Aspergillus niger infection in patients with haematological diseases: a report of eight cases. Fallbericht. Aspergillus niger-Infektionen bei Patienten mit hamatologischen Erkrankungen

Effects of Cationic and Anionic Surfaces on the Perpendicular and Lateral Forces and Binding of Aspergillus niger Conidia

The binding of conidia to surfaces is a prerequisite for biofouling by fungal species. In this study, Aspergillus niger subtypes 1957 and 1988 were used which produced differently shaped conidia (round or spikey respectively). Test surfaces were characterised for their surface topography, wettability, and hardness. Conidial assays included perpendicular and lateral force measurements, as well as attachment, adhesion and retention assays. Anionic surfaces were less rough (Ra 2.4 nm), less wettable (54°) and harder (0.72 GPa) than cationic surfaces (Ra 5.4 nm, 36° and 0.5 GPa, respectively). Perpendicular and lateral force assays demonstrated that both types of conidia adhered with more force to the anionic surfaces and were influenced by surface wettability. Following the binding assays, fewer A. niger 1957 and A. niger 1988 conidia bound to the anionic surface. However, surface wettability affected the density and dispersion of the conidia on the coatings, whilst clustering was affected by their spore shapes. This work demonstrated that anionic surfaces were more repulsive to A. niger 1998 spores than cationic surfaces were, but once attached, the conidia bound more firmly to the anionic surfaces. This work informs on the importance of understanding how conidia become tightly bound to surfaces, which can be used to prevent biofouling.

Diagnosis and Treatment of Invasive Aspergillosis Caused by Non-fumigatus Aspergillus spp

With increasing frequency, clinical and laboratory-based mycologists are consulted on invasive fungal diseases caused by rare fungal species. This review aims to give an overview of the management of invasive aspergillosis (IA) caused by non-fumigatus Aspergillus spp.-namely A. flavus, A. terreus, A. niger and A. nidulans-including diagnostic and therapeutic differences and similarities to A. fumigatus. A. flavus is the second most common Aspergillus spp. isolated in patients with IA and the predominant species in subtropical regions. Treatment is complicated by its intrinsic resistance against amphotericin B (AmB) and high minimum inhibitory concentrations (MIC) for voriconazole. A. nidulans has been frequently isolated in patients with long-term immunosuppression, mostly in patients with primary immunodeficiencies such as chronic granulomatous disease. It has been reported to disseminate more often than other Aspergillus spp. Innate resistance against AmB has been suggested but not yet proven, while MICs seem to be elevated. A. niger is more frequently reported in less severe infections such as otomycosis. Triazoles exhibit varying MICs and are therefore not strictly recommended as first-line treatment for IA caused by A. niger, while patient outcome seems to be more favorable when compared to IA due to other Aspergillus species. A. terreus-related infections have been reported increasingly as the cause of acute and chronic aspergillosis. A recent prospective international multicenter surveillance study showed Spain, Austria, and Israel to be the countries with the highest density of A. terreus species complex isolates collected. This species complex seems to cause dissemination more often and is intrinsically resistant to AmB. Non-fumigatus aspergillosis is difficult to manage due to complex patient histories, varying infection sites and potential intrinsic resistances to antifungals. Future investigational efforts should aim at amplifying the knowledge on specific diagnostic measures and their on-site availability, as well as defining optimal treatment strategies and outcomes of non-fumigatus aspergillosis.

Role of COPD in a case of fatal Aspergillus niger tracheobronchitis

A man with chronic obstructive pulmonary disease (COPD) in his mid-60s was admitted for respiratory failure due to multifocal, necrotising pneumonia. Despite initial improvement with antimicrobial therapy, the patient developed hemoptysis and progressive infiltrates. Subsequent fungal cultures from his bronchoalveolar lavage were positive for Aspergillus niger and treatment with voriconazole was added for suspected invasive pulmonary aspergillosis (IPA). A repeat bronchoscopy revealed cobblestone lesions with mucosal friability throughout the lower trachea and bilateral mainstem bronchi. Endobronchial biopsy showed septated hyphae confirming the diagnosis of IPA. Despite appropriate therapy, the patient declined further and passed away on hospital day 11. Invasive infections with A. niger are infrequent, with a paucity of data on clinical course and outcomes. Our case adds to the current body of literature regarding the potential virulence of this species in patients with COPD.

Possible COVID-19-Associated Pulmonary Aspergillosis Due to Aspergillus niger in Greece

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes direct damage to the pulmonary epithelium, enabling Aspergillus invasion. Rapid progression and high mortality of invasive aspergillosis have been reported. In the present study, we report a rare case of possible COVID-19-associated pulmonary aspergillosis (CAPA) caused by A. niger in a Greek patient. Diagnosis was based on ECMM/ISHAM specific criteria and the new algorithm “BM-AspICU” for the invasive pulmonary aspergillosis diagnostic strategy. The fungal isolate was recovered in a non-bronchoalveolar lavage (non-BAL) sample and its identification was performed by standard macroscopic and microscopic morphological studies. MALDI-TOF analysis confirmed the identification of A. niger. In addition, galactomannan antigen and Aspergillus real-time PCR testing were positive in the non-BAL sample, while in serum they proved negative. The A. niger isolate showed an MIC for fluconazole ≥128 μg/mL, for itraconazole and posaconazole 0.25 μg/mL, for voriconazole 0.5 μg/mL, for flucytosine 4 μg/mL, for amphotericin B 1 μg/mL, and for all echinocandins (caspofungin, anidulafungin, micafungin) >8 μg/mL. The patient was initially treated with voriconazole; amphotericin B was subsequently added, when a significant progression of cavitation was demonstrated on chest computed tomography. A. niger was not isolated in subsequent samples and the patient’s unfavorable outcome was attributed to septic shock caused by a pandrug-resistant Acinetobacter baumannii strain.

Acute respiratory failure due to Aspergillus niger infection with acute fibrinous and organazing pneumonia: A case report

A 59-year-old woman complaining of wet cough, hemoptysis, slight fever, anorexia, and malaise was admitted to hospital with suspected lobar pneumonia. She received treatment for myocardial infarction and deep venous thrombosis caused by familial protein C deficiency. Rapid deterioration due to respiratory failure occurred despite intensive care with broad-spectrum antibiotics. At a later date, sputum examination revealed the presence of Aspergillus niger. Based on clinical and autopsy findings, she was diagnosed with acute respiratory failure due to pulmonary aspergillosis with acute fibrinous and organizing pneumonia. This is the first reported case of pulmonary aspergillosis with acute fibrinous and organizing pneumonia complicated by calcium oxalate resulting from Aspergillus niger infection, leading to severe inflammation and tissue injury in the lungs.

COVID-19-associated mixed mold infection: A case report of aspergillosis and mucormycosis and a literature review

COVID-19-associated mold infections have been increasingly reported, and the main entity is COVID-19-associated aspergillosis (CAPA). Similarly, COVID-19-associated mucormycosis has been reported in hematology, and its prevalence is high and has been increasing in the diabetic population in India during the third COVID-19 pandemic wave. Simultaneous infection with Mucorales and Aspergillus is rare and even rarer during COVID-19. Here, we report the case of a previously immunocompetent patient with severe SARS-CoV-2 infection complicated with probable CAPA and mucormycosis co-infection. Specific diagnostic tools for mucormycosis are lacking, and this case highlights the advantages of analyzing blood and respiratory samples using the quantitative polymerase chain reaction to detect these fungi. We further reviewed the literature on mixed Aspergillus/Mucorales invasive fungal diseases to provide an overview of patients presenting with both fungi and to identify characteristics of this rare infection.

Molecular Diversity of Aspergilli in Two Iranian Hospitals

The Aspergillus species are main causative agents of various infections such as invasive aspergillosis (IA) in immunocompromised patients and these infections have high mortality rates. In this study, we provide insight in the species causing aspergillosis in Iran based on morphology and sequence data. Clinical (n = 117) and environmental isolates (n = 54) collected during 2010-2016 from University hospitals in Mashhad and Tehran (Iran) were identified both morphologically and molecularly using partial calmodulin (CaM) gene sequences. Clinical cases were identified based on EORTC/MSG criteria. Aspergillus flavus (n = 96, 55%) was the most prevalent species among the clinical and environmental isolates while A. fumigatus (n = 13, 7.5%) ranked fourth after A. tubingensis (n = 23, 13%) and A. welwitchiae (n = 18, 10%). Species such as A. tubingensis, A. welwitschiae, A. fumigatus, A. sydowii, A. neoniger and A. terreus were present in both clinical and environmental samples indicating the possible environmental source of infections. Interestingly, A. niger was isolated only once. Furthermore, 13 other rare and cryptic Aspergillus species were detected. Pulmonary and respiratory disorders (n = 33), followed by transplantation (n = 23), invasive fungal rhinosinusitis (n = 14), and haematological malignancies (n = 12) were major predisposing factors. According to EORTC/MSG criteria, there were 43 probable cases identified followed by 36 cases for each of proven and possible ones. Correct molecular identification will be useful for further epidemiological studies.

Aspergillus niger bloodstream infection in gastric cancer after common hepatic artery embolization: A case report

The present case study reported on a 62-year-old male patient with gastric cancer-associated Aspergillus (A.) niger bloodstream infection. The patient presented with massive hemorrhage in the gastrointestinal tract 3 months after total gastrectomy for gastric cancer. Conservative treatment consisting of blood transfusion to supplement blood volume loss was ineffective. Digital subtraction angiography indicated gastroduodenal artery bleeding. The first attempt of performing arterial embolization using gelatin sponges failed, while the second attempt of performing common hepatic artery embolization using gelatin sponges and micro-coil springs stopped the bleeding. Four weeks after angiography, the patient presented with the complication of A. niger bloodstream infection, which was cured using intravenous and oral voriconazole. Clinicians should be aware of the possibility of A. niger bloodstream infection after invasive operations in immunocompromised patients and apply timely antifungal treatment.

Fatal invasive aspergillosis caused by Aspergillus niger after bilateral lung transplantation

Aspergillus niger is usually considered to be a low virulence fungus, not commonly reported to cause invasive infections. Invasive pulmonary aspergillosis due to Aspergillus niger was diagnosed in a 43-year-old woman following bilateral lung transplantation. Intravenous voriconazole failed to control progression of the disease. Despite salvage therapy with a combination of voriconazole and caspofungin for 23 days, the patient developed massive hemoptysis leading to death. The authors report the clinical features and treatment of this case.

Diagnostic significance of Aspergillus species isolated from respiratory samples in an adult pneumology ward

Although the diagnostic significance of isolating Aspergillus spp. from respiratory cultures has been studied in immunocompromised hosts with invasive pulmonary aspergillosis (IPA), little is known of such infections in immunocompetent patients with other forms of aspergillosis. In this study of adult pneumology ward patients, we examined the association between Aspergillus spp. and disease prevalence. Laboratory records from April 1998 to March 2009 were reviewed to identify patients with Aspergillus spp. in respiratory samples. Correlations between the isolated species and clinical characteristics of patients were evaluated. During the study period, 165 Aspergillus spp. isolates were detected in the respiratory cultures of 139 patients. Of these patients, 62 (45%) were colonized with Aspergillus spp. and displayed no clinical symptoms of aspergillosis, while 77 (55%) had a form of pulmonary aspergillosis, characterized as either chronic necrotizing pulmonary aspergillosis (CNPA) (48%), aspergilloma (29%), IPA (13%), or allergic bronchopulmonary aspergillosis (ABPA) (10%). The dominant species were Aspergillus fumigatus (41%), A. niger (32%), and A. versicolor (12%). A. fumigatus was most commonly isolated in patients with IPA, aspergilloma, and CNPA, whereas A. niger was the dominant species in colonized patients and those with ABPA. Isolation of an Aspergillus spp. from respiratory samples does not confirm it as the etiologic pathogen because airway colonization by Aspergillus spp. is a common feature in several chronic lung diseases. Repeated isolation of the identical Aspergillus species and detection of anti-Aspergillus antibodies and/or Aspergillus antigens in sera are needed to determine the isolate represents the etiologic agent of disease.

Characterization of cultivated fungi isolated from grape marc wastes through the use of amplified rDNA restriction analysis and sequencing

Microbial assessment of grape marc wastes, the residual solid by-product of the wine-industry, was performed by identifying phylogenetically the fungal culturable diversity in order to evaluate environmental and disposal safety issues and to discuss ecological considerations of applications on agricultural land. Fungal spores in grape marc were estimated to 4.7 x 10(6) per g dry weight. Fifty six fungal isolates were classified into eight operational taxonomic units (OTUs) following amplified ribosomal DNA restriction analysis (ARDRA) and colony morphology. Based on 18S rRNA gene and 5.8S rRNA gene-ITS sequencing, the isolates representing OTUs #1, #2, #3, and #4, which comprised 44.6%, 26.8%, 12.5%, and 5.3%, respectively, of the number of the total isolates, were identified as Aspergillus fumigatus, Bionectria ochroleuca, Haematonectria haematococca, and Trichosporon mycotoxinivorans. The isolates of OTU#5 demonstrated high phylogenetic affinity with Penicillium spp., while members of OTUs #6 and #7 were closer linked with Geotrichum candidum var. citri-aurantii and Mycocladus corymbifer, respectively (95.4 and 97.9% similarities in respect to their 5.8S rRNA gene-ITS sequences). The OTU#8 with a single isolate was related with Aspergillus strains. It appears that most of the fungal isolates are associated with the initial raw material. Despite the fact that some of the species identified may potentially act as pathogens, measures such as the avoidance of maintaining large and unprocessed quantities of grape marc wastes in premises without adequate aeration, together with its suitable biological treatment (e.g., composting) prior to any agriculture-related application, could eliminate any pertinent health risks.

Aspergillus niger: an unusual cause of invasive pulmonary aspergillosis

Infections due to Aspergillus species cause significant morbidity and mortality. Most are attributed to Aspergillus fumigatus, followed by Aspergillus flavus and Aspergillus terreus. Aspergillus niger is a mould that is rarely reported as a cause of pneumonia. A 72-year-old female with chronic obstructive pulmonary disease and temporal arteritis being treated with steroids long term presented with haemoptysis and pleuritic chest pain. Chest radiography revealed areas of heterogeneous consolidation with cavitation in the right upper lobe of the lung. Induced bacterial sputum cultures, and acid-fast smears and cultures were negative. Fungal sputum cultures grew A. niger. The patient clinically improved on a combination therapy of empiric antibacterials and voriconazole, followed by voriconazole monotherapy. After 4 weeks of voriconazole therapy, however, repeat chest computed tomography scanning showed a significant progression of the infection and near-complete necrosis of the right upper lobe of the lung. Serum voriconazole levels were low–normal (1.0 μg ml⁻¹, normal range for the assay 0.5–6.0 μg ml⁻¹). A. niger was again recovered from bronchoalveolar lavage specimens. A right upper lobectomy was performed, and lung tissue cultures grew A. niger. Furthermore, the lung histopathology showed acute and organizing pneumonia, fungal hyphae and oxalate crystallosis, confirming the diagnosis of invasive A. niger infection. A. niger, unlike A. fumigatus and A. flavus, is less commonly considered a cause of invasive aspergillosis (IA). The finding of calcium oxalate crystals in histopathology specimens is classic for A. niger infection and can be helpful in making a diagnosis even in the absence of conidia. Therapeutic drug monitoring may be useful in optimizing the treatment of IA given the wide variations in the oral bioavailability of voriconazole.

Inhibition of a secreted glutamic peptidase prevents growth of the fungus Talaromyces emersonii

The thermophilic filamentous fungus Talaromyces emersonii secretes a variety of hydrolytic enzymes that are of interest for processing of biomass into fuel. Many carbohydrases have been isolated and characterized from this fungus, but no studies had been performed on peptidases. In this study, two acid-acting endopeptidases were isolated and characterized from the culture filtrate of T. emersonii. One of these enzymes was identified as a member of the recently classified glutamic peptidase family and was subsequently named T. emersonii glutamic peptidase 1 (TGP1). The second enzyme was identified as an aspartyl peptidase (PEP1). TGP1 was cloned and sequenced and shown to exhibit 64 and 47% protein identity to peptidases from Aspergillus niger and Scytalidium lignocolum, respectively. Substrate profiling of 16 peptides determined that TGP1 has broad specificity with a preference for large residues in the P1 site, particularly Met, Gln, Phe, Lys, Glu, and small amino acids at P1' such as Ala, Gly, Ser, or Thr. This enzyme efficiently cleaves an internally quenched fluorescent substrate containing the zymogen activation sequence (k(cat)/K(m)=2 x 10(5) m(-1) s(-1)). Maximum hydrolysis occurs at pH 3.4 and 50 degrees C. The reaction is strongly inhibited by a transition state peptide analog, TA1 (K(i)=1.5 nM), as well as a portion of the propeptide sequence, PT1 (K(i)=32 nM). Ex vivo studies show that hyphal extension of T. emersonii in complex media is unaffected by the aspartyl peptidase inhibitor pepstatin but is inhibited by TA1 and PT1. This study provides insight into the functional role of the glutamic peptidase TGP1 for growth of T. emersonii.