Detection of Aspergillus flavus in maize kernels by conventional and real-time PCR assays

S. Shweta, S. Madhavan, V. Paranidharan, R. Velazhahan

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Aflatoxins are carcinogenic secondary metabolites mainly produced by Aspergillus flavus and A. parasiticus during infection of susceptible crops, such as maize, groundnut, cotton and chillies. Aflatoxin contamination is considered one of the most serious food safety issues worldwide. To secure the safety of food, regular monitoring of the levels of aflatoxins in foods and feeds is necessary. An alternative could be the detection of the aflatoxin-producing fungi in foods and feeds. In this study a polymerase chain reaction (PCR) method was developed for rapid, specific and sensitive detection of A. flavus in maize kernels. A. flavus-specific primers based on the O-methyltransferase gene (omt-A) that is involved in the aflatoxin B1 biosynthesis, were designed and used to detect the fungus by PCR. The designed primers were highly specific to A. flavus. The molecular detection sensitivity of A. flavus was 1 ng of purified fungal DNA template in conventional PCR. A real-time PCR assay was standardized for rapid, specific and sensitive detection of A. flavus in corn kernels by using these primers. The standard curve obtained showed a linear correlation between copy number of the cloned target DNA sequence of A. flavus and Cycle threshold (Ct) values, with R2 of 0.98. These PCR-based assays may be highly useful in food and feed industries and quarantine laboratories for detection of this fungus.

Original languageEnglish
Pages (from-to)3329-3335
Number of pages7
JournalInternational Food Research Journal
Volume20
Issue number6
Publication statusPublished - 2013

Fingerprint

Aspergillus flavus
Zea mays
Real-Time Polymerase Chain Reaction
quantitative polymerase chain reaction
Aflatoxins
corn
aflatoxins
assays
seeds
polymerase chain reaction
Polymerase Chain Reaction
Fungi
Food Safety
fungi
food safety
Fungal DNA
feed industry
Quarantine
Food
Aspergillus parasiticus

Keywords

  • Aflatoxin
  • Aspergillus flavus
  • omt-A gene
  • PCR detection
  • Zea mays

ASJC Scopus subject areas

  • Food Science

Cite this

Detection of Aspergillus flavus in maize kernels by conventional and real-time PCR assays. / Shweta, S.; Madhavan, S.; Paranidharan, V.; Velazhahan, R.

In: International Food Research Journal, Vol. 20, No. 6, 2013, p. 3329-3335.

Research output: Contribution to journalArticle

@article{05d9f009e8b34c30ac46bdb8e73dc28a,
title = "Detection of Aspergillus flavus in maize kernels by conventional and real-time PCR assays",
abstract = "Aflatoxins are carcinogenic secondary metabolites mainly produced by Aspergillus flavus and A. parasiticus during infection of susceptible crops, such as maize, groundnut, cotton and chillies. Aflatoxin contamination is considered one of the most serious food safety issues worldwide. To secure the safety of food, regular monitoring of the levels of aflatoxins in foods and feeds is necessary. An alternative could be the detection of the aflatoxin-producing fungi in foods and feeds. In this study a polymerase chain reaction (PCR) method was developed for rapid, specific and sensitive detection of A. flavus in maize kernels. A. flavus-specific primers based on the O-methyltransferase gene (omt-A) that is involved in the aflatoxin B1 biosynthesis, were designed and used to detect the fungus by PCR. The designed primers were highly specific to A. flavus. The molecular detection sensitivity of A. flavus was 1 ng of purified fungal DNA template in conventional PCR. A real-time PCR assay was standardized for rapid, specific and sensitive detection of A. flavus in corn kernels by using these primers. The standard curve obtained showed a linear correlation between copy number of the cloned target DNA sequence of A. flavus and Cycle threshold (Ct) values, with R2 of 0.98. These PCR-based assays may be highly useful in food and feed industries and quarantine laboratories for detection of this fungus.",
keywords = "Aflatoxin, Aspergillus flavus, omt-A gene, PCR detection, Zea mays",
author = "S. Shweta and S. Madhavan and V. Paranidharan and R. Velazhahan",
year = "2013",
language = "English",
volume = "20",
pages = "3329--3335",
journal = "International Food Research Journal",
issn = "1985-4668",
publisher = "Universiti Putra Malaysia",
number = "6",

}

TY - JOUR

T1 - Detection of Aspergillus flavus in maize kernels by conventional and real-time PCR assays

AU - Shweta, S.

AU - Madhavan, S.

AU - Paranidharan, V.

AU - Velazhahan, R.

PY - 2013

Y1 - 2013

N2 - Aflatoxins are carcinogenic secondary metabolites mainly produced by Aspergillus flavus and A. parasiticus during infection of susceptible crops, such as maize, groundnut, cotton and chillies. Aflatoxin contamination is considered one of the most serious food safety issues worldwide. To secure the safety of food, regular monitoring of the levels of aflatoxins in foods and feeds is necessary. An alternative could be the detection of the aflatoxin-producing fungi in foods and feeds. In this study a polymerase chain reaction (PCR) method was developed for rapid, specific and sensitive detection of A. flavus in maize kernels. A. flavus-specific primers based on the O-methyltransferase gene (omt-A) that is involved in the aflatoxin B1 biosynthesis, were designed and used to detect the fungus by PCR. The designed primers were highly specific to A. flavus. The molecular detection sensitivity of A. flavus was 1 ng of purified fungal DNA template in conventional PCR. A real-time PCR assay was standardized for rapid, specific and sensitive detection of A. flavus in corn kernels by using these primers. The standard curve obtained showed a linear correlation between copy number of the cloned target DNA sequence of A. flavus and Cycle threshold (Ct) values, with R2 of 0.98. These PCR-based assays may be highly useful in food and feed industries and quarantine laboratories for detection of this fungus.

AB - Aflatoxins are carcinogenic secondary metabolites mainly produced by Aspergillus flavus and A. parasiticus during infection of susceptible crops, such as maize, groundnut, cotton and chillies. Aflatoxin contamination is considered one of the most serious food safety issues worldwide. To secure the safety of food, regular monitoring of the levels of aflatoxins in foods and feeds is necessary. An alternative could be the detection of the aflatoxin-producing fungi in foods and feeds. In this study a polymerase chain reaction (PCR) method was developed for rapid, specific and sensitive detection of A. flavus in maize kernels. A. flavus-specific primers based on the O-methyltransferase gene (omt-A) that is involved in the aflatoxin B1 biosynthesis, were designed and used to detect the fungus by PCR. The designed primers were highly specific to A. flavus. The molecular detection sensitivity of A. flavus was 1 ng of purified fungal DNA template in conventional PCR. A real-time PCR assay was standardized for rapid, specific and sensitive detection of A. flavus in corn kernels by using these primers. The standard curve obtained showed a linear correlation between copy number of the cloned target DNA sequence of A. flavus and Cycle threshold (Ct) values, with R2 of 0.98. These PCR-based assays may be highly useful in food and feed industries and quarantine laboratories for detection of this fungus.

KW - Aflatoxin

KW - Aspergillus flavus

KW - omt-A gene

KW - PCR detection

KW - Zea mays

UR - http://www.scopus.com/inward/record.url?scp=84891651944&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84891651944&partnerID=8YFLogxK

M3 - Article

VL - 20

SP - 3329

EP - 3335

JO - International Food Research Journal

JF - International Food Research Journal

SN - 1985-4668

IS - 6

ER -