Aflatoxin contamination of maize vended in Ondo state, Nigeria, and health risk assessment

Aflatoxin contamination of maize is a serious food safety problem worldwide. Despite the widespread consumption of maize in Nigeria, there is limited data on aflatoxin contents of maize vended in open markets in Ondo state, Nigeria. A total of 140 maize samples randomly purchased from major markets in four locations in Ondo state, were screened for total aflatoxins using an ELISA method. Exposure and health risk assessments were performed for the maize consumers by the deterministic and Margin of exposure (MOE) approaches, respectively. About 99% of the maize were contaminated with total aflatoxins (range: 0.65–265 µg/kg; mean: 125.9 µg/kg). Aflatoxin levels exceeding the 4 µg/kg set by the European Union for total aflatoxins were found in 88% of the maize whilst more than one half contained at least 100 µg/kg aflatoxins. The average probable daily intake values were 830, 332 and 138 ng/kg bw/day for the average children, adolescent and adult populations, respectively. Consequently, MOEs for the respective populations were 0.20, 0.51 and 1.23, suggesting a high level of health risk for consumers of maize vended in open markets in Ondo state due to high aflatoxin levels. Maize farmers and households in Ondo state need urgent aflatoxin mitigation interventions

Food safety in the face of climate change: consequences for consumers

Food safety encompasses the elimination of biological, chemical, and physical hazards along the food chain; however, climate change, an abnormal change in weather conditions, is a threat to food safety due to irregularities in the elements of weather essential for food production. Such factors include elevated atmospheric carbon (IV) oxide (CO2), precipitation, rainfall, and temperature. Considering that the aim of food safety is to eliminate food hazards along the food chain, it is threatened by climate change in several ways, resulting in adverse effects such as severe consequences for livestock production, harmful algal bloom, mycotoxins (produced by mycotoxigenic fungi on crops), residues of pesticides and tenacious contaminants, and pathogenic microorganisms from contaminated water. These climate changes include landslides and avalanches, drought and extreme heat waves, drought, heavy precipitation, flooding and tropical storms, ocean warming, climate change related acidification, and changes in ocean salinity. Therefore, there is a great need to employ adaptive strategies such as the establishment of a food safety management programme which would expound on the need to detect food hazards in food as a result of climate change. This programme should include setting up awareness for consumers, the improvement of epidemiological surveillance, improved co-ordination among food safety organizations, public health officials, and veterinary officials, amongst others. Thus, to achieve the sustainable development goal two, of eradicating hunger, it is imperative to harness the strategies for reducing the food safety hazards associated with climate change

Assessing the mycotoxicological risk from consumption of complementary foods by infants and young children in Nigeria

This study assessed, for the first time, the mycotoxicological risks from consumption of complementary foods by infants and young children in Nigeria. Molds belonging to Aspergillus aculeatinus, A. flavus, A. luchuensis, A. tubingensis, A. welwitschiae and Geotrichum candidum were recovered from the complementary foods. Twenty-eight major mycotoxins and derivatives, and another 109 microbial metabolites including chloramphenicol (a bacterial metabolite), were quantified in 137 food samples by LC-MS/MS. Aflatoxins and fumonisins co-contaminated 42% of the cereal- and nut-based food samples, at mean concentrations exceeding the EU limits of 0.1 and 200 μg/kg set for processed baby foods by 300 and six times, respectively. Milk contained mainly beauvericin, chloramphenicol and zearalenone. The trichothecenes, T-2 and HT-2 toxins, were quantified only in infant formula and at levels three times above the EU indicative level of 15 μg/kg for baby food. Chronic exposure estimate to carcinogenic aflatoxin was high causing low margin of exposure (MOE). Exposures to other mycotoxins either exceeded the established reference values by several fold or revealed low MOEs, pointing to important health risks in this highly vulnerable population. The observed mycotoxin mixtures may further increase risks of adverse health outcomes of exposure; this warrants urgent advocacy and regulatory interventions.</p

High-Throughput Sequence Analyses of Bacterial Communities and Multi-Mycotoxin Profiling During Processing of Different Formulations of Kunu, a Traditional Fermented Beverage

Kunu is a traditional fermented single or mixed cereals-based beverage popularly consumed in many parts of West Africa. Presently, the bacterial community and mycotoxin contamination profiles during processing of various kunu formulations have never been comprehensively studied. This study, therefore, investigated the bacterial community and multi-mycotoxin dynamics during the processing of three kunu formulations using high-throughput sequence analysis of partial 16S rRNA gene (hypervariable V3-V4 region) and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. A total of 2,303 operational taxonomic units (OTUs) were obtained across six processing stages in all three kunu formulations. Principal coordinate analysis biplots of the Bray-Curtis dissimilarity between bacterial communities revealed the combined influences of formulations and processing steps. Taxonomically, OTUs spanned 13 phyla and 486 genera. Firmicutes (phylum) dominated (relative abundance) most of the processing stages, while Proteobacteria dominated the rest of the stages. Lactobacillus (genus taxa level) dominated most processing stages and the final product (kunu) of two formulations, whereas Clostridium sensu stricto (cluster 1) dominated kunu of one formulation, constituting a novel observation. We further identified Acetobacter, Propionibacterium, Gluconacetobacter, and Gluconobacter previously not associated with kunu processing. Shared phylotypes between all communities were dominated by lactic acid bacteria including species of Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Weissella. Other shared phylotypes included notable acetic acid bacteria and potential human enteric pathogens. Ten mycotoxins [3-Nitropropionic acid, aflatoxicol, aflatoxin B1 (AFB1), AFB2, AFM1, alternariol (AOH), alternariolmethylether (AME), beauvericin (BEAU), citrinin, and moniliformin] were quantified at varying concentrations in ingredients for kunu processing. Except for AOH, AME, and BEAU that were retained at minimal levels of &lt; 2 μg/kg in the final product, most mycotoxins in the ingredients were not detectable after processing. In particular, mycotoxin levels were substantially reduced by fermentation, although simple dilution and sieving also contributed to mycotoxin reduction. This study reinforces the perception of kunu as a rich source of bacteria with beneficial attributes to consumer health, and provides in-depth understanding of the microbiology of kunu processing, as well as information on mycotoxin contamination and reduction during this process. These findings may aid the development of starter culture technology for safe and quality kunu production

Analysis of squat shear wall with different dimensions and position of opening under different type of static loads

Shear walls are usually used in high-rise building or building on high frequency of wind area as the structural element to restrain lateral forces. Openings are created on the shear wall for the architecture, ventilation or mechanical and electrical purposes. With the existence of the opening, the strength of the wall is reduced by the reduction in concrete area and the discontinuity of the reinforcement due to opening which may lead to structural failure. The main objective is to study the effect of size and position of the opening towards the structural behavior of the shear wall under different type of static loads. The analysis is done using the software ANSYS12.0. The samples are SW1, SW2, SW3, SW4, SW5, SW6, SW7 and SW8 where SW1 is solid shear wall while SW2, SW3, SW4, SW5, SW6, SW7 and SW8 are shear walls with different size and position of opening. They are analyzed by using 2 different types of loads which are uniformly distributed axial load and uniformly lateral load. From the same magnitude of loads applied towards the shear walls, they are compared by the cracking pattern and the stress distribution. Under both axial and lateral loads, it shows a significance results that the shear wall with greater opening size shows less efficiency. The position of opening further from the support shows a more significance effect towards the strength of the wall from axial load but opposite from the lateral load. Besides, the closer the position of the shear wall to the load, the less efficient it is. As a conclusion from the results, the most suitable position of the opening on the shear wall is further from the support and the loads and it shows that there is a significance effect even from a smallest opening

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org)

Introduction to This Special Issue of Toxins : Reduction and Control of Mycotoxins along Entire Food and Feed Chain

Contamination of food and feed by mycotoxins is considered a significant issue in food and feed safety worldwide [...]

Exposure to Mycotoxin-Mixtures via Breast Milk: An Ultra-Sensitive LC-MS/MS Biomonitoring Approach

Exposure to natural food contaminants during infancy may influence health consequences later in life. Hence, breast milk may serve as a vehicle to transport these contaminants, including mycotoxins, from mothers to their infants. Analytical methods mostly focused on single exposures in the past, thus neglecting co-occurrences and mixture effects. Here, we present a highly sensitive multi-biomarker approach by a sophisticated combination of steps during sample preparation including QuEChERS extraction followed by SPE cleanup and utilizing stable isotopes for compensating challenging matrix effects. The assay was validated in-house, reaching limits of detection (LOD) for all 34 analytes in the range of 0.1 to 300 ng/L with satisfying extraction efficiencies (75 - 109%) and stable intermediate precisions (1 - 18%) for most analytes. Compared a similar multi-mycotoxin assay for breast milk, LOD values were decreased by a factor of 2-60x enabling the assessment of chronic low-dose exposures. The new method was applied to a small set of Nigerian breast milk samples (n=3) to compare results with already published data. Concentration levels of samples that were found to be contaminated before could be confirmed. In addition, other mycotoxins were determined in all three samples, for example the newly investigated alternariol monomethyl ether (AME) was found for the first time in this biological fluid at concentrations up to 25 ng/L. Moreover, in a pooled Austrian sample obtained from a milk bank, trace amounts of multiple mycotoxins including AME (1.9 ng/L), beauvericin (5.4 ng/L), enniatin B (4.7 ng/L), enniatin B1

Zearalenone production by naturally occurring fusarium species on maize, wheat and soybeans from Nigeria

The occurrence of Fusarium species on maize, wheat and soybean in store in Southwestern Nigeria was determined followed by the study of the Zearalenone producing capacity of the isolates on soybean using wheat as standard under tested conditions. One hundred and seventy-three isolates representing 12 Fusarium species were isolated and identified as F. acuminatum, F. compactum, F. culmorum, F. equiseti, F. graminearum, F. lateritium, F. poae, F. proliferatum, F. semitectum, F. sporotrichioides, F. subglutinans and F. verticillioides. F. sporotrichioides recorded the highest isolation frequency (96%) on maize, F. graminearum (100%) on wheat and F. semitectum (80%) on soybeans. Zearalenone determination using the Veratox® ELISA quantitative test kit showed that F. equiseti (Corda) Sacc. IMI 393764 (Sos1) produced the highest zearalenone on soybean (27.2µg kg-1) under the tested conditions while no zearalenone was detected for F. poae (Sak1) and F. subglutinans (Sek2). All tested isolates produced ZEA on wheat from day 12. Kinetic study of zearalenone production showed that this toxin was not detected at day 6. The levels of zearalenone produced between day 12 and 18 at 30o C tripled on an average while at 25o C and between the 24th and 30th days, levels almost doubled. This is the first report of F. lateritium occurrence on wheat in Nigeria and zearalenone production by F. equiseti (Corda) Sacc. IMI 393764 on soybean