Aspergillus and Aflatoxin B Contamination of Stored Corn Grains in Western Iran (original) (raw)
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International Journal of Food Microbiology, 2019
Aspergillus section Flavi is widely known as a potential threat to contaminate agricultural products and food commodities. In this study, a polyphasic approach consisting of micro-and macro-morphological, chemical and molecular features, was applied to survey the Aspergillus section Flavi population in corn collected from Guangxi, China. Based on multigene phylogenies as well as morphological observations, Aspergillus flavus (192/195), A. arachidicola (1/195), A. pseudonomius (1/195) and A. novoparasiticus (1/195) were found to be the predominant section Flavi population. Among them, 31 representative isolates were selected for mycotoxin determination. The results showed that Aspergillus flavus chemotype I was most common, chemotype IV was also detected with low incidence and low CPA amounts, while chemotypes II and III were absent. Other tested species including A. arachidicola, A. pseudonomius, and A. novoparasiticus produced all types of aflatoxins, but none of them produced CPA. The polyphasic approach applied in this study permitted reliable understanding of the prevailing Aspergillus section Flavi population and their mycotoxin profiles. Knowledge of the prevailing section Flavi population will aid in developing a sustainable strategy to mitigate the effects of aflatoxin contamination. This study suggests that CPA contamination of food should be considered while conducting mycotoxigenic surveys of food commodities, and the same should be considered while planning a bio-control strategy to control aflatoxin contamination.
Potravinarstvo Slovak Journal of Food Sciences, 2019
The food contaminants by aflatoxins are inevitable even when all precautions and good agricultural practices are applied. Samples of white rice and corn (yellow, red) grains were collected from different local markets and houses. Three Aspergillus flavus strain isolated were identified using molecular characterization of AFLR (aflR) toxin gene. DNA genome of the three A. flavus isolates (namely A. flavus _ YC; A. flavus _ RC; A. flavus _ Rice) which corresponds to isolates from, yellow corn, red corn and white rice respectively were used as a template for PCR to amplify Aspergillus flavus AFLR (aflR) toxin gene. Partially sequenced was amplified using a specific primer set to confirm its identity, phylogenetic relationships between the three isolates as well as determination of the corresponding antigenic determinants. The epitope prediction analysis demonstrated that there were 1, 2, 3 and 4 epitopes whose score were equal 1 in A. flavus _ YC; A. flavus _ RC; A. flavus _ Rice, resp...
IOP Conference Series: Materials Science and Engineering
Aflatoxin is a naturally mutagenic and carcinogenic mycotoxin found in feed and food. Aflatoxin contamination on maize can affect productivity of feed and food manufacture. The purpose of this study was to obtain isolates and to understand the characteristics of aflatoxigenic Aspergillus flavus from maize on livestock feed. The study was divided into two stages: isolation and molecular identification of fungal ITS rDNA region in livestock feed obtained from Bogor, West Java. Isolation was conducted by enrichment and direct method using Dichloran-Glycerol (DG18) medium, while aflatoxin test and fungal characterization were done by CAM (Coconut Agar Medium) and selective medium of Aspergillus flavus and parasiticus (AFPA), respectively. The result showed that 9 of isolates are identified as molds (P2, P3, P4, P5, P7, P8, are green sporulated, while P1, P6, P9 are black sporulated). Aflatoxin detection on P3 and P8 isolates did not produce blue fluorescence fluid in CAM and did not form a beige ring on the back of petri. This indicated P3 and P8 did not produce aflatoxin on CAM media. Molecular identification results that P3 and P8 isolates have 100% and 99% homology with A. flavus, respectively.
Fungal Biota and Occurrence of Aflatoxigenic Aspergillus in Postharvest Corn Grains
2011
A survey of fungi associated with corn and popcorn samples, collected from markets throughout the Riyadh region of Saudi Arabia, was investigated. Seventeen species belonging to nine genera were recovered from corn grains, while 11 species belonging to six genera were recovered from popcorn grains. Frequencies of the isolated genera were statistically compared. Aspergillus flavus, A. niger and Rhizopus stolonifer were most frequently isolated from non-sterilized grains, Aspergillus niger, Fusarium proliferatum and F. verticillioides were dominant in sterilized corn grains, while Aspergillus clavatus, A. flavus var. columnaris and Fusarium subglutinans were dominant in sterilized popcorn grains. Potential ability to produce aflatoxins (AFs) B1, B2, G1 and G2, was studied for isolated cultures by using HPLC analysis. Most A. flavus isolates (75%) and some A. niger isolates (25%) were toxin producers. About 67% of A. flavus var. columnaris isolates produced aflatoxins, mostly B2, while A. flavus produced mostly B1, G1 and G2 aflotoxins. A. niger produced the least aflatoxin levels. These findings indicate that aflatoxigenic A. flavus is predominant in imported corn which may lead to contamination of this food item with aflatoxins. Thus, more effort should be made to minimize the risk of aflatoxin accumulation in imported commodities.
Prevalence of Aflatoxigenic Aspergillus in Food and Feed Samples from Karachi, Pakistan
Journal of Infection and Molecular Biology, 2016
of food products spoilage and grains deterioration during storage, rendering them unfit for human consumption. Some of these contaminants, for instance, few species of Aspergillus and Fusarium produce mycotoxins in many food products. The quality of food and related products, such as seeds/grains, vegetables, fruits and processed products, are significantly deteriorated by these toxigenic strains (Lee et al., 2007). Different types of fungal toxins have been discovered so far, presenting different structural diversity, chemical composition and physicochemical properties. Among all of these, aflatoxins (AFs) are the most commonly occurring and extensively studied mycotoxin in food and feed commodities. They are produced as secondary metabolites and 4 types i.e., aflatoxin B 1 (AFB 1), B 2 (AFB 2), G 1 (AFG 1) and G 2 (AFG 2) are the most important with reference to mutagenic, teratogenic, and immunosuppressive capabilities (Lereau et al., 2012). They are classified in group I as first class carcinogens, mutagens and immunosuppressive
Aflatoxin B1 (AFB1) is a potent carcinogen, teratogen and mutagen. 660 pre-and post-harvest maize samples were collected from major maize growing areas in Tamil Nadu, India. A flatoxin contamination was observed in 40.22% of the samples tested of which, 22.97% of pre-harvest and 53.93% post-harvest maize samples were found to be infected with AFB1 and 12.05% of the total samples exceeded WHO permissible limit of 20 μg/kg. AFB1 contamination ranged from 0 to 149.32 µg/kg. 28 A. flavus isolates were isolated and grouped into three sets based on aflatoxin producing potential viz., highly aflatoxin producing isolates, medium producing isolates and no aflatoxin producer or traces of aflatoxin producing isolates. The genetic coefficient matrix analysis using random amplified polymorphic DNA (RAPD) with ten random primers revealed minimum and maximum percent similarities among the tested A. flavus strains ranging from 35 to 89%. Cluster analysis separated the three sets of isolates into two groups (groups I and II) with each two subgroup confirming the genetic diversity among the A. flavus isolates from maize.
Contamination of maize by aflatoxins is of major concern because of the health hazards associated with it. Therefore, the present study was designed to assess the level of Aspergillus species and Aflatoxin contamination in pre and post-harvest maize grain. Results indicated that from fifteen pre and fifteen post-harvest maize samples 77.7% of pre-harvest with level range from 3.13 to 63.66 μg/kg and 80% of post-harvest sample with level range from 9.02 to 139.8 μg/kg were contaminated by total aflatoxin. The mean total aflatoxin contamination was 18.38 μg/kg for pre-harvest and 43.36 μg/kg for post-harvest. Aflatoxin B1 was detected in 66.7% of pre-harvest maize with the mean level of 5.00 μg/kg and in 87.7% in post-harvest maize with the mean level of 9.86 μg/kg. To be precise, paired t-test statistical analysis for total and aflatoxin B1 in maize samples were showed that both total and aflatoxin B1 increased significantly from pre-harvest to post-harvest maize (p<0.05). About 66.7% of pre-harvest and 86.7% of post-harvest maize samples were exceed the acceptance limit of total aflatoxin and aflatoxin B1 recommended by European Union maximum limit. Aspergillus species contaminations in pre-harvest maize 53.3% of samples were contaminated by A. flavus = 26.7%, A. parasiticus = 13.3% and A. niger group = 13.3% and in post-harvest maize 79.9% of samples were contaminated by A. flavus = 46.6%, A. parasiticus = 20.0% and A. niger group = 13.3%. In conclusion, the results of the present study revealed that although it was expected that pre-harvest maize to have minimal Aspergillus and aflatoxin contamination, the contamination was high in pre harvest and significantly increase from pre-harvest to post harvest. Keywords: Aflatoxin; Aspergillus species; Pre and post-harvest; Maize, Mycotoxin
Agriculture
This study aimed to morphologically characterize and determine the aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates. Forty isolates of A. flavus were obtained from sweet corn kernels and soil samples collected from Kampong Raja, Rose Valley, Kea, and Klebang farms in Malaysia. They were cultured on potato dextrose agar (PDA), dichloran rose-bengal chloramphenicol (DRBC), Aspergillusflavus and Aspergillus parasiticus agar (AFPA), and coconut cream agar (CCA). Macromorphological characteristics were determined by observing the colony color and texture, while the micromorphological characteristics were determined by examining the spore color, size, structure, conidiophore structure, and vesicle shape. The production of aflatoxin was determined by direct visualization of the UV fluorescence of A. flavus colonies on CCA. Aflatoxin was qualitatively detected in 18 (45%) isolates of A. flavus using UV fluorescence screening while the remaining 22 (55%) isolates did not exhib...
Aflatoxins (B 1 , B 2 , G 1 and G 2 ) are hepatotoxic metabolites produced by Aspergillus flavus on a number of agricultural commodities. Their levels were studied in rice samples imported to Iran through a southern port in Bushehr. Aflatoxins analysis was performed by solvent extraction, immunoaffinity clean-up and determination using high performance liquid chromatography (HPLC) equipped with postcolumn photochemical reactor and fluorescence detector. Among 152 samples analyzed, 75% showed levels of aflatoxin B1 (AFB1) contamination. However, there was no sample with AFB 1 above maximum tolerated level (MTL) of 5 ng/g assigned by Institute of Standard and Industrial Research of Iran (ISIRI). AFB1 concentrations in the samples was 0.09 to 3.3 ng/g. Out of the 152 samples analyzed, about 76.97% were contaminated with total aflatoxin (AFT) with the mean of 0.671 ng/g which is lower than MTL of AFT in rice (30 ng/g) assigned by (ISIRI). AFT concentration ranged from 0.15 to 4.27 ng/g. Contamination of aflatoxin in imported rice was dissimilar between different months. The highest levels of AFB 1 and AFT were detected in rice samples imported in September, while the lowest levels were in rice imported during November.
This study aimed to survey the incidence and load of fungi and aflatoxins in cereal grains and peanut, collected from some markets in central delta provinces, Egypt. The levels of aflatoxins produced by isolated strains of Aspergillus flavus were also evaluated. Forty food grains including maize, wheat, rice and peanut seeds were analyzed for fungal contamination. Eight fungal genera belonged to Aspergillus, Penicillium, Fusarium, Mucor, Cladosporium, Trichoderma, Rhizopus and Alternaria were isolated and identified. Total fungal loads as CFU and percentages of fungi in the analyzed samples ranged between 21.7-33.2x103 CFU/g and 1.6-36.7%, respectively. Aflatoxins were analyzed using TLC plates and quantified fluorodensitometry at 366 nm. Percentage of contamination with aflatoxin B1 (AFB1), aflatoxin B2 (AFB2) and aflatoxin G1 (AFG1) differed according to the toxin and the food stuff. AFB1 was more predominant than AFG1. The former was present in 54-100% of the samples and the latt...