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At least 19 recordsLinked to original sources
PubMed1979

Studies on Alternaria allergens. I. Isolation of allergens from Alternaria tenuis and Alternaria solani.

Extracts of Alternaria tenuis and Alternaria solani were separated into dialyzable (molecular weight less than 10,000) and non-dialyzable forms. The latter was further fractionated by gel filtration through Sephadex G-100 followed by ion-exchange chromatography on DEAE-cellulose. The dialyzable material was fractionated by gel filtration through Sephadex G-50. The allergenic activities of the fractions obtained from the A. tenuis extract was measured in vitro by the radioallergosorbent test assay and the allergenic potency was measured by radioallergosorbent test inhibition assay. Allergenic activity was detected in most of the non-dialyzable fractions, the majority of the activity being in the last G-100 fraction (MW approximately 20,000) which was predominantly protein in nature. The same component may be responsible for the activity found in the dialyzate and its first G-50 fraction since the immunodiffusion studies indicated that the last G-100 fraction has antigenic components in common with those of the first G-50 fraction. In addition, cross-reactions between A. tenuis and A. solani extracts show that the two species share common antigenic determinants.

Allergens↗
PubMed1983

Studies on Alternaria allergens. IV. Biologic activity of a purified Alternaria fraction (Alt-I).

We have previously isolated a purified Alternaria fraction (Alt-I) by means of immunochemical (RAST) assays to document allergenicity. In the present study we investigated the allergenicity of Alt-I by in vivo and in vitro biologic tests in a selected group of 16 nonimmunized Alternaria-sensitive patients, all of whom had positive skin tests to crude Alternaria extract; a control group of eight nonallergic individuals was also studied. Intradermal skin-test titration endpoints to Alt-I ranged from 60 pg/ml to 60 ng/ml in the Alternaria-sensitive patients. Alt-I induced greater than 30% in vitro leukocyte histamine in all Alternaria-sensitive patients at submicrogram concentrations. Alt-I did not produce positive skin tests or induce significant leukocyte histamine release in nonallergic individuals. In 14 of 16 Alternaria-sensitive patients bronchoprovocation testing produced greater than 20% fall in forced expiratory volume in one second at Alt-I test concentrations of 0.6 to 60 micrograms/ml. In a separate prospective study of 100 unselected individuals, concordant skin-test reactions were noted to crude Alternaria extract and Alt-I in 96 instances. These results confirm that the Alt-I fraction is a biologically active, major allergenic component of crude Alternaria extract.

Adolescent↗
PubMed1976

Studies on Alternaria allergens. I. Establishment of the radioallergosorbent test for measurement of Alternaria allergens.

The ability to covalently couple Alternaria allergens to microcrystalline cellulose particles has permitted not only the measurement of IgE antibodies to Alternaria in patient serums but also the identification of allergenic fractions from crude Alternaria extracts. Crude aqueous Alternaria extracts from 3 commerical suppliers were coupled to cellulose but failed to bind more than 5% of total radioactive counts (TRC) when reacted with serums from highly sensitive patients. Fractionation of a commercial extract through Sephadex G-25 showed that almost all allergenic activity was located in a protein- and carbohydrate-containing peak eluting at the column void volume. These fractions were pooled and coupled to cellulose to yield a RAST polymer which produced up to 20% TRC binding when tested with serums from over 100 Alternaria-sensitive patients, and only up to 1% TRC binding with 17 nonallergic serums. The study of commercial Alternaria extracts by chromatographic and Rast inhibition techniques showed that present extracts are neither qualitatively or quantitatively comparable.

Allergens↗
PubMed2001

Endopolygalacturonase is essential for citrus black rot caused by Alternaria citri but not brown spot caused by Alternaria alternata.

Alternaria citri, the cause of Alternaria black rot, and Alternaria alternata rough lemon pathotype, the cause of Alternaria brown spot, are morphologically indistinguishable pathogens of citrus: one causes rot by macerating tissues and the other causes necrotic spots by producing a host-selective toxin. To evaluate the role of endopolygalacturonase (endoPG) in pathogenicity of these two Alternaria spp. pathogens, their genes for endoPG were mutated by gene targeting. The endoPGs produced by these fungi have similar biochemical properties, and the genes are highly similar (99.6% nucleotide identity). The phenotypes of the mutants, however, are completely different. An endoPG mutant of A. citri was significantly reduced in its ability to cause black rot symptoms on citrus as well as in the maceration of potato tissue and could not colonize citrus peel segments. In contrast, an endoPG mutant of A. alternata was unchanged in pathogenicity. The results indicate that a cell wall-degrading enzyme can play different roles in the pathogenicity of fungal pathogens. The role of a cell wall-degrading enzyme depends upon the type of disease but not the taxonomy of the fungus.

Alternaria↗
PubMed2005

Toxigenic profile of Alternaria alternata and Alternaria radicina occurring on umbelliferous plants.

Alternaria alternata and Alternaria radicina are fungal species that occur in several food crops and may produce mycotoxins and phytotoxins. The toxigenic profile of A. alternata and A. radicina isolated from carrot and other umbelliferous plants was determined by growing the fungus on rice and carrot discs. Most of the tested isolates of A. alternata produced the mycotoxins tenuazonic acid, alternariol, alternariol methyl ether and altertoxin-I on rice. Only alternariol and alternariol methyl ether were produced on carrot discs. When cultured on rice, none of the isolates of A. alternata from umbelliferous plants produced AAL toxins and fumonisins. AAL toxins, but not fumonisins, were instead produced by A. alternata f. sp. lycopersici isolate NRRL 18822 isolated from tomato. A. radicina produced the phytotoxic compounds radicinin, epi-radicinol and radicinol on carrot discs, whereas it produced radicinin and radicinol on rice. Although A. alternata has been frequently found in organic carrots, none of the above mycotoxins was detected in carrot roots or in carrot commercial products. The reduction of alternariol and alternariol methyl ether during carrot juice processing at laboratory scale was estimated to be >98%. Based on these findings and previous reports, it can be concluded that Alternaria mycotoxins in carrots do not represent a hazard for consumers.

Alternaria↗
PubMed2001

Production of alternaria mycotoxins by Alternaria alternata isolated from weather-damaged wheat.

The production of Alternaria mycotoxins by Alternaria alternata isolated from Chinese weathered wheat kernels were first investigated on polished rice and durum wheat grains. These mycotoxins included alternariol (AOH) and its monomethyl ether (AME), altenuene (ALT), altertoxin I (ATX-I), and tenuazonic acid (TA). Of 25 isolates tested, all were AOH and AME producers, 21 (84%) coproduced ALT and ATX-I, and 8 (32%) produced TA in rice culture. TA was the most abundant toxin produced at a level ranging from 1,369 to 3,563 mg/kg. Much smaller amounts of AOH, AME, ALT, and ATX-I were present with average concentrations of 54, 40, 44, and 8 mg/kg, respectively. There were linear correlations between the level of AOH and AME (r = 0.846), alternariols (AOH plus AME) and ALT (r = 0.785), and ATX-I and TA (r = 0.553). Polished rice medium seems to support a bit more production of Alternaria metabolites than wheat but with an insignificant difference in concentrations (P > 0.05). A study of the time-course of toxin production by A. alternata isolates indicated that AOH production began faster than any other toxins monitored, and ALT production exhibited a progressive increase throughout the experiment. TA producers might reveal their considerably higher ability to produce toxin in the field despite their low frequency.

Alternaria↗
PubMedDate not supplied

Alternaria infection in a patient with acquired immunodeficiency syndrome: case report and review of invasive alternaria infections.

A 31-year-old man with AIDS developed a necrotic lesion on his nasal septum due to Alternaria alternata. Excision and treatment with amphotericin B resulted in cure. This case expands the spectrum of opportunistic pathogens that infect patients with AIDS. Visceral and mucosal infections due to Alternaria have been reported in at least seven other patients.

Acquired Immunodeficiency Syndrome↗
PubMed1977

Tenuazonic acid production by Alternaria alternata and Alternaria tenuissima isolated from cotton.

Cultures of Alternaria alternata (three isolates) and Alternaria tenuissima (three isolates) obtained from cottonseeds and bolls were toxigenic when cultured on various laboratory media. A mycotoxin was isolated and identified as tenuazonic acid by using solvent partition, thin-layer chromatography, and instrument analyses. Toxicity was monitored with brine shrimp and chicken embryo bioassays. All cultures except A. alternata 938 produced tenuazonic acid when grown on cottonseed and on yeast extract-sucrose broth. The most toxin (266 mg/kg) was produced by A. tenuissima 843 on cottonseed.

Alternaria↗
PubMed1976

Studies on Alternaria allergens. II. Measurement of the relative potency of commercial Alternaria extracts by the direct RAST and by RAST inhibition.

The relative potency of 12 commercial Alternaria extracts was analyzed by end-point skin test titrations and compared to in vitro measurements of potency, including (1) the radioallergosorbent test (RAST) inhibition procedure; (2) the direct RAST procedure; and (3) the protein nitrogen unit (PNU) content. Potencies determined by skin testing 10 sensitive patients were strongly correlated among the various patients. Measurements of potency by both RAST inhibition and direct RAST assay were strongly correlated to potency as measured by skin testing. In contrast, neither the weight:volume nor the PNU content bore any relationship to allergenic potency as measured by skin testing or by either of the RAST procedures. Extracts differed by as much as 3,000-fold in allergen content by skin testing. Moreover, the extracts appeared to contain different allergenic determinants when tested by RAST inhibition. RAST inhibition offered several technical advantages over the direct RAST procedure, in that only one solid-phase RAST reagent was required, slopes of dose-response curves could be more easily compared, and a greater discrimination in allergenic potencies among extracts could be made. The RAST appears to offer an excellent method for measuring the potency of allergy extracts, pending the isolation and characterization of actual allergens.

Allergens↗
PubMed1997

Two cases of cutaneous phaeohyphomycosis by Alternaria alternata and Alternaria tenuissima.

Two cases of cutaneous phaeohyphomycosis, one with a nodular appearance and the other with an erythematous infiltrating patch, are reported in immunocompromised patients. Diagnosis was based on histological examination, which revealed hyphae and round-shaped fungal cells in a granulomatous dermal infiltrate, and on identification of the moulds when biopsy fragments were cultured on Sabouraud-dextrose agar without cycloheximide. The pathogens were Alternaria tenuissima in the first case and A. alternata in the second. The fungi were examined by scanning electron microscopy. The patients were checked for bone and lung involvement and were then treated with surgical excision and itraconazole, and itraconazole only, respectively, with clinical and mycological resolution.

Aged↗
PubMed1987

Studies on alternaria allergens. VI. Stability of the allergen components of Alternaria tenuis extracts under a variety of storage conditions.

The allergenic potencies of samples of two commercial Alternaria tenuis extracts stored under various conditions were compared at 3 months intervals over a period of 1 year. Aliquots of the extracts at 5.12 mg/ml were maintained in: saline; 50% glycerol-saline mixture; 0.4% phenol-saline; 0.4% phenol-saline containing 0.03% human serum albumin, and samples were also kept in lyophilized form. The samples were stored at -20, 4, 24, 37 and 56 degrees C. Their potency was measured by radioallergosorbent inhibition assay and by mouse IgE passive cutaneous anaphylaxis (PCA) tests. The lyophilized extracts fully maintained their activity at all temperatures for 12 months. Aqueous extracts with or without preservatives also maintained their potency if stored at -20, 4 and 24 degrees C, but showed a significant loss of PCA activity at 56 degrees C, after 3 months. A deleterious effect of phenol was observed in one of the extracts stored at -20 degrees C for 3 months, by PCA tests. The use of preservatives to retain potency over a period of 12 months is therefore unnecessary and may be deleterious. The results indicate that, while storage of A. tenuis in a lyophilized form is best at all temperatures, aqueous extracts are also remarkedly stable when stored at -20, 4 and 24 degrees C, over a 12-month period.

Allergens↗
PubMed1985

Studies on Alternaria allergens. V. Comparative biochemical and immunological studies of three isolates of Alternaria tenuis cultured on synthetic media.

Six extracts were prepared from Alternaria tenuis isolated ATCC 6663, ATCC 16086 and DAOM (Agriculture Canada) 183905 grown separately on two synthetic media, revised tobacco and Czapek's, and their biochemical and immunological properties were examined. High-performance liquid chromatography revealed considerable variations in UV absorbance and carbohydrate profiles among extracts from the different isolates. These differences were less marked among samples of the same isolate cultured on different media. Enzyme screening showed that all extracts contained large amounts of phosphatases and glucosidases and moderate quantities of esterases. Only the alpha-galactosidase activity showed any correlation with allergenic activity. No significant variation was observed in isoelectric focusing patterns. Extensive antigenic cross-reactivity even between the different isolates was found in precipitin studies. In mouse IgE passive cutaneous anaphylaxis tests, all extracts gave reactions of similar intensity. In direct RAST and RAST inhibition assays, ATCC 16086 grown on revised tobacco medium was found to be the most potent and approached the activity of an extract from a commercial material (B-I). DAOM 183905 grown on either medium was next in potency while ATCC 6663 samples were the least potent. The results indicate that it is possible to obtain extracts of high allergenic potency for standardization purposes from growth of selected A. tenuis isolates on a chemically defined medium.

Allergens↗
PubMed1984

Studies on alternaria allergens. IV. Comparative biochemical and immunological studies of commercial Alternaria tenuis Batches.

The biochemical and immunological characteristics of a series of commercial samples of Alternaria tenuis were examined, including samples from two different companies. There was a considerable variation in the biochemical parameters such as the gel filtration profile on Sephadex G-100, isoelectric focussing pattern and immunodiffusion precipitin band pattern. The content and proportion of two high molecular weight polysaccharides, one a galactomannan and the other a glucan, also varied greatly. In contrast, the allergenic properties of the samples were more consistent. In rat IgE passive cutaneous anaphylaxis tests, extensive cross-reactivity was observed among batches from the same company, but this cross-reactivity was weaker when batches from the two companies were compared. In direct radioallergosorbent tests (RAST) the samples showed similar reactivities, but RAST inhibition tests showed a 40-fold range in activity between samples from one company and 55-fold between batches from the two sources. It was found that the proportions of the major A. tenuis allergen and a related hypoallergenic antigen in the samples were relatively constant, hence RAST inhibition can be used as a measure of allergenic potency despite the presence of this cross-reacting antigen. The lack of correlation between allergenic and biochemical properties of the various samples suggest that a simple biochemical test is unlikely to be a satisfactory replacement for the RAST inhibition assay in standardizing A. tenuis extracts.

Allergens↗
PubMed1981

Studies on alternaria allergens. II. Presence of two related antigens with contrasting allergenic properties in Alternaria tenius extracts.

Earlier, it was reported that most of the allergenic activity of Alternaria tenuis seemed to reside in the last Sephadex G-100 fraction (G3, molecular weight approximately 20,000). These conclusions were based on results obtained by the in vitro techniques of radioallergosorbent tests (RAST) and RAST inhibition. In the present studies, the allergenic activity of A. tenuis fractions was measured in vivo. It was found that fraction G3 was neither capable of inducing reaginic (IgE) antibodies in rats nor eliciting a skin reaction in rats sensitized with reagins against A. tenuis non-dialyzable fraction (MW greater than 12,000). On the other hand, subfractions G2D3 and G2D4 obtained from the middle fraction of G-100 (G2, MW approximately 30,000-40,000) followed by ion-exchange chromatography on DEAE-cellulose, showed the greatest allergenic activity in vivo, giving high titered reaginic antibodies in rats. When compared by RAST inhibition, the activities of fractions G2D3 and G2D4 were slightly lower than that of G3. Fraction G3 was immunogenic in rabbits. In immunodiffusion tests, G2D3, G2D4 and G3 appeared to be identical and they were cross-inhibiting in RAST inhibition tests. It was concluded that the sizes and multivalent properties of G2 and G3 antigens exerted a strong influence on their allergenic activities in rats (IgE antibody production) but this factor was of little importance for their antigenic activity in rabbits (precipitin antibody production) and their behaviour in the in vitro tests.

Alternaria↗
PubMed1982

Studies on Alternaria allergens. III. Effect of Alternaria tenuis on the humoral response to three T cell-dependent antigens in rats.

The effects of an extract of the saprophytic mold, Alternaria tenuis (AT-CE) on the humoral response to a ragweed allergen extract (DWSR), ovalbumin and sheep red blood cells (SRBC) was investigated in female Wistar rats. Animals pretreated with 100 micrograms or 2 mg AT-CE showed enhancement (p less than 0.05) in the reaginic response (IgE antibody) to DWSR at 25 and 18 days postimmunization. On the other hand, animals posttreated with AT-CE showed substantial reduction in anti-DWSR IgE antibody response. Contrasting results were obtained when ovalbumin was used as an immunizing antigen. There was a remarkable enhancement in the reaginic response to ovalbumin in rats pre- or posttreated with 10 micrograms of AT-CE. Pretreatment with AT-CE did not affect the hemagglutination titers to ovalbumin, while posttreatment with 100 micrograms or 1 mg AT-CE increased the hemagglutination titers of IgM antibody. There was a significant reduction in hemagglutinin, and hemolysin titers to SRBC in animals pretreated with all concentrations of AT-CE; at day 21, suppression was noted in animals pre- or posttreated with all concentrations of AT-CE. On the other hand, greatly increased hemagglutination titers were found in animals posttreated with 100 micrograms or 1 mg AT-CE. Hence, enhancement and suppression can both occur depending on the dose and time of administration of AT-CE together with the nature of the immunizing antigen.

Alternaria↗