comparatively less side effects and environment friendly. In recent years, research on the possible use of natural products such as probiotics for clinical use is gaining importance. Probiotics, one of the well studied biological products, are safe upon consumption and are explored to treat various fungal infections. The antifungal potency of major groups of probiotic cultures such as Lactobacillus spp, Leuconostoc spp, Saccharomyces etc. and their metabolic byproducts which act as postbiotics like organic acids, short chain fatty acids, bacteriocin like metabolites, Hydrogen peroxide, cyclic dipeptides etc. to inhibit these opportunistic fungal pathogens have been discussed here.

Effect of invasive aspergillosis on risk for different causes of death in older patients with acute myeloid leukaemia or high-risk myelodysplastic syndrome

PURPOSE

Study objectives were to estimate the cumulative incidence of death due to different causes of death (CODs) and investigate the effect of invasive aspergillosis (IA) on each separate COD in a cohort of older patients with acute myeloid leukaemia (AML) or high-risk myelodysplastic syndrome (MDS) included in the Haemato-Oncology Foundation for Adults in the Netherlands (HOVON) 43 randomized controlled trial.

METHODS

Pre-collected data from the trial was obtained from the HOVON data center and relevant clinical information was extracted. The cumulative incidence of death due to different CODs was estimated with a competing risk model and the association between each COD and prognostic factors, including IA, were investigated with a cause-specific hazard Cox regression model.

RESULTS

In total 806 patients were included, mean age of 70 years and 55% were male. The cumulative incidences of death due to leukaemia or infection at 3, 6, 12 and 36 months were 0.06, 0.11, 0.23, 0.42 and 0.17, 0.19, 0.22, 0.25 respectively. Incidence of IA was 21% and diagnosis of IA up until the final chemotherapy cycle was associated with an increased risk of dying from leukaemia (cause-specific hazard ratio (_CSHR): 1.75, 95% CI 1.34-2.28) and a trend was seen for infection (_CSHR: 1.36, 95% CI 0.96-1.91).

CONCLUSION

Leukaemia was the most likely cause of death over time, however in the first year after diagnosis of AML or high-risk MDS infection was the most likely cause of death. Patients with IA had a relatively increased risk of dying from leukaemia or infection.

Health economic analysis of patients treated with isavuconazole in a German comprehensive cancer centre

BACKGROUND

Invasive fungal diseases (IFD) are life-threatening and demand timely and appropriate treatment. Research showed that isavuconazole treatment positively affects clinical outcome and length of hospital stay (LOS).

OBJECTIVES

The aim of this study was to assess the hospital costs of patients diagnosed with IFD and treated with isavuconazole using real-world data from a German cancer centre.

PATIENTS/METHODS

Data and LOS collected from Jan-2016 to Jun-2021 at Department I of Internal Medicine, University Hospital Cologne were retrieved. Case-related resources consumed during the hospital stay across isavuconazole routes of administration (oral, parenteral, and mixed administration) were identified, quantified, valued and compared via a cost analysis that adopted the healthcare payer perspective.

RESULTS

In total, 101 cases with isavuconazole treatment were identified (oral: n = 22, 21.8%; parenteral: n = 59, 58.4%; mixed: n = 20, 19.8%). Median total LOS was greater in the mixed group (46.5 days; p = .009). Median ICU LOS and ventilation duration were both longest in the parenteral-only group (16 days, p = .008; 224 h, p = .003). Invasive aspergillosis was the most frequent isavuconazole indication (n = 86, 85.2%). Average hospital costs were highest in the mixed group (€ 101,226). The median overall costs of cases treated with isavuconazole was € 52,050.

CONCLUSIONS

Treating IFD is resource intensive, often requires intensive care and implies high rates of in-hospital mortality. Our study emphasises the high hospital treatment costs and thus the need for reimbursement systems to enable live-saving costly treatments.

Fungal Zinc Homeostasis and Its Potential as an Antifungal Target: A Focus on the Human Pathogen Aspergillus fumigatus

Aspergillus fumigatus is an opportunistic airborne fungus that causes severe invasive aspergillosis in immunocompromised patients. Zinc is an essential micronutrient for the growth of A. fumigatus and even for all microorganisms. An increasing number of studies have reported that fungal zinc acquisition ability plays a key role in fungal survival in hosts with an extremely zinc-limited microenvironment. The ability to fight scarcity and excess of zinc are tightly related to fungal virulence and may be used as new potential targets. Because the regulation of zinc homeostasis is important, a thorough understanding of the functional genes involved in the regulatory network for zinc homeostasis is required for fungal pathogens. The current mini-review summarized potential zinc homeostasis regulators in A. fumigatus and classified these regulators according to localization and function, which were identified or predicted based on A. fumigatus or deduced from homologs in model yeasts. Future perspectives for zinc homeostasis regulators as potential antifungal targets to treat invasive aspergillosis are also discussed.

Performance Evaluation of Bruker Biotyper, ASTA MicroIDSys, and VITEK-MS and Three Extraction Methods for Filamentous Fungal Identification in Clinical Laboratories

Filamentous fungi are a major cause of life-threatening infections in immunocompromised patients; thus, rapid and accurate identification is critical. Filamentous fungal identification by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has been demonstrated with high sensitivity and reproducibility; however, its wider application has been limited in clinical laboratories because of practical challenges such as database availability or lack of standardization.

Potential Original Drug for Aspergillosis: In Vitro and In Vivo Effects of 1-N,N-Dimethylamino-5-Isocyanonaphthalene (DIMICAN) on Aspergillus fumigatus

As the recent outbreak of coronavirus disease 2019 (COVID-19) has shown, viral infections are prone to secondary complications like invasive aspergillosis with a high mortality rate, and therefore the development of novel, effective antifungals is of paramount importance. We have previously demonstrated that 1-amino-5-isocyanonaphthalene (ICAN) derivatives are promising original drug candidates against Candida strains (Patent pending), even against fluconazole resistant C. albicans. Consequently, in this study ICANs were tested on Aspergillus fumigatus, an opportunistic pathogen, which is the leading cause of invasive and systematic pulmonary aspergillosis in immunosuppressed, transplanted and cancer- or COVID-19 treated patients. We have tested several N-alkylated ICANs, a well as 1,5-naphthalene-diisocyanide (DIN) with the microdilution method against Aspergillus fumigatus strains. The results revealed that the diisocyanide (DIN) was the most effective with a minimum inhibitory concentration (MIC) value as low as 0.6 µg mL⁻¹ (3.4 µM); however, its practical applicability is limited by its poor water solubility, which needs to be overcome by proper formulation. The other alkylated derivatives also have in vitro and in vivo anti-Aspergillus fumigatus effects. For animal experiments the second most effective derivative 1-N, N-dimethylamino-5-isocyanonaphthalene (DIMICAN, MIC: 7–8 µg mL⁻¹, 36–41 µM) was selected, toxicity tests were made with mice, and then the antifungal effect of DIMICAN was tested in a neutropenic aspergillosis murine model. Compared to amphotericin B (AMB), a well-known antifungal, the antifungal effect of DIMICAN in vivo turned out to be much better (40% vs. 90% survival after eight days), indicating its potential as a clinical drug candidate.

Epidemiology of Aspergillosis in Cancer Patients in Taiwan

Purpose

The incidence of aspergillosis is increasing, and the risk factors for infection include cancer, admission to the intensive care unit, chronic pulmonary diseases, immunocompromised status, and taking immunomodulatory drugs. There are limited data about the incidence of aspergillosis in patients with different types of cancer. The aim of our study was to survey the incidence of aspergillosis in different cancer types from 2006 to 2017.

Patients and Methods

Data were collected from the Taiwan Cancer Registry database and International Classification of Diseases, 9th, 10th Revision, and Clinical Modification codes for diagnosing aspergillosis. Patients with a history of aspergillosis before cancer were excluded, and the secondary outcome was the risk of mortality in cancer patients with and without aspergillosis after 1 year.

Results

Among 951 cancer patients with a diagnosis of aspergillosis, there were 614 hematopoietic and reticuloendothelial system patients, 100 lung cancer patients, and 73 lymphoma cancer patients. The overall incidence rates of aspergillosis tended to increase significantly from 2006 to 2017 (from 3.50 to 13.37 per 10,000 person-years, p value: <0.0001). Regarding sex, the incidence rates of aspergillosis in males and females were 12.52 and 7.53 per 10,000 person-years, respectively. Patients with a diagnosis of aspergillosis had a 2.30-fold (95% CI: 2.14–2.48, p value: <0.0001) higher risk of mortality than those without aspergillosis.

Conclusion

The incidence of aspergillosis was increased in cancer patients, and cancer patients with aspergillosis had a significantly higher risk of mortality than those without aspergillosis.

Differentiation of Pulmonary Lymphoma Manifestations and Nonlymphoma Infiltrates in Possible Invasive Fungal Disease Using Fast T1-weighted Magnetic Resonance Imaging at 3 T Comparison of Texture Analysis, Mapping, and Signal Intensity Quotients

PURPOSE

This study aimed to evaluate the diagnostic performance of texture analysis (TA), T1 mapping, and signal intensity quotients derived from fast T1-weighted gradient echo (T1w GRE) sequences for differentiating pulmonary lymphoma manifestations and nonlymphoma infiltrates in possible invasive fungal disease in immunocompromised hematological patients.

MATERIALS AND METHODS

Twenty patients with hematologic malignancies and concomitant immunosuppression (including 10 patients with pulmonary lymphoma manifestations and 10 patients with nonlymphoma infiltrates) prospectively underwent 3 T magnetic resonance imaging using a conventional T1w GRE sequence and a T1w GRE mapping sequence with variable flip angle. A region of interest was placed around the most representative lesion in each patient. TA was performed using PyRadiomics. T1 relaxation times were extracted from precompiled maps and calculated manually. Signal intensity quotients (lesion/muscle) were calculated from conventional T1w GRE sequences.

RESULTS

Of all TA features, variance, mean absolute deviation, robust mean absolute deviation, interquartile range, and minimum were significantly different between the 2 entities (P<0.05), with excellent diagnostic performance in receiver operating characteristic analysis (area under the curve [AUC] >80%). Neither T1 relaxation times from precompiled maps (AUC=63%; P=0.353) nor manual calculation (AUC=63%; P=0.353) nor signal intensity quotients (AUC=70%; P=0.143) yielded significant differences.

CONCLUSIONS

TA from fast T1w GRE images can differentiate pulmonary lymphoma manifestations and nonlymphoma infiltrates in possible invasive fungal disease with excellent diagnostic performance using the TA features variance, mean absolute deviation, robust mean absolute deviation, interquartile range, and minimum. Combining a fast T1w GRE sequence with TA seems to be a promising tool to differentiate these 2 entities noninvasively.

The sat1 Gene Is Required for the Growth and Virulence of the Human Pathogenic Fungus Aspergillus fumigatus

Aspergillus fumigatus is an important opportunistic pathogenic fungus that causes invasive aspergillosis in immunocompromised humans. Regulated fungal growth is essential for disease development and progression. Thus, screening for genes that regulate fungal growth may lead to the identification of potential therapeutic targets for invasive aspergillosis (IA). Screening of the transfer DNA (T-DNA) random-insertion A. fumigatus mutants identified a severe growth deficiency mutant AFM2954 and featured sat1 as the mutated gene described as a putative intracellular protein transporter of unknown function. The deletion of sat1 exhibited severe growth defects and significantly increased the nematode and mouse survival rates and decreased the fungal loads and histopathological damages in mouse lungs. Transcriptomic analyses revealed expression changes associated with the cell wall synthesis, the tricarboxylic acid cycle (TCA cycle), and oxidative phosphorylation genes in the sat1 mutant. Deletion of the gene resulted in resistance to cell wall-perturbing agents and thickened cell wall as well as reduced ATP contents and mitochondrial membrane potential, suggested that sat1 affected the cell wall synthesis and mitochondrial function of A. fumigatus. All together, our study uncovered novel functions of sat1 in growth and virulence of A. fumigatus and provided a theoretical basis for the development of new therapeutic target for treating IA patients. IMPORTANCE Aspergillus fumigatus is the main causative agent of invasive aspergillosis in immunocompromised hosts, with up to 90% lethality. Nevertheless, the fungal factors that regulate the pathogenesis of A. fumigatus remain largely unknown. Better understanding of the mechanisms controlling growth of A. fumigatus may provide novel therapeutic targets. In the present study, we characterized sat1 in the opportunistic pathogen A. fumigatus. The function of sat1 remains unknown. We proved its important role in growth and virulence, likely because of its effects on cell wall synthesis and mitochondrial functions.

Clinical Characteristics and Prognostic Risk Factors of Patients With Proven Invasive Pulmonary Aspergillosis: A Single-Institution Retrospective Study

Background: The mortality and burden of medical costs associated with invasive pulmonary aspergillosis (IPA) is very high. Currently, the clinical features and prognostic factors of patients with proven IPA are not very clear, especially in the Chinese population. In this retrospective analysis, we aimed to identify the clinical features and prognostic factors of patients with proven IPA. Methods: The diagnostic criteria for proven IPA were based on the international consensus of the EORTC/MSG. Data of patients with proven IPA at the West China Hospital of Sichuan University between January 2012 and December 2018 were collected. The optimal cut-off value of continuous variables was determined by Receiver Operating Characteristic curve and maximum Youden's index. Finally, using the Cox regression analysis to identify correlations between the clinical parameters associated with morbidity. Results: A total of 117 patients with proven IPA were included in the study, and 32 (27.4%) patients died during the follow-up period. Compared with the survivor group, elderly, patients with comorbidities, and patients undergoing chemotherapy and the level of inflammatory biomarkers [erythrocyte sedimentation rate, platelet count, interleukin-6, C-reactive protein (CRP)] in the non-survivor group were higher, while the albumin level was lower (P = 0.018). The imaging features were consolidation, nodules, cavities, pleural effusion, ground-glass shadows, and halo signs in order. Overall, 41.0% patients had mixed imaging features. The results suggested the most appropriate cut-off value of age and CRP were 60 years and 14.1 mg/L, respectively. The multivariate Cox regression analysis suggested that advanced age (>60 years) [hazard ratio (HR): 10.7, confidence interval (CI): 2.5-44.9, P < 0.001), undergoing chemotherapy (HR: 9.5, CI: 2.7-32.9, P < 0.001), presence of pleural effusion (HR: 5.74, CI: 1.6-20.8, P = 0.008), and increased CRP levels (>14.1 mg/L) (HR: 6.3, CI: 1.2-34.3, P = 0.033) were risk factors for all-cause mortality in patients with proven aspergillosis. Conclusions: This study showed that the prognosis of proven IPA is poor, and the age >60 years, undergoing chemotherapy, pleural effusion on CT image, and CRP levels >14.1 mg/L may be as risk factors for mortality in patients with proven IPA. large samples and real-world studies are needed to confirm these results in the future.

Temporal Trends in the Microbiological Characteristics of Sepsis in the United States: A Population Based Study

BACKGROUND

Epidemiologic studies are needed for monitoring population-level trends in sepsis. This study examines sepsis-causing microorganisms from 2006 to 2014 in the United States using data from the Nationwide Inpatient Sample database.

METHODS

7 860 686 adults hospitalized with sepsis were identified using a validated ICD-9 coding approach. Associated microorganisms were identified by ICD-9 code and classified by major groups (Gram-positive, Gram-negative, fungi, anaerobes) and specific species for analysis of their incidence and mortality.

RESULTS

The rate of sepsis incidence has increased for all four major categories of pathogens, while the mortality rate decreased. In 2014, Gram-negative pathogens had a higher incidence than Gram-positives. Anaerobes increased the fastest with an average annual increase of 20.17% (p < 0.001). Fungi had the highest mortality (19.28%) and the slowest annual decrease of mortality (-2.31%, p = 0.006) in 2013, while anaerobic sepsis had the highest hazard of mortality (adjusted HR 1.60, 95% CI 1.53-1.66).

CONCLUSIONS

Gram-negative pathogens have replaced Gram-positives as the leading cause of sepsis in the United States in 2014 during the study period (2006-2014). The incidence of anaerobic sepsis has an annual increase of 20%, while the mortality of fungal sepsis has not decreased at the same rate as other microorganisms. These findings should inform the diagnosis and management of septic patients, as well as the implementation of public health programs.

Antifungal Efficacy of Redox-Active Natamycin against Some Foodborne Fungi-Comparison with Aspergillus fumigatus

The fungal antioxidant system is one of the targets of the redox-active polyene antifungal drugs, including amphotericin B (AMB), nystatin (NYS), and natamycin (NAT). Besides medical applications, NAT has been used in industry for preserving foods and crops. In this study, we investigated two parameters (pH and food ingredients) affecting NAT efficacy. In the human pathogen, Aspergillus fumigatus, NAT (2 to 16 μg mL⁻¹) exerted higher activity at pH 5.6 than at pH 3.5 on a defined medium. In contrast, NAT exhibited higher activity at pH 3.5 than at pH 5.6 against foodborne fungal contaminants, Aspergillus flavus, Aspergillus parasiticus, and Penicillium expansum, with P. expansum being the most sensitive. In commercial food matrices (10 organic fruit juices), food ingredients differentially affected NAT antifungal efficacy. Noteworthily, NAT overcame tolerance of the A. fumigatus signaling mutants to the fungicide fludioxonil and exerted antifungal synergism with the secondary metabolite, kojic acid (KA). Altogether, NAT exhibited better antifungal activity at acidic pH against foodborne fungi; however, the ingredients from commercial food matrices presented greater impact on NAT efficacy compared to pH values. Comprehensive determination of parameters affecting NAT efficacy and improved food formulation will promote sustainable food/crop production, food safety, and public health.

Biological contaminants in the indoor air environment and their impacts on human health

Indoor air environment contains a complex mixture of biological contaminants such as bacteria, fungi, viruses, algae, insects, and their by-products such as endotoxins, mycotoxins, volatile organic compounds, etc. Biological contaminants have been categorized according to whether they are allergenic, infectious, capable of inducing toxic or inflammatory responses in human beings. At present, there is a lack of awareness about biological contamination in the indoor environment and their potential sources for the spreading of various infections. Therefore, this review article examines the association of biological contaminants with human health, and it will also provide in-depth knowledge of various biological contaminants present in different places such as residential areas, hospitals, offices, schools, etc. Moreover, qualitative and quantitative data of bio-contaminants in various indoor environments such as schools, hospitals, residential houses, etc. have also been derived from the recent literature survey.

Nitrogen, Iron and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence

Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.

Aspergillosis of central nervous system in patients with leukemia and stem cell transplantation: a systematic review of case reports

Background

Aspergillosis of Central Nervous System (CNS) is a highly lethal infection in patients with leukemia and Stem Cell Transplantation (SCT).

Methods

Case reports of CNS aspergillosis in patients with leukemia and SCT published between 1990 and August 2020 were gathered using a structured search through PubMed/Medline.

Results

Sixty-seven cases were identified over the searches of the PubMed bibliographic database and then, 59 cases were included in the final analysis. Europe had the largest share of cases at 57.6% (34 reports), followed by Americas and Asia. Affected patients were predominantly males (58.6%) and the mean age of the patients was 36.1 years, while 62.7% of the patients were under the age of 50 years. The most common leukemia types include Acute Lymphoblastic Leukemia (ALL), Chronic Lymphocytic Leukemia (CLL), and Acute Myeloid Leukemia (AML) at 43.4%, 27.4%, and 23.5%, respectively. Furthermore, stem cell transplantation was reported in 11 cases. The overall mortality was 33%; however, the attributable mortality rate of CNS aspergillosis was 24.5%. Altered mental status, hemiparesis, cranial nerve palsies, and seizures were the clearest manifestations of infection and lung involvement reported in 57% of the patients. Histopathologic examination led to the diagnosis of infection in 57% of the patients followed by culture (23.7%), galactomannan assay (8.5%), and molecular method (3.3%). Amphotericin B and voriconazole were the most frequently used drugs for infection treatment. Good results were not obtained in one-third of the patients treated by voriconazole. Finally, neurosurgical intervention was used for 23 patients (39%).

Conclusion

CNS aspergillosis is a rapidly progressive infection in leukemic patients. Thus, these patients should be followed up more carefully. Furthermore, management of induction chemotherapy, use of different diagnostic methods, and use of appropriate antifungal can lead to infection control.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12941-021-00452-9.

Real-life experience with CPX-351 and impact on the outcome of high-risk AML patients: a multicentric French cohort

CPX-351 is a liposomal formulation of cytarabine and daunorubicin approved for the treatment of adults with newly diagnosed, therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (MRC-AML). We retrospectively analyzed the efficacy and safety of CPX-351 in a real-world setting in 103 patients from 12 French centers, including the evaluation of molecular abnormalities at baseline and minimal residual disease (MRD) in responding patients, compared with a historical data set from Bordeaux-Toulouse DATAML registry. A favorable safety profile was observed, with a low frequency of alopecia (11%) and gastrointestinal toxicity (50%). The overall response rate after induction was 59%, and MRD <10-3 was achieved in 57% of complete response (CR)/CR with incomplete hematological recovery (CRi) patients. Only the presence of mutated TP53 (P = .02) or PTPN11 (P = .004) predicted lower response in multivariate analysis. Interestingly, high-risk molecular prognosis subgroups defined by 2017 European LeukemiaNet risk stratification, including ASXL1 and RUNX1 mutations, were not associated with a significantly lower response rate using CPX-351. With a median follow-up of 8.6 months, median overall survival (OS) was 16.1 months. Thirty-six patients underwent allogeneic stem cell transplantation with a significantly longer median OS compared with nontransplanted patients (P < .001). In multivariate analyses, only spliceosome mutations were associated with better OS (P = .04). In comparison with intensive chemotherapy, there was no difference in OS for patients <60 years. These data confirm the efficacy and safety of CPX-351 in high-risk AML (t-AML and MRC-AML) in a real-life setting. CPX-351 is a treatment of choice for patients aged ≥60 years.

Nasal-alar invasive cutaneous aspergillosis in a patient with anaplastic astrocytoma: A case report

Invasive aspergillosis is commonly encountered in immunosuppressed patients either primarily through direct inoculation or secondary from blood dissemination. This report describes a case of 53 years old immunocompromised female patient who was diagnosed with frontotemporal anaplastic astrocytoma and developed nasal skin lesion turned to be invasive cutaneous aspergillosis.

The Clinical Characteristics of Patients With Nonneutropenic Invasive Pulmonary Aspergillosis

Objective: The goal of this study was to reveal the clinical manifestations of nonneutropenic invasive pulmonary aspergillosis (IPA), which are different from those of neutropenic patients.

Methods: The clinical data of patients with nonneutropenic IPA were collected at the Department of Respiratory and Critical Care Medicine, Jinling Hospital, from February 2009 to November 2019. We analyzed the general conditions, clinical manifestations, imaging findings, and laboratory tests of these IPA patients.

Results: A total of 116 patients with nonneutropenic IPA (31 proven and 85 probable) were included. They had an average age of 59.8 years. The most common underlying disease was chronic obstructive pulmonary disease (COPD, n = 33). The common clinical symptoms included cough (93.1%, n = 108), expectoration (59.5%, n = 69), fever (57.8%, n = 67), hemoptysis (30.2%, n = 35), and dyspnea (40.5%, n = 47). The common CT imaging manifestations included consolidation (47.4%, n = 55), cavities (47.4%, n = 55), air crescent sign (14.7%, n = 17), and nodules (8.6%, n = 10). Multiple lesions (74.1%, n = 86) were more common than single lesions (17.2%, n = 20) and diffuse lesions (8.6%, n = 10). The positive rate of laboratory tests was 88.2% (30/34) for BALF galactomannan (GM), 55.4% (56/101) for serum GM, 45.3% (48/106) for 1,3-β-D-glucan (BDG), 43.3% (46/106) for sputum culture, and 36.4% (20/55) for BALF culture. Patients who had high serum GM level [GM optical density index (ODI) >1] were more likely to have severe respiratory symptoms and higher serum ferritin. Further investigation showed that there was a positive correlation between serum GM level and serum ferritin level.

Conclusion: The clinical symptoms and radiological manifestations of nonneutropenic IPA are diverse and often lead to delayed diagnosis. It is important to become more vigilant of aspergillosis in nonneutropenic patients in order to achieve early diagnosis and treatment and to reduce mortality.

Interactions of FK506 and Rapamycin With FK506 Binding Protein 12 in Opportunistic Human Fungal Pathogens

Over the past few decades advances in modern medicine have resulted in a global increase in the prevalence of fungal infections. Particularly people undergoing organ transplants or cancer treatments with a compromised immune system are at an elevated risk for lethal fungal infections such as invasive candidiasis, aspergillosis, cryptococcosis, etc. The emergence of drug resistance in fungal pathogens poses a serious threat to mankind and it is critical to identify new targets for the development of antifungals. Calcineurin and TOR proteins are conserved across eukaryotes including pathogenic fungi. Two small molecules FK506 and rapamycin bind to FKBP12 immunophilin and the resulting complexes (FK506-FKBP12 and rapamycin-FKBP12) target calcineurin and TOR, respectively in both humans and fungi. However, due to their immunosuppressive nature these drugs in the current form cannot be used as an antifungal. To overcome this, it is important to identify key differences between human and fungal FKBP12, calcineurin, and TOR proteins which will facilitate the development of new small molecules with higher affinity toward fungal components. The current review highlights FK506/rapamycin-FKBP12 interactions with calcineurin/TOR kinase in human and fungi, and development of non-immunosuppressive analogs of FK506, rapamycin, and novel small molecules in inhibition of fungal calcineurin and TOR kinase.

Principal-agent theory-based cost and reimbursement structures of isavuconazole treatment in German hospitals

BACKGROUND

Isavuconazole (ISA) is a frequently used antifungal agent for the treatment of invasive fungal diseases (IFDs). However, hospital reimbursement data for ISA is limited.

OBJECTIVES

The primary objective of this study was to analyse the different perspectives of relevant stakeholders and the (dis)incentives for the administration of ISA in Germany. To that aim, the health economic effects of using ISA from a hospital management perspective were analysed.

PATIENTS/METHODS

Based on principal-agent theory (PAT), the perspectives of (a) the patient (principal) as well as (b) physicians, (c) pharmacists and iv. hospital managers (all agents) were analysed. For the evaluation of the cost-containment and reimbursement strategies of ISA, the German diagnosis-related group (G-DRG) system was used.

RESULTS

Hospitals individually negotiating additional payments for innovative treatment procedures (zusatzentgelte [ZE]) within the G-DRG system is a key element of hospital management for the reduction of total healthcare expenditure. Our analysis demonstrated the beneficial role of ISA in healthcare resource utilisation, primarily due to a shortened overall length of hospital stay. Depending on underlying disease, coded G-DRG and ISA formulation, large differences in total reimbursement and the amount of ZE was shown. The PAT demonstrated disincentives for hospital managers to use innovative drugs.

CONCLUSIONS

Based on the PAT, beneficial, detrimental and indifferent perspectives of different stakeholders regarding the usage of ISA were shown. A reduction of bureaucratic hurdles is needed in Germany for the extension of effective and innovative antifungal treatment strategies with ISA.

The pheromone response module, a mitogen-activated protein kinase pathway implicated in the regulation of fungal development, secondary metabolism and pathogenicity

Mitogen-activated protein kinase (MAPK) pathways are highly conserved from yeast to human and are required for the regulation of a multitude of biological processes in eukaryotes. A pentameric MAPK pathway known as the Fus3 pheromone module was initially characterised in Saccharomyces cerevisiae and was shown to regulate cell fusion and sexual development. Individual orthologous pheromone module genes have since been found to be highly conserved in fungal genomes and have been shown to regulate a diverse array of cellular responses, such as cell growth, asexual and sexual development, secondary metabolite production and pathogenicity. However, information regarding the assembly and structure of orthologous pheromone modules, as well as the mechanisms of signalling and their biological significance is limited, specifically in filamentous fungal species. Recent studies have provided insight on the utilization of the pheromone module as a central signalling hub for the co-ordinated regulation of fungal development and secondary metabolite production. Various proteins of this pathway are also known to regulate reproduction and virulence in a range of plant pathogenic fungi. In this review, we discuss recent findings that help elucidate the structure of the pheromone module pathway in a myriad of fungal species and its implications in the control of fungal growth, development, secondary metabolism and pathogenicity.

Breakthrough invasive fungal infections: Who is at risk?

The epidemiology of invasive fungal infections (IFIs) in immunocompromised individuals has changed over the last few decades, partially due to the increased use of antifungal agents to prevent IFIs. Although this strategy has resulted in an overall reduction in IFIs, a subset of patients develop breakthrough IFIs with substantial morbidity and mortality in this population. Here, we review the most significant risk factors for breakthrough IFIs in haematology patients, solid organ transplant recipients, and patients in the intensive care unit, focusing particularly on host factors, and highlight areas that require future investigation.

Impact of invasive aspergillosis occurring during first induction therapy on outcome of acute myeloid leukaemia (SEIFEM-12B study)

BACKGROUND

Acute myeloid leukaemia (AML) patients are at high risk of invasive aspergillosis (IA) after first induction chemotherapy (CHT). Although IA risk factors have been identified, few data are available on impact of IA, occurring during induction phase, on overall AML outcome.

PATIENTS AND RESULTS

The end point of this multicentre, case-control, study was to evaluate whether IA, occurring after first induction CHT, can affect treatment schedule and patient's outcome. We identified 40 AML patients (cases) who developed IA during first induction phase, 31 probable (77.5%) and 9 proven (22.5%). These cases were matched with a control group (80 AML) without IA, balanced according to age, type of CHT, AML characteristics and cytogenetic-molecular risk factors. The overall response rate to induction CHT was the same in the 2 groups. In the 40 cases with IA, the overall response rate to antifungal treatment was favourable (80%) but it was significantly affected by the achievement of leukaemia complete remission (CR) with induction CHT. In fact, in cases with AML responsive to induction CHT, responses of IA to antifungal therapy were 96% compared to 21% in cases of AML not responsive to induction treatment (P < .0001). The adherence to the schedule and full doses of CHT were reported in 35% of cases (14/40) and in 76% of controls (61/80) (P = .0001; OR 6.7; 95% CI 2.7-16.6). After first induction CHT, a significant higher number of cases (15/40; 37.5%) compared to controls (9/80; 11%) could not receive additional cycles of CHT (P = .0011, OR 4.8; 95% CI 1.9-12.3). The IA-related mortality was 22.5%. The median OS of cases was significantly worse than OS of controls with a difference of 12.3 months (12.1 vs 24.4 months, P = .04). However, the occurrence of IA during first induction phase did not have a significant impact on the OS of cases who achieved a CR of AML with induction CHT which are able to proceed, despite the IA, with their therapeutic program, achieving the same OS as the control group with AML in CR (P = ns).

CONCLUSIONS

These data show that IA during first induction CHT can delay the subsequent therapeutic program and has a significant impact on OS, specifically in AML patients who did not achieved a CR of AML with the first course of CHT.

Trapping conformational states of a flavin-dependent N-monooxygenase in crystallo reveals protein and flavin dynamics

The siderophore biosynthetic enzyme A (SidA) ornithine hydroxylase from Aspergillus fumigatus is a fungal disease drug target involved in the production of hydroxamate-containing siderophores, which are used by the pathogen to sequester iron. SidA is an N-monooxygenase that catalyzes the NADPH-dependent hydroxylation of l-ornithine through a multistep oxidative mechanism, utilizing a C4a-hydroperoxyflavin intermediate. Here we present four new crystal structures of SidA in various redox and ligation states, including the first structure of oxidized SidA without NADP(H) or l-ornithine bound (resting state). The resting state structure reveals a new out active site conformation characterized by large rotations of the FAD isoalloxazine around the C1-'C2' and N10-C1' bonds, coupled to a 10-Å movement of the Tyr-loop. Additional structures show that either flavin reduction or the binding of NADP(H) is sufficient to drive the FAD to the in conformation. The structures also reveal protein conformational changes associated with the binding of NADP(H) and l-ornithine. Some of these residues were probed using site-directed mutagenesis. Docking was used to explore the active site of the out conformation. These calculations identified two potential ligand-binding sites. Altogether, our results provide new information about conformational dynamics in flavin-dependent monooxygenases. Understanding the different active site conformations that appear during the catalytic cycle may allow fine-tuning of inhibitor discovery efforts.

The Pheromone Module SteC-MkkB-MpkB-SteD-HamE Regulates Development, Stress Responses and Secondary Metabolism in Aspergillus fumigatus

In order for eukaryotes to efficiently detect and respond to environmental stimuli, a myriad of protein signaling pathways are utilized. An example of highly conserved signaling pathways in eukaryotes are the mitogen-activated protein kinase (MAPK) pathways. In fungi, MAPK pathways have been shown to regulate a diverse array of biological processes, such as asexual and sexual development, stress responses and the production of secondary metabolites (SMs). In the model fungus Aspergillus nidulans, a MAPK pathway known as the pheromone module is utilized to regulate both development and SM production. This signaling cascade consists of the three kinases SteC, MkkB, and MpkB, as well as the SteD adaptor protein and the HamE scaffold. In this study, homologs of each of these proteins have been identified in the opportunistic human pathogen A. fumigatus. By performing epitope tagging and mass spectrometry experiments, we have shown that these proteins form a pentameric complex, similar to what is observed in A. nidulans. This complex has been shown to assemble in the cytoplasm and MpkB enters the nucleus, where it would presumably interact with various transcription factors. Pheromone module mutant strains exhibit drastic reductions in asexual sporulation, vegetative growth rate and production of SMs, such as gliotoxin. Mutants also display increased sensitivity to cell wall and oxidative stress agents. Overall, these data provide evidence of the existence of a conserved MAP kinase signaling pathway in Aspergillus species and suggest that this pathway is critical for the regulation of fungal development and secondary metabolism.

Performance of existing definitions and tests for the diagnosis of invasive aspergillosis in critically ill, adult patients: A systematic review with qualitative evidence synthesis

OBJECTIVES

To summarize the available evidence on the diagnostic performance for invasive aspergillosis (IA) in non-hematological, non-solid organ transplantation critically ill patients of the following: (i) existing definitions of IA (developed either for classical immunocompromised populations or for non-immunocompromised critically ill patients); (ii) laboratory tests; (iii) radiology tests.

METHODS

A systematic review was performed by evaluating studies assessing the diagnostic performance for IA of a definition/s and/or laboratory/radiology test/s vs. a reference standard (histology) or a reference definition.

RESULTS

Sufficient data for evaluating the performance of existing definitions and laboratory tests for the diagnosis of IA in critically ill patients is available only for invasive pulmonary aspergillosis. Against histology/autopsy as reference, the AspICU definition showed a promising diagnostic performance but based on small samples and applicable only to patients with positive respiratory cultures. Studies on laboratory tests consistently indicated a better diagnostic performance of bronchoalveolar lavage fluid (BALF) galactomannan (GM) than serum GM, and a suboptimal specificity of BALF and serum (1,3)-β-D-glucan.

CONCLUSIONS

Evidence stemming from this systematic review will guide the discussion for defining invasive aspergillosis within the FUNDICU project. The project aims to develop a standard set of definitions for invasive fungal diseases in critically ill, adult patients.

Identification of SkpA-CulA-F-box E3 ligase complexes in pathogenic Aspergilli

The ubiquitin proteasome system is critical for the regulation of protein turnover, which is implicated in the modulation of a wide array of biological processes in eukaryotes, ranging from cell senescence to virulence in plant and human hosts. Proteins to be marked for ubiquitination and subsequent degradation are bound by F-box proteins, which are interchangeable substrate-recognising receptors. These F-box proteins bind a wide range of substrates and associate with the adaptor protein Skp1 and the scaffold Cul1 to form Skp1-Cul1-F-box (SCF) complexes. SCF complex components are highly conserved in eukaryotes, ranging from yeast to humans. However, information regarding the composition of these complexes and the biological roles of F-box proteins is limited, specifically in filamentous fungal species like the genus Aspergillus. In this study, we have identified 51 and 55 fbx-encoding genes in the genomes of two pathogenic fungi, A. fumigatus and A. flavus, respectively. Immunoprecipitations of the HA-tagged SkpA adaptor protein revealed that 26 F-box proteins in A. fumigatus and 30 F-box proteins in A. flavus are involved in SCF complex formation during vegetative growth. These interactome data also revealed that a diverse array of SCF complex conformations exist in response to various exogenous stressors. Lastly, we have provided evidence that the F-box protein Fbx45 interacts with SkpA in both species in response to Amphotericin B. Orthologs of the fbx45 gene are highly conserved in Aspergillus species, but are not present within the genomes of organisms such as yeast, plants or humans. This suggests that Fbx45 could potentially be a novel F-box protein that is unique to specific filamentous fungi such as Aspergillus species.

A multicentre prospective study evaluating the impact of proton-pump inhibitors omeprazole and pantoprazole on voriconazole plasma concentrations

Voriconazole is an antifungal metabolised by CYP2C19 enzyme, which can be inhibited by proton-pump inhibitors (PPIs). A prospective observational study was carried out to determine the influence of PPIs on voriconazole pharmacokinetic. The 78 patients included were divided into 4 groups: omeprazole (n = 32), pantoprazole (n = 25), esomeprazole (n = 3) and no PPI (n = 18). Patients with no PPI had no significant difference in plasma voriconazole concentration when compared with those with PPI (2.63 ± 2.13 μg/mL [95% confidence interval {CI} 1.57-3.69] vs 2.11 ± 1.73 μg/mL [95%CI 1.67-2.55], P > .05). However, voriconazole plasma concentration was significantly lower in patients treated with pantoprazole vs those treated with omeprazole (1.44 ± 1.22 μg/mL [95%CI 0.94-1.94) vs 2.67 ± 1.88 μg/mL [95%CI 2.02-3.32], P = .013) suggesting a greater CYP2C19 enzyme inhibitory effect of omeprazole. This study demonstrates the greater CYP inhibition capacity of omeprazole and should be helpful for the choice of PPIs for patients treated with voriconazole.

Diagnostic accuracy of magnetic resonance imaging in the evaluation of pulmonary infections in immunocompromised patients

Purpose

To evaluate the accuracy of magnetic resonance imaging (MRI) for diagnosing pulmonary infections in immunocompromised adults.

Material and methods

Computed tomography (CT) and MRI chest were performed in 35 immuno-compromised patients suspected of pulmonary infection. The MRI sequences that were performed included axial and coronal T2 half-Fourier acquisition single-shot turbo spin-echo (HASTE), spectrally attenuated inversion recovery (SPAIR), true fast imaging with steady-state free precession (TRUFI), and three-dimensional fast low angle shot (3D FLASH) using breath-hold and respiratory triggered BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction). The presence of nodules, consolidations, and ground-glass opacities was evaluated. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for MRI using CT scan as a reference standard.

Results

The sensitivity of MRI in nodule detection was 50% overall and 75% for nodules measuring more than 5 mm. Consolidation was detected with 100% sensitivity. Sensitivity and PPV for the detection of ground-glass opacities (GGOs) were 77.7% and 53.8%, respectively. T2 HASTE axial had the fewest image artefacts. Respiratory triggered MR pulse sequence did not add any significant diagnostic information as compared to the non-respiratory triggered MR pulse sequences.

Conclusions

Sensitivity for detecting small nodules and GGOs on MR is poor; CT scan remains the imaging modality of choice for the evaluation of pulmonary infections in immunocompromised patients. However, MRI can be used in the follow-up imaging of these patients.

Glycobiology of Human Fungal Pathogens: New Avenues for Drug Development

Invasive fungal infections (IFI) are an increasing threat to the developing world, with fungal spores being ubiquitous and inhaled every day. Some fungal species are commensal organisms that are part of the normal human microbiota, and, as such, do not pose a threat to the immune system. However, when the natural balance of this association is disturbed or the host's immune system is compromised, these fungal pathogens overtake the organism, and cause IFI. To understand the invasiveness of these pathogens and to address the growing problem of IFI, it is essential to identify the cellular processes of the invading organism and their virulence. In this review, we will discuss the prevalence and current options available to treat IFI, including recent reports of drug resistance. Nevertheless, the main focus of this review is to describe the glycobiology of human fungal pathogens and how various components of the fungal cell wall, particularly cell wall polysaccharides and glycoconjugates, are involved in fungal pathogenicity, their biosynthesis and how they can be potentially exploited to develop novel antifungal treatment options. We will specifically describe the nucleotide sugar transporters (NSTs) that are important in fungal survival and suggest that the inhibition of fungal NSTs may potentially be useful to prevent the establishment of fungal infections.

Pentraxin 3 Gene Polymorphisms and Pulmonary Aspergillosis in Chronic Obstructive Pulmonary Disease Patients

Background

Pentraxin 3 (PTX3) plays an important role in resistance to Aspergillus infections. Previous studies have suggested that PTX3 polymorphisms influence the risk of invasive aspergillosis among transplantation recipients. This study investigated the association between PTX3 gene polymorphisms and pulmonary aspergillosis in a chronic obstructive pulmonary disease (COPD) population.

Methods

We included 173 consecutive inpatients with COPD. Thirty-six case patients were finally diagnosed with pulmonary aspergillosis. Among these, 25 case patients had invasive pulmonary aspergillosis (IPA), and 11 case patients had chronic pulmonary aspergillosis (CPA). Three single nucleotide polymorphisms (SNPs; rs2305619, rs3816527, and rs1840680) in the PTX3 gene were detected by polymerase chain reaction direct sequencing, and their associations with aspergillosis were evaluated. Plasma PTX3 levels were measured by enzyme-linked immunosorbent assay.

Results

Three SNPs were consistent with Hardy-Weinberg equilibrium. The recessive model for SNP rs1840680 suggests that the AA homozygote is associated with a higher risk for pulmonary aspergillosis (both IPA and CPA) in COPD patients. However, for genotypic and allele frequencies of rs2305619 and rs3816527, no association was observed. The distribution of haplotypes (rs2305619 and rs3816527) also showed no significant differences. Plasma PTX3 levels significantly increased in IPA patients. In the IPA group, the rs1840680 AA genotype subjects showed lower plasma PTX3 levels than those harboring AG and GG genotypes.

Conclusions

This study showed a significant association between PTX3 rs1840680 polymorphisms and the susceptibility of pulmonary aspergillosis in patients with COPD. Plasma PTX3 levels may be potentially used as indicators for the diagnosis of IPA in COPD patients.

Revealing the Virulence Potential of Clinical and Environmental Aspergillus fumigatus Isolates Using Whole-Genome Sequencing

Aspergillus fumigatus is considered a common causative agent of human fungal infections. A restricted number of virulence factors have been described, and none of them lead to a differentiation in the virulence level among different strains. Variations in the virulence phenotype depending on the isolate origin, measured as survival percentage in animal infection models, have been previously reported. In this study, we analyzed the whole-genome sequence of A. fumigatus isolates from clinical and environmental origins to determine their virulence genetic content. The sample included four isolates sequenced at the University Medical Center Groningen (UMCG), three clinical (two of them isolated from the same patient) and the experimental strain B5233, and the draft genomes of one reference strain, two environmental and two clinical isolates obtained from a public database. The fungal genomes were screened for the presence of virulence-related genes (VRGs) using an in-house database of 244 genes related to thermotolerance, resistance to immune responses, cell wall formation, nutrient uptake, signaling and regulation, and production of toxins and secondary metabolites and allergens. In addition, we performed a variant calling analysis to compare the isolates sequenced at the UMCG and investigated their genetic relatedness using the TRESP (Tandem Repeats located within Exons of Surface Protein coding genes) genotyping method. We neither observed a difference in the virulence genetic content between the clinical isolates causing an invasive infection and a colonizing clinical isolate nor between isolates from the clinical and environmental origin. The four novel A. fumigatus sequences had a different TRESP genotype and a total number of genetic variants ranging from 48,590 to 68,352. In addition, a comparative genomics analysis showed the presence of single nucleotide polymorphisms in VRGs and repetitive genetic elements located next to VRG groups, which could influence the regulation of these genes. In conclusion, our genomic analysis revealed a high genetic diversity between environmental and clinical A. fumigatus isolates, as well as between clinical isolates from the same patient, indicating an infection with a mixed-population in the latter case. However, all isolates had a similar virulence genetic content, demonstrating their pathogenic potential at least at the genomic level.