A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily

Oliveri, C.; Torta, Livio; Catara, Vittoria

doi:10.1016/j.ijfoodmicro.2008.06.021

Cited by 27 publications

(31 citation statements)

References 36 publications

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“…Much of the molecular taxonomic work in the Nigri section has been conducted on plant pathogens due to their agricultural significance, although geographical environmental exposure may be medically relevant. A. niger, A. carbonarius, and A. tubingensis have been shown to be common causes of European grape spoilage (26,30). The lack of wine production in the United Kingdom means that the frequency and environmental distribution of Nigri species are unknown.…”

Section: Discussionmentioning

confidence: 99%

“…More commonly, however, the species cause otomycosis. In addition to their clinical significance, they also have agricultural importance as a common food spoilage organism (primarily grapes and coffee) (24,26). The detection of ochratoxin, a potent nephrotoxin and potential carcinogen produced by some species in the section, has raised concerns about incorporation into the food chain (7,31,33).…”

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confidence: 99%

“…More recently, the results of non-culture-based methods have been utilized to differentiate between these species, including extrolite patterns, amplified fragment length polymorphisms, and restriction fragment length polymorphisms (11,17,41). However, the taxonomy of this section has principally been refined by DNA sequencing of the internal transcribed spacer (ITS) region, beta-tubulin, calmodulin, and actin genes, and a polyphasic approach using these targets has been shown to be optimal (11,26). Other targets have also been investigated, including pyruvate kinase, pectin lyase, intergenic spacer, and partial mitochondrial cytochrome b gene, with varying but often limited success (13,41,56,57).…”

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confidence: 99%

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Cryptic Species and Azole Resistance in the Aspergillus niger Complex

Howard

Harrison

Bowyer

et al. 2011

Antimicrob Agents Chemother

121

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Aspergillus niger is a common clinical isolate. Multiple species comprise the Aspergillus section Nigri and are separable using sequence data. The antifungal susceptibility of these cryptic species is not known. We determined the azole MICs of 50 black aspergilli, 45 from clinical specimens, using modified EUCAST (mEUCAST) and Etest methods. Phylogenetic trees were prepared using the internal transcribed spacer, beta-tubulin, and calmodulin sequences to identify strains to species level and the results were compared with those obtained with cyp51A sequences. We attempted to correlate cyp51A mutations with azole resistance. Etest MICs were significantly different from mEUCAST MICs (P < 0.001), with geometric means of 0.77 and 2.79 mg/liter, respectively. Twenty-six of 50 (52%) isolates were itraconazole resistant by mEUCAST (MICs > 8 mg/liter), with limited cross-resistance to other azoles. Using combined beta-tubulin/calmodulin sequences, the 45 clinical isolates grouped into 5 clades, A. awamori (55.6%), A. tubingensis (17.8%), A. niger (13.3%), A. acidus (6.7%), and an unknown group (6.7%), none of which were morphologically distinguishable. Itraconazole resistance was found in 36% of the isolates in the A. awamori group, 90% of the A. tubingensis group, 33% of the A. niger group, 100% of the A. acidus group, and 67% of the unknown group. These data suggest that cyp51A mutations in section Nigri may not play as important a role in azole resistance as in A. fumigatus, although some mutations (G427S, K97T) warrant further study. Numerous cryptic species are found in clinical isolates of the Aspergillus section Nigri and are best reported as "A. niger complex" by clinical laboratories. Itraconazole resistance was common in this data set, but azole cross-resistance was unusual. The mechanism of resistance remains obscure.

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Section: Discussionmentioning

confidence: 99%

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Cryptic Species and Azole Resistance in the Aspergillus niger Complex

Howard

Harrison

Bowyer

et al. 2011

Antimicrob Agents Chemother

121

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“…and Penicillium spp. (Oliveri, 2006;Oliveri et al, 2008). It is postulated that air movement deposits soil fungal spores onto grapes, because their incidence in air samples increases closer to the soil.…”

Section: Vineyard Mycobiotamentioning

confidence: 99%

Mycoflora and Biodiversity of Black Aspergilli in Vineyard Eco-Systems

Oliveri¹,

Catara²

2011

The Dynamical Processes of Biodiversity - Case Studies of Evolution and Spatial Distribution

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“…Em primeiro lugar, constatou-se que as estirpes do agregado A. niger são mais abundantes nas uvas que A. carbonarius. Em segundo lugar, constatou-se, entretanto, que A. carbonarius parece ser muito mais relevante em termos de produção de OTA nas uvas, com uma maior proporção de estirpes produtoras da micotoxina, e em níveis mais elevados que as estirpes do agregado A. niger (ABARCA et al, 2001;BATTILANI & PIETRI 2002;ROSA et al, 2002;MAGNOLI et al, 2003;BELLÍ et al, 2004b;OLIVERI et al, 2008;.…”

Section: Aspectos Toxicológicos Da Ocratoxina Aunclassified