Isolation, enumeration and PCR characterization of aflatoxigenic fungi from food and feed samples in India

Somashekar, D.; Rati, E. R.; Anand, S.; Chandrashekar, A.

doi:10.1016/j.fm.2004.01.012

Cited by 42 publications

(34 citation statements)

References 11 publications

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“…Among the structural genes activated by the aflR gene product (AFLR) is the sterigmatocystin-o-methyltransferase gene (omt-1 or aflP) (Sweeney et al, 2000). This gene has been demonstrated to be necessary in AF production and it has been used as a target to detect or quantify AFproducing molds by molecular techniques such as conventional PCR (Färber et al, 1997;Richard et al, 2009;Shapira et al, 1996) or quantitative PCR (qPCR) methods (Rodríguez et al, 2012a(Rodríguez et al, , 2012bSomashekar et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Influence of temperature and substrate conditions on the omt-1 gene expression of Aspergillus parasiticus in relation to its aflatoxin production

Lozano‐Ojalvo

Rodríguez

Bernáldez

et al. 2013

International Journal of Food Microbiology

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Section: Introductionmentioning

confidence: 99%

Influence of temperature and substrate conditions on the omt-1 gene expression of Aspergillus parasiticus in relation to its aflatoxin production

Lozano‐Ojalvo

Rodríguez

Bernáldez

et al. 2013

International Journal of Food Microbiology

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“…A diagnostic method based on the PCR is rapid, as there is no need to culture organisms prior to their identification. They are specific, since identification of species is made on the basis of genotypic differences, and are highly sensitive, detecting the target DNA molecules in complex mixtures, even when the mycelia are no longer viable (Xia and Achar, 2001;Somashekar et al, 2004;Sreenivasa et al, 2008). In our study, though Aspergillus species were more prevalent than either Fusarium or Penicillium in the samples tested, it was difficult to differentiate the Aspergillus group at the early stages of development by microscopic studies.…”

Section: Resultsmentioning

confidence: 56%

Studies of food thickeners in Nigeria for contamination by aflatoxigenic forms of Aspergillus and their detection by PCR

Okwu¹,

Achar²,

Ikenebomeh³

et al. 2011

Afr. J. Biotechnol.

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This paper reports the contamination of ready-to-use food thickeners, collected from the South-East geo-political zone in Nigeria, by aflatoxigenic form of Aspergillus species. A total of 150 samples from different open markets were observed for fungal contamination by using serial dilution-spread plate method. Although, Aspergillus, Fusarium and Penicillium were the most frequently isolated fungi, Aspergillus species were found to be the most prevalent in all the samples. Furthermore, Aspergillus flavus and Aspergillus parasiticus produced aflatoxin on yeast extract sucrose (YES) media incubated for 10 to 15 days at 27°C in a CO 2 incubator. Aspergillus niger showed no sign of any secondary metabolite on the media, set at similar conditions. Although, light microscopy was used to identify these fungi, based on colony morphology, PCR method was used to confirm genetic variation among the Aspergillus group, using ITS set of primers. Gel electrophoresis of PCR products confirmed the presence of Aspergillus species at an amplification range from 500 to 600 bp in all the samples tested. PCR was found to be a sensitive and a more reliable tool for detection and identification of Aspergillus species in food thickeners as opposed to conventional light microscopy. This is a first kind of mycological survey on the contamination of ready-to-use food thickeners sold in Nigeria.

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“…To amplify the DNA, based on Somashekar et al (2004) method, a 20-mer forward primer (5 0 -AAC CGC ATC CAC AAT CTC AT-3 0 ) and a 20-mer reverse primer (5 0 -AGT GCA GTT CGC TCA GAA CA-3 0 ) was used. The primers were synthesised by Toba Negin Co. of Iran.…”

Section: Dna Amplificationmentioning

confidence: 99%

“…In the past, dilution plate technique, using special culture media and immunological methods were employed to detect aflatoxigenic fungi (Somashekar et al 2004). These methods were time consuming, expensive, required purification of the fungi, had limitations for aflatoxigenic fungi and also required mycologists.…”

Section: Introductionmentioning

confidence: 99%

Detection of aflatoxigenic fungi in pistachio nuts by polymerase chain reaction

Panjehkeh

Khodadadi

Ahmadinejad

et al. 2012

Archives Of Phytopathology And Plant Protection

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Aflatoxins which are secondary metabolites are low-molecular weight toxins produced by some fungal species such as Aspergillus flavus, Aspergillus nomius and Aspergillus parasiticus. The aflatoxin regulatory gene, aflR, is encoded to generate aflatoxin. To detect aflatoxigenic fungi, DNA was extracted from 22 isolates of A. flavus and A. parasiticus separated from contaminated pistachio nuts to the fungi. Twenty mer forward and reverse gene-specific primers were designed to target aflR gene in the DNA. Positive amplification was achieved only with DNA from aflatoxigenic isolates of A. flavus and A. parasiticus. A 798 bp band was detected in the amplified DNA of each of the isolates indicating that aflatoxin regulatory gene, aflR, was a part of the DNA genome.

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Isolation, enumeration and PCR characterization of aflatoxigenic fungi from food and feed samples in India

Cited by 42 publications

References 11 publications

Influence of temperature and substrate conditions on the omt-1 gene expression of Aspergillus parasiticus in relation to its aflatoxin production

Influence of temperature and substrate conditions on the omt-1 gene expression of Aspergillus parasiticus in relation to its aflatoxin production

Studies of food thickeners in Nigeria for contamination by aflatoxigenic forms of Aspergillus and their detection by PCR

Detection of aflatoxigenic fungi in pistachio nuts by polymerase chain reaction

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