A limited survey of fumonisins in corn and corn-based products in Asian countries

Natural occurrence of fumonisins B₁ (FB₁) and B₂ (FB₂), a promoter for hepato-carcinogenesis, was investigated in corn and corn — based products sampled in Japan, Nepal, and China by high — performance liquid chromatographic method. From the 9 imported corn kernel and 6 gluten feed samples, FB₁ was detected in 8 corn (0.6 ～ 4.1μg/g) and all gluten feed (0.3 ～ 2.4μg/g) samples, while FB₂ was found in the same corn (0.3 ～ 10μg/g) and 3 gluten feed (0.8 ～ 8.5μg/g) samples. ELISA analysis also revealed the contamination of aflatoxin B₁ in 2 corn and all gluten feed samples along with fumonisins. Of 17 corn grit samples, 14 and 5 samples were contaminated with fumonisin B₁ and B₂, with maximum levels of 2.6 and 2.8μg/g, respectively. As for corn-based foodstuffs marketed in Japan, no significant contamination of fumonisins was observed. Among 24 corn kernel samples in Nepal, 12 and 7 samples were positive for FB₁ and FB₂, and averaged to 0.6 and 1.6μg/g, respectively. One sample showed the highest fumonisin contents as 4.6 and 5.5μg/g, respectively. In corn samples harvested at Shanghai and Beijing, China, FB₁ and FB₂ were detected in various concentrations. Mycological survey has also revealed the presence of a fumonisin — producing fungus in a crop field of Japan. These findings have for the first time demonstrated high levels of contamination of fumonisins in corn and corn — based products in Asian countries. Natural co — occurrence of fumonisins and aflatoxin B₁ was also detected in raw materials for mixed feed.     

Conventional detection method of fibrinogen and fibrin degradation products using latex piezoelectric immunoassay

We developed a conventional immunosensor for fibrinogen and fibrin degradation products (FDP) to combine a quartz crystal microbalance (QCM) with the agglutination reaction of immunized latex beads. FDP induced an immunoreaction due to anti-FDP antibody immobilized latex particles. We successfully measured FDP concentration of in human serum within 10 min by QCM method. The detection range of QCM immunosensor is covered with screening concentration of FDP in serum (<10 microg/ml of FDP). The time course of latex agglutination obtained from QCM immunosensor is synchronized to that of latex photometric immunoassay. SEM was used to observe the surface of QCM that applied FDP serum. The size of latex particles agglutinated on the QCM electrode increased concomitant with FDP concentration. Frequency shift on immunoreaction explains the increased adsorption amount of agglutinated latex on QCM.     

A survey of aflatoxins in sesame in Iran

A study of the occurrence of aflatoxins (AF) in sesame seeds was conducted in the Khorasan province of Iran between September 2009 and August 2010. Samples (n = 182) were analyzed by liquid chromatography (LC), and detection limits for AFB₁, AFB₂, AFG₁ and AFG₂, were 0.45, 0.19, 0.61, and 0.22 ng/g, respectively. AFB₁ was detected in 33 samples (18.1%), at a mean level of 1.62 ± 1.32 ng/g, and a maximum level of 5.54 ng/g. AFB₁ levels exceeded the European Union (EU) maximum tolerated level (MTL, 2 ng/g) in 9 samples, and the Iran MTL (5 ng/g) in 1 sample. Regarding total aflatoxins (AFT), the mean level was 0.92 ± 1.36 ng/g, and the maximum level was 5.54 ng/g. No sesame sample exceeded the Iran MTL (15 ng/g), but two samples exceeded the EU MTL (4 ng/g) for AFT. It is concluded that low levels of AFs occur frequently in sesame from Iran.     

Indirect competitive immunoassay for detection of aflatoxin B1 in corn and nut products using the array biosensor

Because of the potential health risks of aflatoxin B₁ (AFB₁), it is essential to monitor the level of this mycotoxin in a variety of foods. An indirect competitive immunoassay has been developed using the NRL array biosensor, offering rapid, sensitive detection and quantification of AFB₁ in buffer, corn and nut products. AFB₁-spiked foods were extracted with methanol and Cy5-anti-AFB₁ added to the resulting sample. The extracted sample/antibody mix was passed over a waveguide surface patterned with immobilized AFB₁. The resulting fluorescence signal decreased as the concentration of AFB₁ in the sample increased. The limit of detection for AFB₁ in buffer, 0.3 ng/ml, was found to increase to between 1.5 and 5.1 ng/g and 0.6 and 1.4 ng/g when measured in various corn and nut products, respectively.     

Analysis of cocoa products for ochratoxin A and aflatoxins

Eighty-five samples of cocoa products sampled in Canada were analysed for ochratoxin A (OTA) and aflatoxins in 2011–2012. Inclusion of the aflatoxins in this survey required additional method development. Chocolate was extracted with methanol–water plus NaCl, while for cocoa two successive extractions with methanol and methanol–water were made. Extracts were cleaned on an AflaOchra immunoaffinity column (IAC). Determination was by reversed phase high performance liquid chromatography (HPLC). Detection of the aflatoxins was with a post-column photochemical reactor and of OTA by fluorescence detection. Mean limits of quantification (LOQ) of chocolate and cocoa powders were 0.16 ng/g (OTA) and 0.07 ng/g (aflatoxin B₁), respectively. Survey results showed that the incidences of OTA above the LOQ in natural cocoa were 15/15 (mean 1.17 ng/g), 20/21 for alkalized cocoa (mean 1.06 ng/g), 9/9 for baking chocolate (mean 0.49 ng/g), 20/20 for dark chocolate (mean 0.39 ng/g), 7/10 for milk chocolate (mean 0.19 ng/g), 5/5 for cocoa liquor (mean 0.43 ng/g), and 0/5 for cocoa butter. These results confirm our previous work with OTA. In the same samples, incidences of aflatoxin B₁ above the LOQ were 14/15 for natural cocoa (mean 0.86 ng/g), 20/21 for alkalized cocoa (mean 0.37 ng/g), 7/9 for baking chocolate (mean 0.22 ng/g), 16/20 for dark chocolate (mean 0.19 ng/g), 7/10 for milk chocolate (mean 0.09 ng/g), 4/5 for cocoa liquor (mean 0.43 ng/g), and 0/5 for cocoa butter. Both aflatoxins and OTA were confirmed by HPLC-MS/MS when OTA or aflatoxin levels found were above 2 ng/g in cocoa.     

Iodine in plant-based dairy products is not sufficient in the UK: A market survey

BackgroundFollowing a well-balanced diet ensures that a person gets all the essential elements for health sustenance. However, in the United Kingdom an increasing proportion of people are transiting to become vegans who exclude animal-based products in their diets. Consequently, people may have a deficit of essential elements such as iodine which is not present in most plant-based meals, additionally iodide fortified table salt is not commonly used in the UK. Without iodine people consuming a vegan diet risk developing iodine deficiency and diseases like goiter.MethodsThe objective of this study is to determine the difference in iodine content and iodine speciation between plant-based and dairy products. More than 100 market samples of plant-based and dairy milk products were collected in Scotland, UK.ResultsIodine concentrations in dairy milk is ten times higher compared to plant-based milks. Similar differences were also apparent for butter, yogurt and cheese. A total of 20% of plant-based milk products were fortified with iodine, however these products had lower iodine concentrations compare to the equivalent dairy products. In this study we calculated that people with average diet have an iodine intake of 226 + /- 103 μg day⁻¹ from dairy products which satisfies the WHO recommended intake of adults and 90% of the recommend intake for pregnant and breast-feeding women. A diet from substituted dairy products gives only 21.8 µg day⁻¹ for the respective WHO guideline intake values, which accounts only 15% of the iodine intake for adults and 9% for pregnant and lactating women. Iodine fortified diet could increase the iodine intake to 55% or 33% of the WHO recommended daily intake respectively.ConclusionPlant-based dairy consumers are encouraged to use iodine fortified dairy products or use of iodized salt in the UK for home cooking, otherwise there are at risk to get iodine deficient.     

Survey and risk assessment of the mycotoxins deoxynivalenol,zearalenone, fumonisins,ochratoxin A,and aflatoxins in commercial dry dog food

The aim of the present study was to investigate the occurrence of mycotoxins in commercial dog food, as a basis to estimate the risk of adverse effects. Seventy-six dry dog food samples from 27 producers were purchased from retail shops, supermarkets, and specialized pet food shops in Vienna, Austria. The frequency and levels of deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FUM), ochratoxin A (OTA). and aflatoxins (AF) in dry dog food were determined. Mycotoxin analysis were performed by commercial enzyme-linked immunosorbent assay (ELISA) test kits. Confirmatory analyses were done for DON, ZEA, and FUM by high performance liquid chromatography (HPLC) after extract clean-up with immunoaffinity columns. The correlations between ELISA and HPLC results for DON and ZEA were acceptable and indicated that ELISA could be a simple, low cost, and sensitive screening tool for mycotoxins detection, contributing to quality and safety of pet food. DON was the mycotoxin most frequently found (83% positives; median 308 μg/kg, maximum 1,390 μg/kg). ZEA (47% positives, median 51 μg/kg and maximum 298 μg/kg) and FUM (42% positives, median 122 μg/kg and maximum 568 μg/kg) were also frequently detected in dog food. OTA was less frequently found (5%, median 3.6 μg/kg, maximum 4.7 μg/kg. AF were not detected (<0.5 μg/kg) in any sample. The results show that dry dog food marketed in Vienna are frequently contaminated with mycotoxins (DON > ZEA > FUM > OTA) in low concentrations, but do not contain AF. The high frequency of Fusarium toxins DON, ZEA, and FUM indicates the need for intensive control measures to prevent mycotoxins in dog foods. The mycotoxin levels found in dry dog food are considered as safe in aspects of acute mycotoxicoses. However, repeated and long-time exposure of dogs to low levels of mycotoxins may pose a health risk.     

A nationwide survey of the quality of antimalarials in retail outlets in Tanzania

Introduction

Retail pharmaceutical products are commonly used to treat fever and malaria in sub-Saharan African countries. Small scale studies have suggested that poor quality antimalarials are widespread throughout the region, but nationwide data are not available that could lead to generalizable conclusions about the extent to which poor quality drugs are available in African communities. This study aimed to assess the quality of antimalarials available from retail outlets across mainland Tanzania.

Methods and Findings

We systematically purchased samples of oral antimalarial tablets from retail outlets across 21 districts in mainland Tanzania in 2005. A total of 1080 antimalarial formulations were collected including 679 antifol antimalarial samples (394 sulfadoxine/pyrimethamine and 285 sulfamethoxypyrazine/pyrimethamine), 260 amodiaquine samples, 63 quinine samples, and 51 artemisinin derivative samples. A systematic subsample of 304 products was assessed for quality by laboratory based analysis to determine the amount of the active ingredient and dissolution profile by following the published United States Pharmacopoeia (USP) monogram for the particular tablet being tested. Products for which a published analytical monogram did not exist were assessed on amount of active ingredient alone. Overall 38 or 12.2% of the samples were found to be of poor quality. Of the antifolate antimalarial drugs tested 13.4% were found to be of poor quality by dissolution and content analysis using high-performance liquid chromatography (HPLC). Nearly one quarter (23.8%) of quinine tablets did not comply within the tolerance limits of the dissolution and quantification analysis. Quality of amodiaquine drugs was relatively better but still unacceptable as 7.5% did not comply within the tolerance limits of the dissolution analysis. Formulations of the artemisinin derivatives all contained the stated amount of active ingredient when analysed using HPLC alone.

Conclusions

Substandard antimalarial formulations were widely available in Tanzania at the time of this study. No products were detected that did not contain any amount of the stated active ingredient. Quinine and sulfadoxine/pyrimethamine products were the most widely available and also the most likely to be of poor quality. Substandard products were identified in all parts of the country and were labeled as made by both domestic and international manufacturers. With the expansion of the retail pharmaceutical sector as a delivery channel for antimalarial formulations the need for regular nationwide monitoring of their quality will become increasingly important.     

Rapid detection of Staphylococcus aureus using bioluminescent enzyme immunoassay

A bioluminescent enzyme immunoassay (BLEIA) method for detecting protein A-bearing Staphylococcus aureus was developed using biotinylated firefly luciferase. The BLEIA was able to detect protein A at one pg ml-1 and 103 cfu ml-1 level of Staph. aureus. The BLEIA showed significant signals with overnight cultures of all 24 Staph. aureus strains, and the BLEIA did not show any significant signals with overnight cultures of all 44 strains of coagulase-negative staphylococci and the other genus bacteria. After 5 h cultivation beginning at approximately 50 cfu ml-1, the BLEIA was able to detect all 35 Staph. aureus strains isolated from healthy humans.     

Mycobiota in poultry feeds and natural occurrence of aflatoxins, fumonisins and zearalenone in the Rio de Janeiro State, Brazil

The intake of mycotoxin-contaminated feeds can lead to nutrient losses and may have adverse effects on animal health and on productivity. The aims of this study were (1) to determine the mycobiota present in poultry feed samples, and (2) to evaluate the natural occurrence of aflatoxin B₁, fumonisin B₁ and zearalenone. Fungal counts were similar between all culture media tested (10³ CFU g⁻¹). The most frequent genus isolated was Penicillium spp. (41.26%) followed by Aspergillus spp. (33.33%) and Fusarium spp. (20.63%). High precision liquid chromatography was applied to quantify aflatoxin B₁ and fumonisin B₁. Thin layer chromatography was used to determine zearalenone levels. Aflatoxin B₁ values ranged between 1.2 and 17.5 μg kg⁻¹. Fumonisin B₁ levels ranged between 1.5 and 5.5 μg g⁻¹. Zearalenone levels ranged between 0.1 and 7 μg g⁻¹. The present study shows the simultaneous occurrence of two carcinogenic mycotoxins, aflatoxin B₁ and fumonisin B₁, together with another Fusarium mycotoxin (zearalenone) in␣feed intended for poultry consumption. Many samples contained AFB₁ levels near the permissible maximum and it could affect young animals. A synergistic toxic response is possible in animals under simultaneous exposure.     

MRSA in conventional and alternative retail pork products

In order to examine the prevalence of Staphylococcus aureus on retail pork, three hundred ninety-five pork samples were collected from a total of 36 stores in Iowa, Minnesota, and New Jersey. S. aureus was isolated from 256 samples (64.8%, 95% confidence interval [CI] 59.9%-69.5%). S. aureus was isolated from 67.3% (202/300) of conventional pork samples and from 56.8% (54/95) of alternative pork samples (labeled "raised without antibiotics" or "raised without antibiotic growth promotants"). Two hundred and thirty samples (58.2%, 95% CI 53.2%-63.1%) were found to carry methicillin-sensitive S. aureus (MSSA). MSSA was isolated from 61.0% (183/300) of conventional samples and from 49.5% (47/95) of alternative samples. Twenty-six pork samples (6.6%, 95% CI 4.3%-9.5%) carried methicillin-resistant S. aureus (MRSA). No statistically significant differences were observed for the prevalence of S. aureus in general, or MSSA or MRSA specifically, when comparing pork products from conventionally raised swine and swine raised without antibiotics, a finding that contrasts with a prior study from The Netherlands examining both conventional and "biologic" meat products. In our study spa types associated with "livestock-associated" ST398 (t034, t011) were found in 26.9% of the MRSA isolates, while 46.2% were spa types t002 and t008--common human types of MRSA that also have been found in live swine. The study represents the largest sampling of raw meat products for MRSA contamination to date in the U.S. MRSA prevalence on pork products was higher than in previous U.S.-conducted studies, although similar to that in Canadian studies.     

A survey of aflatoxins in sesame seeds imported into Khorasan Province, Iran

Sesame seed is one of the main nutrient substances which is used in the food industries of Khorasan Razavi, Iran. Because it is likely that stored sesame seeds are contaminated with mycotoxins, the levels of aflatoxins (AF) in five lots of imported sesame seeds before their distribution to the market were studied during one year. A total of 269 sub-samples were obtained from a total of 9,321 tons of sesame seeds from five importing companies. Aflatoxins at >1 μg/kg were found in 50 % of all samples, but at low levels in most cases, which is illustrated by mean AFB₁ and total AF levels of 1.25?±?3.70 and 1.43?±?4.38 μg/kg, respectively. A few (1.9 %) samples exceeded the National Iranian Standard maximum accepted level for AFB₁ (5 μg/kg) or total AF (15 μg/kg); the maximum total AF level found in one sample was 48 μg/kg. The results indicate that the risk of a violative AF contamination in imported sesame seeds is not negligible but is currently relatively low.     

Validation of an ELISA test kit for the detection of total aflatoxins in grain and grain products by comparison with HPLC

An ELISA Microtiter Plate, Total Aflatoxin Test called AgraQuant^® was validated to measure total aflatoxins in a range from 4 to 40 ppb in corn, corn meal, corn gluten feed, corn gluten meal, corn germ meal, corn/soy blend, popcorn, sorghum, wheat, milled rice, soybeans, peanuts and cottonseed. The test is performed as a solid phase direct competitive ELISA using a horseradish peroxidase conjugate as the competing, measurable entity. For the test method, aflatoxins are extracted from ground samples with 70 % methanol and sample extracts plus conjugate are mixed and then added to the antibody-coated microwells. After 15 min incubation at room temperature, the plate is washed and enzyme substrate is added and allowed to incubate for an additional 5 min. Stop solution is then added and the intensity of the resulting yellow color is measured optically with a microplate reader at 450 nm. Results obtained from internal validation studies assessing accelerated stability indicate a minimum of 1 year shelf life for the kits; accuracy and precision are comparable to HPLC in the range of 0–320 ppb and limit of detection in corn is 2.5 ppb. Comparison of the method to HPLC, ability to detect individual aflatoxins and ruggedness of the test kits at 18–30°C determined this test to be rugged, sensitive, accurate, precise and effective comparable to HPLC for measuring total aflatoxins ranging from 4 to 40 ppb in the commodities evaluated.     

Evaluation of test kits for the determination of aflatoxins in meat products

A study was conducted to evaluate the performance of 4 different assays for rapidly screening samples of artificially contaminated hams and salami for the presence of aflatoxins (B₁+B₂+G₁+G₂) at concentrations ≥5 μg/kg. Test samples were contaminated in the range of 0 – 100μg/kg. At 0 μg/kg level no false positive (all <5 μg/kg) were found for all commodities by the kits tested; all test samples spiked at level >20 μg/kg were found positive by each kit, while most of the errors associated in the assays occurred on samples containing <10μg/kg. For samples either negative or contaminated above 20μg/kg all the methods were suited for use as rapid screening tests.     

A UK survey of the use and management of cover crops

There is a growing trend in the use of cover crops in the United Kingdom, and whilst research shows there are many soil and environmental benefits, little is known about the farmer's perspective of cover cropping. A survey was designed and distributed to ask farmers about their use and management of cover crops. The online survey received 117 usable responses between January and March 2017, following distribution through social media in the United Kingdom. The survey highlighted that 66% of respondents used cover crops following harvest in 2016. Respondents observed benefits to soil structure, soil erosion control and water infiltration in addition to reductions in the use of chemical fertilisers, herbicide and fuel use. Of those not using cover crops, 90% would consider their use in the future if additional information on their use and benefits were known in a UK context. Changes to the 2016 Basic Payment Scheme guidelines for cover crops would have been welcomed by 71% of respondents using cover crops.     

Application of an automated immunomagnetic separation-enzyme immunoassay for the detection of Salmonella spp during an outbreak associated with a retail premises

AIMS: The application of an automated immunomagnetic separation-enzyme immunoassay (AIMS-EIA) during the investigation of a suspected outbreak of Salmonella food poisoning at a retail premises. METHODS AND RESULTS: Six food samples and 24 environmental swabs were taken from the retail premises and six food handlers' submitted faecal samples during the investigation of the outbreak. Isolation and identification of Salmonella from these samples was performed according to established standard operating procedures and by AIMS-EIA. Twelve of the 18 (67%) Salmonella culture positive samples were AIMS-EIA positive on testing pre-enrichment samples after 24 h, whilst 17 (94%) samples were AIMS-EIA positive following selective enrichment for a further 48 h. One food handler was found to be positive for Salmonella by both culture and AIMS-EIA. All Salmonella isolates were confirmed as Salmonella Enteritidis phagetype 21c. CONCLUSIONS: The AIMS-EIA protocol compliments the conventional culture approach to produce more timely results for the management of the risk to public health without significantly increasing the workload of the laboratory. SIGNIFICANCE AND IMPACT OF THE STUDY: The food production premise investigated in this study was heavily contaminated with Salmonella Enteritidis. Application of the AIMS-EIA was significant in the effective intervention of control measures for the protection of public health.