Sample clean-up methods, immunoaffinity chromatography and solid phase extraction, for determination of deoxynivalenol and deepoxy deoxynivalenol in swine serum

Sourdough lactic acid bacteria as antifungal and mycotoxin-controlling agents

Sourdough starter cultures are rich sources of endogenous lactic acid bacteria. The extended shelf lives of sourdough breads are attributed to a large array of organic acids and low-molecular-weight metabolites produced during the fermentation process. Different species belonging to the lactic acid bacteria group of microorganisms, mainly Lactobacillus and Leuconostoc, are increasingly gaining the attention as possible means for inhibiting mold growth in animal feed and human food chains. In addition, certain lactic acid bacteria strains isolated from sourdough starters were also shown to reduce mycotoxins concentrations in contaminated products either by binding or degradation. This short review will summarize the findings in this context that pertain to lactic acid bacteria isolated specifically from sourdough starters and acquaint the reader with the most recent advancements in this bio-preservation trend.

Intestinal transport of deoxynivalenol across porcine small intestines

Deoxynivalenol (DON) is one of the most important trichothecenes, due to its worldwide distribution and common contamination of animal feed. It mainly affects the gastrointestinal tract and the immune system with a high susceptibility for swine. Lipopolysaccharides (LPS) are endotoxins and are part of the outer membrane of most gram-negative bacteria. They induce inflammatory responses under systemic application. We hypothesised that dietary DON as well as LPS challenge could affect the transport of DON in vitro. For assessment of this hypothesis, a total of 16 pigs were divided into two groups, Control and DON-feeding. In each group, four animals were injected intraperitoneally with LPS (5 µg/kg BW). Jejunal preparations were mounted on the Ussing chambers, and after luminal addition of DON at two different concentrations (4000 and 8000 ng/ml), buffer samples were collected at different time points to measure the concentration of DON using LC-MS/MS analysis. Our findings revealed a significant interaction effect between dietary DON and DON in vitro represented by higher mucosal uptake of DON in DON-fed animals. Animals challenged with LPS showed higher mucosal uptake but without significant effect of LPS. We concluded that the transport of DON was proportional to its concentration and DON in feed could have an effect on the transport of DON across porcine jejunal mucosa. LPS challenge induced no apparent significant effect on DON transport, although induction of acute phase reaction was present.

Immunochemical detection of masked mycotoxins: A short review

Mycotoxin derivatives that escape conventional analytical detection of parent (free) forms because their structure has been changed are designated masked mycotoxins. Masking phenomena are due to a defensive response of the host plant or can occur during food processing. Failure to detect masked mycotoxins will lead to a significant underestimation of the mycotoxin content of a particular sample. To date, mainly chromatographic methods were developed for masked mycotoxin determination and quantification. However, for fast screening, it is important to develop on-site methods for detection of masked and parent (free) forms. Although immunochemical methods could provide a simple and economical alternative to chromatography, their use for masked forms is only at the start of development. The key-point for antibody-based methods for masked mycotoxin determination is cross-reactivity of the specific antibody towards masked mycotoxins. If the antibody does not show meaningful affinity for masked forms, they will be latent, and the total content of this mycotoxin will be underestimated. If the antibody shows affinity for masked forms, the sum of free and masked forms will be determined. Currently, neither antibodies nor immuno-based methods were specifically developed for masked mycotoxins, but some enzyme-linked immunosorbent assay test-kits and immunoaffinity columns for mycotoxins were evaluated for their detection. This paper describes possible applications of antibody-based techniques for masked mycotoxin detection on the basis of recent literature.

Determination of deoxynivalenol in cereals by immunoaffinity clean-up and ultra-high performance liquid chromatography tandem mass spectrometry

An immunoaffinity column (IAC) was prepared with a new deoxynivalenol (DON) monoclonal antibody and used as a clean-up tool before ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analysis of DON in cereals. The developed IAC clean-up method showed high recoveries for DON. They ranged from 61% to 103% in wheat, rice, and millet with intra-day and inter-day variations below 19% and 17%, respectively. The column capacity was 2.86μg DON per mL of gel, and it maintained above 0.68μg/mL of gel after 10 cycles of usage at 2 days intervals. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 0.8μg/kg, respectively. Twenty-one out of 40 analyzed commercial cereal samples were positive at DON concentrations from 7 to 534μg/kg.

Cross-reactivity of some commercially available deoxynivalenol (DON) and zearalenone (ZEN) immunoaffinity columns to DON- and ZEN-conjugated forms and metabolites

Seven commercially available deoxynivalenol (DON) and zearalenone (ZEN) immunoaffinity columns (IACs) were tested for cross-reactivity to conjugated forms (3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, DON-3-glucoside, DON-3-glucuronide, ZEN-glucosides, ZEN-glucuronide) and metabolites (de-epoxydeoxynivalenol, α-zearalenol, β-zearalenol) and nivalenol (NIV), using a semi-quantitative multi-mycotoxin ultra-performance liquid chromatography-tandem mass spectrometry method. The DON IACs showed cross-reactivity for nearly all DON derivatives tested. The ZEN IACs showed limited cross-reactivity to some of the ZEN derivatives. The IACs were evaluated for their potential use as sample clean-up for mycotoxins in serum.

Efficacy of detoxification of deoxynivalenol-contaminated corn by Bacillus sp. LS100 in reducing the adverse effects of the mycotoxin on swine growth performance

Biodetoxification of mycotoxins is a novel strategy to control mycotoxicoses in animals. Bacillus sp. LS100, which transforms deoxynivalenol (DON) to a less toxic chemical de-epoxy DON (DOM-1), was evaluated for its efficacy in reducing the adverse effects of DON on swine growth performance. A feeding trial was conducted in growing pigs with four treatments: (1) corn meal without detectable DON served as control (Non-toxic Corn); (2) Fusarium-infected corn giving a toxic diet containing 5 µg DON g(-1) (Toxic Corn); (3) Toxic Corn detoxified with Bacillus sp. LS100 giving a detoxified diet containing 5 µg DOM-1 g(-1) (LS100-De-toxic Corn); (4) Non-toxic Corn treated with Bacillus sp. LS100 serving as bacterial control (LS100-Non-toxic Corn). During 9 days of exposure to the treatments, pigs on Toxic Corn showed a significant reduction in daily feed consumption, daily weight gain and feed efficiency by 29, 48 and 29%, respectively, compared to pigs on Non-toxic Corn. These parameters of the pigs fed LS100-De-toxic Corn diet were 45, 82 and 32% greater, respectively, than those of pigs fed Toxic Corn diet, and were similar to those pigs fed Non-toxic Corn and LS100-Non-toxic Corn diets. There were no significant differences between the treatments of LS100-Non-toxic Corn and Non-toxic Corn diets, implying that the bacterial isolate might not have significantly affected nutrition and palatability of the feed or had negative effects on the pig's feeding performance. The results have proved that microbial detoxification of DON in contaminated feed can eliminate negative effects of the mycotoxin, and the pre-feeding detoxification approach may be applied in the livestock industry.