Toxic tall fescue grazing increases susceptibility of the Angus steer fecal microbiota and plasma/urine metabolome to environmental effects.

Impaired thermoregulation and lowered average daily gains (ADG) result when livestock graze toxic endophyte (Epichloë coenophialum)-infected tall fescue (E+) and are hallmark signs of fescue toxicosis (FT), a disease exacerbated by increased temperature and humidity (+temperature-humidity index; +THI). We previously reported FT is associated with metabolic and microbiota perturbations under thermoneutral conditions; here, we assessed the influence of E+ grazing and +THI on the microbiota:metabolome interactions. Using high-resolution metabolomics and 16S rRNA gene sequencing, plasma/urine metabolomes and the fecal microbiota of Angus steers grazing non-toxic or E+ tall fescue were evaluated in the context of +THI. E+ grazing affected the fecal microbiota profile; +THI conditions modulated the microbiota only in E+ steers. E+ also perturbed many metabolic pathways, namely amino acid and inflammation-related metabolism; +THI affected these pathways only in E+ steers. Integrative analyses revealed the E+ microbiota correlated and co-varied with the metabolomes in a THI-dependent manner. Operational taxonomic units in the families Peptococcaceae, Clostridiaceae, and Ruminococcaceae correlated with production parameters (e.g., ADG) and with multiple plasma/urine metabolic features, providing putative FT biomarkers and/or targets for the development of FT therapeutics. Overall, this study suggests that E+ grazing increases Angus steer susceptibility to +THI, and offers possible targets for FT interventions.

Simultaneous LC-MS/MS determination of aflatoxin M1, ochratoxin A, deoxynivalenol, de-epoxydeoxynivalenol, α and ß-zearalenols and fumonisin B1 in urine as a multi-biomarker method to assess exposure to mycotoxins.

Humans and animals can be simultaneously exposed through the diet to different mycotoxins, including aflatoxins, ochratoxin A, deoxynivalenol, zearalenone, and fumonisins, which are the most important. Evaluation of the frequency and levels of human and animal exposure to these mycotoxins can be performed by measuring the levels of the relevant biomarkers in urine. Available data on the toxicokinetics of these mycotoxins in animals suggest that aflatoxin M(1) (AFM(1)), ochratoxin A (OTA), deoxynivalenol (DON)/de-epoxydeoxynivalenol (DOM-1), alpha-zearalenol (α-ZOL)/beta-zearalenol (ß-ZOL), and fumonisin B(1) (FB(1)) can be used as urinary biomarkers. A liquid chromatographic-tandem mass spectrometric method has been developed for simultaneous determination of these mycotoxin biomarkers in human or animal urine. Urine samples were purified and concentrated by a double cleanup approach, using a multitoxin immunoaffinity column and a reversed-phase SPE Oasis HLB column. Separation of the biomarkers was performed by reversed-phase chromatography using a multi-step linear methanol-water gradient containing 0.5% acetic acid as mobile phase. Detection and quantification of the biomarkers were performed by triple quadrupole mass spectrometry (LC-ESI-MS/MS). The clean-up conditions were optimised to obtain maximum analyte recovery and high sensitivity. Recovery from spiked samples was performed at four levels in the range 0.03-12 ng mL(-1), using matrix-matched calibration curves for quantification. Mean recoveries of the biomarkers tested ranged from 62 to 96% with relative standard deviations of 3-20%. Enzymatic digestion with ß-glucuronidase/sulfatase resulted in increased concentrations of the biomarkers, in both human and pig urine, in most samples containing measurable concentrations of DON, DOM-1, OTA, α-ZOL, or ß-ZOL. A highly variable increase was observed between individuals. Co-occurrence of OTA and DON in human urine is reported herein for the first time.

[Mycotoxin research in humans]. / Investigación del efecto de las micotoxinas en el ser humano.

This study investigates the occurrence of aflatoxins in Ecuador. Early investigators proved the presence of aflatoxins in human and animal food, but the disturbing data lead to the formation of two research teams at Guayaquil University and the Agrarian University of Ecuador to investigate aflaxotins and other mycotoxins in food and their relationship to human health. Because the concept of mycotoxicosis as a result of the secondary metabolites produced by different species of moulds could cause different clinical patterns, the research team includes Aspergillus metabolites found in the urine of a patient with pulmonary aspergilloma. We considered that the body itself could create secondary metabolites. An ELISA method was used to detect mycotoxins with the specific reactive compounds using a company base assay. This allows the detection quantitative of such metabolites in 24 h collected urine. The patient was treated with itraconazole for nine months, after clinical, radiological and aflatoxins testing. We also investigated three other cases in children with a second level of malnutrition and only with vomitoxins results and in three investigated cases of otomycosis caused by Aspergillus niger only in one case traces of aflatoxins were found.