Aflatoxin Research Papers - Academia.edu (original) (raw)

Fifty eight (58) samples of cereals for human consumption (20 corn flour, 17 wheat flour) and poultry feeds (n = 21) purchased from popular markets of Rabat in Morocco were analyzed for aflatoxins (AF) by HPLC with immunoaffinity column... more

Fifty eight (58) samples of cereals for human consumption (20 corn flour, 17 wheat flour) and poultry feeds (n = 21) purchased from popular markets of Rabat in Morocco were analyzed for aflatoxins (AF) by HPLC with immunoaffinity column (IAC) clean-up and fluorimetric detection. The incidence of AF in corn, wheat flour and poultry feeds was about 80, 17.6 and 66.6% respectively. High contamination levels were found in corn and poultry feeds samples. Levels of contamination of analyzed samples with AFB1 ranged from 0.23 to 11.2, 0.03 to 0.15 and 0.05 to 5.38 ng/g for corn, wheat and poultry feeds respectively. Results showed also that the contamination of 10% of samples of corn was higher than the limit set by EU regulations for AFB1 and total AF. This is the first report on the determination of AF in corn, wheat and poultry feeds from Morocco by HPLC and IAC.

Context: Although it is known that aflatoxins have many adverse health effects, there is no systematic summary of how it affects the reproductive system or its reproductive health effects. Objective: Summarize evidence on the reproductive... more

Context: Although it is known that aflatoxins have many adverse health effects, there is no systematic summary of how it affects the reproductive system or its reproductive health effects. Objective: Summarize evidence on the reproductive health effects of aflatoxins. Results: The search yielded 121 potential studies, of which 25 were retained. One study found a higher concentration of aflatoxins in the semen of infertile men (40% of cases compared to 8% of controls). Six studies found significant associations or correlations between low birth weight and aflatoxins while one study did not find any correlation. One study found maternal serum aflatoxin to be a risk factor for jaundice in infants (OR, 2.68; CI, 1.18-6.10). Overall, maternal breast milk in developing countries had higher rates of aflatoxin contamination than in high income countries. Conclusions: Stakeholders in developing countries need to take steps to reduce exposure of vulnerable populations to the toxic effects of aflatoxins.

ABSTRACT Maize grain yields have increased dramatically over the past fifty years, and concurrently end-uses have proliferated requiring special quality characteristics. Plant breeders have developed many specialty types of maize, all of... more

ABSTRACT Maize grain yields have increased dramatically over the past fifty years, and concurrently end-uses have proliferated requiring special quality characteristics. Plant breeders have developed many specialty types of maize, all of which are influenced by the agronomic practices used to produce the crop. Grain yield increases have resulted in lower protein concentration except when the yield increase resulted from nitrogen fertilizer application. Irrigation improves the biological value of protein, while higher nitrogen application rates alter the amino acid balance thereby reducing the nutritional value. Kernel breakage susceptibility and kernel density increase with higher nitrogen fertilizer application rates, and are reduced by irrigation. Extractable starch and oil concentration are largely influenced by hybrid choice, but small production practice effects have been documented. Essential mineral nutrient levels are often influenced by soil or foliar fertilizer application. The production of aflatoxin can be reduced by irrigation or other strategies to avoid water stress during grain fill. Although genetics usually exerts the largest effect on maize grain quality, agronomic practices are also important.

Aflatoxins (AFs) represent the most important single mycotoxin-related food safety problem in developed and developing countries as they have adverse effects on human and animal health. They are produced mainly by Aspergillus flavus and... more

Aflatoxins (AFs) represent the most important single mycotoxin-related food safety problem in developed and developing countries as they have adverse effects on human and animal health. They are produced mainly by Aspergillus flavus and A. parasiticus. Both species have different aflatoxinogenic profile. In order to distinguish between A. flavus and A. parasiticus, gene-specific primers were designed to target the intergenic spacer (IGS) for the AF biosynthesis genes, aflJ and aflR. Polymerase chain reaction (PCR) products were subjected to restriction endonuclease analysis using BglII to look for restriction fragment length polymorphisms (RFLPs). Our result showed that both species displayed different PCR-based RFLP (PCR-RFLP) profile. PCR products from A. flavus cleaved into 3 fragments of 362, 210, and 102 bp. However, there is only one restriction site for this enzyme in the sequence of A. parasiticus that produced only 2 fragments of 363 and 311 bp. The method was successfully applied to contaminated grapes samples. This approach of differentiating these 2 species would be simpler, less costly, and quicker than conventional sequencing of PCR products and/or morphological identification.

Peanuts are likely to be infested by fungi with consequent contamination by aflatoxin in post-harvest industries. A hazard analysis critical control point (HACCP) plan is proposed for a typical Brazilian post-harvest industry from raw... more

Peanuts are likely to be infested by fungi with consequent contamination by aflatoxin in post-harvest industries. A hazard analysis critical control point (HACCP) plan is proposed for a typical Brazilian post-harvest industry from raw in-shell reception to the unpeeled peanuts transportation. Codex Alimentarius Commission guidelines were followed, with four critical control points (CCP) for aflatoxin being identified. The process steps with highest probability of aflatoxin occurrence (risk) are the in-shell reception, the dried in-shell storage, and the unpeeled kernel storage. During the storage steps there is a lack of control of air moisture and temperature. Therefore, there is no option but to keep rigid monitoring and control over each CCP, and detour lots with high aflatoxin levels to either oil or seed production. Attempts to correlate the aflatoxin levels with the rainfall showed an irregular trend of the toxin level.

This study was carried out on the storage rot of yam tubers Dioscorea spp in Ibadan, Nigeria. The Dioscorea spp examined were Dioscorea rotundata (white yam) and Dioscorea alata (water yam) which were the common species available at the... more

This study was carried out on the storage rot of yam tubers Dioscorea spp in Ibadan, Nigeria. The Dioscorea spp examined were Dioscorea rotundata (white yam) and Dioscorea alata (water yam) which were the common species available at the time of study. The study area was visited six times in three months for collection of rotted yams which were selected randomly at a particular barn. The symptoms of the diseases were described and their associated organisms isolated and identified. The diseases include dry rot and soft rot which accounted for 54.22% and 45.78% of post-harvest diseases of the yams respectively. Out of 60 yam samples examined 52 yam samples had fungi isolates.The fungi isolated include

Groundnut is an important cash crop for domestic markets as well as for foreign trade in several developing and developed countries. It is also one of the most valuable cash crops in eastern Ethiopia. However, its production is... more

Groundnut is an important cash crop for domestic markets as well as for foreign trade in several developing and developed countries. It is also one of the most valuable cash crops in eastern Ethiopia. However, its production is constrained by Aspergillus species, which cause quantitative losses and produce highly toxic and carcinogenic chemical substances known as aflatoxins. This article critically reviews Aflatoxin Contamination in Groundnut (Arachis hypogaea L.) in Ethiopia and Its Management. Although groundnut has a huge potential as a cash crop to improve livelihoods of farmers and traders in various parts of Ethiopia, its market is declining and export of the crop has come to a standstill. This is due to aflatoxin contamination of the crop and the difficulty of meeting tolerance limits by importers and food processors, leading to rejection of the crop and reduction in market demand. Aflatoxin contamination is both a pre-harvest and postharvest problem. Therefore, management o...

A reversed-phase HPLC method with fluorescence detection for the determination of the aflatoxins B1, B2, G1 and G2 in 42 animal feeds, comprising corn (16), soya bean meal (8), mixed meal (13), sunflower, wheat, canola, palm kernel, copra... more

A reversed-phase HPLC method with fluorescence detection for the determination of the aflatoxins B1, B2, G1 and G2 in 42 animal feeds, comprising corn (16), soya bean meal (8), mixed meal (13), sunflower, wheat, canola, palm kernel, copra meals (1 each) was carried out. The samples were first extracted using acetonitrile:water (9:1), and was further cleaned-up using a multifunctional column. Optimum conditions for the extraction and chromatographic separation were investigated. By adopting an isocratic chromatographic system using a mobile phase comprising acetonitrile:methanol:water (8:27:65, v/v/v), the separation of the four aflatoxins was possible within 30 min. Recoveries for aflatoxins B1, B2, G1 and G2 were 98 ± 0.7%, 95 ± 1.0%, 94 ± 3.6% and 97 ± 4.3%, respectively. The results show that eight samples (19%) were contaminated with aflatoxins, ranging from 6.5 to 101.9 ng g À1 . Total aflatoxin levels in three samples exceed the legal limits of many countries of 20 ng g À1 .

Quantitative losses in various biochemical constituents like capsaicin, carotenes, ascorbic acid, polyphenols, mineral matter, sugars (soluble and insoluble), protein and fat were estimated after the successful growth of Aspergillus... more

Quantitative losses in various biochemical constituents like capsaicin, carotenes, ascorbic acid, polyphenols, mineral matter, sugars (soluble and insoluble), protein and fat were estimated after the successful growth of Aspergillus flavus for 30 days on powdered red pepper. The fungal biomass was measured by ergosterol content and Aflatoxin B1 by HPLC. Amongst the various nutritional constituents evaluated for nutritional losses and changes the highest nutritional loss was reported in total carotenoids (88.55%) followed by total sugars (85.5%). The protein content of the infected sample increased from 18.01 % to 23%. The nutritional profile of chilli powder (Capsicum annum var. sannam L.) shows highest share of total soluble sugars (32.89%) and fiber content (21.05%), followed by protein (18.01%) and fat (13.32%) making it an ideal solid-substrate for mould growth. At the end of incubation the fungal biomass was 192. 25 mg / 100 gram powder, total plate count 17.5 X 10 4 CFU/g and ...

Fungi that belong to the genera Aspergillus, Fusarium, and Penicillium pose serious phytopathological and mycotoxicological risks at pre-harvest and post-harvest stages, as well as in processed food products because they can produce... more

Fungi that belong to the genera Aspergillus, Fusarium, and Penicillium pose serious phytopathological and mycotoxicological risks at pre-harvest and post-harvest stages, as well as in processed food products because they can produce several mycotoxins. Mycotoxins pose a serious problem for animal and human health and have a significant economic impact worldwide. The Mediterranean basin is a large geographical region with a temper-ate climate supporting the cultivation of a wealth of field and greenhouse crops with a high risk of mycotoxin contamination. The most important mycotoxins that occur in the Mediterranean basin are aflatoxins (B1, B2, G1 and G2) in dried fruits and nuts, ochratoxin A in grapes and raisins as well as trichothecenes and fumonisins in cereals. A variety of chemical, biological and physical strategies have been developed to control the mycotoxigenic pathogens; to minimize mycotoxin production at pre-or post-harvest level; to contribute to decontamination and/ o...

Aspergillus flavus isolated from naturally infected leaf-eating caterpillar (Opisina arenosella W.), lace bug (Stephanitis typica D.) and plant hopper (Proutista moesta Westwood), insect pests of the coconut palm, were tested for... more

Aspergillus flavus isolated from naturally infected leaf-eating caterpillar (Opisina arenosella W.), lace bug (Stephanitis typica D.) and plant hopper (Proutista moesta Westwood), insect pests of the coconut palm, were tested for aflatoxin (AT) production by employing various media formulations. These A. flavus isolates were earlier found to be entomopathogenic in laboratory bioassays. A laboratory contaminant and four standard aflatoxigenic A. flavus isolates were also included in this study as reference strains. All A. flavus isolates were tested on seven AT detection media: coconut extract agar, coconut extract-sodium desoxycholate agar, coconut extract-ascorbic acid agar, coconut extract-Czapek Dox agar, coconut extract-milk powder agar, 10% commercial coconut milk powder agar (CCMPA) and 20% CCMPA. Only two isolates of A. flavus, originally isolated from O. arenosella and P. moesta, produced ATs. AT production was detected within 48 h of incubation and was detected continually up to 1 month. These AT-producing A. flavus isolates also produced bright yellow pigmentation in the medium. Of all the seven media used for AT detection, CCMPA (10%) was found to be the best one, followed by 20% CCMPA, for direct and rapid AT detection. AT production was not necessary for pathogenicity in the insects.

The aim of the current study was to prepare organo-modified nano montmorillonite (OMNM) and to evaluate its chemopreventive effects against the hapatonephrotoxicity induced by aflatoxin B1 (AFB1) and ochratoxin A (OA) singly or in... more

The aim of the current study was to prepare organo-modified nano montmorillonite (OMNM) and to evaluate its chemopreventive effects against the hapatonephrotoxicity induced by aflatoxin B1 (AFB1) and ochratoxin A (OA) singly or in combination in rats. OMNM was prepared using Cetyltrimethylammoniumbromide (CTAB) as organic modifier. Eighty male Sprague Dawley were divided into 8 groups and treated for 8 weeks as follow: the control group; the group treated orally with AFB1 (80 µg/kg b.w.); the group treated with OA (100 µg/kg b.w.); the group treated with AFB1 plus OA, the group treated with OMNM (5 g/kg diet) and the groups treated with AFB1 and/or OA plus OMNM. At the end of treatment period, blood and tissue samples were collected from all animals for biochemical and histological analysis. The results revealed that the expansion in the basal spacing of the montmorillonite due to the intercalation of CTAB was 7.20 Å and the average particle size of OMNM was 120 nm. The in vivo results indicated that treatment with both AFB1 and OA singly or in combination resulted in a significant increase in liver and kidney function parameters, oxidative stress and tumor markers accompanied with a significant decrease in antioxidant enzyme activities and significant histological changes in liver and kidney tissues. These changes * Corresponding author. M. A. Abdel-Wahhab et al. 22 were severe in the group received the combined treatment of AFB1 and OA. OMNM alone did not show any toxic effect and it succeeded to prevent or at least diminish the toxic effects and the histological changes in liver and kidney. It can be concluded that treatment with AFB1 and OA has a synergistic toxic effects and OMNM is safe and it is a promise candidate as an additive to protect against the exposure to multi-mycotoxins in high risk population.

The present study sought to investigate the role of palm oil, in conjunction with the duration of fermentation, on cyanide and aflatoxin (AFT) loads of processed cassava tubers (Garri). Materials and Methods: Matured cassava (Manihot... more

The present study sought to investigate the role of palm oil, in conjunction with the duration of fermentation, on cyanide and aflatoxin (AFT) loads of processed cassava tubers (Garri). Materials and Methods: Matured cassava (Manihot esculenta Crantz) tubers were harvested from three different locations (Akunna, Mkporo-Oji and Durungwu) in Njaba Local Government Area, Imo State, Nigeria. The cassava tubers were processed into Garri according to standard schemes with required modifications and measured for cyanide content using titrimetric methods. Samples of Garri for determination of AFT levels were stored for 30 days before the commencement of spectrophotometric analysis. Results: Cyanide content of peeled cassava tubers was within the range of 4.07 ± 0.16-5.20 ± 0.19 mg hydrocyanic acid (HCN) equivalent/100 g wet weight, whereas the various processed cassava tubers was within the range of 1.44 ± 0.34-3.95 ± 0.23 mg HCN equivalents/100 g. For the 48 h fermentation scheme, Garri treated with palm oil exhibited marginal reduction in cyanide contents by 0.96%, 3.52% and 3.69%, whereas 4 h fermentation scheme is in concurrence with palm oil treatment caused 4.42%, 7.47% and 5.15% elimination of cyanide contents compared with corresponding untreated Garri samples (P > 0.05). Levels of AFT of the various Garri samples ranged between 0.26 ± 0.07 and 0.55 ± 0.04 ppb/100 g. There was no significant difference (P > 0.05) in AFT levels among the various samples in relation to their corresponding sources. Conclusion: The present study showed that the 48 h fermentation scheme for Garri production caused significant (P < 0.05) reduction, but did not obliterate the cyanide content of cassava tubers. Conversely, the 48 h fermentation scheme promoted the elevation of AFT levels, but was relatively reduced in Garri samples treated with palm oil.

In April 2004, one of the largest aflatoxicosis outbreaks occurred in rural Kenya, resulting in 317 cases and 125 deaths. Aflatoxin-contaminated homegrown maize was the source of the outbreak, but the extent of regional contamination and... more

In April 2004, one of the largest aflatoxicosis outbreaks occurred in rural Kenya, resulting in 317 cases and 125 deaths. Aflatoxin-contaminated homegrown maize was the source of the outbreak, but the extent of regional contamination and status of maize in commercial markets (market maize) were unknown. We conducted a cross-sectional survey to assess the extent of market maize contamination and evaluate the relationship between market maize aflatoxin and the aflatoxicosis outbreak. We surveyed 65 markets and 243 maize vendors and collected 350 maize products in the most affected districts. Fifty-five percent of maize products had aflatoxin levels greater than the Kenyan regulatory limit of 20 ppb, 35% had levels > 100 ppb, and 7% had levels > 1,000 ppb. Makueni, the district with the most aflatoxicosis case-patients, had significantly higher market maize aflatoxin than did Thika, the study district with fewest case-patients (geometric mean aflatoxin = 52.91 ppb vs. 7.52 ppb, p = 0.0004). Maize obtained from local farms in the affected area was significantly more likely to have aflatoxin levels > 20 ppb compared with maize bought from other regions of Kenya or other countries (odds ratio = 2.71; 95% confidence interval, 1.12–6.59). Contaminated homegrown maize bought from local farms in the affected area entered the distribution system, resulting in widespread aflatoxin contamination of market maize. Contaminated market maize, purchased by farmers after their homegrown supplies are exhausted, may represent a source of continued exposure to aflatoxin. Efforts to successfully interrupt exposure to aflatoxin during an outbreak must consider the potential role of the market system in sustaining exposure.

Aflatoxin levels in common foods of South Western Uganda: a risk factor to hepatocellular carcinomae cc_1087 516..521 D. KITYA, m med (surgery), associate professor of surgery, , G.S. BBOSA, msc clinical pharmacology, master of... more

Aflatoxin levels in common foods of South Western Uganda: a risk factor to hepatocellular carcinomae cc_1087 516..521 D. KITYA, m med (surgery), associate professor of surgery, , G.S. BBOSA, msc clinical pharmacology, master of neuroscience, msc iphc, phd student, Aflatoxin levels in common foods of South Western Uganda: a risk factor to hepatocellular carcinoma Prolonged exposure to aflatoxins by humans and animals leads to adverse effects to the various body systems of affected individuals including death. Studies have linked aflatoxins to hepatocellular carcinoma (HCC). In Uganda, HCC is observed to be on increase in communities of South-Western Uganda. A cross-sectional study was therefore conducted in five districts of the region and 90 various food samples were collected for total aflatoxin determination. They included ground nuts, cassava, millet, sorghum flour and eshabwe sauce. The aflatoxin levels were determined using Vicam aflatest method. The results were compared with acceptable European Union aflatoxin levels. Aflatoxin levels in the food samples ranged from 0 to 55 ppb with a mean total aflatoxin level of 15.7 Ϯ 4.9 ppb. Eshabwe sauce had the highest mean total aflatoxin levels (18.6 Ϯ 2.4 ppb). Traditional methods of food processing in this study were found to be contributing risk factor of food contamination and hence the observed increased HCC cases and mortalities in the region.

A total 180 samples of pellet poultry feed were collected from poultry feed stores and local markets .They were cultured on potato dextrose agar(PDA) and malt extract agar (MEA) for isolation and identification of Aspergillus flavus.They... more

A total 180 samples of pellet poultry feed were collected from poultry feed stores and local markets .They were cultured on potato dextrose agar(PDA) and malt extract agar (MEA) for isolation and identification of Aspergillus flavus.They were Sub-cultured on sabouraud dextrose agar(SDA) .Then the isolates were cultured on coconut agar medium(CAM). The rapid detection of 50 selected isolates of contaminated poultry feed samples with A.flavus were achieved by blue –green fluorescence under UV light and by ammonia vapor on CAM medium to determine the aflatoxigenic isolates of A.flavus. The detection by UV light revealed that 26 (52%) of isolates were aflatoxigenic (positive) by produce blue-green fluorescence under UV light at 356nm , and also 26 (52%) of isolates were aflatoxigenic (positive) by turned the colony reverse to pink color by exposure to ammonia vapor.

Numerous studies have established that aflatoxin is a potent developmental toxin in animals. Previous research has demonstrated that a phyllosilicate clay, hydrated sodium calcium aluminosilicate (HSCAS or Novasil™), tightly binds and... more

Numerous studies have established that aflatoxin is a potent developmental toxin in animals. Previous research has demonstrated that a phyllosilicate clay, hydrated sodium calcium aluminosilicate (HSCAS or Novasil™), tightly binds and immobilizes aflatoxins in the gastrointestinal tract of animals and markedly reduces the bioavailability and toxicity of aflatoxin. Our objective in this study was to utilize the pregnant rat as an in vivo model to compare the potential of HSCAS and bentonite to prevent the developmental toxicity of aflatoxin. Aluminosilicates (HSCAS) and bentonite were added to the diet at a level of 0.5% (w/w) and fed to the pregnant rat throughout pregnancy (i.e. days 0-20). Test animals were fed an aflatoxin-contaminated diet (2.5 mg kg ؊1 diet) with or without sorbents during gestation days 6-15. Evaluations of toxicity were performed on day 20. These included maternal (mortality, body weights, feed intake and litter weights), developmental (embryonic resorptions and fetal body weights) and biochemical (ALT, AST and AP) evaluations. Sorbents alone were not toxic and aflatoxin alone resulted in significant maternal and developmental toxicity. Animals treated with phyllosilicate (plus aflatoxin) were comparable to controls following evaluations for resorptions, live fetuses and fetal body weights, as well as biochemical parameters. While bentonite plus aflatoxin resulted in significant reduction in fetal body weight, none of the fetuses from HSCAS or bentonite plus aflatoxin-treated groups had any gross, internal soft tissue or major skeletal malformations.

Aflatoxins, a group of closely related, extremely toxic mycotoxins produced by Aspergillus flavus and A. parasiticus, can occur as natural contaminants of foods and feeds. Aflatoxins have been shown to be hepatotoxic, carcinogenic,... more

Aflatoxins, a group of closely related, extremely toxic mycotoxins produced by Aspergillus flavus and A. parasiticus, can occur as natural contaminants of foods and feeds. Aflatoxins have been shown to be hepatotoxic, carcinogenic, mutagenic and teratogenic to different animal species. Nigella sativa (black cumin) and Syzygium aromaticum (clove) oil are used for the treatment of inflammatory diseases and have antioxidant properties. The aim of this study was to investigate the ability of these volatile oils to scavenge free radicals generated during aflatoxicosis. Sixty male rats were divided into six treatment groups, including a control group, and the groups were treated for 30 days with Nigella sativa and Syzygium aromaticum oils with or without aflatoxin. Blood samples were collected at the end of the experimental period for haematological and biochemical analysis. The results indicated that exposure to aflatoxins resulted in haematological and biochemical changes typical for aflatoxicosis. Treatment with Nigella sativa and Syzygium aromaticum oil of rats fed an aflatoxin-contaminated diet resulted in significant protection against aflatoxicosis. Moreover, Nigella sativa oil was found to be more effective than Syzygium aromaticum oil in restoring the parameters that were altered by aflatoxin in rats.

Development of aflatoxin-resistant cotton against Aspergillus flavus is handicapped by the lack of resistance source in available germplasm. Genetic engineering warrants for identification of resistanceassociated genes in cotton. As a... more

Development of aflatoxin-resistant cotton against Aspergillus flavus is handicapped by the lack of resistance source in available germplasm. Genetic engineering warrants for identification of resistanceassociated genes in cotton. As a first step toward this, we isolated 44 differentially expressed genes (DEGs) in response to A. flavus infection, using annealing control primer system. Different functional classification of the DEGs suggested a complex and multi-factorial plantefungus interaction. Eight DEGs, including transcription factors, kinase, and downstream stress responsive genes, showed a tissue-and time-dependent differences in their expression. The upregulated genes can be used as transgenes and/or functional markers for breeding aflatoxin-resistant cottonseed.

An experiment was carried out to investigate 1) the transfer of aflatoxin M1 (AFM1) into the milk of dairy ewes fed diets naturally contaminated with aflatoxin B1 (AFB1); 2) the effect of the addition of dried yeast culture in the diet on... more

An experiment was carried out to investigate 1) the transfer of aflatoxin M1 (AFM1) into the milk of dairy ewes fed diets naturally contaminated with aflatoxin B1 (AFB1); 2) the effect of the addition of dried yeast culture in the diet on this transfer; and 3) the alteration of enzymatic activities in the liver of ewes fed diets contaminated with AFB1. Twenty-four Sarda dairy ewes were divided in 4 groups and fed a concentrate mix containing 4 amounts of wheat meal naturally contaminated with aflatoxins. The diet of the control group had no wheat meal, whereas that of treated groups had low, medium, or high amounts of contaminated wheat, which corresponded to 1.13, 2.30, and 5.03 microg of AFB1/kg of feed, respectively. The experiment lasted 14 d. On d 8 to 14 from the beginning of the trial, 12 g/d of a commercial dried yeast product (DYP) of Kluyveromyces lactis was added to the diet of each ewe. The AFM1 concentration in individual milk samples and the blood serum metabolites wer...

In this study, we investigated the binding ability of Saccharomayces cerevisiae to aflatoxin in pistachio nuts. The obtained results indicate that S. cerevisiae has an aflatoxin surface binding ability of 40% and 70% (with initial... more

In this study, we investigated the binding ability of Saccharomayces cerevisiae to aflatoxin in pistachio nuts. The obtained results indicate that S. cerevisiae has an aflatoxin surface binding ability of 40% and 70% (with initial aflatoxin concentrations of 10 and 20 ppb) in the exponential phase. Acid treatments increase this ability to approximately 60% and 73% for the two concentrations of aflatoxin, respectively.

The preservation of feedstuff for animal consumption (forages) by fermentation or dehydration is a common practice to supplement pastures and achieve better yields. Currently, the quality of a forage has been evaluated only through... more

The preservation of feedstuff for animal consumption (forages) by fermentation or dehydration is a common practice to supplement pastures and achieve better yields. Currently, the quality of a forage has been evaluated only through chemico-fermentative parameters. However, animals' health can also be affected by the presence of bacteria, molds, and/or some of their metabolites, e.g. mycotoxins. The quality of 147 forage samples (55 sorghum, 49 lucerne, and 43 maize) used for feeding dairy cattle, was evaluated using chemicofermentative (pH, ammonial nitrogen/total nitrogen ratio) characteristics, fungal propagule counts, and the presence of Aspergillus fumigatus and mycotoxins (aflatoxins and deoxynivalenol). Most lucerne samples (55.1%) were of bad chemico-fermentative quality (risky for consumption). In addition, a high percentage of samples (38.8% lucerne, 65.1% maize and 69.1% sorghum) presented Fairly Good (doubtful) chemico-fermentative characteristics. Maize samples showed the highest frequency of contaminated samples by high counts (25.6%), followed by lucerne (with a lower fermentative sugar content) (18.4%), and sorghum (16.4%). The mycoflora was distributed in 59 species belonging to 26 genera. In all forages, molds were the most numerous isolates, with the greatest number of isolates being Aspergillus species (17% isolates) with numerous isolates in the section Flavi, followed by Penicillium (9.7%) in maize, Fusarium (12.3%) in lucerne, and Byssochlamys (8.5%), Fusarium and Geotrichum (6.1% each) in sorghum. Even though the lucerne and maize samples presented a high mycotoxin incidence, and in most of them the simultaneous presence of AF and DON was detected, average values were not very high (AF: 6.78 and 6.96 g/kg, DON: 1666.67 and 717.50 g/kg, respectively for lucerne and maize). The high degree of contamination registered in the samples (81.6% lucerne, 67.4% maize and 45.5% sorghum) indicates the need for improving the technology applied during the development of crops, their harvest and the preparation and conservation of forages. It could be determined (p < 0.05) that AF + DON are contamination markers in lucerne and maize silages. In sorghum forages, a significant association (p < 0.01) was detected between risk and storage method.

Determination of aflatoxin B1 and total aflatoxin (B1 + B2 + G1 + G2) in red paprika powder is described using column chromatographic sample clean-up, overpressured layer chromatography (OPLC) separation and fluorescence densitometric... more

Determination of aflatoxin B1 and total aflatoxin (B1 + B2 + G1 + G2) in red paprika powder is described using column chromatographic sample clean-up, overpressured layer chromatography (OPLC) separation and fluorescence densitometric evaluation. Two OPLC methods were developed for separation of the four aflatoxins. The detection limit and quantification limit of aflatoxins in red paprika were 0.5 and 1 μg/kg in both methods, respectively. Recovery experiment was carried out with sample containing 1.74 μg/kg aflatoxin B1 and 3.56 μg/kg total aflatoxins measured by European standard HPLC method. Mean recovery amounted to 78.5% (SD 16.1%, n = 5) for aflatoxin B1 and 81.8% (SD 17.1%, n = 5) for total aflatoxins in the case of method 1. It was 105.3% (SD 10.7%, n = 5) for aflatoxin B1 and 97.4% (SD 18.6%, n = 5) for total aflatoxins using the method 2. Despite of that the Hungarian climate is not proper for the toxin production of moulds high aflatoxin B1 contaminated red paprika purchased from the market was found, which may originate from mixing of imported paprika containing very high level toxin with Hungarian one.

The effects of 16 essential oils from aromatic plants were tested for their inhibitory effect on Aspergillus flavus IMI 242684 on PDA. The results showed that the essential oil of white wood (Melaleuca cajeputi) gave the highest... more

The effects of 16 essential oils from aromatic plants were tested for their inhibitory effect on Aspergillus flavus IMI 242684 on PDA. The results showed that the essential oil of white wood (Melaleuca cajeputi) gave the highest inhibition followed by the essential oils of cinnamon (Cinnamomum cassia) and lavender (Lavandula officinalis), respectively. Furthermore, the inhibitory effects of these three essential oils at different concentrations were examined. It was found that the essential oil of white wood at 1.5625% (v/v) and of cinnamon and lavender at 50% (v/v) were the optimum concentrations for fungal growth inhibition. The essential oil of white wood at 25% (v/v) completely inhibited the growth of A. flavus IMI 242684 on PDA for 28 days.

This study evaluated the efficiency of ozone for the degradation of aflatoxins in pistachio kernels and ground pistachios. Pistachios were contaminated with known concentrations of aflatoxin (AF) B 1 , B 2 , G 1 and G 2 . Pistachio... more

This study evaluated the efficiency of ozone for the degradation of aflatoxins in pistachio kernels and ground pistachios. Pistachios were contaminated with known concentrations of aflatoxin (AF) B 1 , B 2 , G 1 and G 2 . Pistachio samples were exposed to gaseous ozone in a chamber at 5.0, 7.0 and 9.0 mg L −1 ozone concentrations for 140 and 420 min at 20 • C and 70% RH. Aflatoxin degradation was determined by high performance liquid chromatography (HPLC). The efficiency of ozone for aflatoxin degradation in pistachios increased with increasing exposure time and ozone concentration. The results indicated that AFB 1 and total aflatoxins could be reduced by 23 and 24%, respectively, when pistachio kernels were ozonated at 9.0 mg L −1 ozone concentration for 420 min. Only a 5% reduction in AFB 1 and total aflatoxin levels could be achieved for ground pistachios under the same conditions. No significant changes occurred in pH, color, moisture content and free fatty acid values of pistachio kernels and ground pistachios. Fatty acid compositions of pistachios did not change significantly after the ozonation treatments. No significant changes were found between sweetness, rancidity, flavor, appearance and overall palatability of ozonated and non-ozonated pistachio kernels. Significant changes were observed in the organoleptic properties of ground pistachios, except rancidity, after 5.0 mg L −1 ozone treatment for 140 min. Ozonation was found to be more effective for degrading aflatoxins in pistachio kernels than ground pistachios.

Several strains of lactic acid bacteria (LAB), frequently used in food fermentation and preser-Q2 vation, have been reported to bind different types of toxins in liquid media. This study was carried out to investigate the effect of... more

Several strains of lactic acid bacteria (LAB), frequently used in food fermentation and preser-Q2 vation, have been reported to bind different types of toxins in liquid media. This study was carried out to investigate the effect of different concentrations of Lactobacillus rhamnosus GG (ATCC 53103) to bind aflatoxin M1 (AFM1) in liquid media. AFM1 binding was tested following repetitive washes or filtration procedures in combination with additional treatments such as heating, pipetting, and centrifugation. The mixture of L. rhamnosus GG and AFM1 was incubated for 18 h at 37 • C and the binding efficiency was determined by quantifying the unbound AFM1 using HPLC. The stability of the complexes viable bacteria-AFM1 and heat treated bacteria-AFM1 was tested. Depending on the bacterial concentration and procedure used, the percentages of bound AFM1 by L. rhamnosus GG varied from as low as undetectable to as high as 63%. The highest reduction in the level of unbound AFM1 was recorded for the five washes procedure that involved heating and pipetting. Results also showed that binding was partially reversible and AFM1 was released after repeated washes. These findings highlight the effect of different treatments on the binding of AFM1 to L. rhamnosus GG in liquid matrix.

Aflatoxin B 1 antibody (aAFB 1 ) covalently attached to cysteamine functionalized-gold nanoparticles (C-AuNP) has been immobilized onto 4-mercaptobenzoic acid (MBA) based self assembled monolayer (SAM) on gold electrode (MBA/Au), for the... more

Aflatoxin B 1 antibody (aAFB 1 ) covalently attached to cysteamine functionalized-gold nanoparticles (C-AuNP) has been immobilized onto 4-mercaptobenzoic acid (MBA) based self assembled monolayer (SAM) on gold electrode (MBA/Au), for the fabrication of BSA/aAFB 1 -C-AuNP/MBA/Au immunoelectrode. This immunoelectrode has been characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and electrochemical characterization techniques. The electrochemical response studies reveal that the BSA/aAFB 1 -C-AuNP/MBA/Au immunoelectrode can be used to detect AFB 1 in the range of 10-100 ng dL − 1 and has sensitivity as 0.45 μA ng − 1 dL, limit of detection as 17.90 ng dL − 1 and a response time of 60 s.

Aflatoxins (AF) are important foodborne mycotoxins implicated in human health and have immunocytotoxic effects. The aims of this study were to evaluate a new aflatoxin B1 (AFB1) and fumonisin B1 (FB1)-binding/degrading micro-organism for... more

Aflatoxins (AF) are important foodborne mycotoxins implicated in human health and have immunocytotoxic effects. The aims of this study were to evaluate a new aflatoxin B1 (AFB1) and fumonisin B1 (FB1)-binding/degrading micro-organism for biological detoxification, to examine its ability to degrade AFB1 and FB1 in liquid medium, and to evaluate its potential in vivo protective role against any combined effects from AFB1 and FB1 on host splenocyte caspase-3 activity (reflecting DNA damage/cell death) and mRNA levels of select inflammation-regulating cytokines. Balb/c mice were divided into groups (10/group) and treated daily for 2 weeks by oral gavage with AFB1 (80 µg/kg BW), FB1 (100 µg/kg), AFB1 + FB1, or lactic acid bacteria (Lactobacillus paracasei BEJ01, 2 × 10(9) CFU/L, ∼2 mg/kg) - alone or in combination with the AFB1 and/or FB1. After the exposures, spleens were collected for measures of caspase-3 activity, lipid peroxidation (LP), and glutathione (GSH) content, expression of ...

Background and objectives: Contamination of food products with mycotoxins is a public health problem. The International Agency for Research on Cancer has identified mycotoxins as hepatotoxic and carcinogenic agents to humans (Group 1).... more

Background and objectives: Contamination of food products with mycotoxins is a public health problem. The International Agency for Research on Cancer has identified mycotoxins as hepatotoxic and carcinogenic agents to humans (Group 1). The Kurdistan Province is the ninth largest producer of wheat in Iran. We aimed to determine the level of contamination with total aflatoxin (TAF), aflatoxin B1 (AFB1) and ochratoxin A (OTA) in 66 wheat samples randomly selected from 11 wheat flour factories in spring and summer. Methods: The level of toxins was measured by microtiter plate enzyme-linked immunosorbent assay (ELISA) using a microtitre plate ELISA reader and total AF, AFB1 and OTA commercial kits. Results: Overall, the level of TAF and AFB in 16.67% of the samples exceeded the maximum tolerable limit set by the Institute of Standard and Industrial Research of Iran (ISIRI). However, the level of OTA contamination did not exceed the maximum tolerable limit set by the ISIRI. In addition, the level of TAF, AFB1 and OTA exceeded the maximum tolerable limit set by the EU in 68.18, 90.91 and 36.36% of the samples, respectively. The level of contamination with these mycotoxins differed significantly in spring and summer (P<0.05). Conclusion: The level of mycotoxin contamination in wheat samples produced in the Kurdistan Province is alarmingly high and appropriate measures should be taken to eliminate the causes of this issue.

Natural mycoflora and co-occurrence of fumonisins and aflatoxins were evaluated in 300 freshly-harvested corn samples (2003 and 2004 crops) collected at two points of the production chain in the Northern region of Paraná State, Brazil. In... more

Natural mycoflora and co-occurrence of fumonisins and aflatoxins were evaluated in 300 freshly-harvested corn samples (2003 and 2004 crops) collected at two points of the production chain in the Northern region of Paraná State, Brazil. In the 2003 crop, fumonisins were detected in 100% of samples and the mean levels were 2.54 μg/g in the reception and 3.12 μg/g in the pre-drying samples. On the other hand, in the 2004 crop fumonisins were detected in 98.9% and 95% of the reception and pre-drying samples, respectively. The mean levels were 1.31 μg/g in the reception, and 1.36 μg/g in the pre-drying samples. Aflatoxins were not detected in 92% of the samples analysed. The maximum probable daily intake (PDIM) estimated for the Brazilian population (0.95 μg/kg body weight/day) is below the tolerable daily intake of 2.0 μg/kg body weight/day for fumonisin B1.

A liquid chromatography-tandem mass spectrometric with electrospray ionization (LC/ESI-MS/MS) method for determining the four naturally occurring aflatoxins (AFs) B1, B2, G1, and G2 in olive oil is proposed. AFs were extracted from oil... more

A liquid chromatography-tandem mass spectrometric with electrospray ionization (LC/ESI-MS/MS) method for determining the four naturally occurring aflatoxins (AFs) B1, B2, G1, and G2 in olive oil is proposed. AFs were extracted from oil sample by means of matrix solid phase dispersion (MSPDE), utilizing C18 as dispersing material. No further purification step, such as lipid removal, was performed. Aflatoxin M1, the hepatic metabolite of AFB1, was employed as internal standard. Olive oil extract was analyzed by LC/ESI-MS/MS in positive ionization mode, with multireaction monitoring acquisition. Due to a signal suppression ranging between 4 and 23%, quantitation was performed by matrix-matched calibration curves. The regression line coefficients of determination were above 0.9991. Sample recoveries ranged from 92 to 107%, with relative standard deviations below 13% for spiking levels between 0.5 and 5 ng g −1 ; method quantification limits ranged between 0.04 and 0.12 ng g −1 . The developed LC/ESI-MS/MS method, although not as sensitive as LC coupled to fluorescence detection, is rapid, selective, accurate and precise, thus it can be used as confirmatory assay. The MSPDE appears suitable for application to other oleaginous matrices and for multiresidue investigation.

This study aimed to examine the efficacy of zeolite addition in the reduction of aflatoxin B 1 (AFB 1 ) levels in household bread waste used as animal feed. Three levels of zeolite (1, 3 and 5%) were added to two dry bread waste samples... more

This study aimed to examine the efficacy of zeolite addition in the reduction of aflatoxin B 1 (AFB 1 ) levels in household bread waste used as animal feed. Three levels of zeolite (1, 3 and 5%) were added to two dry bread waste samples naturally contaminated by AFB 1 at 11.48 and 4.8 ppm levels. Samples were then analyzed before zeolite treatment (day 0) and after 7 and 14 days of storage for chemical (pH, moisture content and ash) and microbial (mesophilic bacteria and molds) changes as well as aflatoxin levels relative to the control. Data analysis showed that aflatoxin levels significantly decreased as zeolite and storage time increased, so that the lowest level of aflatoxin was found in sample treated with 5% zeolite after 14 days of storage compared with the control (p<0.05). Such a trend was also observed in bacterial and mold counts. However, storage time had less effect than zeolite. Chemical analyses of bread samples exhibited significant increases in pH values and corresponding decreases in moisture and ash contents in all storage time points compared with the control. These findings suggest zeolite addition as a viable method of reduction of AFB 1 levels in household bread waste used as animal feed.

Mycotoxins are toxic fungal metabolites which are structurally diverse, common contaminants of the ingredients of animal feed and human food. To date, mycotoxins with carcinogenic potency in experimental animal models include aflatoxins,... more

Mycotoxins are toxic fungal metabolites which are structurally diverse, common contaminants of the ingredients of animal feed and human food. To date, mycotoxins with carcinogenic potency in experimental animal models include aflatoxins, sterigmatocystin, ochratoxin, fumonisins, zearalenone, and some Penicillium toxins. Most of these carcinogenic mycotoxins are genotoxic agents with the exception of fumonisins, which is currently believed to act by disrupting the signal transduction pathways of the target cells. Aflatoxin B1 (AFB1), a category I known human carcinogen and the most potent genotoxic agent, is mutagenic in many model systems and produces chromosomal aberrations, micronuclei, sister chromatid exchange, unscheduled DNA synthesis, and chromosomal strand breaks, as well as forms adducts in rodent and human cells. The predominant AFB1-DNA adduct was identified as 8, 9-dihydro-8-(N7-guanyl)-9-hydroxy-AFB1 (AFB1-N7-Gua), which derives from covalent bond formation between C8 o...

In this study, the effects of total aflatoxin (AF) given orally on silver-staining nucleolus organizer regions (AgNORs) activity were studied in glomerulus and tubular epithelial cells of kidney in Merino rams. In addition, this study was... more

In this study, the effects of total aflatoxin (AF) given orally on silver-staining nucleolus organizer regions (AgNORs) activity were studied in glomerulus and tubular epithelial cells of kidney in Merino rams. In addition, this study was conducted in order to evaluate the efficacy of an esterified glucomannan (EG) for protection against to aflatoxicosis. As materials, 1 year-old 32 Merino rams were used. Rams were fed through the 92 days. Control group (C) fed with the commercial feed. AF group fed with commercial feed added 250 µg/day of total AF. EG group fed with commercial feed added 2 g/day of EG daily. AF+EG group fed with commercial feed added 250 µg/day of total AF and 2 g/day of EG. At the end of the 92nd day the animals were sacrificed, and tissue samples were taken from the kidneys. Whereas ratio of nuclear area of the AgNOR area of cells in examinated regions of kidney was found decreased significantly (P<0.05) in the AF group compared to the control group, AF+EG group was found similar to control group (P>0.05). In conclusion, the adverse effects causing by aflatoxicosis on the kidney AgNOR activity could be ameliorated by adding EG to the ration.

The carry-over of contaminants from feed to animal products is an important issue in the animal production chain, therefore, the quality control of those animal products should include the control of the animal feed. The current study was... more

The carry-over of contaminants from feed to animal products is an important issue in the animal production chain, therefore, the quality control of those animal products should include the control of the animal feed. The current study was carried out to assess the contamination levels of three types of animal feed (dairy animal feed, poultry feed, and fish feed) by Aflatoxin B1. A total of 68 animal feed samples were collected from the Northeastern Moroccan area (Tangier-Tétouan-AL Hoceima). The samples were extracted with a mixture of acetone/water. The sample extractions were filtered, diluted with phosphate-buffered saline, and applied to an immunoaffinity column. Aflatoxin B1 was eluted with methanol then analyzed by high-performance liquid chromatography with fluorescence detection, after post-column photochemical derivatization. The analytical results for the level of Aflatoxin B1 in the animal feed samples revealed an average presence of 44.12% for all analyzed samples. The concentrations were between 1.02 and 13.59 µg/Kg, with a mean value of 4.08 ± 3.11 µg/Kg. The results indicated that there was a significant difference across the three types of animal feeds regarding the concentrations of Aflatoxin B1.

Aflatoxin contamination of food and feed is a major concern due to the carcinogenic properties of this mycotoxin. Previous studies using classical approaches have identified a cluster of genes responsible for aflatoxin production under... more

Aflatoxin contamination of food and feed is a major concern due to the carcinogenic properties of this mycotoxin. Previous studies using classical approaches have identified a cluster of genes responsible for aflatoxin production under the control of the pathway-specific transcriptional regulator aflR, but it is unknown whether aflR controls expression of other genes within the genome. Transcription profiling comparing wild type and DaflR strains of Aspergillus parasiticus grown under conditions conducive for aflatoxin production identified only 23 upregulated genes in the wild type. These included 20 genes in the aflatoxin biosynthetic cluster, and three additional genes outside the aflatoxin biosynthetic cluster (nadA, hlyC, and niiA), all with AflR binding sites. This report is the first to demonstrate genes outside the biosynthetic cluster as being associated with aflR expression.

Natural mycoflora and co-occurrence of fumonisins and aflatoxins were evaluated in 300 freshly-harvested corn samples (2003 and 2004 crops) collected at two points of the production chain in the Northern region of Paraná State, Brazil. In... more

Natural mycoflora and co-occurrence of fumonisins and aflatoxins were evaluated in 300 freshly-harvested corn samples (2003 and 2004 crops) collected at two points of the production chain in the Northern region of Paraná State, Brazil. In the 2003 crop, fumonisins were detected in 100% of samples and the mean levels were 2.54 lg/g in the reception and 3.12 lg/g in the pre-drying samples. On the other hand, in the 2004 crop fumonisins were detected in 98.9% and 95% of the reception and pre-drying samples, respectively. The mean levels were 1.31 lg/g in the reception, and 1.36 lg/g in the pre-drying samples.

The purpose of this study is to investigate the insecticidal activity of two benzoic acids 2(3)-tert-butyl-4 hydroxyanisole (BHA) and 2,6-di(tert-butyl)-p-cresol (BHT); two phenolic acids 3-phenyl-2-propenoic acid (CA) and... more

The purpose of this study is to investigate the insecticidal activity of two benzoic acids 2(3)-tert-butyl-4 hydroxyanisole (BHA) and 2,6-di(tert-butyl)-p-cresol (BHT); two phenolic acids 3-phenyl-2-propenoic acid (CA) and trans-4-hydroxy-3-methoxycinnamic acid (FA); and two essential oils of Eugenia caryophyllata (clove tree) and Thymus vulgaris (thyme) against Oryzaephilus surinamensis (L.) vector carrier of aflatoxigenic fungi on stored peanut. The weight loss of peanut, susceptibility of insects, Aspergillus isolation frequency from insects and peanut, and aflatoxin B 1 analyses from peanut were determined. BHA, BHT, and BHA/BHT mixture were highly effective against O. surinamensis, these chemical agents give 100% mortality at the doses assayed. Essential oil of thyme at 2,000 and 3,000 ppm were highly effective against O. surinamensis, these concentrations gave 100% mortality. No Aspergillus section Flavi contamination was observed in dead insects collected from peanut treated with BHA/BHT mixture. No differences were observed in the fresh weight of pods peanut among treatments with and without chemical agents. All samples of treated peanut pods showed complete inhibition of this toxin after 120 days of storage.

Neem seed kernels artificially infested with Aspergillus parasiticus (NRRL 2999) was evaluated for aflatoxin elaboration and fungal growth, and compared with groundnut, a high risk commodity for aflatoxin contamination. At optimal... more

Neem seed kernels artificially infested with Aspergillus parasiticus (NRRL 2999) was evaluated for aflatoxin elaboration and fungal growth, and compared with groundnut, a high risk commodity for aflatoxin contamination. At optimal moisture content (10-12%) the total, individual toxins (AFB 1 , AFB 2 , AFG 1 and AFG 2 ) and ergosterol content increased and showed maximum levels on day 9. Crude protein and polyphenols increased while, fat and total sugar content decreased during the period of infection. The protein content correlated positively (r = 0.734) with total toxin levels, whereas fat content (r = -0.761) and total sugars (r = -0.891) showed negative correlation and they were all statistically significant (p<0.01). The polyphenols showed negative and non-significant correlation with total toxin levels. Azadirachtin one of the major active principles of neem seed kernel showed significant decrease on day 3 (P<0.05) and day 6 (P<0.01). Neem seed kernel has shown 54 and 74% less aflatoxin production on day 9 and 12, respectively in comparison to groundnut seeds. Ergosterol content also showed 60% decrease on day 9, conferring it a poor substrate for fungal growth and aflatoxin elaboration.

The number of elevator facilities with laboratories to test shelled corn for aflatoxin on site is increasing. The inherent difficulty in accurately determining the true aflatoxin concentration of a lot of corn may have serious... more

The number of elevator facilities with laboratories to test shelled corn for aflatoxin on site is increasing. The inherent difficulty in accurately determining the true aflatoxin concentration of a lot of corn may have serious implications. Deviations from the true value are of even greater significance at busy locations where a high throughput is desired. This study was instituted to measure (1) the differences in aflatoxin test results between elevator laboratories and the Louisiana Agricultural Chemistry (LAC) laboratory and (2) the variability in aflatoxin test results associated with sampling, sample preparation, and analysis of shelled corn at such locations. One hundred lots of shelled corn from 10 elevators in Louisiana were analyzed for aflatoxin using the Aflatest method (at elevators and at the LAC laboratory) and high-performance column liquid chromatography (HPLC; LAC laboratory only). Mean aflatoxin levels determined at elevator laboratories were significantly (P < 0.05) lower from those obtained in the LAC laboratory using the Aflatest method. Overall, Aflatest method results were lower than those obtained by HPLC. This difference may be attributed to analyst technical dexterity, difficulty in providing careful attention to detail in a high throughput environment, and/or substandard facilities found at elevators. The total variance was

Fungal pathogens need regulated mechanical and morphological fine-tuning for pushing through substrates to meet their metabolic and functional needs. Currently very little is understood on how coordinated colony level morphomechanical... more

Fungal pathogens need regulated mechanical and morphological fine-tuning for pushing through substrates to meet their metabolic and functional needs. Currently very little is understood on how coordinated colony level morphomechanical modifications regulate their behavior. This is due to an absence of a method that can simultaneously map, quantify, and correlate global fluctuations in physical properties of the expanding fungal colonies. Here, we show that three-dimensional ultrasonic reflections upon decoding can render acoustic contrast tomographs that contain information on material property and morphology in the same time scale of one important phytopathogen, Aspergillus parasiticus, at multiple length scales. By quantitative analysis of the changes in acoustic signatures collected as the A. parasiticus colony expands with time, we further demonstrate that the pathogen displays unique acoustic signatures during synthesis and release of its hepatocarcinogenic secondary metabolite, aflatoxin, suggesting an involvement of a multiscale morphomechanical reorganization of the colony in this process. Our studies illustrate for the first time, the feasibility of generating in any invading cell population, four-dimensional maps of global physical properties, with minimal physical perturbation of the specimens. Our developed method that we term quantitative acoustic contrast tomography (Q-ACT), provides a novel diagnostic framework for the identification of in-cell molecular factors and discovery of small molecules that may modulate pathogen invasion in a host.

Predictive mycology has dealt mainly with germination, growth and inactivation of fungi while the issue of mycotoxin production remains relatively unexplored. Very few studies provide biomass dry weight/colony size data along with... more

Predictive mycology has dealt mainly with germination, growth and inactivation of fungi while the issue of mycotoxin production remains relatively unexplored. Very few studies provide biomass dry weight/colony size data along with mycotoxin data for the same sample times, thus the ratio mycotoxin accumulation per fungal biomass dry weight/colony size has rarely been reported. For this reason, the objective of the present study was to model the kinetics of mycotoxin production under the assumption of existing both no-growthassociated and growth-associated production. Aspergillus flavus was chosen as a model mycotoxigenic microorganism, and it was grown in maize agar medium and maize grain at 0.90 and 0.99 a w at 25°C. A significant positive correlation (p b 0.05) was observed among the biomass responses (colony radius and biomass dry weight) in agar medium and colony radius in maize at both a w levels assayed. The Luedeking-Piret model was used to model AFB1 production and reasonable percentages of variability were explained. Moreover, AFB1 production was in general slightly better predicted through colony area. As conclusion, aflatoxin production may follow a mixed-growth associated trend, confirming that toxin formation does not present a clear delay in relation to growth under certain conditions.

This study was a screening survey to determine the occurrence of aflatoxin M 1 (AFM 1 ) in 82 cheese samples composed of white cheese (45 samples) and Lighvan cheese (37 samples) obtained from supermarkets and retail outlets in Rafsanjan... more

This study was a screening survey to determine the occurrence of aflatoxin M 1 (AFM 1 ) in 82 cheese samples composed of white cheese (45 samples) and Lighvan cheese (37 samples) obtained from supermarkets and retail outlets in Rafsanjan city of Iran. The competitive enzyme immunoassay method was used for determination of the toxin in the samples. Aflatoxin M 1 was detected in 39 (47.6%) samples, consisting of 29 (64.4%) white cheese (mean: 135 ng/kg; range: 93.3e309 ng/kg) and 10 (27%) Lighvan cheese samples (mean: 90.8 ng/kg; range: 70.5e203 ng/kg). According to Iranian national standard limit for AFM 1 in cheese (200 ng/kg), 9 samples (20%) of white cheese and 1 sample (2.70%) of Lighvan cheese had levels above the limit. It was concluded that the contamination of the samples with AFM 1 in such a level could be considered as a serious public health problem.

In this study the aflatoxin B₁ (AFB₁) removal capacity, the tolerance to salivary and gastrointestinal conditions, autoaggregation and coaggregation with pathogenic bacteria of Saccharomyces cerevisiae strains isolated from broiler feces,... more

In this study the aflatoxin B₁ (AFB₁) removal capacity, the tolerance to salivary and gastrointestinal conditions, autoaggregation and coaggregation with pathogenic bacteria of Saccharomyces cerevisiae strains isolated from broiler feces, were evaluated. Only four of twelve isolated strains were identified as Saccharomyces cerevisiae using molecular techniques. The results obtained in AFB₁ binding studies indicated that the amount of AFB₁ removed was both strain and mycotoxin-concentration dependent. Therefore, a theoretical model was applied in order to select the most efficient strain to remove AFB₁ in a wide range of mycotoxin concentration. The results indicated that S. cerevisiae 08 and S. cerevisiae 01 strains were the most efficient microorganisms in the mycotoxin removal. Viability on simulated salivary and gastrointestinal conditions was investigated and S. cerevisiae 08 strain showed the best results, achieving 98% of total survival whereas S. cerevisiae 01 reached only 75%. Autoaggregation and coaggregation assays showed S. cerevisiae 08 as the most appropriate strain, mainly because it was the unique strain able to coaggregate with the four bacterial pathogens assayed. Consequently, S. cerevisiae 08 is the best candidate for future in vivo studies useful to prevent aflatoxicosis. Further quantitative in vitro and in vivo studies are required to evaluate the real impact of yeast-binding activity on the bioavailability of AFB₁ in poultry. However, this study could be useful in selecting efficient strains in terms of AFB₁ binding and provide an important contribution to research into microorganisms with potential probiotic effects on the host.

Mycotoxins are toxigenic fungal secondary metabolites and known carcinogens that pose a significant threat to economies, trade, health and compromises food safety. Favourable environmental conditions on the African continent encourage the... more

Mycotoxins are toxigenic fungal secondary metabolites and known carcinogens that pose a significant threat to economies, trade, health and compromises food safety. Favourable environmental conditions on the African continent encourage the proliferation of fungal species, increasing the possibility of attendant mycotoxins to be present in foods, a situation that aggravates challenges to address them. Due to the susceptibility of common food crops to these toxins and the general inability of some conventional food processes to eliminate them, they are found in derived/processed foods. Detoxification and reduction of mycotoxins in the food chain still remains a significant topic necessitating a sustainable, affordable and effective strategy for mycotoxin control. Fermentation of food confers desirable properties and improves food quality. This food processing technique is also a notable inexpensive mycotoxin decontamination strategy that can be explored not only to improve the constituents in food, but equally reduce and at best eliminate mycotoxins. In the absence of sophisticated monitoring and prevention mechanisms in Africa, exploiting fermentation would be vital in improving nutrition and ensuring food safety. While this processing technique generally favours mycotoxin reduction, preventing the occurrence of these toxins in crops, effective handling and storage practices before fermentation may ensure complete prevention of the heinous effect of these toxins on human health.

A high performance liquid chromatographic method with fluorimetric detection for the determination of aflatoxin M 1 (AFM 1) in milk has been optimized and validated according to Commission Decision 2002/657/EC by using the conventional... more

A high performance liquid chromatographic method with fluorimetric detection for the determination of aflatoxin M 1 (AFM 1) in milk has been optimized and validated according to Commission Decision 2002/657/EC by using the conventional validation approach. The procedure for determining selectivity, recovery, precision, decision limit (CC α), detection capability (CC β) and ruggedness of the method has been reported. The results of the validation process demonstrate the agreement of the method with the provisions of Commission Regulation 401/2006/EC. The mean recovery calculated at three levels of fortification (0.5, 1.0, and 1.5-fold the MRL) was 91% and the maximum relative standard deviation value for the within-laboratory reproducibility was 15%. Limit of detection (LOD) and limit of quantitation (LOQ) values were 0.006 g kg −1 and 0.015 g kg −1 while the CC α and CC β values were 0.058 g kg −1 and 0.065 g kg −1 , respectively. The relative expanded measurement uncertainty of the method was 7%. The method was not affected by slight variations of some critical factors (ruggedness minor changes) as pre-treatment and clean-up of milk samples, thermal treatment and different storage conditions, as well as by major changes valued in terms of milk produced by different species (buffalo, goat and sheep). The method allowed accurate confirmation analyses of milk samples, resulted positive by the screening method. In fact, the Z-score values attained in a proficiency test round were well below the reference value of 1, proving the excellent laboratory performances.