
Chibundu N EzekielBOKU University | boku
Chibundu N Ezekiel
Ph.D.
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161
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Publications (161)
Aflatoxins and ochratoxins are among the most important mycotoxins of all and producers of both types of mycotoxins are present in Aspergillus section Flavi, albeit never in the same species. Some of the most efficient producers of aflatoxins and ochratoxins have not been described yet. Using a polyphasic approach combining phenotype, physiology, s...
Low moisture content ready-to-eat foods vended in Nigerian markets could be pre-packaged or packaged at point of sale. These foods are widely and frequently consumed across Nigeria as quick foods. Despite their importance in the daily diets of Nigerians, a comprehensive study on the diversity of fungi, fungal metabolite production potential, and my...
Mycological investigation of various foods (mainly cowpea, groundnut, maize, rice, sorghum) and agricultural soils from two states in north-central Nigeria (Nasarawa and Niger), was conducted in order to understand the role of filamentous fungi in food contamination and public health. A total of 839 fungal isolates were recovered from 84% of the 25...
A multi-specimen, multi-mycotoxin approach involving ultra-sensitive LC-MS/MS analysis of breast milk, complementary food and urine was applied to examine mycotoxin co-exposure in 65 infants, aged 1–18 months, in Ogun state, Nigeria. Aflatoxin M1 was detected in breast milk (4/22 (18%)), while six other classes of mycotoxins were quantified; includ...
Mycotoxins are toxic chemicals that adversely affect human health. Here, we assessed the influence of mycotoxin exposure on the longitudinal development of early life intestinal microbiota of Nigerian neonates and infants (NIs). Human biomonitoring assays based on liquid chromatography tandem mass spectrometry were applied to quantify mycotoxins in...
Rhizopus rot is considered one of the most common diseases influencing global production and yield of horticulture commodities. However, the factors contributing to this pattern of prevalence are uncertain. Here, we focused on R. microsporus , which is known to rely on its endosymbiotic bacterium, Mycetohabitans , to produce toxins that interfere w...
Mycotoxin exposure from contaminated food is a significant global health issue, particularly among vulnerable children. Given limited data on mycotoxin exposure among Namibian children, this study investigated mycotoxin types and levels in foods, evaluated dietary mycotoxin exposure from processed cereal foods in children under age five from rural...
In Cameroon, dietary staples are frequently contaminated with diverse toxic fungal metabolites, known as mycotoxins. Aflatoxins and fumonisins are a public health concern, particularly concerning cancer and/or early life stunting. Mycotoxin mixtures are predicted from food measures; and this study reports the levels and frequencies of urinary mycot...
Background
Cow milk, which is sometimes consumed raw, hosts a plethora of microorganisms, some of which are beneficial, while others raise food safety concerns. In this study, the draft genome of an extended-spectrum β-lactamase-producing Klebsiella pneumoniae subsp. pneumoniae strain Cow102, isolated from raw cow milk used to produce traditional f...
Complementary foods (CFs) commonly consumed by infants and young children (IYC) in sub‐Saharan Africa (SSA) are processed using either single or multi‐grain ingredients through simple technologies such as fermentation, malting and roasting. Interestingly, CFs (e.g., ogi, kunu, and dabo) are prepared and fed to infants alongside breastmilk until the...
The draft genome of a previously documented potential probiotic Weissella cibaria strain GM93m3 from raw goat milk in Nigeria is reported. The total genome size was 2,447,229 with 46 contigs and G+C content of 44.86%.
Background
Many developing countries, Namibia included, have a high prevalence of malnutrition among children, especially in rural subsistence farming areas where inadequate food supply is common. Poor diets in children under 5 years may result in negative health impacts. This study determined the association of food consumption patterns and nutrit...
Background
Cow milk which is sometimes consumed raw host a plethora of microorganisms of beneficial or food safety concern. The draft genome of an extended-spectrum β-Lactamase-producing Klebsiella pneumoniae subsp. pneumoniae strain Cow102, isolated from cow milk used for production of traditional foods in Nigeria, is reported.
Result
The genome...
Exposure to polyphenols is relevant throughout critical windows of infant development, including the breastfeeding phase. However, the quantitative assessment of polyphenols in human breast milk has received limited attention so far, though polyphenols may positively influence infant health. Therefore, a targeted LC–MS/MS assay was developed to inv...
Early-life exposure to natural and/or synthetic chemicals can impact acute and chronic health conditions. Here, a suspect screening workflow anchored on high-resolution mass spectrometry was applied to elucidate xenobiotics in breast milk and matching stool samples collected from Nigerian mother-infant pairs (n = 11) at three-time points. Potential...
A comprehensive study of bacterial and biotoxin contaminants of ready-to-eat (RTE) foods in Nigeria is yet to be reported. Hence, this study applied 16S rRNA gene sequencing and a dilute-and-shoot LC-MS/MS method to profile bacteria and biotoxins, respectively, in 199 RTE food samples comprising eko (n = 30), bread (n = 30), shawarma (n = 35), aadu...
Contamination of food and feed by mycotoxins is considered a significant issue in food and feed safety worldwide [...]
The present study aimed to reveal the microbial (bacteria and yeast) composition of raw milk from dairy camel (n = 10), cow (n = 10) and goat (n = 10) in Northwestern Nigeria. High-throughput DNA metabarcoding was used to compare microbial compositions in raw milk among the three species. Although the three species had similar dominant bacterial (F...
Probiotic microorganisms are incorporated in foods due to their numerous health benefits. We investigated lactic acid bacteria (LAB) and yeasts isolated from goat milk in Nigeria for novel probiotic strains. In this study, a total of 27 LAB and 23 yeast strains were assessed for their probiotic potentials. Only six LAB strains (Weissella cibaria GM...
The totality of environmental exposures and lifestyle factors, commonly referred to as the exposome, is poorly understood. Measuring the myriad of chemicals that humans are exposed to is immensely challenging, and identifying disrupted metabolic pathways is even more complex. Here, we present a novel technological approach for the comprehensive, ra...
The totality of environmental exposures and lifestyle factors, commonly referred to as the exposome, are poorly understood. Measuring the myriad of chemicals that humans are exposed to is immensely challenging and identifying disrupted metabolic pathways is even more complex. Here, we present a novel technological approach for the comprehensive, ra...
This study assessed the profiles of mycotoxins and other contaminants present in complementary foods consumed by Nigerian infants and young children (IYC) within the first 18 months of life. In total, 92 complementary foods and one herbal mixture collected at 3-months interval were subjected to LC/MS-MS analysis. Aflatoxin B1 contaminated ogi and t...
Draft genomes of multidrug-resistant Shiga toxin-producing Escherichia coli (STEC) strains IPK9(1) and IKS1(2), which were isolated from ready-to-eat foods (kokoro and shawarma) sold in Lagos, Nigeria, are reported. The genomes possessed genetic determinants for virulence and the antibiotic resistance gene for macrolide-associated resistance mdf(A)...
The gut microbiome of neonates, infants, and toddlers (NITs) is very dynamic, and only begins to stabilize towards the third year of life. Within this period, exposure to xenobiotics may perturb the gut environment, thereby driving or contributing to microbial dysbiosis, which may negatively impact health into adulthood. Despite exposure of NITs gl...
Environmental drivers of disease susceptibility, referred to as the exposome in its totality, are poorly understood. Measuring the myriad of chemicals that humans are exposed to is immensely challenging and identifying disrupted metabolic pathways is an even more complex task. Here, we present a novel technological approach for the comprehensive, r...
Environmental drivers of disease susceptibility, referred to as the exposome in its totality, are poorly understood. Measuring the myriad of chemicals that humans are exposed to is immensely challenging and identifying disrupted metabolic pathways is an even more complex task. Here, we present a novel technological approach for the comprehensive, r...
The mycotoxin profile of 135 raw milk samples from camel (n=25), cow (n=23) and goat (n=87) in Nigeria was assessed by an ultra-sensitive LC-MS/MS method. Four, seven and 17 of the tested 36 mycotoxins were detected in camel, cow and goat milk, respectively. Among these were aflatoxin P1, alternariol monomethyl ether, citrinin, dihydrocitrinone, en...
Infants are sensitive to negative effects caused by food contaminants such as mycotoxins. To date, analytical methods assessing mycotoxin mixture exposure in infant stool are absent. Herein, we present a novel multi-mycotoxin LC-MS/MS assay capable of detecting 30+ analytes including the regulated mycotoxin classes (aflatoxins, trichothecenes, ochr...
Since the last revision in 2015, the taxonomy of section Flavipedes evolved rapidly along with the availability of new species delimitation techniques. This study aims to re-evaluate the species boundaries of section Flavipedes members using modern delimitation methods applied to an extended set of strains (n = 90) collected from various environmen...
Globally, cassava is an important food crop that contributes significantly to food security. In Nigeria, cassava can be traditionally processed into abacha (fermented strips), fufu (submerged‐fermented porridge) and garri (solid‐state fermented farinated granules) for human consumption. Despite the widespread consumption of these foods, there is a...
This study characterized the health risks due to the consumption of mycotoxin-contaminated foods and assessed the consumer awareness level of mycotoxins in households in two north-central Nigerian states during the harvest and storage seasons of 2018. Twenty-six mycotoxins and 121 other microbial and plant metabolites were quantified by LC-MS/MS in...
Exposure to food and environmental contaminants is a global environmental health issue. In this study, innovative LC-MS/MS approaches were applied to investigate mycotoxin co-exposure in mother-infant pairs (n = 23) by analyzing matched plate-ready food, breast milk and urine samples of mothers and their exclusively breastfed infants. The study rev...
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 distin...
Grains and cassava-based foods serve as major dietary sources for many households in Nigeria. However, these foods are highly prone to contamination by moulds and aflatoxins owing to poor storage and vending practices. Therefore, we studied the fungal diversity in maize, cassava-based flour (pupuru), and rice vended in markets from Ondo state, Nige...
Cereals and cassava-based foods serve as major dietary sources for several households in Nigeria. However, these foods are highly prone to contamination by moulds and aflatoxins owing to poor storage and vending practices. We therefore studied the fungal diversity of maize, cassava-based flour (pupuru) and rice vended in markets from Ondo state, Ni...
A total of 144 samples of milk and milk products comprising 23 raw camel milk, 77 cow milk, 24 goat milk and 20 kindirmo (fermented milk) were randomly purchased across four states in northern Nigeria during July 2020 and screened for aflatoxin M1 (AFM1) using an Enzyme-linked immunosorbent assay method. The incidence (and mean values) of AFM1 in t...
The mycotoxicological safety of 85 mouldy dried fish (n=40) and meat (n=45) samples purchased from Ijebu-ode, Ogun State and Aleshinloye, Ibadan, Oyo State markets both in South Western part of Nigeria respectively, was assessed due to heavy consumption of these animal protein sources by many low-income families in Nigeria. The presence of aflatoxi...
Cereals, legumes and nuts are widely produced and consumed in Nigeria. Despite the availability of these food crops, their safety is often compromised by the presence of mycotoxins. In Nigeria, mixtures of several mycotoxins, including the highly carcinogenic aflatoxins together with fumonisins, ochratoxins and the trichothecenes, commonly co-occur...
Evidence about the magnitude of the aflatoxin menace can help policy makers appreciate the importance of the problem and strengthen policies to support aflatoxin mitigation measures. In this study, we estimated aflatoxin-induced liver cancer risk in 2016 for Tanzania and used the information to estimate the health burden due to the aflatoxin exposu...
Ogi is a fermented cereal beverage, made primarily from maize (Zea mays) and rarely from millets. Unlike maize-based ogi, little is known about the bacterial community and mycotoxin profile during the production of millet-based ogi. Therefore, the bacterial community dynamics and mycotoxin reduction during ogi processing from three millet varieties...
Contamination of ready-to-eat (RTE) foods by pathogenic bacteria may predispose consumers to foodborne diseases. This study investigated the presence of bacterial contaminants and their antibiotic susceptibility patterns in three locally processed RTE foods (eko, fufu and zobo) vended in urban markets in Ogun state, Nigeria. Bacteria isolated from...
Animal milk types in sub‐Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered...
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...
Globally, more than 20 kinds of fruits are vended as minimally processed or fresh-cut fruits (FCFs). In Nigeria, pineapple (Ananas comosus) and watermelon (Citrullus lanatus) are among the commonest FCFs retailed and consumed regularly. However, the consumption of FCFs vended in open markets may constitute health risks owing to microbial contaminat...
In this study, melon (n = 60) and sesame (n = 60) seeds purchased from markets within Benue and Nasarawa states, respectively, in Nigeria, during two seasons (dry and wet), were analysed for fungal and mycotoxin contamination in order to determine the safety of these foods for human consumption. Molecular analysis revealed the following seven funga...
A multi-specimen, multi-mycotoxin approach involving ultra-sensitive LC-MS/MS analysis of breast milk, complementary food and urine was applied to examine mycotoxin co-exposure in 65 infants, aged 1–18 months, in Ogun state, Nigeria. Aflatoxin M 1 was detected in breast milk (4/22 (18%)), while six other classes of mycotoxins were quantified; inclu...
Background
In Cameroon dietary staples are contaminated with diverse toxic fungal metabolites, known as mycotoxins. Aflatoxins and fumonisins are of particular public health concern, particularly in relation to cancer and/or early life stunting. Mixtures of these toxins are predicted from food measures, and in this work, the levels and frequencies...
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. H...
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...
Background:
Aflatoxins are carcinogenic mycotoxins that contaminate many food crops. Maize and groundnuts are prone to aflatoxin contamination, and are the major sources of human exposure to aflatoxins, due to their high intake as staple foods, particularly in low- and middle-income countries (LMICs). Observational studies suggest an association b...
Despite the efforts to control mycotoxin contamination worldwide, extensive contamination has been reported to occur in food and feed. The contamination is even more intense due to climate changes and different stressors. This study examined the impact of fullerol C 60 (OH) 24 nanoparticles (FNP) (at 0, 1, 10, 100, and 1000 ng mL −1) on the seconda...
There is scarce data on the mycotoxin profile in retailed fruit juices in Nigeria. Thirty-five industrially-processed fruit juice samples randomly purchased from retailers in Ogun state, Nigeria, were analysed for the presence of > 650 toxic fungal and plant metabolites using a liquid chromatography tandem mass spectrometric method. Only 18 metabol...
Deoxynivalenol (DON), one of the most abundant mycotoxins in cereal products, was recently detected with other mycotoxins and the emetic bacterial toxin cereulide (CER) in maize porridge. Within a cereal-based diet, co-exposure to these toxins is likely, hence raising the question of combinatory toxicological effects. While the toxicological evalua...
Ready‐to‐eat foods (RTEs) are foods consumed without any further processing. They are widely consumed as choice meals especially by school‐aged children and the fast‐paced working class in most low‐ and middle‐income countries (LMICs), where they contribute substantially to the dietary intake. Depending on the type of processing and packaging mater...
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. H...
The impact of fullerene C60 water soluble daughter molecules - fullerols C60(OH)24 nanoparticles (FNP) on emerging (non-aflatoxin biosynthetic pathway) toxins production in mycelia and yeast extract sucrose (YES) media of A. flavus was investigated under growth conditions of 29 °C in the dark for a 168 h period. The FNP solution (10, 100 and 1000 n...
Fungi and mycotoxin contamination of cocoa beans during fermentation and storage may constitute a hazard in the cocoa value chain and risk to consumers of its products. In this study, fungal profile and secondary metabolite patterns in two cocoa bean hybrids, F and T series, during fermentation and storage were determined. Additionally, secondary m...
In this study, 81 samples of two cowpea varieties (brown: 54; white: 27) collected from various markets in southwestern Nigeria were examined for fungal and mycotoxin contamination. Moulds belonging to Aspergillus, Fusarium, and Penicillium were recovered from 99% of the samples. In both cowpea varieties, Aspergillus (52–53%) dominated Fusarium (29...
Across sub-Saharan Africa, chili peppers are fundamental ingredients of many traditional dishes. However, chili peppers may contain unsafe aflatoxin concentrations produced by Aspergillus section Flavi fungi. Aflatoxin levels were determined in chili peppers from three states in Nigeria. A total of 70 samples were collected from farmers' stores and...
In order to understand the changes in toxic metabolite profiles in uncooked and cooked foods, samples of flour/grain (n = 40) and their corresponding plate-ready food (n = 39) were collected from 40 households in two states of northern Nigeria. The food samples were analyzed for multiple fungal metabolites by LC-MS/MS and daily intakes of mycotoxin...
Mycotoxins are secondary metabolites produced by various moulds, which contaminate many staple foods and cause a broad range of detrimental health effects in animals and humans through chronic exposure or acute toxicity. As such, the worldwide contamination of food and feed with mycotoxins is a significant problem, especially in Sub-Saharan Africa....
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-...