scholarly journals Identification of Sources of Resistance for Peanut Aspergillus flavus Colonization and Aflatoxin Contamination

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Richard Moise Alansou Dieme ◽  
Issa Faye ◽  
Yedomon Ange Bovys Zoclanclounon ◽  
Daniel Fonceka ◽  
Ousmane Ndoye ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Concentration Level ◽  
Disease Incidence ◽  
Hierarchical Classification ◽  
Mean Value ◽  
Aflatoxin Contamination ◽  
Conidial Suspension ◽  
Sources Of Resistance ◽  
Aflatoxin Concentration ◽  
Low Incidence

Peanut aflatoxin contamination caused by Aspergillus flavus is a serious constraint for food safety and human health in Senegal. The present study aimed to identify sources of resistance for A. flavus colonization and aflatoxin contamination. Thus, seeds from 67 peanut genotypes were tested under laboratory conditions. Aqueous conidial suspension of an aflatoxinogenic strain of A. flavus was used for inoculation in Petri dishes containing ten seeds of each genotype, and data on incidence and severity were recorded. Total aflatoxin concentration in seeds was determined on 15th day after inoculation using mReader® method. Results showed a significant (p<0.001) variation of aflatoxin, incidence and severity among the tested peanut genotypes. Incidence ranged from 0 to 70% with a mean of 20.36 ± 0.8%. Out of the 67 genotypes, eight showed incidence less than 10%. Severity ranged from 0 to 44% with a mean value of 8.82 ± 0.45%. The genotype 12CS_104 showed aflatoxin concentration level in conformity with the European standard (4 ppb). Out of three clusters revealed by hierarchical classification based on disease incidence and severity, the cluster 1 contained 33 genotypes characterised by low incidence and severity values. These genotypes can be tested under field conditions to confirm their resistance to A flavus.

scholarly journals Detection of Aflatoxin in Poultry Feed and Feed Materials through Immuno Based Assay from Different Poultry Farms and Feed Factories in Bangladesh

2019 ◽  
Vol 35 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Mahbuba Akter Lubna ◽  
Mita Debnath ◽  
Farzana Hossaini
Keyword(s):  
Health Risk ◽  
Positive Result ◽  
Mean Value ◽  
Aflatoxin Contamination ◽  
Control Measures ◽  
Poultry Feed ◽  
Enzyme Linked Immunosorbent Assay ◽  
Total Aflatoxin ◽  
Poultry Farms ◽  
Aflatoxin Concentration

Current study investigated the occurrence of aflatoxin contamination in poultry feed and feed materials in different poultry farms and feed factories in Bangladesh. A total of 100 samples of finished feed and raw feed materials were collected and tested through direct competitive Enzyme-Linked Immunosorbent Assay (ELISA) for total aflatoxin detection. Overall, 97% samples (n=97/100) in our study, were found positive for aflatoxin contamination. Among finished feed categories, layer grower feed contained highest level of aflatoxin with a mean value of 21.64 ppb whereas layer feed was less susceptible for aflatoxin contamination (mean value 9.49 ppb). Between raw feed materials, maize samples were highly contaminated (n=15/15, 100%) with aflatoxin while 86.67% soybean samples showed positive result. Twenty one percent (21%) of the samples in our study contained aflatoxin concentration more than the acceptable limit employed by USFDA and many other countries which might pose severe health risk to poultry and human consumer. Proper surveillance and immediate control measures should be taken to ensure safe poultry feed and feed materials. Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 75-78

scholarly journals Evaluation of Arachis Species and Interspecific Tetraploid Lines for Resistance to Aflatoxin Production by Aspergillus flavus

2004 ◽  
Vol 31 (2) ◽  
pp. 134-141 ◽  
Author(s):  
H. Q. Xue ◽  
T. G. Isleib ◽  
H. T. Stalker ◽  
G. A. Payne ◽  
G. OBrian
Keyword(s):  
Aspergillus Flavus ◽  
Insect Pests ◽  
Low Cost ◽  
Aflatoxin Production ◽  
Management Program ◽  
Aflatoxin Contamination ◽  
Sources Of Resistance ◽  
Resistant Parent ◽  
Arachis Species ◽  
Aflatoxin Accumulation

Abstract Anatoxins are carcinogenic and extremely toxic secondary metabolites produced primarily by two fungi, Aspergillus flavus Link ex Fries and A. parasiticus Speare. Elimination of aflatoxin contamination in peanut (Arachis hypogaea L.) is a high priority of the peanut industry. Resistant cultivars should be an effective and low-cost part of an integrated aflatoxin management program. To date, no cultivated peanut has been reported with stable high levels of resistance to aflatoxin production. Arachis species and interspecific tetraploid lines have been evaluated for resistance to several peanut diseases and insect pests, and highly resistant accessions have been reported. Seven accessions of A. cardenasii Krapov. and W.C. Gregory, 29 of A. duranensis Krapov. and W.C. Gregory, and 17 interspecific tetraploid lines derived from A. hypogaea × A. cardenasii were inoculated with A. flavus strain NRRL 3357 and analyzed for aflatoxin content after incubation. On average, A. duranensis and A. cardenasii accumulated significantly less aflatoxin than A. hypogaea checks. The mean difference between the two wild species was not significant. Arachis duranensis accessions PI 468319 (GKBSPSc 30073), PI 468200 (GKBSPSc 30064), and PI 262133 (GKP 10038 sl.); and A. cardenasii accessions PI 262141 (GKP 10017) and PI 475997 (KSSc 36018) had reduced levels of aflatoxin accumulation and should be valuable sources of resistance to aflatoxin contamination. Of the interspecific tetraploid lines, only GP-NC WS 2 supported aflatoxin production not significantly different from resistant parent A. cardenasii GKP 10017, and it appears to be a line with reduced capacity for aflatoxin accumulation.

Quantification of the aflatoxin biocontrol strain Aspergillus flavus AF36 in soil, and nuts and leaves of pistachio by real-time PCR

Plant Disease ◽  
2020 ◽  
Author(s):  
MARÍA TERESA GARCÍA LOPEZ ◽  
Yong Luo ◽  
Alejandro Ortega-Beltran ◽  
Ramon Jaime ◽  
Juan Moral Moral ◽  
...  
Keyword(s):  
Real Time ◽  
Aspergillus Flavus ◽  
Real Time Pcr ◽  
Management Strategies ◽  
Cost Savings ◽  
Aflatoxin Contamination ◽  
Conidial Suspension ◽  
Toxigenic Strains ◽  
Important Time ◽  
Biocontrol Strain

The species Aspergillus flavus and A. parasiticus are commonly found in the soils of nut-growing areas in California. Several isolates can produce aflatoxins that occasionally contaminate nut kernels conditioning their sale. The strain AF36 of A. flavus, which does not produce aflatoxins, is registered as a biocontrol agent for use in almond, pistachio, and fig crops in California. After application in the orchards, AF36 displaces aflatoxin-producing Aspergillus spp. and thus reduces aflatoxin contamination. Vegetative compatibility assays (VCA) have traditionally been used to track AF36 in soils and crops where it has been applied. However, VCA is labor-intensive and time-consuming. Here, we developed a quantitative real-time PCR (qPCR) protocol to quantify proportions of AF36 accurately and efficiently in different substrates. Specific primers to target AF36 and toxigenic strains of A. flavus and A. parasiticus were designed based on sequence of aflC, a gene essential for aflatoxin biosynthesis. Standard curves were generated to calculate proportions of AF36 based on threshold values (Cq). Verification assays using pure DNA and conidial suspension mixtures demonstrated a significant relationship by regression analysis between known and qPCR-measured AF36 proportions in DNA (R2 = 0.974; P < 0.001) and conidia mixtures (R2 = 0.950; P < 0.001). The tests conducted by qPCR in pistachio leaves, nuts, and soil samples demonstrated the usefulness of the qPCR method to precisely quantify proportions of AF36 in diverse substrates, ensuring important time and cost savings. The outputs of the current study will serve to design better aflatoxin management strategies for pistachio and other crops.

Aflatoxin Reduction in Corn Through Field Application of Competitive Fungi†

1999 ◽  
Vol 62 (6) ◽  
pp. 650-656 ◽  
Author(s):  
JOE W. DORNER ◽  
RICHARD J. COLE ◽  
DONALD T. WICKLOW
Keyword(s):  
Biological Control ◽  
Aspergillus Flavus ◽  
Weather Conditions ◽  
Type A ◽  
Field Application ◽  
Aflatoxin Contamination ◽  
Applied Strain ◽  
Wild Type ◽  
Separate Part ◽  
Aflatoxin Concentration

Soil in corn plots was inoculated with nonaflatoxigenic strains of Aspergillus flavus and A. parasiticus during crop years 1994 to 1997 to determine the effect of application of the nontoxigenic strains on preharvest aflatoxin contamination of corn. Corn plots in a separate part of the field were not inoculated and served as controls. Inoculation resulted in significant increases in the total A. flavus/parasiticus soil population in treated plots, and that population was dominated by the applied strain of A. parasiticus (NRRL 21369). In the years when weather conditions favored aflatoxin contamination (1996 and 1997), corn was predominately colonized by A. flavus as opposed to A. parasiticus. In 1996, colonization by wild-type A. flavus was significantly reduced in treated plots compared with control plots, but total A. flavus/parasiticus colonization was not different between the two groups. A change to a more aggressive strain of A. flavus (NRRL 21882) as part of the biocontrol inoculum in 1997 resulted in a significantly (P &lt; 0.001) higher colonization of corn by the applied strain. Weather conditions did not favor aflatoxin contamination in 1994 and 1995. In 1996, the aflatoxin concentration in corn from treated plots averaged 24.0 ppb, a reduction of 87% compared with the aflatoxin in control plots that averaged 188.4 ppb. In 1997, aflatoxin was reduced by 66% in treated corn (29.8 ppb) compared with control corn (87.5 ppb). Together, the data indicated that although the applied strain of A. parasiticus dominated in the soil, the nonaflatoxigenic strains of A. flavus were more responsible for the observed reductions in aflatoxin contamination. Inclusion of a nonaflatoxigenic strain of A. parasiticus in a biological control formulation for aflatoxin contamination may not be as important for airborne crops, such as corn, as for soilborne crops, such as peanuts.

scholarly journals First Report of Aflatoxin in Dried Yam Chips in Benin

Plant Disease ◽  
2001 ◽  
Vol 85 (9) ◽  
pp. 1032-1032 ◽  
Author(s):  
S. Bassa ◽  
C. Mestres ◽  
D. Champiat ◽  
K. Hell ◽  
P. Vernier ◽  
...  
Keyword(s):  
Mean Value ◽  
Aflatoxin Contamination ◽  
World Health ◽  
Maximum Residue Limit ◽  
Luminescence Method ◽  
Two Samples ◽  
The World ◽  
Aflatoxin Concentration ◽  
Marketing Chain

Dried yam (Dioscorea spp.) chips are widely consumed in Bénin but are often attacked by molds. Invasion of food by Aspergillus flavus may lead to aflatoxin contamination. We report here the result of a survey on the sanitary quality of dried yam chips in Bénin. During July and August 2000, 50 dried yam chips samples were collected from different points in the marketing chain; 10 samples were collected from each of 5 stages: producers, wholesalers, retailers, dried yam-based food sellers and consumers. Aflatoxin content was assayed by the bio-luminescence method (1) after methanol/water extraction. Aflatoxins were detected in all dried yam chip samples, with levels ranging from 2.2 to 200 ppb and a mean value of 14 ppb. An aflatoxin concentration higher than the European Union's maximum residue limit (MRL) of 4 ppb was found in 98% of the samples (N = 50), while 6% had an aflatoxin concentration higher than the World Health Organization's MRL of 20 ppb. Molds were analyzed from two samples, each with aflatoxin levels around 5 ppb, on colony unit medium specific for A. flavus (2). Aspergillus spp. were detected in the inner part of dried yam chips of both samples, with a mean level of 9,000 CFU/g. Fusarium colonies were also present but were not identified to species. References: (1) D. Champiat and J. Larpent. Bio-chimie-luminescence: Principes et Applications. Masson, Paris, France. 1993. (2) P. J. Cotty. Mycopathologia 125:157, 1994.

scholarly journals Verticillium Wilt Incited by Verticillium dahliae in Eggplant Grafted on Solanum torvum in Italy

Plant Disease ◽  
2005 ◽  
Vol 89 (7) ◽  
pp. 777-777 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Vascular Tissue ◽  
Disease Incidence ◽  
Conidial Suspension ◽  
Root Knot Nematode ◽  
Solanum Torvum ◽  
Meloidogyne Spp ◽  
Resistant Rootstock ◽  
Low Incidence

Eggplant cultivars grafted on rootstocks resistant to root-knot nematodes (Meloidogyne spp.) are increasingly grown in Italy to reduce nematode infection. During the winter of 2003-2004, eggplants (cv Black Bell and Mirabell) grafted on the nematode-resistant rootstock Solanum torvum were observed with symptoms of a wilt disease in several greenhouses in Sicily (southern Italy). The vascular tissue in stems of affected plants appeared brown. These plants were stunted and developed yellow leaves with brown or black streaks in the vascular tissue. The wilt appeared in several greenhouses at a very low incidence (0.01 to 0.05%). Later, during the fall of 2004, disease incidence was approximately ten times greater in the same greenhouses on new crops. Verticillium dahliae was consistently and readily isolated from symptomatic vascular tissue of the rootstock (S. torvum) and the scion (cv Black bell) when cultured on potato dextrose agar (PDA) (1). Healthy, 50-day-old plants of S. torvum and eggplant (cv. Black Bell) were separately inoculated by root dip with a conidial suspension (1 × 107 CFU/ml) of two isolates of V. dahliae obtained from the rootstock and the scion of the infected grafted plants and with a known pathogenic isolate of V. dahliae from nongrafted eggplant. Noninoculated S. torvum and eggplant served as control treatments. Plants (30 per treatment) were grown in a glasshouse at temperatures ranging between 12 and 41°C (weekly average 15 to 36°C) and relative humidity ranging between 36 and 99% (weekly average 54 to 95%). The first wilt symptoms and vascular discoloration in the roots, crowns, and veins developed 26 and 21 days after inoculation on S. torvum and eggplant, respectively. Seventy-two days after inoculation, 20, 26, and 27% of S. torvum plants and 97, 100, and 87% of the eggplants showed symptoms caused by V. dahliae isolates obtained from the scion of diseased grafted plants, the rootstock of diseased grafted plants, and nongrafted eggplants, respectively. Noninoculated plants remained healthy. To our knowledge, this is the first report in Italy of Verticillium wilt on eggplant grafted on S. torvum rootstocks under commercial conditions. Use of eggplant grafted on the nematode-resistant rootstock of S. torvum presents an interesting opportunity to control the root-knot nematode but has to be carefully considered when dealing with soils severely infested by V. dahliae. Reference: (1) G. F. Pegg and B. L. Brady. Verticillium Wilts. CABI Publishing, Wallingford, UK, 2002.

scholarly journals Evaluation of Corn Inbreds and Advanced Breeding Lines for Resistance to Aflatoxin Contamination in the Field

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 232-234 ◽  
Author(s):  
G. L. Windham ◽  
W. P. Williams
Keyword(s):  
Aspergillus Flavus ◽  
Field Studies ◽  
Inbred Lines ◽  
Aflatoxin Contamination ◽  
Sources Of Resistance ◽  
Corn Hybrids ◽  
Breeding Lines ◽  
Needle Technique ◽  
Corn Inbred

Eighteen corn inbred lines and advanced breeding lines were evaluated for resistance to aflatoxin contamination when artificially inoculated with Aspergillus flavus in 1998, 1999 (two tests), and 2000 at Mississippi State, MS, in field studies. The top ear of each plant was inoculated with the A. flavus isolate NRRL 3357 seven days after midsilk (50% of the plants in a plot had silks emerged) using the side-needle technique. Ears were harvested at kernel maturity approximately 63 days after midsilk and aflatoxin levels were measured using the Vicam AflaTest. Aflatoxin contamination in the inbreds was extremely high in 1998. Levels ranged from 139 to 21,090 ng/g. In 1999, aflatoxin contamination ranged from 17 to 1,070 ng/g in one test and 14 to 1,278 ng/g in another test. In 2000, aflatoxin levels ranged from 237 to 7,503 ng/g. Lines that supported lowest levels of aflatoxin contamination included Mp81:112, Mp92:673, Mp92:679, and Mp494. These lines provide potential new sources of resistance that can be used to move aflatoxin resistance into commercial corn hybrids.

A Maize Lectin-Like Protein with Antifungal Activity against Aspergillus flavus

2009 ◽  
Vol 72 (1) ◽  
pp. 120-127 ◽  
Author(s):  
R. L. BAKER ◽  
R. L. BROWN ◽  
Z.-Y. CHEN ◽  
T. E. CLEVELAND ◽  
A. M. FAKHOURY
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin Contamination ◽  
Partial Characterization ◽  
Ear Rot ◽  
Sources Of Resistance ◽  
Fungistatic Activity ◽  
Maize Genotypes ◽  
Proteomics Approach ◽  
Maize Kernels

The filamentous fungus Aspergillus flavus causes an ear rot on maize and produces a mycotoxin (aflatoxin) in colonized maize kernels. Aflatoxins are carcinogenic to humans and animals upon ingestion. Aflatoxin contamination results in a large loss of profits and marketable yields for farmers each year. Several research groups have worked to pinpoint sources of resistance to A. flavus and the resulting aflatoxin contamination in maize. Some maize genotypes exhibit greater resistance than others. A proteomics approach has recently been used to identify endogenous maize proteins that may be associated with resistance to the fungus. Research has been conducted on cloning, expression, and partial characterization of one such protein, which has a sequence similar to that of cold-regulated proteins. The expressed protein, ZmCORp, exhibited lectin-like hem-agglutination activity against fungal conidia and sheep erythrocytes. Quantitative real-time PCR assays revealed that ZmCOR is expressed 50% more in maize kernels from the Mp420 line, a type of maize resistant to A. flavus, compared with the expression level of the gene in the susceptible B73 line. ZmCORp exhibited fungistatic activity when conidia from A. flavus were exposed to the protein at a final concentration of 18 mM. ZmCORp inhibited the germination of conidia by 80%. A 50% decrease in mycelial growth resulted when germinated conidia were incubated with the protein. The partial characterization of ZmCORp suggests that this protein may play an important role in enhancing kernel resistance to A. flavus infection and aflatoxin accumulation.

Biological Control of Aflatoxin Contamination in Corn Using a Nontoxigenic Strain of Aspergillus flavus

2009 ◽  
Vol 72 (4) ◽  
pp. 801-804 ◽  
Author(s):  
JOE W. DORNER
Keyword(s):  
Biological Control ◽  
Aspergillus Flavus ◽  
Untreated Control ◽  
Aflatoxin Contamination ◽  
Apparent Effect ◽  
Aflatoxin Concentration ◽  
Spray Formulation ◽  
Hulled Barley ◽  
Spray Applications

A 2-year study was conducted to determine the efficacy of different applications of a nontoxigenic strain of Aspergillus flavus for reducing aflatoxin contamination in corn. Treatments consisted of the nontoxigenic strain in the form of (i) conidia-coated hulled barley applied to soil when corn was about 0.8 m tall, (ii) conidia-coated hulled barley applied in plant whorls prior to tasseling, (iii) multiple applications of a spray formulation of conidia during silking, and (iv) untreated control. Treatments were replicated eight times in individual plots consisting of four rows of 18 m each. In year 1, no significant differences were associated with treatments for aflatoxin, total A. flavus colonization, or incidence of nontoxigenic isolates of A. flavus in corn, which were all relatively high, ranging from 83.8 to 93.1%. In year 2, the whorl application produced a significantly lower mean aflatoxin concentration of 49.5 ppb compared with all other treatments, while both the soil (108.3 ppb) and spray applications (173.7 ppb) were significantly reduced compared with the control (191.6 ppb). The whorl application was the only treatment that had a significantly higher incidence (86.5%) of nontoxigenic isolates of A. flavus than the control had, which was still relatively high at 69.1%. Data indicated that applications of the nontoxigenic strain influenced untreated corn, thus reducing the apparent effect of the biocontrol treatments. Larger-scale studies with greater separation between treated and untreated fields are warranted.

Occurrence of Aflatoxin and Aflatoxigenic Molds in Foods and Feed in Spain

1986 ◽  
Vol 49 (6) ◽  
pp. 445-448 ◽  
Author(s):  
V. SANCHIS ◽  
N. SALA ◽  
A. PALOMES ◽  
P. SANTAMARINA ◽  
P. A. BURDASPAL
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Aflatoxin Contamination ◽  
Cereal Grains ◽  
Maize Flour ◽  
Fungal Contamination ◽  
Bread Making ◽  
Low Incidence ◽  
Aflatoxin B2 ◽  
Mixed Feeds

A survey was carried out to obtain data on the occurrence of aflatoxin and aflatoxigenic mold contamination of foods in Spain. A variety of commodities amounting to 338 samples were analyzed, comprising cereal grains, mixed feeds, edible nuts, wheat flour for bread-making, biscuits, sliced bread, soya beans and breakfast cereals. The results reveal a rather low incidence of aflatoxin contamination in samples tested. Aflatoxins were detected in 4 of 27 samples of mixed feeds at levels below 5 μg/kg; one sample of peanuts was contaminated with 120 μg aflatoxin B1/kg and 22 μg aflatoxin B2/kg. Aflatoxins B1 and B2 were also detected in a lot of whole maize flour, averaging 8 μg/kg and 3 μg/kg, respectively. Of a total of 288 samples tested, 100% showed variable incidences of fungal contamination. Maize samples were the ones most frequently contaminated with Aspergillus flavus (54.5%). Strains of A. flavus isolated from maize samples also showed the highest proportion of aflatoxigenic molds (17.2%) compared with those isolated from other sources.

Sign in / Sign up

Export Citation Format

Share Document