Aspergilli as Ochratoxin Producers

Hesseltine, C. W.; Vandegraft, E. E.; Fennell, Dorothy I.; Smith, M. L.; Shotwell, Odette L.

doi:10.1080/00275514.1972.12019299

Cited by 84 publications

(24 citation statements)

References 11 publications

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“…While Aspergillus ochraceus strains clearly vary in ochratoxin production (1,13,23,25,26), comparing results among studies is difficult. For example, some early studies had high limits of detection for ochratoxins (e.g., 100 ng/ml [13]), so some ochratoxin-producing strains may have been missed.…”

Section: Discussionmentioning

confidence: 99%

Ochratoxin Production by the Aspergillus ochraceus Group and Aspergillus alliaceus

Bayman

Baker

Doster

et al. 2002

Appl Environ Microbiol

245

130

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Ochratoxin A is a toxic and carcinogenic fungal secondary metabolite; its presence in foods is increasingly regulated. Various fungi are known to produce ochratoxins, but it is not known which species produce ochratoxins consistently and which species cause ochratoxin contamination of various crops. We isolated fungi in the Aspergillus ochraceus group (section Circumdati) and Aspergillus alliaceus from tree nut orchards, nuts, and figs in California. A total of 72 isolates were grown in potato dextrose broth and yeast extract-sucrose broth for 10 days at 30°C and tested for production of ochratoxin A in vitro by high-pressure liquid chromatography. Among isolates from California figs, tree nuts, and orchards, A. ochraceus and Aspergillus melleus were the most common species. No field isolates of A. ochraceus or A. melleus produced ochratoxin A above the level of detection (0.01 g/ml). All A. alliaceus isolates produced ochratoxin A, up to 30 g/ml. We examined 50,000 figs for fungal infections and measured ochratoxin content in figs with visible fungal colonies. Pooled figs infected with A. alliaceus contained ochratoxin A, figs infected with the A. ochraceus group had little or none, and figs infected with Penicillium had none. These results suggest that the little-known species A. alliaceus is an important ochratoxin-producing fungus in California and that it may be responsible for the ochratoxin contamination occasionally observed in figs.

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Section: Discussionmentioning

confidence: 99%

Ochratoxin Production by the Aspergillus ochraceus Group and Aspergillus alliaceus

Bayman

Baker

Doster

et al. 2002

Appl Environ Microbiol

245

130

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“…In genus Penicillium, OTA is produced by P. verrucosum (53) and P. nordicum (33) (3,10,22,62). Aspergillus alliaceus and Aspergillus albertensis, formerly placed in section Circumdati, but recently shown to be more closely related to section Flavi, have also been described as OTA producers (50).…”

mentioning

confidence: 99%

Study of Spanish Grape Mycobiota and Ochratoxin A Production by Isolates of Aspergillus tubingensis and Other Members of Aspergillus Section Nigri

Medina

Mateo

López-Ocaña

et al. 2005

Appl Environ Microbiol

143

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The native mycobiota of five grape varieties grown in Spain has been studied. Four (Bobal, Tempranillo, Garnacha, and Monastrell) were red varieties and one (Moscatel) was white. The main fungal genera isolated were Alternaria, Cladosporium, and Aspergillus. The isolation frequency of Aspergillus spp. section Nigri in contaminated samples was 82%. Ochratoxin A (OTA) production was assessed using yeast extract-sucrose broth supplemented with 5% bee pollen. Cultures of 205 isolates from this section showed that 74.2% of Aspergillus carbonarius and 14.3% of Aspergillus tubingensis isolates produced OTA at levels ranging from 1.2 to 3,530 ng/ml and from 46.4 to 111.5 ng/ml, respectively. No Aspergillus niger isolate had the ability to produce this toxin under the conditions assayed. Identification of the A. niger aggregate isolates was based on PCR amplification of 5.8S rRNA genes and its two intergenic spacers, internal transcribed spacer 1 (ITS1) and ITS2, followed by digestion with restriction endonuclease RsaI of the PCR products. The restriction patterns were compared with those from strains of A. niger CECT 2807 and A. tubingensis CECT 20393, held at the Spanish Collection of Type Cultures. DNA sequencing of the ITS1-5.8S rRNA gene-ITS2 region of the OTA-producing isolates of A. tubingensis matched 99 to 100% with the nucleotide sequence of strain A. tubingensis CBS 643.92. OTA determination was accomplished by liquid chromatography with fluorescence detection. OTA confirmation was carried out by liquid chromatography coupled to ion trap mass spectrometry. The results showed that there are significant differences with regard to the isolation frequency of ochratoxinogenic fungi in the different grape varieties. These differences were uncorrelated to berry color. The ability of A. tubingensis to produce OTA and the influence of grape variety on the occurrence of OTA-producing fungi in grapes are described in this report for the first time.

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“…Ochratoxins, the principal one of which is ochratoxin A, are fungal metabolites first isolated from Aspergillus ochraceus [33] and later identified as metabolites of Penicillium viridicatum [34] and other members of the A . ochraceus group [13,191. The pathologic changes produced by ochratoxin A have been studied in the duckling [26,32], rat [23,25,27,28,321, chick [3, 10, 241 and trout 191.…”

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confidence: 99%

Ochratoxicosis in Beagle Dogs. II. Pathology

1973

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(With 1 color plate)Absruact. The gross lesions in 23 young male Beagle dogs given daily oral doses of 0.2-3.0 nig/kg body weight ochratoxin A consisted of moderate to severe niucohemorrhagic enteritis of the cecum, colon, and rectum; tonsillitis; and enlargement of lymph nodes, which were edematous, hyperemic, and focally necrotic. Histopathologic alterations in the kidneys consisted of necrosis and desquamation of epithelial cells mainly in, but not limited to, proximal convoluted tubules. Many proximal and distal convoluted tubules contained eosinophilic, granular casts. Necrosis of lymphoid tissues was a prominent feature of the niycotoxicosis and focally occurred in, but was not limited to, germinal centers in the spleen, tonsils, thymus, and lymph nodes and the lymphoid nodules of the jejunum, ileum, cecum, colon, rectum and nictitating membrane. Necrosis did not occur in bone marrow. Hepatic alterations consisted of slight to moderate centrilobular necrosis and fatty change and occurred mainly in dogs receiving 0.2-0.3 mg/kg body weight ochratoxin A daily for 11-14 days.In a companion paper [30], we described the clinical and clinicopathologic features of ochratoxicosis in Beagle dogs. Ochratoxins, the principal one of which is ochratoxin A, are fungal metabolites first isolated from Aspergillus ochraceus [33] and later identified as metabolites of Penicillium viridicatum [34] and other members of the A . ochraceus group [13, 191. The pathologic changes produced by ochratoxin A have been studied in the duckling [26,32], rat [23, 25, 27, 28, 321, chick [3, 10, 241 and trout 191. In the species studied, ochratoxicosis is characterized by renal and hepatic damage and alterations in the intestinal and lymphoid tissues. The severity of the lesions varies somewhat with species and dose of ochratoxin.The present report describes the gross and microscopic pathologic alterations produced in dogs by either an ochratoxin-A-containing rice culture of A . ochraceus or commercial ochratoxin A.

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Aspergilli as Ochratoxin Producers

Cited by 84 publications

References 11 publications

Ochratoxin Production by the Aspergillus ochraceus Group and Aspergillus alliaceus

Ochratoxin Production by the Aspergillus ochraceus Group and Aspergillus alliaceus

Study of Spanish Grape Mycobiota and Ochratoxin A Production by Isolates of Aspergillus tubingensis and Other Members of Aspergillus Section Nigri

Ochratoxicosis in Beagle Dogs. II. Pathology

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