A multi-year survey of mycotoxins and ergosterol in Canadian oats.

Canadian oat harvest samples, deliveries to processors, and train shipments from primary elevators were collected from mid-2014 through mid-2017 and analyzed for 26 mycotoxins and the fungal biomarker ergosterol. Of the 26 mycotoxins, 7 were not detected in any sample. The most frequently measured mycotoxins were beauvericin (in over 95% of samples analyzed), followed by tentoxin, culmorin, alternariol, alternariol methyl ether, and deoxynivalenol. Median concentrations of the Fusarium-produced mycotoxins ranged from 68 to 1142 µg/kg for deoxynivalenol, 39 to 188 µg/kg for HT-2 and T-2 toxins, 66 to 232 µg/kg for nivalenol, and less than 35 µg/kg for beauvericin. Median concentrations of the sum of Alternaria-produced mycotoxins were all less than 250 µg/kg. Concentrations of analytes varied among years, as well as among growing areas, for the harvest samples. Ergosterol, Fusarium, and Alternaria mycotoxin concentrations appeared to increase from the west toward the eastern Prairies and the province of Quebec; the differences were not statistically significant though. Ochratoxin A in deliveries and train shipments showed annual cyclic increases in the late summer. The results of the survey demonstrate the general compliance of Canadian oats with existing maximum levels for mycotoxins and indicate that in late summer and in years with increased Fusarium infection, there can be a need for monitoring of ochratoxin A and deoxynivalenol, respectively, to mitigate risks of noncompliant grain.

Fate of Ergot Alkaloids during Laboratory Scale Durum Processing and Pasta Production.

The fate of ergot alkaloids during the milling of durum and subsequent production and cooking of pasta was examined. Durum samples containing varying amounts of ergot sclerotia (0.01⁻0.1% by mass) were milled, and all milling product was analyzed for 10 ergot alkaloids using liquid chromatography with tandem mass spectrometry. Spaghetti was prepared from the semolina obtained during milling. Ergocristine, ergocristinine, and ergotamine were the predominant ergot alkaloids observed in the milling fractions and spaghetti. Approximately 84% of the total ergot alkaloid mass of the whole grain durum resided in the milling product fractions associated with the outer kernel layers (bran, shorts, feeds). No consistent loss of ergot alkaloids was observed during the production or cooking of spaghetti. However, changes in the ratio of R- to S-enantiomers occurred during the milling and cooking of spaghetti. Products containing bran, shorts, and feeds, as well as cooked spaghetti, contained a higher proportion of the less biologically active S-enantiomers. The results of this study emphasize the need to monitor R- and S-enantiomers, and to consider food and feed products, as opposed to whole grain, when assessing any exposure of consumers to ergot alkaloids.

Analysis of quinclorac and quinclorac methyl ester in canola from the 2015 harvest using QuEChERS with liquid chromatography polarity-switching tandem mass spectrometry.

A method using QuEChERS sample preparation with liquid chromatography polarity-switching tandem mass spectrometry was developed and validated for the analysis of quinclorac and its degradation product quinclorac methyl ester in canola seed. The method was used to analyse canola treated with quinclorac, harvest sample composites and samples of canola shipments. Quinclorac residues were present in all samples of canola treated with a quinclorac-containing herbicide that were analysed. Quinclorac was found in 93% of samples, with an average of 0.018 mg kg(-1). All samples contained quinclorac methyl ester, with an average of 0.061 mg kg(-1). The average concentration of total residues (as quinclorac equivalents) on treated canola was 0.075 mg kg(-1), with a range of 0.016-0.124 mg kg(-1). The observed residues were all at least 10 times lower than the Canadian maximum residue limit of 1.5 mg kg(-1). Quinclorac and quinclorac methyl ester were not found in any harvest and export composite samples, which represented the majority of canola grown in western Canada in 2015 and canola exported in late 2015. Even though usage of quinclorac-containing herbicide on canola can result in the presence of low concentrations of residues, the absence of quinclorac residues in harvest and shipment samples suggests that use of quinclorac-containing herbicide was not widespread, and that any residues present were diluted as canola was combined along the grain-handling chain into shipment lots, or segregated and prevented from entering shipment lots.

Reliability and Validity of PAEA End of Rotation™ Examination Scores for Predicting Performance on the Physician Assistant National Certification Examination.

PURPOSE: In 2013, the Physician Assistant Education Association (PAEA) launched its End of Rotation™ examinations for student assessment of core clinical rotation content. Although being similar to the National Board of Medical Examiner's subject examinations ("shelf exams"), these examinations have not been characterized for reliability or validated against outcomes such as the Physician Assistant National Certification Examination (PANCE). This study's objective was to determine whether a composite scale based on all 7 PAEA End of Rotation examinations can be used as an effective measure of comprehensive medical knowledge for physician assistant (PA) students in their clinical year. METHODS: This study was a retrospective analysis of deidentified data gathered by 3 PA programs. Scores for all 7 PAEA End of Rotation examinations and for the PANCE were available for all students in the class of 2014 for all programs, with an overall N = 134. SPSS version 21 was used for descriptive and inferential data analysis. RESULTS: The overall Cronbach alpha for the 7 End of Rotation examination scores was 0.871. Pearson correlation coefficients for the End of Rotation examinations and the PANCE ranged from 0.47 to 0.68 and were statistically significant. Simple regression of a composite 7-item End of Rotation examination average gave an R of 0.810 and an adjusted R = 0.654 (P < .0005), explaining 65% of the variance in PANCE scores. CONCLUSIONS: This study provides solid evidence for the reliability of the composite 7-item End of Rotation score and the validity of using this composite score for the purpose of predicting whether the medical knowledge base in clinical PA students is adequate to pass the PANCE.

Occurrence of Ergot and Ergot Alkaloids in Western Canadian Wheat and Other Cereals.

A new method was developed to analyze 10 ergot alkaloids in cereal grains. Analytes included both "ine" and "inine" type ergot alkaloids. Validation of the method showed it performed with good accuracy and precision and that minor enhancement due to matrix effects was present during LC-MS/MS analysis, but was mitigated by use of an internal standard. The method was used to survey durum and wheat harvested in 2011, a year in which ergot infection was particularly widespread in western Canada. A strong linear relationship between the concentration of ergot alkaloids and the presence of ergot sclerotia was observed. In addition, shipments of cereals from 2010-2012 were also monitored for ergot alkaloids. Concentrations of total ergot alkaloids in shipments were lower than observed in harvest samples, and averaged from 0.065 mg/kg in barley to 1.14 mg/kg in rye. In shipments, the concentration of ergot alkaloids was significantly lower in wheat of higher grades.

Occurrence of ochratoxin A in Canadian wheat shipments, 2010-12.

Randomly selected domestic and export shipments (n = 1907) of Canadian durum and other wheat that occurred between 1 January 2010 and 31 December 2012 were analysed for ochratoxin A (OTA). The majority of samples did not contain OTA above the LOQ of 1 µg kg⁻¹. Only 37% of samples analysed contained quantifiable OTA; the median OTA of the positive results was 2.10 µg kg⁻¹. Canada Western Amber Durum shipments contained OTA more frequently, and at slightly higher concentrations, than Canada Western Red Spring wheat. For both wheat classes the frequency of OTA occurrence and mean concentrations appeared to increase in the lower grades, but these increases were not statistically significant. A periodic trend of a late summer increase of mean monthly OTA concentrations in shipments appears tied to the cycle of producer deliveries of wheat to primary grain elevators.

Single laboratory evaluation of a planar waveguide-based system for a simple simultaneous analysis of four mycotoxins in wheat.

The accuracy and precision of a commercially available system based on an indirect competitive immunoassay and planar waveguide technology was evaluated for the analysis of deoxynivalenol (DON), ochratoxin A (OTA), zearalenone (ZEAR), and T-2 toxin in wheat. The system generally performed well at the tested concentrations that were close to the regulatory limits of DON and OTA in wheat. The mean percent recovery of OTA from certified and in-house reference materials ranged from 90 to 111 %, with a relative standard deviation of 8-16 % (at 4.2, 4.9, and 7.0 µg/kg). Mean percent recoveries of DON ranged from 75 to 103 %, with a relative standard deviation of 14-20 % (at 610, 940, and 1300 µg/kg). As analyte concentrations approached the lower limits of the working range of 3 µg/kg OTA and 400 µg/kg DON, the mean percent recoveries and relative standard deviation increased for both DON and OTA. A lack of reference materials precluded a thorough evaluation of the method for the analysis of ZEAR and T-2. The particular strength of the technology was that multiple mycotoxins were analyzed simultaneously.

Fusarium damage in small cereal grains from Western Canada. 2. Occurrence of fusarium toxins and their source organisms in durum wheat harvested in 2010.

Samples of Canadian western amber durum harvested in 2010 were obtained as part of the Canadian Grain Commission Harvest Sample Program, inspected, and graded according to Canadian guidelines. A subset of Fusarium -damaged samples were analyzed for Fusarium species as well as mycotoxins associated with these species, including deoxynivalenol and other trichothecenes, moniliformin, enniatins, and beauvericin. Overall, Fusarium avenaceum and F. graminearum were the top two most frequently recovered species. Phaeosphaeria nodorum (a.k.a. Septoria nodorum ), F. culmorum , F. poae , F. acuminatum , and F. sporotrichioides were observed in samples as well. All samples analyzed for mycotoxins contained quantifiable concentrations of enniatins, whereas beauvericin, deoxynivalenol, and moniliformin were measured in approximately 75% of the samples. Concentrations in Fusarium -damaged samples ranged from 0.011 to 34.2 mg/kg of enniatins plus beauvericin, up to 4.7 mg/kg of deoxynivalenol, and up to 6.36 mg/kg of moniliformin. Comparisons of enniatins, beauvericin, and moniliformin concentrations to the occurrence of various Fusarium species suggest the existence of an infection threshold above which these emerging mycotoxins are present at higher concentrations. The current grading factor of Fusarium -damaged kernels manages concentrations of these emerging mycotoxins in grain; lower provisional grades were assigned to samples that contained the highest concentrations of enniatins, beauvericin, and moniliformin.

Fusarium damage in cereal grains from Western Canada. 1. Phylogenetic analysis of moniliformin-producing fusarium species and their natural occurrence in mycotoxin-contaminated wheat, oats, and rye.

Harvest samples of common wheat (Triticum aestivum), oats (Avena sativa), and rye (Secale cereale) from producers in western Canada were analyzed for fungal infection by toxigenic Fusarium species and contamination by trichothecenes and moniliformin (MON). Fusarium graminearum and F. avenaceum were the two most frequently isolated species from samples of rye and wheat collected in 2010. F. poae and F. sporotrichioides were more commonly detected in randomly selected oat seeds. Other toxigenic Fusarium species including F. acuminatum, F. culmorum, and F. pseudograminearum as well as Phaeosphaeria nodorum (a.k.a. Septoria nodorum) were recovered primarily from fusarium-damaged kernels of wheat. Pure cultures of F. avenaceum, F. acuminatum, and other related species known to produce moniliformin were isolated from incubated seeds based on micro- and macromorphological criteria. The phylogenetic analysis inferred from partial DNA sequences of the acl1 and tef-1α genes revealed two major clades representing F. avenaceum and F. acuminatum, respectively. These clades comprised all Canadian isolates of the two species and a number of reference cultures studied earlier for their propensity to form moniliformin in vitro and in planta. However, some reference cultures previously reported to produce significant amounts of moniliformin formed minor phylogenetic lineages that represent rather distinct but closely related species. Concomitantly, cereal samples were analyzed for the presence of deoxynivalenol and moniliformin. These two Fusarium toxins were observed most frequently in common wheat, at concentrations up to 1.1 and 4.0 mg/kg, respectively. There was no apparent relationship between moniliformin concentrations and detection of F. avenaceum and F. acuminatum in rye and oat samples. Geographical analysis of the distribution of moniliformin and F. avenaceum and F. acuminatum across the Canadian Prairies also did not indicate a strong relationship.