Development and in-house validation of a rapid and simple to use ELISA for the detection and measurement of the mycotoxin sterigmatocystin

Abstract

Sterigmatocystin (STG) is a highly toxic secondary fungal metabolite structurally closely related to the well-known carcinogenic aflatoxins. Its presence has been reported in grains and grain-based products as well as in other foodstuffs like nuts, green coffee beans, spices, beer and cheese. Due to the lack of suitable data on the occurrence of STG, in 2013, the European Food Safety Authority (EFSA) could not characterise its risk for human health and recommended that more data on STG in food and feed needed to be collected. In order to provide a new tool for the specific detection of STG, a competitive enzyme-linked immunosorbent assay (ELISA) was developed, optimised and validated in this study based on a sensitive monoclonal antibody specific to STG with no cross-reactivity with aflatoxins. The sample preparation method for rice, wheat and maize was based on a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) approach. The assay was validated for the detection of STG in rice, wheat and maize in accordance with the guidelines for validation of semi-quantitative screening methods included in Commission Regulation (EU) 519/2014. The screening target concentration (STC) was set at 1.5 μg/kg. The cutoffs for rice, wheat and maize were 1.2, 1.2 and 1.3 μg/kg and the false suspected rates were 0.34, 1.15 and 0.78%, respectively. Good correlation was found between the results obtained by the STG ELISA and LC-MS/MS method for naturally contaminated rice samples. This validated method can be applied as a sensitive and high-throughput screening for the presence of STG in a range of agricultural commodities. Graphical abstract A new enzyme-linked immunosorbent assay based on an antibody specific to sterigmatocystin for the detection of this mycotoxin in corn, wheat and rice.

Mycotoxin exposure biomonitoring in breastfed and non-exclusively breastfed Nigerian children

“…Furthermore, it agrees with the suggestions of Ali and Degen (2019) who retrospectively estimated high CIT exposure assessment/intake above the “level of no concern for nephrotoxicity” of 0.2 μg/kg bwt/day set by EFSA (EC, 2014; EFSA, 2012) in participants in a previous urinary biomarker study in Nigeria (Šarkanj et al, 2018). Due to sparse data on its occurrence and toxicity, there is no regulation on maximum levels (ML) of STER in food, including infant diets, in most countries, Nigeria inclusive (EC, 2006; Oplatowska-Stachowiak et al, 2018). Nonetheless, this mycotoxin may be carcinogenic in humans (EFSA, 2013; IARC, 1987), as such, its detection in breast milk samples provides a basis for the consideration of more investigations into the occurrence and regulation of this mycotoxin in foods intended for infants and young children.…”

The Existing Methods and Novel Approaches in Mycotoxins’ Detection

“…In addition to the sensitive but complex and costly chromatographic techniques, immunochemical methods such as ELISA are fast and simple screening techniques for on-site mycotoxin analysis [ 16 , 103 ]. ELISA is simple in design, enables simultaneous testing of multiple samples and its detection is precise [ 72 , 104 ]. It is a high-throughput assay with low sample volume requirements and less clean-up procedures compared to chromatographic methods such as HPLC or TLC [ 85 ].…”

Using Magnetic Multiwalled Carbon Nanotubes as Modified QuEChERS Adsorbent for Simultaneous Determination of Multiple Mycotoxins in Grains by UPLC-MS/MS

“…Several methods have been reported for the analysis of mycotoxins, including electrochemical biosensors, optical biosensors based on specific antibodies or aptamers, − enzyme-linked immunosorbent assays (ELISAs), and liquid chromatography–tandem mass spectrometry (LC-MS/MS). − Although the electrochemical biosensors and ELISA methods address the challenges associated with mycotoxin detection, they are only suitable for single mycotoxin and cannot simultaneously detect multiple mycotoxins. However, multiple mycotoxins always exist in the same sample, leading to additive or even synergistic effects and increased toxicity .…”

“…Most of these mycotoxins are chemically stable and highly resistant even when cooked at high temperatures, so mycotoxins can easily enter the feed and food chain, resulting in a serious threat to human and animal health. 8,9 Several methods have been reported for the analysis of mycotoxins, including electrochemical biosensors, 10 optical biosensors based on specific antibodies or aptamers, 11−13 enzyme-linked immunosorbent assays (ELISAs), 14 and liquid chromatography−tandem mass spectrometry (LC-MS/ MS). 15−19 Although the electrochemical biosensors and ELISA methods address the challenges associated with mycotoxin detection, they are only suitable for single mycotoxin and cannot simultaneously detect multiple mycotoxins.…”