Study on the possibility of aflatoxin M1 milk contamination from ingestion of contaminated feed by dairy cattle

ICFC 2017 - International Conference on Food Contaminants (Book of Abstracts)GA/EFSA/AFSCO/2016/01-02, from EFSAinfo:eu-repo/semantics/publishedVersio

Mycotoxins production by Aspergillus section Flavi isolated from harvested maize

Mycotoxins are toxic compounds produced by some species of filamentous fungi known to cause serious health problems in humans and animals. In cereals, the key mycotoxigenic fungi in partially dried grains are Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxin A) and some Fusarium species (fumonisins, trichothecenes), being maize is one of the more susceptible commodities. Aflatoxins (AF) produced by Aspergillus section Flavi species and fumonisins produced by Fusarium verticillioides are prominent mycotoxins associated with maize economic losses. Cyclopiazonic acid (CPA) is produced predominantly by A. flavus strains and occurs naturally in a wide variety of crop products as a co-contaminant with AF. In Portugal, maize is one of the most important field crops. In 1999, maize occupied 163 497 ha, with a production of 933 800 tons. The aim of this work was to detect whether the isolated species of Aspergillus section Flavi were AF and CPA producers and whether these mycotoxins were present in post-harvested maize samples. In order to do so, ninety five maize samples were collected from different agroclimatic regions of Portugal. From these samples, 25 grains chosen randomly were plated in 5 Petri dishes with solidified agar, incubated and the Aspergillus section Flavi strains were isolated under stereomicroscope observation. All these strains were screened for AF and CPA production, as described elsewhere (Soares et al, 2010). Also, the maize samples were screened for AF and CPA. The extraction methodology was based on protocols provided by Vicam for aflatoxins (AF), with immunoaffinity clean-up and a chloroform extraction was used for cyclopiazonic acid (CPA). Both methods were validated by analysis of replicate spiked samples with 40 µg/Kg of AF and 4000 µg/Kg of CPA. A matrix blank was also analyzed to determine any residual mycotoxin levels. In conclusion, four hundred and seventeen strains of Aspergillus section Flavi isolated from maize grains from three Portuguese regions were evaluated for AF and CPA production on agar plates. These were found in seventy four samples (78%). CPA and AF were produced by 74% and 40% of the isolates, respectively. Mycotoxin detection of the 95 samples obtained was also performed revealing that 8% of the samples were positive for aflatoxins. CPA was not detected in any sample.Fundação para a Ciência e a Tecnologia (FCT) - SFRH / BD / 37264 / 200

Pronociceptive changes in response properties of rostroventromedial medullary neurons in a rat model of peripheral neuropathy

The spared nerve injury (SNI) model of peripheral neuropathy produces a robust and long-lasting hypersensitivity. Previous behavioural studies suggest that brainstem–spinal pathways originating in or relaying through the rostroventromedial medulla (RVM) contribute to neuropathic hypersensitivity. We determined whether SNI induces changes in response properties of RVM neurons that might influence descending modulation of nociception. RVM neurons included in the study were classified into presumably pronociceptive ON-cells and antinociceptive OFF-cells (giving excitatory or inhibitory responses to noxious stimulation, respectively). Spontaneous activity and the response to cold, pinch and colorectal distension were assessed under light anaesthesia in the rat, 1 week and 8 weeks following nerve injury or sham operation. Spontaneous activity was increased 1 week but not 8 weeks after nerve injury in ON-cells but decreased in OFF-cells at both time points. In the SNI group, cold-evoked responses were enhanced particularly in ON-cells, independent of the postoperative time point. Responses of ON-cells to pinch and visceral stimulation were enhanced 8 weeks but not 1 week following nerve injury, whereas OFF-cell responses to pinch or colorectal distension were not changed. The results indicate that SNI induces pronociceptive changes in spontaneous activities of ON-cells and OFF-cells and peripherally evoked responses of ON-cells that vary with the postoperative time point. Increased ON-cell activity and decreased OFF-cell activity in the RVM are likely to enhance spinal nociception in a tonic fashion, whereas increased responses of ON-cells to peripheral stimulation are likely to enhance ascending nociceptive signals by a positive feedback following peripheral noxious stimulation

Mycotoxins in post-harvest maize in three Portuguese regions

The reduction of yield, quality, and nutritional value of grain cereals by filamentous fungi and subsequent contamination with mycotoxins is of great concern around the world. Mycotoxins are known to cause serious health problems in animals causing weight gain reduction, capillary fragility, reduced fertility, suppressed disease resistance, and even death. Some mycotoxins such as fumonisins, aflatoxins and ochratoxins, in particular, have also been associated with human health problems. The key mycotoxigenic moulds in partially dried grain are Aspergillus flavus(aflatoxins), A. ochraceus (ochratoxins) and some Fusarium species (fumonisins, trichothecenes) on temperate and tropical cereals. Aflatoxins, produced by Aspergillus section Flavi species, and fumonisins, produced by Fusarium verticillioides, are prominent among the mycotoxins associated to maize economic losses (Zea mays L.). The presence of aflatoxins and fumonisins in maize is of particular concern for maize products, as both mycotoxins are heat stable and survive the temperatures used in drying and maize processing. The presence of a given fungus does not mean that the mycotoxin(s) associated with that fungus are also present. There are many factors, especially environmental conditions and agricultural practices, involved in the production of mycotoxins.The aim of this work was to detect whether mycotoxins were present in post-harvested maize. Ninety five maize samples collected from different agroclimatic regions of Portugal (Beira Litoral, Ribatejo, Alto Alentejo) were analyzed by HPLC for mycotoxin contamination. These samples were taken in three different steps of the storage chain and moisture content was measured immediately after sampling. Strains of Aspergillus section Flavi and Aspergilllus section Nigri were isolated after plating in MEA10. Several assays with different solvent mixes and shaking times were tested allowing the development of a simultaneous extraction based in protocols provided by Vicam of aflatoxins (AF), ochratoxin A (OTA) and fumonisins B1 and B2 (FB1 and FB2) with immunoaffinity columns. This method was validated by analysis of replicate spiked samples with 40µg/Kg of AF; 7 µg/Kg of OTA and 200µg/Kg of FB2. Cyclopiazonic acid (CPA) extraction was the one used by Mictotox LTDA. This method was validated by analysis of replicate spiked samples with 4000µg/Kg of CPA. Spiked samples were allowed to equilibrate for 24 hours prior to extraction. In addition, a matrix blank was also analyzed to determine any residual mycotoxin levels. Overall, three batches of duplicate spiked samples and one blank sample were analysed. From the 95 samples obtained 287 strains belonging to Aspergillus section Nigri and 417 strains belonging to Aspergillus section Flavi were isolated. Mycotoxins were detected in 67% the samples. Sixty four percent of the samples were positive for FB1 and FB2 with values below 100µg/Kg (LOD of 0.1µg/Kg). Only 8% of the samples were positive for aflatoxins (LOD of 0.1µg/Kg), being AFB1, AFG1 and AFG2 detected in 5, 5 and 1 sample, respectively. AFB2 was not detected. Levels for AFB1 and AFG1 ranged from 0.1-0.5 µg/Kg. Neither OTA (LOD of 0.04µg/Kg) nor CPA (LOD of 10µg/Kg) was detected in any sample. Validation tests revealed recovery values between 61- 68 % for AF, 70% for OTA, 81 % for FB2 and 83% for CPA.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/37264/200

Mycotoxin detection of harvested maize kernels

Mycotoxins are known to cause serious health problems in animals. Some mycotoxins such as fumonisins, aflatoxins and ochratoxins, in particular, have also been associated with human health problems. Aflatoxins, produced by Aspergillus section Flavi species, and fumonisins, produced by Fusarium verticillioides, are prominent among the mycotoxins associated to maize economic losses (Zea mays L.) (Kumar et al. 2008). There are many factors, especially environmental conditions and agricultural practices, involved in the production of mycotoxins (Chulze, 2010).The aim of this work was to detect whether mycotoxins were present in post-harvested maize. Ninety five maize samples collected from different agroclimatic regions of Portugal (Beira Litoral, Ribatejo, Alto Alentejo) were analyzed by HPLC for mycotoxin contamination. Mycotoxins were detected in 67% the samples. Sixty four percent of the samples were positive for FB1 and FB2. Only 8% of the samples were positive for aflatoxins (LOD of 0.1µg/Kg). Neither OTA (LOD of 0.04µg/Kg) nor CPA (LOD of 10µg/Kg) was detected in any sample

Fungos produtores de micotoxinas

As micotoxinas são metabolitos tóxicos secundários produzidos por alguns fungos filamentosos que surgem de forma natural em produtos agroalimentares em todo o Mundo. As mais relevantes para a segurança sanitária de alimentos são as aflatoxinas, a ocratoxina A, a patulina, as fumonisinas, a zearalenona e o desoxinivalenol, estando a sua presença em alimentos regulamentada. Estas micotoxinas são produzidas principalmente por espécies que pertencem aos géneros Aspergillus, Penicillium e Fusarium, sendo tóxicas para humanos e animais, quando ingeridas em pequenas quantidades. Podem ser carcinogénicas, mutagénicas, teratogénicas, citotóxicas, neurotóxicas, nefrotóxicas, estrogénicas e imunossupressoras. Este trabalho faz uma revisão dos principais fungos produtores destas micotoxinas, das condições em que podem ser produzidas e do seu impacto na segurança alimentar

Um contributo para o estudo da difusão das tic nas escolas com projecto nónio

[Resumo] Já é generalizada a ideia que a escola deve preparar o aluno para as exigencias da vida actual, isto é, corresponder as complexas exigencias da nova era das Tecnologias de Informação e Comunicação. Deste modo, para que a Educação escolar nao se tome obsoleta e para que a sua função primordial de educar o aluno para a vida nao se desvie, é importante repensar as funçoes e métodos da escola. Toma-se necessário uma escola capaz de dotar os alunos de competencias relativas as formas de acessibilidade e de processamento de informaçao. A introdução das Tecnologias da Informação e Comunicação é uma realidade no nosso contexto educativo, por isso, pretende-se esbçar um diagnóstico possível do grau de implementação das novas tecnologias, tendo como referencia o contributo do Programa Nónio Século XXI nas escolas Portuguesas. A renovação é urna exigencia da sociedade actual que se norteia por elevados padroes de qualidade, desde o conhecimento científico e tecnológico até a produtividade em geral, passando pela qualidade da Educação em geral. Os resultados aqui apresentados poderao constituir urna plataforma de recolha de informação e de análise para futuras abordagens desta temática

Towards a Generic Trace for Rule Based Constraint Reasoning

CHR is a very versatile programming language that allows programmers to declaratively specify constraint solvers. An important part of the development of such solvers is in their testing and debugging phases. Current CHR implementations support those phases by offering tracing facilities with limited information. In this report, we propose a new trace for CHR which contains enough information to analyze any aspects of \CHRv\ execution at some useful abstract level, common to several implementations. %a large family of rule based solvers. This approach is based on the idea of generic trace. Such a trace is formally defined as an extension of the $\omega_r^\lor$ semantics of CHR. We show that it can be derived form the SWI Prolog CHR trace