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At least 19 recordsLinked to original sources

The Cu,Zn superoxide dismutases of Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, and Aspergillus terreus: purification and biochemical comparison with the Aspergillus fumigatus Cu,Zn superoxide dismutase.

Cu,Zn superoxide dismutases (SODs) have been purified to homogeneity from Aspergillus flavus and A. niger, which are significant causative agents of aspergillosis, and from A. nidulans and A. terreus, which are much rarer causative agents of disease, using a combination of isoelectric focusing and gel filtration fast protein liquid chromatography. The purified enzymes have been compared with the previously described SOD from the most important pathogen in the genus, A. fumigatus (M. D. Holdom, R. J. Hay, and A. J. Hamilton, Free Radical Res. 22:519-531, 1995). The N-terminal amino acid sequences of the four newly purified enzymes were almost identical and demonstrated homology to known Cu,Zn SODs from a range of organisms including that from the previously described SOD from A. fumigatus. SOD activity was detectable in the culture filtrates of all species, and intracellular Cu,Zn SOD activity as a proportion of total protein was highest in early-log-phase cultures. The specific activities of the purified enzymes were similar, and all four of the newly described enzymes were inhibited by potassium cyanide and diethyldithiocarbamate, known Cu,Zn SOD inhibitors. Sodium azide and o-phenanthroline demonstrated inhibition at concentrations from 5 to 30 mM, and EDTA also exhibited a varying degree of inhibition of SOD activity. However, there were differences in the nonreduced molecular masses, the reduced molecular masses, and the isoelectric points of the four newly described SODs and the A. fumigatus enzyme; these varied from 55 to 123 kDa, 17.5 to 19.5 kDa, and 5.0 to 5.9, respectively. Of particular note was the observation that the A. fumigatus enzyme was thermostable compared with the SODs from the other species; in addition, the A.fiumigatus enzyme retained all of its activity at 37 degrees C relative to 20 degrees C, whereas the SODs of A. nidulans and A. terreus lost significant activity at the higher temperature. Aspergillus Cu,Zn SOD plays a hypothetical role in the avoidance of oxidative killing mechanisms, and our data suggest that the thermotolerant A. fumigatus Cu,Zn SOD would be more effective in such a protective system than, for example, the equivalent enzyme from the more rarely pathogenic A. nidulans.

Amino Acid Sequence↗

Osteomyelitis due to Aspergillus spp. in patients with chronic granulomatous disease: comparison of Aspergillus nidulans and Aspergillus fumigatus.

OBJECTIVE: Chronic granulomatous disease (CGD) is a rare inherited disorder of NADPH oxidase in which phagocytes fail to generate reactive antimicrobial oxidants. Invasive fungal infections are an important cause of morbidity and mortality in CGD patients, with Aspergillus spp. being the most frequent fungal pathogens. We reviewed the reported cases of osteomyelitis in CGD patients due to Aspergillus nidulans and compared them with those due to Aspergillus fumigatus. METHODS: Twenty-four cases of osteomyelitis due to Aspergillus spp. in 22 male CGD patients were found in MEDLINE. RESULTS: Fourteen cases (58%) were due to Aspergillus nidulans and ten cases to Aspergillus fumigatus. No other aspergilli were reported as causes of osteomyelitis. Osteomyelitis due to Aspergillus nidulans was associated with pulmonary infection and involved 'small bones' more frequently than Aspergillus fumigatus osteomyelitis (p=0.032). Half of the CGD patients with Aspergillus nidulans osteomyelitis died compared with none of those with Aspergillus fumigatus osteomyelitis (p=0.019). In both Aspergillus nidulans and Aspergillus fumigatus cases, cure was achieved by prompt antifungal treatment combined with surgery and immunotherapy. CONCLUSION: Aspergillus nidulans causes osteomyelitis in CGD patients relatively frequently compared with Aspergillus fumigatus and may be accompanied by higher mortality. This contrasts with the low frequency with which Aspergillus nidulans causes osteomyelitis in patients with other types of immunodeficiency.

Adolescent↗

Transformation of Aspergillus aculeatus using the drug resistance gene of Aspergillus oryzae and the pyrG gene of Aspergillus nidulans.

Transformation systems for Aspergillus aculeatus has been developed, based on the use of the pyrithiamine resistance gene of Aspergillus oryzae and the orotidine-5'-monophosphate decarboxylase gene (pyrG) of Aspergillus nidulans. An A. aculeatus mutant which can be transformed effectively by the A. nidulans pyrG gene was isolated as a transformation host. This is the first report of transformation of A. aculeatus.

Aspergillus↗

Structure of the Aspergillus niger pelA gene and its expression in Aspergillus niger and Aspergillus nidulans.

Aspergillus niger pectin lyases are encoded by a multigene family. The complete nucleotide sequence of the pectin lyase PLA-encoding gene pelA has been determined. Comparison of the deduced amino acid sequence with the deduced amino acid sequence of the other characterized pectin lyase, PLD, shows that the proteins share 69% amino acid identity. When grown on media with pectin as the sole carbon source, A. niger transformants containing multiple copies of the pelA gene show raised mRNA levels and overexpression of the gene product PLA compared with the wild-type strain. PLA was purified and characterized. In A. nidulans transformants PLA is also produced in medium containing a high concentration of glucose and no pectin.

Amino Acid Sequence↗

Aspergillus nomius, a new aflatoxin-producing species related to Aspergillus flavus and Aspergillus tamarii.

Aspergillus nomius is described and represents a new aflatoxigenic species phenotypically similar to A. flavus. Strains examined were isolated from insects and agricultural commodities. Separation from A. flavus is based on the presence of indeterminate sclerotia and a lower growth temperature. Comparisons of DNA relatedness show A. nomius to have only relatively recently evolved from A. flavus and A. tamarii.

Aflatoxins↗

[Study of immunological activity of Aspergillus flavus Link. II. Immunogenicity, antigenic properties and evaluation of cross reactions of Aspergillus flavus antibodies with Aspergillus fumigatus antigens].

The aim of this study was to determine immunogenic and antigenic properties of tested strain. Chemically characterised AEM and APP antigens were used for immunisation of laboratory animals. Immunogenic, antigenic and multideterminant character of tested preparations was shown by immunodiffusion technique. It was found that AEM and its two fractions AS and API share common immunodeterminant what requires additional studies on their further separation. Using techniques described in this study no antigenic relationship was found between tested A. flavus strain and antigens derived from A. fumigatus and A. candidus. Multideterminant character of AEM and APP was confirmed by rockett immunoelectrophoresis, defining 6 different immunodeterminants for APP and 9-10 determinants for AEM, showing by the method used as separate precipitation arcs. In this study a fused rockett immunoelectrophoresis was highly appreciated as an usefull technique for investigation of fungal antigens. The results obtained require further confirmation by testing human sera. They indicate that it would be usefull to apply other antigens than derived from A. fumigatus and A. candidus for clinical diagnostic of Aspergillosis and related diseases.

Animals↗

Aspergillosis caused by non-fumigatus Aspergillus species: risk factors and in vitro susceptibility compared with Aspergillus fumigatus.

Invasive aspergillosis (IA) caused by inherently more antifungal-resistant non-fumigatus Aspergillus species has become an important life-threatening complication in severely immunocompromised patients with cancer. The purpose of this study was to compare the relative incidence of, risk factors for, and in vitro correlation of amphotericin B and itraconazole with the clinical outcome of IA caused by Aspergillus fumigatus with those of IA caused by non-fumigatus Aspergillus spp. in patients with cancer. A retrospective search of our tertiary care cancer center's microbiology laboratory reports from 1998-2001 revealed 40 patients with cancer and IA. A non-fumigatus Aspergillus species caused IA in 28 (70%) of those patients. A. fumigatus was the predominant cause of late-onset IA after bone marrow transplantation (p = 0.05), whereas IA due to non-fumigatus Aspergillus spp. was more common in patients with neutropenia (p = 0.01). The minimum inhibitory concentration (50/90) and minimum fungicidal concentration (50/90) for amphotericin B were higher in the non-fumigatus Aspergillus spp. group than in the A. fumigatus one. The Aspergillus species distribution in IA cases in our institution shows a predominance of the more antifungal-resistant or -tolerant non-fumigatus Aspergillus spp.

Adult↗

Selective expression of a major allergen and cytotoxin, Asp f I, in Aspergillus fumigatus. Implications for the immunopathogenesis of Aspergillus-related diseases.

Asp f I is a major 18-kDa Aspergillus fumigatus allergen and a member of the mitogillin family of cytotoxins. The nucleotide sequence of the Asp f I gene was determined by sequencing polymerase chain reaction products amplified from A. fumigatus spore DNA. The entire 678-bp DNA includes an 81-bp leader sequence, preceding the N-terminal alanine codon, a 52-bp intron, and a 444-bp open reading frame, encoding a 149-amino acid protein (M(r) 16,899), which is 99% homologous to mitogillin from Aspergillus restrictus. A mAb-based ELISA was used to compare Asp f I levels in spores, mycelia, and culture filtrate, and to determine the kinetics of allergen production. Disrupted hyphae or spore extracts had a 1000-fold lower level of Asp f I than culture filtrate, suggesting that germination of spores and growth of the fungus are essential for allergen production. Asp f I levels in A. fumigatus and A. restrictus peaked at day 3 (0.87 to 12.1 micrograms/ml), however, the allergen was not detected in Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Aspergillus nidulans cultures (< 1.5 ng/ml) on either days 3 or 8. Northern analysis confirmed that Asp f I mRNA was detected only in A. fumigatus and A. restrictus, but not in the other four Aspergillus spp. Asp f I-specific DNA was generated after polymerase chain reaction amplification of genomic mycelial DNA obtained from A. fumigatus and A. restrictus, but not from the other Aspergillus spp. The results show that Asp f I is selectively expressed in A. fumigatus, and suggest that this cytotoxin could be a specific virulence factor for A. fumigatus.

Allergens↗

[Development of infection with Aspergillus flavus in woman being treated for allergic pulmonary Aspergillosis caused by Aspergillus fumigatus].

A 36-year-old woman who raised plants in a large greenhouse came to our hospital because of a cough and purulent sputum. A chest X-ray film showed infiltrative shadows in the left middle lung field. Aspergillus fumigatus was isolated from samples of sputum and bronchoalveolar lavage fluid obtained from the left B5. Biopsy specimens revealed hyphae elements of aspergillus species and eosinophils in a plug of viscous material. Also, eosinophils and lymphocytes had infiltrated through bronchial epithelium without aspergillus species. She was given a diagnosis of allergic aspergillosis caused by Aspergillus fumigatus. Fluconazole was given and her symptoms and infiltrative shadows improved. Seventy days after treatment with fluconazole began, her symptoms recurred along with an abnormal shadow in the left upper lung field on a chest x-ray film. Aspergillus flavus, but not Aspergillus fumigatus, was isolated from samples of sputum and bronchoalveolar lavage fluid obtained from the left lung (S1+2). Biopsy specimens of the lung showed eosinophilic pneumonia. She was treated with itraconazole and her symptoms and abnormal radiographic shadows disappeared. She had no asthmatic attack or central bronchiectasis du ring the illness. This was a case of allergic pulmonary aspergillosis without asthmatic symptoms. It is interesting that one species of aspergillus was replaced by another during treatment.

Adult↗

Aspergillus fumigatus specific IgE and IgG antibodies for diagnosis of Aspergillus-related lung diseases.

IgE and IgG antibodies against Aspergillus fumigatus were detected by crossed radio immunoelectrophoresis (CRIE) on the sera of seven patients with aspergilloma, six patients with allergic broncho-pulmonary aspergillosis (ABPA) and 25 patients with extrinsic asthma with Aspergillus allergy. IgE-CRIE analysis indicated the presence of A. fumigatus-specific IgE in sera of patients with ABPA and Aspergillus asthma but not of aspergilloma patients. IgG-CRIE showed that both aspergilloma and ABPA patient sera contained high levels of circulating specific IgG antibodies in contrast to sera of Aspergillus asthma patients, which did not show detectable amounts of Aspergillus-specific IgG antibodies. Specific IgE binding could be demonstrated for the major allergens Ag-10 and AG-40 in all ABPA patients, in 80% of Aspergillus asthma patients but not in sera from aspergilloma patients. Specific IgG antibodies directed towards the major allergens could be detected in most of the aspergilloma patients, between 30-70% of the ABPA patients but not in sera from patients with Aspergillus asthma.

Aspergillosis↗

Sequences from the aspergillopepsin PEP gene of Aspergillus fumigatus: evidence on their use in selective PCR identification of Aspergillus species in infected clinical samples.

In immunodeficient patients, Aspergillus species emerge as circumstantial pathogens. Aspergillus fumigatus is a distant first among the pathogenic aspergilli, which cause deep-seated mycoses. Sequences of the pep gene of A. fumigatus as potential PCR primers, which have not been tested before, were used to identify this species and if possible, differentiate it from other, co-identified, clinically important species of the genus. We present results of the three most promising primer pairs, pep-1/pep-22, pep-15/pep-22 and pep-21/pep32. The second pair was of better specificity when tested with DNA extracted from pure cultures of a multitude of aspergilli, whereas the first co-amplified four clinically significant Aspergillus species. The compatibility of the PCR method with the CTAB DNA extraction protocol varied according to the biological fluid tested and the primer pair used. The first two pairs showed moderate adaptability to the different commercial DNA extraction kits, which were tested in whole blood, spiked with Aspergillus fumigatus hyphae and conidia - as were all the biological fluids used. Restriction of the amplification products with MspI produced distinct patterns for different Aspergillus spp. This approach, as a potential diagnostic tool, seems reliable and sensitive due to its flexibility, speed, low cost, ease of application and selectable breadth of detection.

Aspartic Acid Endopeptidases↗

Density and molecular epidemiology of Aspergillus in air and relationship to outbreaks of Aspergillus infection.

After five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus and A. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in Rotterdam (The Netherlands) was begun. A. fumigatus isolates obtained from the Department of Hematology were studied for genetic relatedness by randomly amplified polymorphic DNA (RAPD) analysis. This was repeated with A. fumigatus isolates contaminating culture media in the microbiology laboratory. The density of the conidia of nonpathogenic fungi in the outside air showed a seasonal variation: higher densities were measured during the summer, while lower densities were determined during the fall and winter. Hardly any variation was found in the numbers of Aspergillus conidia. We found decreasing numbers of conidia when comparing air from outside the hospital to that inside the hospital and when comparing open areas within the hospital to the closed department of hematology. The increase in the number of patients with invasive aspergillosis could not be explained by an increase in the number of Aspergillus conidia in the outside air. The short-term presence of A. flavus can only be explained by the presence of a point source, which was probably patient related. Genotyping A. fumigatus isolates from the department of hematology showed that clonally related isolates were persistently present for more than 1 year. Clinical isolates of A. fumigatus obtained during the outbreak period were different from these persistent clones. A. fumigatus isolates contaminating culture media were all genotypically identical, indicating a causative point source. Knowledge of the epidemiology of Aspergillus species is necessary for the development of strategies to prevent invasive aspergillosis. RAPD fingerprinting of Aspergillus isolates can help to determine the cause of an outbreak of invasive aspergillosis.

Air Microbiology↗

Polymerase chain reaction-mediated characterization of molds belonging to the Aspergillus flavus group and detection of Aspergillus parasiticus in peanut kernels by a multiplex polymerase chain reaction.

The Aspergillus flavus group covers species of A. flavus and Aspergillus parasiticus as aflatoxin producers and Aspergillus oryzae and Aspergillus sojae as koji molds. Genetic similarity among these species is high, and aflatoxin production of a culture may be affected by cultivation conditions and substrate composition. Therefore, a polymerase chain reaction (PCR)-mediated method of detecting the aflatoxin-synthesizing genes to indicate the degree of risk a genotype has of being a phenotypic producer was demonstrated. In this study, 19 strains of the A. flavus group, including A. flavus, A. parasiticus, A. oryzae, A. sojae, and one Aspergillus niger, were subjected to PCR testing in an attempt to detect four genes, encoding for norsolorinic acid reductase (nor-1), versicolorin A dehydrogenase (ver-1), sterigmatocystin O-methyltransferase (omt-1), and a regulatory protein (apa-2), involved in aflatoxin biosynthesis. Concurrently, the strains were cultivated in yeast-malt (YM) broth for aflatoxin detection. Fifteen strains were shown to possess the four target DNA fragments. With regard to aflatoxigenicity, all seven aflatoxigenic strains possessed the four DNA fragments, and five strains bearing less than the four DNA fragments did not produce aflatoxin. When peanut kernels were artificially contaminated with A. parasiticus and A. niger for 7 days, the contaminant DNA was extractable from a piece of cotyledon (ca. 100 mg), and when subjected to multiplex PCR testing using the four pairs of primers coding for the above genes, they were successfully detected. The target DNA fragments were detected in the kernels infected with A. parasiticus, and none was detected in the sound (uninoculated) kernels or in the kernels infected with A. niger.

Aflatoxins↗

[Peracute disseminated course of fatal Aspergillus fumigatus infection in liver failure and corticoid therapy. A case report on the epidemiology, pathogenesis and diagnosis of the systemic course of Aspergillus infections].

Cytostatic-treated persons and cases of severe hepatic failure under corticoid therapy are predisposed to disseminating Aspergillus infections. Constant exposure to Aspergillus spores may result in a fatal Aspergillus infection. The triad of hepatic failure, corticoid therapy and constant exposure to Aspergillus spores is described in a 70-year-old female patient. A painless icterus was clinically diagnosed as non-A non-B hepatitis, with a protracted cholestatic course. She had been treated with an oral corticoid preparation. After leaving the hospital at her own insistance when still in the icteric stage, severe pneumonia due to Aspergillus developed within 14 days; this was confirmed radiologically. The autopsy results showed unexpected infarction, similar to pneumonic foci, in all lobes and dissemination in the myocardium, stomach, kidneys and brain. The liver showed subacute dystrophy. Constant exposure to the conidia of A fumigatus came about as a result of the soil of potted ornamental plants in the patient's living room. The fungus could only be successfully cultured by putting infected tissue particles on Sabouraud dextrose agar; it was not possible by the common method of fractionated streaking.

Aged↗

[Presence of sexual forms (cleistothecia and Hülle cells) in a case of human maxillary sinus aspergillosis caused by Aspergillus nidulans in association with Aspergillus fumigatus].

The authors observed, in a biopsic sample from a human maxillary sinus, the coexistence, in parasitic stages, of two different Aspergillus species: A. fumigatus and A. nidulans. After having described the morphologies of each species, in sections on slides, and particularly those of cleistothecia and Hülle-cells for the second, they draw attention to the three interests of such an observation: -- rarety of observing Aspergillus nidulans in a parasitic stage, in spite of its particular thermotolerant character. -- association of two different Aspergillus species in a same sample, in parasitic stages, observed in man for the first time, at least according their informations. -- presence of reproductive sexual forms, observed in vivo for the first time, in an Aspergillus species.

Adult↗

Immunochemical assay applied to mycotoxin biosynthesis: ELISA comparison of sterigmatocystin production by Aspergillus versicolor and Aspergillus nidulans.

Conventional thin layer and instrumental methods for analyzing mycotoxins and their precursors are time-consuming and make the investigation of mycotoxin biosynthesis particularly difficult. As an alternative, sensitive enzyme-liked immunosorbent assays (ELISAs) can be utilized to analyze for these compounds. In this report, sterigmatocystin production in test tube cultures of Aspergillus versicolor ATCC 18643 and Aspergillus nidulans ATCC 32610 were compared using competitive ELISA. Polyclonal antiserum that was prepared against a sterigmatocystin hemiacetal-bovine serum albumin conjugate exhibited greatest specificity for sterigmatocystin hemiacetal and sterigmatocystin with less reactivity for O-methylsterigmatocystin. The antiserum could be used to detect as little as 50 ng/ml sterigmatocystin in ELISA. Direct ELISA could be performed on diluted culture broth and on mycelial extracts solubilized with N,N-dimethylformamide. Aspergillus versicolor ATCC 18643 produced more sterigmatocystin in SLS medium than in YES medium, and showed maximal levels at between 9 to 12 days incubation. Approximately 75% of sterigmatocystin was detectable in mycelium (254 micrograms/ml culture) compared to the extracellular fraction (87 micrograms/ml culture). Aspergillus nidulans exhibited qualitatively similar patterns of growth and toxigenesis in SLS medium but accumulated maximal levels of only 15 micrograms mycelial sterigmatocystin/ml culture and 5 micrograms extracellular sterigmatocystin/ml broth, respectively.

Aspergillus↗