Quantitative Detection of Aflatoxin and Species Identification of Aspergillus section Flavi Isolates from Peanuts using Molecular Approaches

2020 ◽  
Author(s):  
I. Lavkor
Keyword(s):  
Sequence Data ◽  
Aflatoxin Production ◽  
Quantitative Detection ◽  
Aflatoxin Biosynthesis ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Dna Sequence Data ◽  
Aspergillus Section Flavi ◽  
Molecular Approaches ◽  
Aspergillus Section

Totally, 50 Aspergillus section Flavi were identified isolates having aflatoxin biosynthesis genes on peanut by molecular method and aflatoxin production. Primer pair (IGS-F/R) recognized the aflatoxin biosynthesis gene (aflJ-aflR) targeting the intergenic region (IGS) on DNA was amplified by polymerase chain reactions (PCR). The PCR product were restricted by BglII enzyme within Restriction Fragment Length Polymorphism (RFLP) and obtained from 33 (66%) Aspergillus flavus was cleaved into three band sizes of 362, 210 and 102 bp. However, BglII enzyme generated two band sizes of 363 and 311 bp for 17 (34%) Aspergillus parasiticus. An investigation examined DNA sequence data to characterize these isolates and describe the species. Phylogenetic analysis showed that A. flavus and A. parasiticus have been identified in different groups. All the A. flavus and A. parasiticus isolates produced aflatoxins. The present study provides a new method on molecular characterization of A. section Flavi in Turkey.

PCR-based analysis of the intergenic spacers of the Nor loci on the A genomes of Triticum diploids and polyploids

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 116-128 ◽  
Author(s):  
Robert Sallares ◽  
Terence A Brown
Keyword(s):  
Sequence Data ◽  
Random Noise ◽  
Intergenic Spacer ◽  
Population Variation ◽  
Chain Reactions ◽  
Intergenic Spacers ◽  
Polymerase Chain Reactions ◽  
Dna Sequence Data ◽  
Polymerase Chain ◽  
Ribosomal Dnas

We present DNA sequence data showing population variation in the intergenic spacer (IGS) regions of the ribosomal DNAs (rDNAs) on the A genomes of 27 diploid and polyploid wheats. PCRs (polymerase chain reactions) specific for the Am genome gave products with five populations of Triticum monococcum but did not give products with AABB or AABBDD wheats. PCRs specific to the Au genome of T. urartu gave products with all the AABB and AABBDD polyploids that were tested, but not with T. monococcum. AAGG tetraploids gave products only with the Au-specific primers, but the AAAAGG hexaploid T. zhukovskyi gave products with both the Au and Am primers. Phylogenetic analysis showed a substantial degree of IGS divergence for both the Am and Au genomes in diploids and polyploids compared with other genomes of Triticum and Aegilops. The rate of evolution of the IGS is much greater than previously reported for the internal transcribed region of the rDNAs but the view that the IGS only gives random noise is rejected, the IGS sequences presented here reflecting the general evolutionary trends affecting the wheat genome as a whole.Key words: wheat, ribosomal DNA, intergenic spacer, polymerase chain reaction.

scholarly journals Discrimination between aflatoxigenic and non-aflatoxigenic Aspergillus section Flavi strains from Egyptian peanuts using molecular and analytical techniques

2011 ◽  
Vol 4 (1) ◽  
pp. 69-77 ◽  
Author(s):  
A. Abdel-Hadi ◽  
D. Carter ◽  
N. Magan
Keyword(s):  
Expression Profiles ◽  
Regulatory Gene ◽  
Analytical Techniques ◽  
Aflatoxin Production ◽  
Natural Food ◽  
Aspergillus Section Flavi ◽  
Molecular Approaches ◽  
Wide Range ◽  
Aspergillus Section

A wide range of Aspergillus section Flavi strains were isolated from Egyptian peanut samples. Eighteen of these strains were compared with two type strains (Aspergillus flavus SRRC G1907 and Aspergillus parasiticus 2747) for aflatoxin production based on (a) qualitative fluorescence using a coconut cream agar medium (CAM), and (b) aflatoxin production on a conducive Yeast Extract-Sucrose (YES) medium using HPLC. These results were validated by using molecular approaches (the structural genes, aflD (nor-1), aflM (ver-1) and aflP (omt A) and the regulatory gene aflR) to discriminate between aflatoxigenic and non-aflatoxigenic strains of the Aspergillus section Flavi group in vitro and on peanut seeds. Overall, 13/18 strains producing aflatoxins B1 and B2 in the range 1.27-213.35 µg/g medium were identified. In addition, 5 non-aflatoxin producing strains were found. The expression of these four genes was assessed using PCR and RT-PCR. PCR showed that all strains contained the four aflatoxin genes examined, regardless of expression profiles. Our results also showed that aflD expression is a reliable marker to discriminate between aflatoxin and non-aflatoxin producers. Interestingly, when an aflatoxin producing strain and three non-aflatoxigenic strains were subsequently grown on peanuts at 0.95 water activity, two of the non-producers were able to initiate aflatoxin biosynthesis. This suggests that growth of strains on the natural food matrix is important for confirming aflatoxigenic production potential.

scholarly journals Molecular Characterisation of Aflatoxigenic and Non-Aflatoxigenic Strains of Aspergillus Section Flavi Isolated from Imported Peanuts along the Supply Chain in Malaysia

Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 501 ◽  
Author(s):  
Mahror Norlia ◽  
Selamat Jinap ◽  
Mahmud Ab Rashid Nor-Khaizura ◽  
Son Radu ◽  
Cheow Keat Chin ◽  
...  
Keyword(s):  
Aflatoxin Production ◽  
Storage Conditions ◽  
Aflatoxin Contamination ◽  
Aflatoxin Biosynthesis ◽  
Asian Countries ◽  
Aspergillus Section Flavi ◽  
Aflatoxigenic Fungi ◽  
Tropical Weather ◽  
Southeast Asian Countries ◽  
Aspergillus Section

Peanuts are widely consumed in many local dishes in southeast Asian countries, especially in Malaysia which is one of the major peanut-importing countries in this region. Therefore, Aspergillus spp. and aflatoxin contamination in peanuts during storage are becoming major concerns due to the tropical weather in this region that favours the growth of aflatoxigenic fungi. The present study thus aimed to molecularly identify and characterise the Aspergillus section Flavi isolated from imported peanuts in Malaysia. The internal transcribed spacer (ITS) and β-tubulin sequences were used to confirm the species and determine the phylogenetic relationship among the isolates, while aflatoxin biosynthesis genes (aflR, aflP (omtA), aflD (nor-1), aflM (ver-1), and pksA) were targeted in a multiplex PCR to determine the toxigenic potential. A total of 76 and one isolates were confirmed as A. flavus and A. tamarii, respectively. The Maximum Likelihood (ML) phylogenetic tree resolved the species into two different clades in which all A. flavus (both aflatoxigenic and non-aflatoxigenic) were grouped in the same clade and A. tamarii was grouped in a different clade. The aflatoxin biosynthesis genes were detected in all aflatoxigenic A. flavus while the non-aflatoxigenic A. flavus failed to amplify at least one of the genes. The results indicated that both aflatoxigenic and non-aflatoxigenic A. flavus could survive in imported peanuts and, thus, appropriate storage conditions preferably with low temperature should be considered to avoid the re-emergence of aflatoxigenic A. flavus and the subsequent aflatoxin production in peanuts during storage.

A reappraisal of fungi producing aflatoxins

2009 ◽  
Vol 2 (3) ◽  
pp. 263-277 ◽  
Author(s):  
J. Varga ◽  
J. Frisvad ◽  
R. Samson
Keyword(s):  
Secondary Metabolites ◽  
Biosynthetic Pathway ◽  
Aflatoxin Production ◽  
Aspergillus Species ◽  
Aflatoxin Biosynthesis ◽  
Aspergillus Section Flavi ◽  
Naturally Occurring ◽  
Aflatoxin B ◽  
Aspergillus Section

Aflatoxins are decaketide-derived secondary metabolites which are produced by a complex biosynthetic pathway. Aflatoxins are among the economically most important mycotoxins. Aflatoxin B1 exhibits hepatocarcinogenic and hepatotoxic properties, and is frequently referred to as the most potent naturally occurring carcinogen. Acute aflatoxicosis epidemics occur in several parts of Asia and Africa leading to the death of several hundred people. Aflatoxin production has incorrectly been claimed for a long list of Aspergillus species and also for species assigned to other fungal genera. Recent data indicate that aflatoxins are produced by 13 species assigned to three sections of the genus Aspergillus: section Flavi (A. flavus, A. pseudotamarii, A. parasiticus, A. nomius, A. bombycis, A. parvisclerotigenus, A. minisclerotigenes, A. arachidicola), section Nidulantes (Emericella astellata, E. venezuelensis, E. olivicola) and section Ochraceorosei (A. ochraceoroseus, A. rambellii). Several species claimed to produce aflatoxins have been synonymised with other aflatoxin producers, including A. toxicarius (=A. parasiticus), A. flavus var. columnaris (=A. flavus) or A. zhaoqingensis (=A. nomius). Compounds with related structures include sterigmatocystin, an intermediate of aflatoxin biosynthesis produced by several Aspergilli and species assigned to other genera, and dothistromin produced by a range of non-Aspergillus species. In this review, we wish to give an overview of aflatoxin production including the list of species incorrectly identified as aflatoxin producers, and provide short descriptions of the 'true' aflatoxin producing species.

scholarly journals Detection of the European epidemic strain of Trichomonas gallinae in finches, but not other non-columbiformes, in the absence of macroscopic disease

Parasitology ◽  
2016 ◽  
Vol 143 (10) ◽  
pp. 1294-1300 ◽  
Author(s):  
ERASMUS K.H.J. ZU ERMGASSEN ◽  
CHRIS DURRANT ◽  
SHINTO JOHN ◽  
ROXANNE GARDINER ◽  
ABDULWAHED F. ALREFAEI ◽  
...  
Keyword(s):  
Great Britain ◽  
Sequence Data ◽  
Histopathological Examination ◽  
Its2 Region ◽  
Rrna Gene ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Trichomonas Gallinae ◽  
Single Subunit ◽  
Pyrrhula Pyrrhula

SUMMARYFinch trichomonosis is an emerging infectious disease affecting European passerines caused by a clonal strain of Trichomonas gallinae. Migrating chaffinches (Fringilla coelebs) were proposed as the likely vector of parasite spread from Great Britain to Fennoscandia. To test for such parasite carriage, we screened samples of oesophagus/crop from 275 Apodiform, Passeriform and Piciform birds (40 species) which had no macroscopic evidence of trichomonosis (i.e. necrotic ingluvitis). These birds were found dead following the emergence of trichomonosis in Great Britain, 2009–2012, and were examined post-mortem. Polymerase chain reactions were used to detect (ITS1/5·8S rRNA/ITS2 region and single subunit rRNA gene) and to subtype (Fe-hydrogenase gene) T. gallinae. Trichomonas gallinae was detected in six finches [three chaffinches, two greenfinches (Chloris chloris) and a bullfinch (Pyrrhula pyrrhula)]. Sequence data had 100% identity to the European finch epidemic A1 strain for each species. While these results are consistent with finches being vectors of T. gallinae, alternative explanations include the presence of incubating or resolved T. gallinae infections. The inclusion of histopathological examination would help elucidate the significance of T. gallinae infection in the absence of macroscopic lesions.

scholarly journals Aflatoxin Contamination of Dried Insects and Fish in Zambia

2018 ◽  
Vol 81 (9) ◽  
pp. 1508-1518 ◽  
Author(s):  
PAUL W. KACHAPULULA ◽  
JULIET AKELLO ◽  
RANAJIT BANDYOPADHYAY ◽  
PETER J. COTTY
Keyword(s):  
Dietary Protein ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Food Contaminants ◽  
Edible Insect ◽  
Aspergillus Section Flavi ◽  
Regulatory Limits ◽  
Data Gaps ◽  
Dried Fish ◽  
Aspergillus Section

ABSTRACT Dried insects and fish are important sources of income and dietary protein in Zambia. Some aflatoxin-producing fungi are entomopathogenic and also colonize insects and fish after harvest and processing. Aflatoxins are carcinogenic, immune-suppressing mycotoxins that are frequent food contaminants worldwide. Several species within Aspergillus section Flavi have been implicated as causal agents of aflatoxin contamination of crops in Africa. However, aflatoxin producers associated with dried fish and edible insects in Zambia remain unknown, and aflatoxin concentrations in these foods have been inadequately evaluated. The current study sought to address these data gaps to assess potential human vulnerability through the dried fish and edible insect routes of aflatoxin exposure. Caterpillars (n = 97), termites (n = 4), and dried fish (n = 66) sampled in 2016 and 2017 were assayed for aflatoxin by using lateral flow immunochromatography. Average aflatoxin concentrations exceeded regulatory limits for Zambia (10 μg/kg) in the moth Gynanisa maja (11 μg/kg), the moth Gonimbrasia zambesina (Walker) (12 μg/kg), and the termite Macrotermes falciger (Gerstacker) (24 μg/kg). When samples were subjected to simulated poor storage, aflatoxins increased (P < 0.001) to unsafe levels in caterpillars (mean, 4,800 μg/kg) and fish (Oreochromis) (mean, 23 μg/kg). The L strain morphotype of A. flavus was the most common aflatoxin producer on dried fish (88% of Aspergillus section Flavi), termites (68%), and caterpillars (61%), with the exception of Gynanisa maja, for which A. parasiticus was the most common (44%). Dried fish and insects supported growth (mean, 1.3 × 109 CFU/g) and aflatoxin production (mean, 63,620 μg/kg) by previously characterized toxigenic Aspergillus section Flavi species, although the extent of growth and aflatoxigenicity depended on specific fungus-host combinations. The current study shows the need for proper storage and testing of dried insects and fish before consumption as measures to mitigate human exposure to aflatoxins through consumption in Zambia.

Fungal screening and aflatoxin production by Aspergillus section Flavi isolated from pre-harvest maize ears grown in two Argentine regions

2017 ◽  
Vol 92 ◽  
pp. 41-48 ◽  
Author(s):  
Boris X. Camiletti ◽  
Ada K. Torrico ◽  
M. Fernanda Maurino ◽  
Diego Cristos ◽  
Carina Magnoli ◽  
...  
Keyword(s):  
Aflatoxin Production ◽  
Aspergillus Section Flavi ◽  
Aspergillus Section
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