Invasive Aspergillosis: Current Strategies for Diagnosis and Management

Evidence-based clinical standard for the diagnosis and treatment of invasive lung aspergillosis in the patient with oncohematologic disease

Aspergillosis is a disease caused by the filamentous fungus Aspergillus spp. with a spectrum of clinical presentation that includes invasive and noninvasive forms. The invasive clinical presentation of aspergillosis most frequently affects people with compromised immune systems. In patients with oncohematologic pathology, invasive lung aspergillosis is a significant opportunistic mycosis, because it occurs frequently and has a major impact on morbidity, mortality, and high costs. The global problem of antimicrobial resistance, to which improper use of antifungals contributes, has put Aspergilus spp. in the spotlight, so it is important to generate guidelines for guidance in the proper use of antifungals in the management of invasive lung aspergillosis, to obtain better clinical outcomes and promote rational use of antifungals. This guideline contains recommendations for diagnosing and treating invasive lung aspergillosis in patients with oncohematologic disease, based on evidence and defined through a participatory process of expert consensus, for the Latin American context.

Clinical evaluation of droplet digital PCR in suspected invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis (IPA), the most common fungal infection, is associated with high mortality of affected patients. Traditional diagnostic methods exhibit limited sensitivity and specificity, raising big challenges for precise management of the patients. There is thus an urgent need to find out a timely and accurate diagnostic method in clinical practice. In this study, 163 patients suspected with IPA were enrolled. The medical data of the patients were retrieved from hospital information system. The 158 patients with complete data were classified into an IPA group with 122 cases (58 putative IPA, 19 probable IPA, and 45 possible IPA cases) and a non-IPA group with 36 cases. Cell-free DNA (cfDNA) of bronchoalveolar lavage fluid (BALF) or plasma samples was detected via a droplet digital PCR (ddPCR) assay targeting Aspergillus spp. Overall, this ddPCR assay demonstrated a higher sensitivity of 50.8 % for IPA diagnosis, compared with that of fungal culture (44.3 %) and smear test (10.7 %). Moreover, its sensitivity was higher in the IPA group (73.1 %) and putative IPA subgroup (88.2 %) when using BALF samples, compared with those using plasma samples (P < 0.01). It achieved a high specificity of 94.4 % for IPA diagnosis, with significant variations in cfDNA copy numbers across the subgroups (P < 0.05). In addition, the ddPCR results were associated with the prognosis of the patients at the discharge (P < 0.05). In conclusion, ddPCR assay demonstrated a good performance for IPA diagnosis when using BALF samples, especially for putative IPA. The ddPCR results could be integrated with clinical data to improve prognostic prediction.

A Unique Case of Fungal Endometritis Caused by Aspergillus quadrilineatus in an Immunocompetent Woman and Literature Review

Abnormal uterine bleeding (AUB) is a common gynecological concern often attributed to hormonal disorders, malignancies, or infections. While bacterial and viral infections are frequently investigated, fungal infections, such as aspergillosis, are often overlooked. This case report highlights a rare instance of endometrial aspergillosis caused by Aspergillus quadrilineatus in an immunocompetent woman. A 64-year-old woman presented with persistent vaginal bleeding. Histopathological examination of endometrial tissue revealed septate hyphae consistent with fungal infection. Molecular analysis identified the causative agent as A. quadrilineatus. The A. quadrilineatus isolate demonstrated susceptibility to various antifungal agents, including azoles and amphotericin B. This report emphasizes the need for increased awareness of fungal infections, including aspergillosis, as a potential cause of AUB. Further research is needed to enhance understanding of the epidemiology, risk factors, and clinical manifestations of endometrial aspergillosis.

Invasive Aspergillosis with Cavernous Sinus Thrombosis Following High-Dose Corticosteroid Therapy: A Challenging Case of Rhino-Orbital-Cerebral Mycosis

Invasive aspergillosis is a rare but severe fungal infection primarily affecting immunocompromised individuals. The Coronavirus Disease-2019 (COVID-19) pandemic has introduced new complexities in managing aspergillosis due to the widespread use of corticosteroids for treating COVID-19-related respiratory distress, which can increase susceptibility to fungal infections. Here, we present a challenging case of progressive cerebral aspergillosis complicated by cavernous sinus thrombosis (CST) in a 67-year-old male with a history of COVID-19. The patient, initially misdiagnosed with temporal arteritis, received pulse corticosteroid therapy twice before presenting with persistent left-sided headaches and vision loss. Cranial imaging revealed findings consistent with fungal sinusitis, Tolosa-Hunt syndrome, and orbital pseudotumor, which progressed despite initial antifungal therapy. Subsequent magnetic resonance imaging indicated an invasive mass extending into the left cavernous sinus and other intracranial structures, raising suspicion of aspergillosis. A transsphenoidal biopsy confirmed Aspergillus infection, leading to voriconazole therapy. Despite aggressive treatment, follow-up imaging revealed significant progression, with extension to the right frontal region and left cavernous sinus. The patient then developed visual impairment in the right eye and was diagnosed with CST secondary to fungal sinusitis. Management included a combination of systemic antifungals and antibiotics; however, the patient declined surgical intervention. This case underscores the diagnostic challenges and rapid progression associated with cerebral aspergillosis in post-COVID-19 patients treated with corticosteroids. This report highlights the need for heightened clinical suspicion and prompt, targeted interventions in similar cases to improve patient outcomes. Further research is required to understand the optimal management of invasive fungal infections.

Invasive aspergillosis: A comprehensive review

Invasive aspergillosis (IA) is a severe fungal infection caused by Aspergillus species, particularly Aspergillus fumigatus, although new species, sometimes resistant to antifungals are becoming more common. IA predominantly affects immunocompromised patients, such as those with haematological malignancies, solid organ transplant recipients, and critically ill patients. However, new at-risk populations have emerged in recent years, such as IA associated with severe viral infections. Advanced diagnostic methods are crucial, especially considering the rising concern of antifungal resistance. Early detection is critical for successful treatment, typically involving antifungal medications like voriconazole or amphotericin B, but new antifungals are arriving to complete the therapeutic strategies. Despite advancements, mortality rates remain high, underscoring the importance of timely interventions and ongoing research. Healthcare providers should maintain a high index of suspicion, especially in immunocompromised patients and other new risk factors that are arising, to promptly diagnose and manage invasive aspergillosis.

An immunocompetent lady with invasive aspergillosis presenting as disseminated lesions: a case report

BACKGROUND

Invasive Aspergillosis is a fungal infection caused by Aspergillus species, typically posing life-threatening risks to immunocompromised individuals. While occurrences in immunocompetent hosts are rare, a recent case report documented fulminant pulmonary aspergillosis in an immunocompetent patient during autopsy. Here, we present a case of invasive aspergillosis in an immunocompetent woman, manifesting with disseminated lesions.

CASE PRESENTATION

A 29-year-old Asian woman presented to our hospital in March 2022, reporting chest pain and shortness of breath persisting for two months. Upon examination, she appeared thin and unwell, with no notable abnormalities otherwise. Radiographic imaging revealed an ill-defined lesion in her left lung. Subsequent bronchoscopy and lavage were performed, followed by initiation of empirical antibiotic therapy. Lavage results were negative for gram staining, culture, and ZN staining for AFB, but revealed numerous septate hyphae on fungal smear. Histopathological examination indicated chronic granulomatous inflammation with septal fungal hyphae, indicative of aspergillosis. Subsequent culture confirmed Aspergillus species, prompting initiation of voriconazole therapy. Remarkably, the patient exhibited significant improvement, with weight gain and restored appetite observed within a short period. Within 2 months of treatment, her symptoms resolved, and she resumed near-normal daily activities.

CONCLUSION

This case highlights the diagnosis of aspergillosis in an immunocompetent individual presenting with disseminated nodular lesions across the lungs, mediastinum, and abdomen. Clinicians should maintain a high index of suspicion for aspergillosis in cases of non-resolving pneumonia and disseminated nodular lesions, even in patients lacking traditional predisposing factors.

Neosartorya udagawae pulmonary infection requiring a surgical treatment in a paediatric haematopoietic progenitor cell recipient

Neosartorya udagawae is a known cause of fungal infection in humans and animals. It is found to be more refractory to antifungal treatment in comparison to other Aspergillus species. With this report we present a case of proven invasive infection with Neosartorya udagawae in a child with chronic myeloid leukaemia after haematopoietic stem cell transplant. The patient received several lines of antifungal therapy including dual therapy appropriate to the antifungal susceptibility profile with progression of the invasive fungal disease requiring left lung upper lobe lobectomy. The case emphasizes the importance of early biopsy with antifungal susceptibility testing for targeted therapy and demonstrates the potential requirement for surgical management in addition to appropriate antifungal treatment.

In vivo pharmacodynamic characterization of a next-generation polyene, SF001, in the invasive pulmonary aspergillosis mouse model

SF001 is a next-generation polyene antifungal drug in development, designed to have increased specificity to fungal ergosterol, which is absent in humans, and decreased binding to cholesterol. SF001 demonstrates long-acting, potent, broad-spectrum fungicidal activity. The goal of the current study was to determine the pharmacodynamic index and target of SF001 in an immunocompromised mouse model of invasive pulmonary aspergillosis against six Aspergillus fumigatus isolates. Minimum inhibitory concentration (MIC) values ranged from 0.5 to 2.0 mg/L. Plasma and epithelial lining fluid (ELF) pharmacokinetics were performed following single intraperitoneal doses of 1, 4, 16, and 64 mg/kg. Treatment efficacy was assessed with each of the six fungal isolates using daily doses of SF001 ranging from 0.25 to 64 mg/kg/day over a 96-h treatment duration. Efficacy was assessed by A. fumigatus quantitative PCR of conidial equivalents from lung homogenates. Nonlinear regression analysis using the Hill equation demonstrated that the 24-h exposure-response relationships for both plasma and ELF area under the concentration/MIC and Cmax/MIC ratios were strong and relatively similar [coefficient of determination (R2) = 0.74-0.75). Exposure-response relationships included a median plasma 24-h Cmax/MIC target for stasis and 1-log kill endpoint of 0.5 and 0.6, respectively. The present studies demonstrated in vitro and in vivo SF001 potency against A. fumigatus. These results have potential relevance for SF001 clinical dose selection and evaluation of susceptibility breakpoints.

HIF‑1 and macrophage activation signalling pathways are potential biomarkers of invasive aspergillosis

Invasive aspergillosis (IA) is a severe disease, the pathogenesis of which remains unclear. The present study aimed to determine the molecular mechanism of IA and to identify potential biomarkers using bioinformatics analysis. The GSE78000 dataset, which includes data from patients with IA and healthy individuals, was downloaded from Gene Expression Omnibus. Differentially expressed genes (DEGs) between the IA and control groups were identified with the 'affy' package in R software. The Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) databases were then used to analyse the function and pathway enrichment of DEGs. The protein-protein interaction network was analysed with the Search Tool for the Retrieval of Interacting Genes (STRING) website. In addition, DEGs were confirmed using reverse transcription-quantitative PCR and western blotting in samples with IA (n=6) and control samples (n=6) collected from the Department of Respiratory and Critical Care Medicine of the First Affiliated Hospital of Henan University of Science and Technology (Luoyang, China). The present study identified 735 DEGs, including 312 upregulated and 423 downregulated genes. Through GO and KEGG analyses of the DEGs, macrophage activation and hypoxia-inducible factor 1 (HIF-1) signalling pathways were revealed to be significantly upregulated and downregulated, respectively, in patients with IA compared with that of the healthy individuals. Subsequently, correlation analysis of macrophage activation and HIF-1 signalling pathways was revealed using correlation as a distance metric for hierarchical clustering correlation analysis. However, there was no protein-protein interaction between the macrophage activity regulation and HIF-1 signalling pathways based on STRING analysis. In summary, the present study identified candidate genes and associated molecules that may be associated to IA and revealed potential biomarkers and therapeutic targets for IA.

Invasive Fungal Infections in the Paediatric Intensive Care Unit: A Hong Kong Study

INTRODUCTION

Invasive fungal infections (IFI) cause significant mortality and morbidity in the Paediatric Intensive Care Unit (PICU). Early recognition and prompt treatment of invasive fungal infections are important. This article reviewed the mortality and morbidity of IFIs in the PICU of Hong Kong Children's Hospital.

METHODS

A retrospective review of all PICU admissions from April 2019 to May 2021 was performed. The following data were retrieved: age, gender, diagnosis, comorbidity, clinical manifestation, type of fungus, duration of stay at PICU, absolute neutrophil count, use of immunosuppressive therapy, presence of central venous catheter and use of total parental nutrition. The primary outcomes were the incidence and mortality of IFIs among PICU patients. The secondary outcomes were risk factors for developing IFI in PICU and clinical course of IFIs. Numerical variables were compared between groups by Mann-Whitney U test and categorical variables by Fisher's exact test.

RESULTS

There were 692 PICU admissions over the study period from April 2019 to May 2021. The crude mortality was 3% (n=24 death cases) in the PICU. Fourteen patients (2%) fulfilling the criteria for IFIs were identified using hospital electronic record system and according to PICU documentation. Eight of these 14 patients (57%) had hematological malignancy, 2 (17%) had solid tumours and 4 had non-oncological conditions. Eight (57%) patients were neutropenic with absolute neutrophil count less than 1x 109 at diagnosis of IFI. Ten (71%) had received immunosuppressive therapy including steroid, cyclosporin A, Mycophenolate mofetil (MMF), Sirolimus or tacrolimus. 12 (86%) had had central venous catheter. Eight (57%) were on parenteral nutrition. IFIs due to Rhizopus or Aspergillus infection (5/14), or in post-haematopoietic stem cell transplant patients (5/14) were associated with non-survival (p = 0.031).

CONCLUSION

All patients with IFIs managed in the PICU had haemato-oncology diseases or were recipients of stem cell transplantation. IFIs with Rhizopus or Aspergillus as a group were associated with high mortality in the PICU. Awareness of this pathology with prompt diagnosis and treatment may improve the outcome of these infections and reduce the mortality.

Distribution of Aspergillus species and risk factors for aspergillosis in mainland China: a systematic review

Background

Aspergillus, a widespread fungus in the natural environment, poses a significant threat to human health by entering the human body via the airways and causing a disease called aspergillosis. This study comprehensively analyzed data on aspergillosis in published articles from mainland China to investigate the prevalence of Aspergillus, and risk factors, mortality rate, and underlying condition associated with aspergillosis.

Methods

Published articles were retrieved from Google Scholar, PubMed, and Science Direct online search engines. In the 101 analyzed studies, 3558 Aspergillus isolates were meticulously collected and classified. GraphPad Prism 8 was used to statistically examine the epidemiology and clinical characteristics of aspergillosis.

Results

Aspergillus fumigatus was prominently reported (n = 2679, 75.14%), followed by A. flavus (n = 437, 12.25%), A. niger (n = 219, 6.14%), and A. terreus (n = 119, 3.33%). Of a total of 9810 patients, 7513 probable cases accounted for the highest number, followed by confirmed cases (n = 1956) and possible cases (n = 341). In patients, cough emerged as the most common complaint (n = 1819, 18.54%), followed by asthma (n = 1029, 10.48%) and fever (1024, 10.44%). Of total studies, invasive pulmonary aspergillosis (IPA) was reported in 47 (45.53%) studies, exhibiting an increased prevalence in Beijing (n = 12, 25.53%), Guangdong (n = 7, 14.89%), and Shanghai (n = 6, 12.76%). Chronic pulmonary aspergillosis (CPA) was reported in 14 (13.86%) studies. Among the total of 14 studies, the occurrence of CPA was 5 (35.71%) in Beijing and 3 (21.42%) in Shanghai. Allergic bronchopulmonary aspergillosis (ABPA), was reported at a lower frequency (n = 8, 7.92%), Guangdong recorded a relatively high number (n = 3, 37.5%), followed by Beijing (n = 2, 25.0%), and Shanghai (n = 1, 12.5%). Percentage of death reported: IPA had the highest rate (n = 447, 68.87%), followed by CPA (n = 181, 27.88%) and ABPA (n = 14, 2.15%). Among the aspergillosis patients, 6220 had underlying conditions, including chronic lung disease (n = 3765, 60.53%), previous tuberculosis (n = 416, 6.68%), and organ transplant or organ failure (n = 648, 10.41%). Aspergillosis was also found in patients using corticosteroid therapy (n = 622, 10.0%).

Conclusion

This review sheds light on the prevalence patterns of Aspergillus species, risk factors of aspergillosis, and gaps in surveillance that could be helpful for the control and treatment of aspergillosis and guide the researchers in future studies.

Registration

This systematic review was prospectively registered on PROSPERO: Registration ID CRD42023476870.

Evolution of neuroimaging findings in angioinvasive cerebral aspergillosis in a pediatric patient with leukemia during long-term observation

The central nervous system is one of the most common sites of aspergillosis involvement in immunocompromised people, just after sinopulmonary infections. Neuroimaging modalities are crucial for the diagnosis of cerebral aspergillosis (CA). Here, we describe a rare case of concurrent mixed aspergillosis infection with Aspergillus fumigatus and Aspergillus niger in a 2-year-old leukemic boy. The first neuroimaging finding, which was followed by focal seizures, was recognized as extensive cerebral hemorrhage in the absence of thrombocytopenia and coagulopathy. As the patient survived for more than 4 months after diagnosis, we were able to perform a neuroimaging evaluation during long-term observation. In serial neuroimaging studies, a secondary fungal abscess was observed at the site of hemorrhagic infarctions. Finally, the patient died from bacterial sepsis. In this case study, we try to categorize the neuroimaging findings of CA into distinct phases to better understand how CA changes over time.

CYP3A and CYP2C19 Activity Determined by Microdosed Probe Drugs Accurately Predict Voriconazole Clearance in Healthy Adults

BACKGROUND AND OBJECTIVE

Voriconazole is an important broad-spectrum anti-fungal drug with nonlinear pharmacokinetics. The aim of this single centre fixed-sequence open-label drug-drug interaction trial in healthy participants (N = 17) was to determine whether microdosed probe drugs for CYP3A and CYP2C19 reliably predict voriconazole clearance (CLVRZ).

METHODS

At baseline, a single oral microdose of the paradigm substrates midazolam (CYP3A) and omeprazole (CYP2C19) were given to estimate their clearances (CL). Thereafter, a single oral dose of voriconazole was administered (50, 100, 200 or 400 mg), followed by the microdosed probe drugs.

RESULTS

The clearances of midazolam (CLMDZ 790-2790 mL/min at baseline; 248-1316 mL/min during voriconazole) and omeprazole (CLOMZ 66.4-2710 mL/min at baseline; 30.1-1420 mL/min during voriconazole) were highly variable. CLMDZ [geometric mean ratio (GMR) 0.586 at 50 mg voriconazole decreasing to GMR 0.196 at 400 mg voriconazole] and CLOMZ (GMR 0.590 at 50 mg decreasing to GMR 0.166 at 400 mg) were reduced with higher voriconazole doses. CLMDZ was linearly correlated with CLVRZ (slope 1.458; adjusted R2 0.528) as was CLOMZ (slope 0.807; adjusted R2 0.898). Multiple linear regression resulted in an adjusted R2 of 0.997 for the relationship CLVRZ ~ log CLOMZ + log CLMDZ using data during voriconazole treatment and an adjusted R2 of 0.997 for the relationship CLVRZ ~ log CLOMZ + log CLMDZ + voriconazole dose, using baseline data for CLMDZ and CLOMZ.

CONCLUSION

Microdosed midazolam and omeprazole accurately described and predicted total CLVRZ TRIAL REGISTRATION: EudraCT No: 2020-001017-20, registered on March 5th, 2020. DRKS: DRKS00022547, registered on August 6th, 2020.

A score for predicting invasive pulmonary aspergillosis in immunocompetent critically ill patients

BACKGROUND

Delayed treatment leads to increased mortality in critically ill patients with invasive pulmonary aspergillosis (IPA). We aimed to develop and validate a prediction score based on novel biomarkers and clinical risk factors to identify IPA in immunocompetent patients in the intensive care unit (ICU).

METHODS

A retrospective study was conducted to collect medical information and novel biomarkers upon ICU admission. Risk factors adopted for the final prediction score were identified using multivariate logistic regression analysis.

RESULTS

We retrospectively collected 1841 critical ill patients between January 2018 and August 2022. Patients with IPA had higher C-reactive protein-to-albumin ratio (CAR), neutrophil-to-lymphocyte ratio, systemic immune-inflammation index and lower prognostic nutritional index (PNI). Chronic obstructive pulmonary disease (COPD), continuous renal replacement therapy (CRRT), high dose of corticosteroids, broad-spectrum antibiotics, blood galactomannan (GM) positivity and high CAR were independent risk factors for IPA and were entered into the final prediction score. The score had good discrimination, with the area under receiver operating characteristic curve of 0.816 and 0.780 for the training and validation cohorts, respectively, and good calibration.

CONCLUSION

A score based on six clinical and novel immunological biomarkers showed promising predictive value for antifungal treatment in immunocompetent ICU patients.

Evaluation of metagenomic next-generation sequencing diagnosis for invasive pulmonary aspergillosis in immunocompromised and immunocompetent patients

BACKGROUND

Invasive pulmonary aspergillosis (IPA) can occur in both immunocompromised and non-immunocompromised hosts, and early diagnosis of IPA is difficult. Metagenomic next-generation sequencing (mNGS) is a novel non-migratory pathogen detection method; however, utilising this method for IPA diagnosis is challenging due to the current lack of a unified clinical interpretation standard following Aspergillus detection using mNGS.

OBJECTIVES

To investigate the accuracy of IPA diagnosis by positive bronchoalveolar lavage fluid (BALF) mNGS results in immunocompromised and immunocompetent patients.

METHODS

We retrospectively included patients with confirmed pulmonary infections having a BALF mNGS result of Aspergillus reads ≥1. We compared the accuracy of using mNGS for IPA diagnosis in patients with different immune statuses based on the revised EORTC/MSG criteria.

RESULTS

Overall, 62 mNGS Aspergillus-positive patients were divided into two groups: with (41) and without IPA (21). In univariate logistic regression analysis, immunocompromised function, fever, halo sign on CT image, and multiple masses or nodules were associated with mNGS Aspergillus-positive IPA diagnosis. In multivariate logistic regression analysis, immunocompromised function (OR = 6.68, 95% CI: 1.73-25.87, p = .006) and a halo sign (OR = 7.993, 95% CI: 2.07-30.40, p = .003) were independent risk factors. The concordance rate of IPA diagnosis was significantly higher in immunocompromised patients [82.1% (23/28)] than in non-immunocompromised patients [52.9% (18/34); p = .016].

CONCLUSIONS

For immunocompromised patients, a combination of mNGS testing and lung CT imaging can be used for IPA diagnosis. However, caution is required in IPA diagnosis based on positive mNGS results in non-immunocompromised patients.

Potential Strategies to Control the Risk of Antifungal Resistance in Humans: A Comprehensive Review

Fungal infections are becoming one of the main causes of morbidity and mortality in people with weakened immune systems. Mycoses are becoming more common, despite greater knowledge and better treatment methods, due to the regular emergence of resistance to the antifungal medications used in clinical settings. Antifungal therapy is the mainstay of patient management for acute and chronic mycoses. However, the limited availability of antifungal drug classes limits the range of available treatments. Additionally, several drawbacks to treating mycoses include unfavourable side effects, a limited activity spectrum, a paucity of targets, and fungal resistance, all of which continue to be significant issues in developing antifungal drugs. The emergence of antifungal drug resistance has eliminated accessible drug classes as treatment choices, which significantly compromises the clinical management of fungal illnesses. In some situations, the emergence of strains resistant to many antifungal medications is a major concern. Although new medications have been developed to address this issue, antifungal drug resistance has grown more pronounced, particularly in patients who need long-term care or are undergoing antifungal prophylaxis. Moreover, the mechanisms that cause resistance must be well understood, including modifications in drug target affinities and abundances, along with biofilms and efflux pumps that diminish intracellular drug levels, to find novel antifungal drugs and drug targets. In this review, different classes of antifungal agents, and their resistance mechanisms, have been discussed. The latter part of the review focuses on the strategies by which we can overcome this serious issue of antifungal resistance in humans.

Transcriptomics-based investigation of molecular mechanisms underlying synergistic antimicrobial effects of AgNPs and Domiphen on the human fungal pathogen Aspergillus fumigatus

Critically ill patients have higher risk of serious fungal infections, such as invasive aspergillosis (IA) which is mainly caused by the human fungal pathogen Aspergillus fumigatus. Triazole drugs are the primary therapeutic agents for the first-line treatment of IA, which could easily cause drug resistance problems. Here, we assess the potential of AgNPs synthesized with Artemisia argyi leaf extract and domiphen as new antifungal agents to produce synergistic antimicrobial effects on Aspergillus fumigatus, and dissect possible molecular mechanisms of action. Plate inoculation assays combined with drug susceptibility test and cytotoxicity test showed that the combination of AgNPs and domiphen has synergistic antimicrobial effects on A. fumigatus with low cytotoxicity. Gene Ontology (GO) enrichment analysis showed that AgNPs and domiphen inhibit the growth of A. fumigatus by suppressing nitrate assimilation, and purine nucleobase metabolic process and amino acid transmembrane transport, respectively. When the two drugs are combined, AgNPs has epistatic effects on domiphen. Moreover, the combination of AgNPs and domiphen primarily influence secondary metabolites biosynthesis, steroid biosynthesis and nucleotide sugar metabolism of A. fumigatus via Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Furthermore, protein-protein interactions (PPI) analysis combined with validation experiments showed that the combination of AgNPs and domiphen could enhance the expression of copper transporter and inhibit nitrogen source metabolism. In addition, the synergistic antimicrobial effects could be enhanced or eliminated depending on exogenous addition of copper and nitrogen source, respectively. Taken together, the results of this study provide a theoretical basis and a new strategy for the treatment of IA.

Nanotechnology-Based Approaches for Voriconazole Delivery Applied to Invasive Fungal Infections

Invasive fungal infections increase mortality and morbidity rates worldwide. The treatment of these infections is still limited due to the low bioavailability and toxicity, requiring therapeutic monitoring, especially in the most severe cases. Voriconazole is an azole widely used to treat invasive aspergillosis, other hyaline molds, many dematiaceous molds, Candida spp., including those resistant to fluconazole, and for infections caused by endemic mycoses, in addition to those that occur in the central nervous system. However, despite its broad activity, using voriconazole has limitations related to its non-linear pharmacokinetics, leading to supratherapeutic doses and increased toxicity according to individual polymorphisms during its metabolism. In this sense, nanotechnology-based drug delivery systems have successfully improved the physicochemical and biological aspects of different classes of drugs, including antifungals. In this review, we highlighted recent work that has applied nanotechnology to deliver voriconazole. These systems allowed increased permeation and deposition of voriconazole in target tissues from a controlled and sustained release in different routes of administration such as ocular, pulmonary, oral, topical, and parenteral. Thus, nanotechnology application aiming to delivery voriconazole becomes a more effective and safer therapeutic alternative in the treatment of fungal infections.

Isolated renal and urinary tract aspergillosis: a systematic review

Background

Aspergillosis localized to the kidneys and the urinary tract is uncommon. We conducted a comprehensive systematic review to evaluate risk factors and clinical outcomes of patients with isolated renal and genito-urinary tract aspergillosis.

Methods

We systematically searched Medline, CINAHL, Embase, African Journal Online, Google Scholar, and the Cochrane Library, covering the period from inception to August 2023 using the key terms 'renal' OR 'kidney*' OR 'prostate' OR 'urinary bladder' OR 'urinary tract*AND 'aspergillosis' OR 'aspergillus' OR 'aspergilloma' OR 'mycetoma'. We included single case reports or case series. Review articles, guidelines, meta-analyses, animal studies, protocols, and cases of genitourinary and /or renal aspergillosis occurring as a part of disseminated disease were excluded.

Results

We identified 91 renal and urinary aspergillosis cases extracted from 76 publications spanning 1925-2023. Among the participants, 79 (86.8%) were male, with a median age of 46 years. Predominantly, presentations consisted of isolated renal infections (74 instances, 81.3%), followed by prostate (5 cases, 5.5%), and bladder (7 cases, 7.7%) involvement. Aspergillus fumigatus (42.9%), Aspergillus flavus (9.9%), and Aspergillus niger/glaucus (1.1% each) were isolated. Underlying risk factors included diabetes mellitus (29.7%), HIV (12.1%), haematological malignancies (11%), and liver cirrhosis (8.8%), while common symptoms encompassed flank pain (36.3%), fever (33%), and lower urinary tract symptoms (20.9%). An autopsy was conducted in 8.8% of cases. Diagnostic work-up involved histopathology (70.5%), renal CT scans and urine microscopy and culture (52.6% each), and abdominal ultrasound (17.9%). Treatments included amphotericin B (34 cases, 37.4%) and azole-based regimens (29 cases, 31.9%). Nephrectomy was performed in 16 of 78 renal cases (20.5%). All-cause mortality was 24.4% (19 cases). No significant mortality rate difference was observed among antifungal regimens (p = 0.739) or nephrectomy status (p = 0.8).

Conclusion

Renal and urinary aspergillosis is an important cause of morbidity and mortality, particularly in immunocompromised and people with diabetes mellitus. While varied treatment strategies were observed, mortality rates showed no significant differences based on treatments or nephrectomy status. Further research is needed to refine diagnostics, optimize treatments, and enhance awareness among clinicians for early detection and management.

PROSPERO registration number

CRD42023430959.

Ovarian aspergilloma in an immunocompetent patient masquerading as ovarian neoplasm

Aspergillus is a ubiquitous fungus that can cause a variety of clinical syndromes. It can lead to a spectrum of clinical presentations depending upon the severity of the disease, degree of immune compromisation, nature and intensity of inflammatory host response. Ovarian aspergilloma is extremely unusual, only a few case reports have been described in the literature. Here, we report a case of ovarian aspergilloma which was masquerading as ovarian neoplasm on clinical examination and radiology. To the best of our knowledge, this is the first case report of isolated ovarian aspergillosis in an immunocompetent patient.

HIF1-α upregulation induces proinflammatory factors to boost host killing capacity after Aspergillus fumigatus exposure

Aims: HIF1-α is an important transcription factor in the regulation of the immune response. The protective function of HIF1-α in the host epithelial immune response to Aspergillus fumigatus requires further clarification. Methods: In this study we demonstrated the effect of upregulation of HIF1-α expression in A549 cells and mouse airway cells exposed to A. fumigatus in vivo. Results: The killing capacity was enhanced by boosting proinflammatory factors both in vitro and in vivo. Moreover, airway inflammation was reduced in the HIF1-α-upregulated mice. Conclusion: We identified a protective role for HIF1-α in anti-A. fumigatus immunity. Modulation of HIF1-α might be a target for the development of aspergillosis therapy.

Comparison of Aspergillus-specific antibody cut-offs for the diagnosis of aspergillosis

Background

Aspergillus diseases are frequently encountered in patients who are immunocompromised. Without a prompt diagnosis, the clinical consequences may be lethal. Aspergillus-specific antibodies have been widely used to facilitate the diagnosis of Aspergillus diseases. To date, universally standardized cut-off values have not been established. This study aimed to investigate the cut-off values of Aspergillus-specific antibodies and perform a narrative review to depict the geographic differences in the Taiwanese population.

Methods

We analyzed enrolled 118 healthy controls, 29 patients with invasive aspergillosis (IA), chronic pulmonary aspergillosis (CPA), and allergic bronchopulmonary aspergillosis (ABPA) and 99 with disease control, who were tested for Aspergillus fumigatus and Aspergillus niger-specific IgG and IgE using ImmunoCAP. 99 participants not fulfilling the diagnosis of IA, CPA, and ABPA were enrolled in the disease control group. The duration of retrieval of medical records from June 2018 to September 2021. Optimal cut-offs and association were determined using receiver operating characteristic curve (ROC) analysis.

Results

We found that patients with CPA had the highest A. fumigatus-specific IgG levels while patients with ABPA had the highest A. fumigatus-specific IgE, and A. niger-specific IgG and IgE levels. In patients with CPA and ABPA, the optimal cut-offs of A. fumigatus-specific IgG and A. niger-specific IgG levels were 41.6, 40.8, 38.1, and 69.9 mgA/l, respectively. Geographic differences in the cut-off values of A. fumigatus-specific IgG were also noted. Specifically, the levels were different in eco-climatic zones.

Conclusion

We identified the optimal cut-offs of Aspergillus-specific antibodies to facilitate a precise diagnosis of aspergillosis. The observed geographic differences of the antibody levels suggest that an eco-climatic-specific reference is needed to facilitate a prompt and accurate diagnosis of aspergillosis.

Comparative Host-Pathogen Interaction Analyses of SARS-CoV2 and Aspergillus fumigatus, and Pathogenesis of COVID-19-Associated Aspergillosis

COVID-19 caused a global catastrophe with a large number of cases making it one of the major pandemics of the human history. The clinical presentations of the disease are continuously challenging healthcare workers with the variation of pandemic waves and viral variants. Recently, SARS-CoV2 patients have shown increased occurrence of invasive pulmonary aspergillosis infection even in the absence of traditional risk factors. The mechanism of COVID-19-associated aspergillosis is not completely understood and therefore, we performed this system biological study in order to identify mechanistic implications of aspergillosis susceptibility in COVID-19 patients and the important targets associated with this disease. We performed host-pathogen interaction (HPI) analysis of SARS-CoV2, and most common COVID-19-associated aspergillosis pathogen, Aspergillus fumigatus, using in silico approaches. The known host-pathogen interactions data of SARS-CoV2 was obtained from BIOGRID database. In addition, A. fumigatus host-pathogen interactions were predicted through homology modeling. The human targets interacting with both pathogens were separately analyzed for their involvement in aspergillosis. The aspergillosis human targets were screened from DisGeNet and GeneCards. The aspergillosis targets involved in both HPI were further analyzed for functional overrepresentation analysis using PANTHER. The results indicate that both pathogens interact with a number of aspergillosis targets and altogether they recruit more aspergillosis targets in host-pathogen interaction than alone. Common aspergillosis targets involved in HPI with both SARS-CoV2 and A. fumigatus can indicate strategies for the management of both conditions by modulating these common disease targets.

Sterylglucosides in Fungi

Sterylglucosides (SGs) are sterol conjugates widely distributed in nature. Although their universal presence in all living organisms suggests the importance of this kind of glycolipids, they are yet poorly understood. The glycosylation of sterols confers a more hydrophilic character, modifying biophysical properties of cell membranes and altering immunogenicity of the cells. In fungi, SGs regulate different cell pathways to help overcome oxygen and pH challenges, as well as help to accomplish cell recycling and other membrane functions. At the same time, the level of these lipids is highly controlled, especially in wild-type fungi. In addition, modulating SGs metabolism is becoming a novel tool for vaccine and antifungal development. In the present review, we bring together multiple observations to emphasize the underestimated importance of SGs for fungal cell functions.

Invasive fungal infections

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Pediatric Invasive Fungal Rhinosinusitis: A Comprehensive Analysis of Prognostic Factors for Survival

OBJECTIVE

Pediatric invasive fungal rhinosinusitis (IFS) is a devastating infection that manifests almost exclusively in immunocompromised children. The goal of this work was to determine which clinical features carry prognostic value for survival.

METHODS

A retrospective review of children with a histopathological diagnosis of IFS was performed at an academic tertiary care institution from 1990 to 2021. Clinical variables were collected to generate survival and life-table estimators at 6-months and 1-year.

RESULTS

Eighteen patients were included in this analysis, with a mean age of 9.8 years (range, 1-17 years). Most children were neutropenic (n = 15, 83.3%), with acute lymphoblastic leukemia (n = 10, 55.6%) representing the most common primary diagnosis. A mean of 3.2 operations (range 1-7 operations) was performed per patient for either mucormycosis (n = 10, 55.6%) or aspergillosis (n = 8, 44.4%). The mean time to absolute neutrophil count recovery was 65.8 days (range 20-137 days), with a 6-month and 1-year survival rate of 47.6% and 41.7%, respectively. Gross total resection (p = 0.006, p < 0.001), number of antifungals (p = 0.0004, p = 0.0003), and total operation number (p = 0.0032, p = 0.0035), served as positive prognostic factors for 6-month and 1-year survival. Conversely, altered mental status (p = 0.0026), cerebral involvement (p = 0.0010), cranial neuropathies (p < 0.0001), hyperglycemia (p = 0.0445, p = 0.0208), and intensive care unit status (p = 0.0013) served as negative prognostic factors for 6-month and 1-year survival.

CONCLUSION

Several key elements were identified and found to play a vital role in influencing survival for pediatric IFS. Early diagnosis, prompt medical therapy, and aggressive surgical intervention remain at the forefront in the treatment of this complex opportunistic infection.

LEVEL OF EVIDENCE

IV Laryngoscope, 2022.

Novel Treatment Approach for Aspergilloses by Targeting Germination

Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.

A Systematic Review to Assess the Relationship between Disseminated Cerebral Aspergillosis, Leukemias and Lymphomas, and Their Respective Therapeutics

Disseminated disease following invasive pulmonary aspergillosis (IPA) remains a significant contributor to mortality amongst patients with hematologic malignancies (HMs). At the highest risk of mortality are those with disseminated disease to the central nervous system, known as cerebral aspergillosis (CA). However, little is known about the risk factors contributing to disease amongst HM patients. A systematic review using PRISMA guidelines was undertaken to define HM patient subgroups, preventative measures, therapeutic interventions, and outcomes of patients with disseminated CA following IPA. The review resulted in the identification of 761 records, of which 596 articles were screened, with the final inclusion of 47 studies and 76 total patients. From included articles, the proportion of CA was assessed amongst HM patient subgroups. Further, pre-and post-infection characteristics, fungal species, and mortality were evaluated for the total population included and HM patient subgroups. Patients with acute myeloid leukemia and acute lymphoid lymphoma, patients receiving corticosteroids as a part of their HM therapeutic regimen, and anti-fungal prophylaxis constitute the top identified patient populations at risk for disseminated CA. Overall, information presented here indicates that measures for the prevention of IPA should be taken in higher-risk HM patient subgroups. Specifically, the type of anti-fungal therapy used should be carefully considered for those patients with IPA and increased risk for cerebral dissemination. Additional reports detailing patient characteristics are needed to define further the risk of developing disseminated CA from IPA in patients with HMs.

Fungicidal Activity of AP10W, a Short Peptide Derived from AP-2 Complex Subunit mu-A, In Vitro and In Vivo

With the increase in the incidence of fungal infections, and the restrictions of existing antifungal drugs, the development of novel antifungal agents is urgent. Here we prove that AP10W, a short peptide derived from AP-2 complex subunit mu-A, displays conspicuous antifungal activities against the main fungal pathogens of human infections Candida albicans and Aspergillus fumigatus. We also show that AP10W suppresses the fungal biofilm formation, and reduces the pre-established fungal biofilms. AP10W appears to exert its fungicidal activity through a mode of combined actions, including interaction with the fungal cell walls via laminarin, mannan and chitin, enhancement of cell wall permeabilization, induction of membrane depolarization, and increase in intracellular ROS generation. Importantly, we demonstrate that AP10W exhibits little toxicity towards mammalian fibroblasts, and effectively promotes the healing of wounded skins infected by C. albicans. These together indicate that AP10W is a new member of fungicidal agents. It also suggests that AP10W has a considerable potential for future development as a novel antifungal drug.

Antifungal Activity of NP20 Derived from Amphioxus Midkine/Pleiotrophin Homolog Against Aspergillus niger and Aspergillus fumigatus

With the emergence of antifungal resistance, systematic infections with Aspergillus are becoming the major cause of the clinical morbidity. The development of novel antifungal agents with high efficacy, low drug tolerance, and few side effects is urgent. In response to that need, we have identified NP20. Here we demonstrate clearly that NP20 has antifungal activity, capable of killing the spores of Aspergillus niger and Aspergillus fumigatus as well as causing direct damage to the surface, membrane, cytoplasm, organelle, and nucleus of the fungal spores. Interestingly, NP20 is active under temperature stress and a wide range of pH. Subsequently, MTT assay, assay for binding of NP20 to fungal cell wall components, membrane depolarization assay, confocal microscopy, ROS assay, DNA replication, and protein synthesis assay are performed to clarify the mechanisms underlying NP20 against Aspergillus. The results show that NP20 can bind with and pass through the fungal cell wall, and then interfere with the lipid membrane. Moreover, NP20 can induce intracellular ROS production, DNA fragmentation, and protein synthesis inhibition of the fungal cells. These together indicate that NP20 is a novel antifungal peptide, which has considerable potential for future development as novel peptide antibiotics against Aspergillus.

Aspergillus Utilizes Extracellular Heme as an Iron Source During Invasive Pneumonia, Driving Infection Severity

BACKGROUND

Depriving microbes of iron is critical to host defense. Hemeproteins, the largest source of iron within vertebrates, are abundant in infected tissues in aspergillosis due to hemorrhage, but Aspergillus species have been thought to lack heme import mechanisms. We hypothesized that heme provides iron to Aspergillus during invasive pneumonia, thereby worsening the outcomes of the infection.

METHODS

We assessed the effect of heme on fungal phenotype in various in vitro conditions and in a neutropenic mouse model of invasive pulmonary aspergillosis.

RESULTS

In mice with neutropenic invasive aspergillosis, we found a progressive and compartmentalized increase in lung heme iron. Fungal cells cultured under low iron conditions took up heme, resulting in increased fungal iron content, resolution of iron starvation, increased conidiation, and enhanced resistance to oxidative stress. Intrapulmonary administration of heme to mice with neutropenic invasive aspergillosis resulted in markedly increased lung fungal burden, lung injury, and mortality, whereas administration of heme analogs or heme with killed Aspergillus did not. Finally, infection caused by fungal germlings cultured in the presence of heme resulted in a more severe infection.

CONCLUSIONS

Invasive aspergillosis induces local hemolysis in infected tissues, thereby supplying heme iron to the fungus, leading to lethal infection.

Advances in prophylaxis and treatment of invasive fungal infections: perspectives on hematologic diseases

Invasive fungal infections (IFIs) are common causes of mortality and morbidity in patients with hematologic diseases. Delayed initiation of antifungal treatment is related to mortality. Aspergillus sp. is the leading cause of IFI followed by Candida sp. Diagnosis is often challenging owing to variable conditions related to underlying diseases. Clinical suspect and prompt management is important. Imaging, biopsy, and non-culture-based tests must be considered together. New diagnostic procedures have been improved, including antigen-based assays and molecular detection of fungal DNA. Among hematologic diseases, patients with acute myeloid leukemia, myelodysplastic syndrome, recipients of hematopoietic stem cell transplantation are at high risk for IFIs. Antifungal prophylaxis is recommended for these high-risk patients. There are continuous attempts to achieve ideal management of IFIs. Scoring system for quality control has been developed with important recommendations of current guidelines. Higher adherence to guidelines is related to decreased mortality in IFIs.

An unusual presentation of invasive aspergillosis with submandibular swelling in a 49-year-old man with end-stage renal disease: A case report

Invasive aspergillosis (IA) is a fatal disease and is related to immunocompromised patients like HIV, solid organ/allogeneic stem cell transplant patients, patients on immunosuppressive therapy or chemotherapy agents, burn patients and malnourished patients. Diagnosis is challenging due to the non-specific nature of symptoms. Usually, the patient presents with fever and respiratory symptoms such as cough and haemoptysis. We present a case of IA in a 49-year-old man with end-stage renal disease who presented with fever and developed a submandibular swelling. Further imaging studies supported the possibility of having underlying IA and accordingly he was promptly treated with systemic antifungal therapy with good response. As per our knowledge, IA presenting as submandibular swelling has not been reported in the literature. Our main aim is to highlight the significance of early diagnosis and management in such a rare presentation associated with a life-threatening condition like IA.

Successful treatment of angioinvasive aspergillosis causing diaphragmatic rupture with bowel perforation and cerebral aspergillosis in a patient with FLT3-mutated acute myeloid leukemia: A case report

RATIONALE

Throughout the clinical course of acute myeloid leukemia (AML), aspergillosis infection remains a significant determinant of treatment outcomes and survival. To emphasize the importance of early diagnosis and appropriate application of integrated therapeutic approaches, we present a case of AML patient who survived through angioinvasive aspergillosis infection causing diaphragmatic rupture with bowel perforation and cerebral aspergillosis during active AML treatment.

PATIENT CONCERNS

A 39-year old male with FLT3-mutated AML was transferred to our hospital due to persistent fever after induction therapy.

DIAGNOSIS AND INTERVENTIONS

During voriconazole treatment for his invasive pulmonary aspergillosis, the patient was diagnosed with colon perforation at splenic flexure and suspected perforation of left diaphragm with communication with left pleural space. Although pancytopenic, emergency laparotomy was performed with granulocyte transfusion. Also, dual antifungal therapy with voriconazole and micafungin was applied. With supportive care, he was able to successfully complete 3 cycles of consolidation using tyrosine kinase inhibitor. However, 80 days after the last chemotherapy, the patient experienced seizure caused by a single 1.5 cm sized enhancing mass in the right occipital lobe. Diagnostic and therapeutic mass removal was carried out, and pathology-confirmed cerebral aspergillosis was diagnosed.

OUTCOMES

The patient's neurologic symptoms are resolved and he is leukemia free, but remains on voriconazole for his cerebral aspergillosis till this day.

CONCLUSIONS

Our case highlights the importance of timely integrated intervention and adequate underlying disease control in treatment of invasive aspergillosis in immunocompromised patients. Such rigorous efforts can save even the most seemingly dismal case.

Metagenomic Next-Generation Sequencing of Cerebrospinal Fluid for the Diagnosis of Cerebral Aspergillosis

Purpose: Cerebral aspergillosis (CA) is a rare but often fatal, difficult-to-diagnose, opportunistic infection. The utility of metagenomic next-generation sequencing (mNGS) for diagnosis of CA is unclear. We evaluated the usefulness of mNGS of the cerebrospinal fluid (CSF) for the diagnosis of CA. Methods: This prospective study involved seven consecutive patients with confirmed CA in whom CSF mNGS was performed. Serum (1→3)-β-D-glucan and galactomannan levels were determined, and histopathological examination and mNGS of the CSF were conducted. CSF specimens from three non-infected patients were used as positive controls. Results: mNGS of the CSF was positive in six of the seven confirmed CA cases (85.71% sensitivity). In the cryptococcal meningitis group (control), mNGS of the CSF was positive for Aspergillus in two patients (84.62% specificity). The positive likelihood ratio, negative likelihood ratio, and Youden's index of mNGS for CA in the CSF were 5.565, 0.169, and 0.7, respectively. Among the six mNGS-positive cases, more than two Aspergillus species were found in four (4/6, 66.67%). In the positive controls, the addition of one A. fumigatus spore yielded a standardised species-specific read number (SDSSRN) of 25.45 by mNGS; the detection rate would be 0.98 if SDSSRN was 2. Conclusion: mNGS facilitates the diagnosis of CA and may reduce the need for cerebral biopsy in patients with suspected CA. Trial Registration Number: Chinese Clinical Trial Registry, ChiCTR1800020442.

Uncommon pathogens in an immunocompetent host: respiratory isolation of Cunninghamella bertholletiae, Aspergillus niger, Staphylococcus pseudintermedius and adenovirus in a patient with necrotising pneumonia

We present the unusual case of a 60-year-old immunocompetent woman with chronic obstructive pulmonary disease who developed a necrotising pneumonia with isolation of Cunninghamella bertholletiae, Aspergillus niger, Staphylococcus pseudintermedius and adenovirus. The patient recovered with antimicrobial therapy and supportive care in the intensive care unit. The current literature on diagnosis and treatment of these pathogens is reviewed.

Two Monoclonal Antibodies That Specifically Recognize Aspergillus Cell Wall Antigens and Can Detect Circulating Antigens in Infected Mice

Invasive aspergillosis (IA) is a life-threatening disease mainly caused by Aspergillus fumigatus and Aspergillus flavus. Early diagnosis of this condition is crucial for patient treatment and survival. As current diagnostic techniques for IA lack sufficient accuracy, we have raised two monoclonal antibodies (1D2 and 4E4) against A. fumigatus cell wall fragments that may provide a platform for a new diagnostic approach. The immunoreactivity of these antibodies was tested by immunofluorescence and ELISA against various Aspergillus and Candida species in vitro and by immunohistochemistry in A. fumigatus infected mouse tissues. Both monoclonal antibodies (mAbs) showed intensive fluorescence with the hyphae wall of A. fumigatus and A. flavus, but there was no staining with other Aspergillus species or Candida species. Both mAbs also showed strong immunoreactivity to the cell wall of A. fumigatus hyphae in the infected liver, spleen and kidney of mice with IA. The antigens identified by 1D2 and 4E4 might be glycoproteins and the epitopes are most likely a protein or peptide rather than a carbohydrate. An antibody-based antigen capture ELISA detected the extracellular antigens released by A. fumigatus, A. flavus, A. niger and A. terreus, but not in Candida species. The antigen could be detected in the plasma of mice after 48 h of infection by double-sandwich ELISA. In conclusion, both 1D2 and 4E4 mAbs are potentially promising diagnostic tools to investigate invasive aspergillosis.

Clinical and Epidemiological Profile of Patients with Invasive Aspergillosis from a Fourth Level Hospital in Bogota, Colombia: A Retrospective Study

Invasive aspergillosis (IA) is a severe mycosis caused by Aspergillus species. The infection mainly affects immunocompromised patients with a significant clinical burden. This study aimed to determine the clinical and epidemiological characteristics of patients diagnosed with IA in a fourth level hospital in Colombia, as these data are scarce in the country. A retrospective, observational study, from a single center was conducted with 34 male and 32 female patients, between 1 month- and 90-year-old, diagnosed with proven (18.2%), probable (74.2%) and possible (7.6%) IA, during a 21-year period. The most frequent underlying conditions for IA were chemotherapy (39.4%) and corticosteroid use (34.8%). The lung was the most common affected organ (92.4%). Computed tomography (CT) imaging findings were mainly nodules (57.6%) and consolidation (31.8%). A low positive correlation was found between serum galactomannan and hospitalization length. Aspergillus fumigatus prevailed (73.3%) in sputum and bronchoalveolar lavage cultures. Most patients were hospitalized in general wards (63.6%) and treated with voriconazole (80.3%). Mortality rate was 15.2%. Common risk factors for IA were identified in the Colombian cohort, including medications and underlying diseases. However, their frequency differs from other countries, reinforcing the idea that local surveillance is essential and at-risk patients should be carefully monitored.

Long Terminal Repeat Retrotransposon Afut4 Promotes Azole Resistance of Aspergillus fumigatus by Enhancing the Expression of sac1 Gene

Aspergillus fumigatus causes a series of invasive diseases, including the high-mortality invasive aspergillosis, and has been a serious global health threat because of its increased resistance to the first-line clinical triazoles. We analyzed the whole-genome sequence of 15 A. fumigatus strains from China and found that long terminal repeat retrotransposons (LTR-RTs), including Afut1, Afut2, Afut3, and Afut4, are most common and have the largest total nucleotide length among all transposable elements in A. fumigatus. Deleting one of the most enriched Afut4_977-sac1 in azole-resistant strains decreased azole resistance and downregulated its nearby gene, sac1, but it did not significantly affect the expression of genes of the ergosterol synthesis pathway. We then discovered that 5'LTR of Afut4_977-sac1 had promoter activity and enhanced the adjacent sac1 gene expression. We found that sac1 is important to A. fumigatus, and the upregulated sac1 caused elevated resistance of A. fumigatus to azoles. Finally, we showed that Afut4_977-sac1 has an evolution pattern similar to that of the whole genome of azole-resistant strains due to azoles; phylogenetic analysis of both the whole genome and Afut4_977-sac1 suggests that the insertion of Afut4_977-sac1 might have preceded the emergence of azole-resistant strains. Taking these data together, we found that the Afut4_977-sac1 LTR-RT might be involved in the regulation of azole resistance of A. fumigatus by upregulating its nearby sac1 gene.

Spinal epidural abscess caused by Aspergillus spp masquerading as spinal tuberculosis in a person with HIV

Spinal epidural abscess caused by Aspergillus spp is a debilitating form of invasive aspergillosis that can easily be misdiagnosed as spinal tuberculosis due to shared risk factors and clinical features. In this Grand Round, we describe a case of thoracic aspergillus spinal epidural abscess in a patient with underlying HIV infection. The initial diagnostic consideration was that of spinal tuberculosis. Consequently, despite positive microbiological cultures of Aspergillus fumigatus, antifungal therapy was delayed until histopathological evaluation of the affected tissue confirmed the presence of fungal hyphae. The patient showed an initial favourable response after surgical removal of the infected focus, but unfortunately never returned to premorbid functioning. This case highlights the importance of early diagnosis, urgent surgery, and prompt antifungal therapy for the management of aspergillus spinal epidural abscesses. Associated morbidity and mortality can be substantially increased if physicians fail to recognise this condition and do not institute appropriate and timely surgical and medical treatment.

Are Point Mutations in HMG-CoA Reductases (Hmg1 and Hmg2) a Step towards Azole Resistance in Aspergillus fumigatus?

Invasive aspergillosis, mainly caused by Aspergillus fumigatus, can lead to severe clinical outcomes in immunocompromised individuals. Antifungal treatment, based on the use of azoles, is crucial to increase survival rates. However, the recent emergence of azole-resistant A. fumigatus isolates is affecting the efficacy of the clinical therapy and lowering the success rate of azole strategies against aspergillosis. Azole resistance mechanisms described to date are mainly associated with mutations in the azole target gene cyp51A that entail structural changes in Cyp51A or overexpression of the gene. However, strains lacking cyp51A modifications but resistant to clinical azoles have recently been detected. Some genes have been proposed as new players in azole resistance. In this study, the gene hmg1, recently related to azole resistance, and its paralogue hmg2 were studied in a collection of fifteen azole-resistant strains without cyp51A modifications. Both genes encode HMG-CoA reductases and are involved in the ergosterol biosynthesis. Several mutations located in the sterol sensing domain (SSD) of Hmg1 (D242Y, G307D/S, P309L, K319Q, Y368H, F390L and I412T) and Hmg2 (I235S, V303A, I312S, I360F and V397C) were detected. The role of these mutations in conferring azole resistance is discussed in this work.

First report of invasive Aspergillus rhinosinusitis in a critically ill COVID-19 patient affected by acute myeloid leukemia, northeastern Iran

This is a report of established invasive Aspergillus rhinosinusitis in a patient diagnosed with COVID-19 and afflicted by AML, which was initially considered to be rhinocerebral mucormycosis.

Multi-Drug Resistance Bacterial Infections in Critically Ill Patients Admitted with COVID-19

Introduction. It is known that bacterial infections represent a common complication during viral respiratory tract infections such as influenza, with a concomitant increase in morbidity and mortality. Nevertheless, the prevalence of bacterial co-infections and secondary infections in critically ill patients affected by coronavirus disease 2019 (COVID-19) is not well understood yet. We performed a review of the literature currently available to examine the incidence of bacterial secondary infections acquired during hospital stay and the risk factors associated with multidrug resistance. Most of the studies, mainly retrospective and single-centered, highlighted that the incidence of co-infections is low, affecting about 3.5% of hospitalized patients, while the majority are hospital acquired infections, developed later, generally 10–15 days after ICU admission. The prolonged ICU hospitalization and the extensive use of broad-spectrum antimicrobial drugs during the COVID-19 outbreak might have contributed to the selection of pathogens with different profiles of resistance. Consequently, the reported incidence of MDR bacterial infections in critically ill COVID-19 patients is high, ranging between 32% to 50%. MDR infections are linked to a higher length of stay in ICU but not to a higher risk of death. The only risk factor independently associated with MDR secondary infections reported was invasive mechanical ventilation (OR 1.062; 95% CI 1.012–1.114), but also steroid therapy and prolonged length of ICU stay may play a pivotal role. The empiric antimicrobial therapy for a ventilated patient with suspected or proven bacterial co-infection at ICU admission should be prescribed judiciously and managed according to a stewardship program in order to interrupt or adjust it on the basis of culture results.