The aim of the present investigation was to study the influence of the sympathetic nervous system and of various adrenoceptor agents on enzyme secretion and morphology in rat parotid and guinea-pig submandibular glands. Biochemical methods were combined with electron microscopical techniques. Two different in vitro systems were employed, batch-incubation and microperifusion, to characterize the sympathetically evoked amylase release and its correlation to cyclic AMP. By using various selective β-adrenoceptor agonists and antagonists a dominance of the β1-adrenoceptor over the β2 - in regulating amylase release - was establ ished. Continuous noradrenaline perifusion caused a rapid initial amylase discharge, closely correlated to tissue levels of cyclic AMP; no correlation between the two was observed during the later phase. Prenalterol (a β1-agonist) failed to elevate glandular cyclic AMP. This was in contrast to its potent secretagogic effect. On the other hand, terbutaline (a β2-agonist) was a weak secretagogue but markedly raised the levels of cyclic AMP. Thus, β-adrenoceptor activation may lead to release of large amounts of amylase despite minimal or no increase in cyclic AMP. Moreover, these effects seemed to be dissociated in salivary glands with regard to the β-adrenoceptor subtypes. This was further substantiated by the findings that repeated injections of prenalterol induced qualitative changes in the granule populations, similar to those caused by the non-selective β-agonist isoprenaline. Terbutaline was without effect. However, acinar cells size was increased following both prenalterol and terbutaline treatment. The data suggest that the 3-adrenergic effects on acinar cell size and granule population may be independently regulated. A decreased sympathetic activity of long duration was induced by neonatal or adult extirpation of the superior cervical ganlion on one side. Acinar cell size, as well as granule and amylase content was reduced 9 weeks after neonatal denervation. Ganglionectomy performed in adult animals was without significant effects. The secretory behaviour of neonatally denervated glands was characterized by an increased postjunctional sensitivity to 3-adrenoceptor agonists. Of special interest was the finding that neonatal denervation seemed to transform terbutaline from a partial to a full secretory agonist, thus changing its effects in the direction of those of prenalterol and noradrenaline. Moreover, increased levels of cyclic AMP as well as an enhanced response to DBcAMP were noted in the denervated glands as were intracellular changes. The denervation supersensitivity after neonatal denervation seems to differ from that observed in adult denervated glands. The results of the studies on denervated glands suggest that the sympathetic nervous system plays a fundamental role in the early maturation of the rat parotid gland as well as for the development of the β-adrenoceptor subtypes. / <p>S. 1-34: sammanfattning, s. 35-128: 6 uppsatser</p> / digitalisering@umu

Abstract This thesis aimed at developing methods for tracking the environmental origins of microbial contaminants of the food chain. We worked on three targets: i) environmental mycobacteria ii) toxinogenic Bacillus species iii) post-harvest fungi in strawberry jam. Our aim was to develop methods for early detection of the above contaminants, which have the potential to endanger consumer health. We developed a novel method based on 16S rRNA hybridization for tracking the reservoirs of potentially pathogenic environmental mycobacteria in piggeries and soil. From 1010 to 1012 16S rRNA molecules of environmental mycobacteria were found per gram of peat, wood shavings and straw in piggeries with a high prevalence of infections. These beddings may thus be a source of mycobacteria for pigs. We found 1010–1011 of mycobacterial 16S rRNA molecules per gram of Finnish forest soil, indicating that the soil contained 107–109 mycobacteria per gram. These numbers exceed the previous cultivation-based estimates of mycobacterial content in Finnish soils. To elucidate the role of mastitis in the input of toxinogenic Bacillus into the dairy production chain, milks were sampled from mastitic cows. Twenty-three Bacillus isolates were screened for toxins using the sperm cell motility inhibition assay. Four of the six toxinogenic isolates found were identified as Bacillus pumilus and two as Bacillus licheniformis. The isolates produced toxic substances that were heat-stable (100 °C) and soluble in methanol, thus being of non-protein nature. The extracts prepared from the toxin-producing isolates disrupted the plasma membrane of exposed sperm cells at concentrations 1–15 μg ml-1 (B. pumilus) 20–30 μg ml-1 (B. licheniformis). The toxic action of the mastitis-associated B. licheniformis strains was similar to that of the lipopeptide lichenysin A. The genes for lichenysin synthetase were found in these strains by PCR. This study revealed that heat-stable toxin-producing strains of B. pumilus and B. licheniformis occur in milk of mastitic milking cows. They may enter the dairy production chain when milk of clinically healthy cows recovered from mastitis is sent to dairies. Many foodborne contaminant fungi are known to produce volatile organic compounds. We investigated the suitability of such metabolites as early indicators of fungal contamination of strawberry jam. We found that volatile organic compounds commonly produced by the contaminant fungi in strawberry jam were 2-pentanone, styrene, 3-methyl-1-butanol, 1,3-pentadiene and ethanol. The results indicate that these compounds could be used to detect fungal contamination of jam.

Les défauts d’odeurs, liés à l’accumulation d’androsténone et de scatol dans le tissu adipeux, sont le frein majeur à l’élevage des porcs mâles entiers. L’androsténone est produite par les testicules et le scatol dans le colon. En dehors de la génétique et de l’alimentation, les facteurs de variation ont été peu étudiés.La thèse aborde le problème des odeurs sexuelles sous quatre angles : 1) estimer l’héritabilité des composés odorants du tissu gras et leurs corrélations génétiques avec des indicateurs de santé, du développement sexuel et de l’agressivité ; 2) étudier l’effet de la dominance sur ces composés ; 3) déterminer l’impact d’un état inflammatoire chronique modéré sur le développement sexuel et la concentration en androsténone ; 4) rechercher les effets de conditions d’hygiène contrastées sur la teneur en scatol et analyser l’implication du microbiote intestinalNos résultats confirment l’héritabilité forte des teneurs en composés odorants mais les corrélations génétiques avec les paramètres de santé sont faibles. Une sélection pour réduire la concentration plasmatique en œstradiol et testostérone permettrait de réduire à la fois les teneurs en composés odorants et l’agressivité des porcs. Les porcs de rang de dominance élevé ont une teneur en androsténone supérieure dans le gras. Un état inflammatoire chronique modéré ne semble pas affecter la teneur en androsténone. Enfin, la dégradation de l’hygiène du logement augmente fortement la concentration en scatol, probablement via des changements de composition du microbiote intestinal. / Boar taint, due to the accumulation of androstenone and skatole in the fat tissue, is the major constraint to the production of entire male pigs. Androstenone is produced by the testes. Its synthesis increases during pubertal development. Skatole is produced in the hind gut. Its hepatic catabolism is inhibited by sexual steroids. Apart from genetics and feeding, the factors affecting boar taint have been little studied.The current thesis approaches four aspects of the boar taint problem: 1) the heritability of the fat content of odorous compounds in the fat tissue and their genetic correlations with indicators of health, sexual development and aggressiveness; 2) to study the effect of dominance on the fat content of boar taint compounds; 3) to determine the influence of a moderate chronic inflammatory status on the sexual development and the fat concentration in androstenone; 4) to evaluate the effect of contrasting hygiene conditions on the fat concentration in skatole and, to analyOur results confirm the high heritability of the fat concentrations of boar taint compounds but their genetic correlations with health indicators are low. A selection to decrease the plasma concentrations in estradiol and testosterone should decrease both boar taint compound concentrations and aggressiveness of boars. Boars with a high dominance rank have a higher fat concentration in androstenone. Lastly, the degradation of the housing hygiene conditions strongly increases the concentration in skatole, probably through modifications in gut microbiota composition

La production de viande à moindre coût nécessite de disposer d’animaux robustes, efficaces, capables de s’adapter aux contraintes d’élevage. Ceci requiert l’évaluation de la capacité de l’animal à constituer et restituer ses réserves énergétiques. Ce travail de thèse a donc pour objectif d’identifier de potentiels biomarqueurs sanguins en lien avec la composition corporelle. Pour cela, deux espèces monogastriques sont étudiées, le porc et le poulet. Au sein de chaque espèce, les animaux de deux lignées génétiques (sélection divergente sur la Consommation Moyenne Journalière Résiduelle chez le porc et sur la proportion de gras abdominal chez le poulet) ont reçu des régimes alimentaires contrastés (riches en lipides et en fibres vs. riches en amidon) mais isoprotéiques et isoénergétiques. Les paramètres plasmatiques et le transcriptome du sang ont été étudiés en réponse à ces régimes alimentaires.Les métabolites et hormones plasmatiques sont affectés par le régime chez le porc alors que ces paramètres sont affectés par le régime et la lignée chez le poulet. L’analyse du métabolome associée aux mesures ciblées des concentrations en métabolites et hormones montre que l’association de plusieurs paramètres sanguins explique entre 37 et 75% de la variabilité de la masse adipeuse chez le porc ou le poulet. Pour les deux espèces, le transcriptome du sang est plus affecté par la lignée génétique que par le régime alimentaire. Les porcs et les poulets nourris avec un régime riche en lipides et en fibres, surexpriment le gène codant la forme hépatique d’une enzyme mitochondriale : CP / Meat production at a lower cost requires robust and efficient animals able to adapt to different rearing conditions. This requires assessing animal’s abilities to store and restore its energy reserves. The objective of the current thesis was to identify potential blood markers of body composition. Two monogastric species were studied, pig and chicken. For each species, animals of two genetic lines (divergent selection on Residual Feed Intake in pigs and abdominal fat proportion in chicken) received two diets contrasted in energy sources (high vegetable oils and fibers vs. rich in starch) but isoproteic and isoenergetic. Plasma parameters and the blood transcriptome were studied in response to those diets.Plasma metabolites and hormones were affected by the diet in pigs whereas those parameters were affected by the diet and the genetic lines in chickens. Metabolome analysis, associated with targeted measurement of metabolites and hormones concentrations, shows that the combination of several blood parameters explained between 37 and 75% of the variability of body fat in pig or chicken. For both species, the blood transcriptome was more affected by the line than by the diet. Pigs and chickens fed a diet rich in lipids and fibers, overexpressed the gene encoding the hepatic form of a mitochondrial enzyme: CPT1A. In summary, this work supports the potential use of blood transcriptome to study variations of phenotypes in a dynamic way throughout the life of the animal and to highlight biomarkers for future selection process.

Introduction : Partant du constat qu'il est possible de conserver plus longtemps les denrées alimentaires grâce à un conditionnement sous atmosphère modifiée enrichie en gaz nobles, nous avons développé une stratégie innovante de conservation de transplants rénaux. Nous avons évalué l'effet protecteur d'une solution de conservation saturée en gaz nobles pour la préservation des transplants rénaux.Matériels et méthodes : Dans un modèle d'autotransplantation rénale hétérotopique chez le porc, les transplants prélevés ont été rincés et mis en conservation 30h à 4°C dans du Celsior présaturée en gaz (air, azote, argon 100% ou xénon 100%, n=6 dans chaque groupe) avant transplantation. Les porcs ont été surveillés quotidiennement pendant 21 j.Résultats : L'argon a amélioré la survie (83,3% vs 33,3% avec l'Air, p=0,04) et la reprise de fonction du transplant. Une sortie de tubulopathie significativement plus précoce des transplants a été observé avec l'Argon. Tous les porcs xénon et azote sont décédés. A J21 les transplants argon avaient une meilleure préservation de leur intégrité structurelle cellulaire avec moins d'inflammation, de fibrose interstitielle et d'atrophie tubulaire. Les rapports RAA/TBARS, et d'Hsp 27, étaient significativement plus élevés avec l'argon. Les taux de TNF alpha, Il 6 et 8 ont montré une diminution de la réponse inflammatoire avec l'argon.Conclusion : Nous avons démontré l'effet bénéfique de l'argon sur la reprise précoce de fonction de transplant et en limitant les lésions d'ischémie-reperfusion. Bien que le mécanisme d'action de l'Argon ne soit pas élucidé, il semble que Hsp 27 soit un élément central de la renoprotection. / Introduction: Based on prolonged preservation of perishable food products under modified atmosphere, we developed an innovative method to preserve kidneys during transplantation using nobles gases. We evaluated the protective effect of argon and xenon on preserving kidney graft functionality and integrity in a clinically relevant pig model of transplantation. Methods: The left kidneys of pigs (n=6 per group) were removed, flushed and stored for 30 h in Celsior solution saturated with air, nitrogen, 100% argon, or 100% xenon. Next, autotransplantation and controlateral nephrectomy were performed. The survival rate, renal function, Hsp27, thiobarbituric acid (TBARS), reduced ascorbic acid (RAA), and TNF alpha were analyzed. A histological examination was completed.Results: Argon improved survival (83.3% for argon vs 33.3% for air, p=0.04) and transplant function recovery. All pigs in the nitrogen and the xenon group died. Diuresis recovery occurred earlier in the argon group (n= 5) when compared with the air group (n=2), p=0.05. On day 7 argon transplants had lower serum creatinine levels and a large reduction in primary non function than the air group. Argon-treated tissues showed better cell structural integrity with minor signs of inflammation, fibrosis, and tubular atrophy. The argon group showed significantly higher RAA/TBARS ratios and Hsp27 levels.Conclusion: We demonstrated that modified atmosphere preservation packaging with argon in cold-storage solution improved early transplant function recovery and long-term quality by minimizing IRI in a pig model of prolonged cold-ischemia. The renoprotective effect of argon may involve the Hsp27 pathway.

F. graminearum est l’une des espèces prédominantes en tant que pathogène des céréales en Europe et dans les régions tempérées du monde. Cette moisissure appartient au genre Fusarium qui est l’un des genres qui produit le plus de métabolites secondaires, dont de nombreuses mycotoxines. Cependant, les connaissances sur son génome laissent présager que F. graminearum produit une très grande variété de métabolites qui sont encore inconnus. C’est pourquoi l’objectif de cette thèse a été de caractériser le métabolome de cette moisissure en identifiant de nouveaux métabolites ainsi qu’en étudiant leur toxicité. Pour cela, une méthode analytique combinant la spectrométrie de masse de haute résolution et le marquage des métabolites secondaires avec des isotopes stables a été développée. Celle‐ci à tout d’abord était validée avec le métabolome bien connu d’Aspergillus fumigatus avant d’être appliquée au métabolome de F. graminearum. Cette méthode a permis d’identifier 37 nouveaux métabolites, dont les fusaristatines A, C et D qui on été détectées pour la première fois chez F. graminearum. Le deoxynivalenol (DON) est une mycotoxine majeure produite par F. graminearum, c’est pourquoi sa toxicité a été comparée in vivo sur un modèle porcin à celle d’un mélange de fusariotoxines. Les résultats de cette étude ont montré une toxicité bien différente du mélange par rapport au DON seul, que ce soit par rapport à la performance des animaux ou à leur réponse immunitaire. Ceci suggère que certaines des fusariotoxines présentes dans le mélange auraient des répercutions biologiques et donc que leur toxicité reste encore à être élucidée. De plus, l’importance de la caractérisation de la toxicité du métabolome de F. graminearum a été soulignée par les résultats obtenus dans une seconde étude, qui ont révélés une possible implication du DON dans les maladies inflammatoires chroniques de l’intestin par l’intermédiaire des lymphocytes Th17. / F. graminearum is one of the most predominant cereal pathogen in Europe and temperate regions of the world. It belongs to the genera Fusarium, which is one of the most important in terms of the production of secondary metabolites, among which stand several mycotoxins. However, recent advances on the study of its genome suggest that only a small fraction of the secondary metabolites produced by F. graminearum have been identified so far. Therefore, the main objective of this thesis was to characterize the metabolome of this fungus by identifying new metabolites and by analyzing their toxicity. First, an analytical method combining high resolution mass spectrometry and isotopically labeled secondary metabolites was developed. The method was validated with the well known metabolome of Aspergillus fumigatus before it was applied to F. graminearum. As a result, 37 new metabolites were identified such as fusaristatin A, C and D, which were detected for the first time in the metabolome of F. graminearum. Deoxynivalenol (DON) is one of the major mycotoxins produced by this fungus. Therefore, its toxicity was compared to that of a blend of fusariotoxins in vivo in a pig model. The results of this study showed different effects of the blend compared to DON alone on animal performances and immune response. This suggests that some of the fusariotoxins present in the blend could be biologically active and their toxicity should be further investigated. Toxicity of the metabolome of F. graminearum has also been highlighted by the results of a second study which showed a possible implication of DON on the appearance of inflammatory bowel diseases by the action of Th17 lymphocytes.

La conservation de la biodiversité génétique du cochon d’Inde (Cavia porcellus) est importante en tant qu’animal de consommation endémique de la région andine ainsi qu’en tant qu’animal modèle précieux pour la recherche biomédicale.L’objectif de ce travail était de mettre en place les protocoles qui permettront une conservation ex situ des ressources génétiques de cette espèce par la voie femelle. Les étapes nécessaires à la concrétisation d’un projet de cryobanque sont :- la maîtrise de la production d’embryons grâce à des traitements hormonaux de synchronisation du cycle œstral et de superovulation des femelles,- la cryoconservation dans l’azote liquide des embryons obtenus et leur transfert dans des femelles receveuses.Une méthode standardisée de synchronisation des chaleurs basée sur l’administration d’altrenogest per os pendant 15 jours a été définie. Les chaleurs des femelles donneuses et receveuses d’embryons apparaissent dans les 4 à 5 jours qui suivent l’arrêt du traitement de ce progestagène.Des traitements de superovulation basés sur 3 injections à 24 heures d’intervalle d’hMG, ou 6 injections à 12 heures d’intervalle de FSH-recombinante humaine, permettent une augmentation du taux d’ovulation de l’ordre de fois 3 à fois 4 par rapport à des femelles non-traitées. Toutefois les réponses au traitement restent variables et il faudra réitérer l’expérience sur de plus grands lots d’animaux afin d’ajuster les doses et les moments d’application.La méthode de congélation lente, utilisant l’éthylène glycol comme cryoprotecteur, a permis d’obtenir des taux de survie embryonnaire satisfaisants (70,3%). La méthode de vitrification a également donné de bons résultats, avec un taux de survie embryonnaire de 41,7%.Le premier transfert au monde d’embryons frais réalisé avec succès dans une femelle receveuse préalablement synchronisée a été obtenu lors de ce travail. Les transferts d’embryons décongelés n’ont pas encore donné lieu à des gestations. / The preservation of the guinea pig (Cavia porcellus) genetic biodiversity is important as a native source of protein for many highlanders in the Andean region and as a precious laboratory animal for biomedical research.The aim of this work was to establish the protocols that will enable an ex situ preservation of the genetic resources of this species by the female way.The necessary steps for the achievement of a cryobank project are:- the control of the embryo production thanks to hormonal treatments to synchronize the estrous cycles and to superovulate the females,- the cryopreservation in liquid nitrogen of the obtained embryos and their transfer into recipient females.A standard method for synchronization of heat periods based on the per os administration of altrenogest during 15 days has been defined. The heat periods of the females, donors and recipients of embryos, appears 4 to 5 days after the end of the progestagen treatment. Superovulation treatments, based on 3 injections at 24-hour intervals of hMG or 6 injections at 12-hour intervals of human recombinant-FSH, lead to an increase of the ovulation rate of about 3 to 4 times when compared to untreated females. However, the responses to the treatments remain variable and further studies involving a larger number of animals should be carried out in order to adjust the dose and the moment of application of the treatment.The slow-freezing method, using ethylene glycol as cryoprotectant, enables the attainment of a satisfactory in vitro embryo survival rate (70,3%). The vitrification method also gives good results, with a 41,7% in vitro embryo survival rate.The first successful transfer of fresh embryos into a synchronized recipient female has been achieved in this study. The transfers of frozen-thawed embryos did not yet lead to gestation.

Studies in zoo-archaeological Neolithic contexts is the study of early animal domestication in relation to humans transitioning into a more sedentary species. Research and documentation are vital for reconstructing the mechanisms behind the threshold event. In this thesis, teeth of Suidae have been documented, analysed and compared osteologically and interpreted cross-culturally. In addition, aDNA, isotope, coat colour and physical mammal size affecting factor studies are presented to contextualise this thesis. Primary osteological methods are Mandibular Wear Stage (MWS), Linear Enamel Hypoplasia (LEH) recordings and lower jaw third molar (M3) length measurement. These methods can detect biometric domestication markers. The analysed Suidae teeth are from the Middle Neolithic site of Ajvide, Gotland, Sweden. A collection of modern wild boar act as Control sample. These teeth are compared primarily with known domestic pig teeth sample statistics from the British Late Neolithic site of Durrington Walls, Wiltshire, United Kingdom. Results indicate that the Middle Neolithic Pitted Ware culture (PWC) on Gotland hunted during winter and kept limited numbers of captive wild boars as totemic animals (pets) possibly bound to land and ancestry. However, an exact reconstruction of the PWC pig pet keeping practices are uncertain due to human-pig relationships being highly dynamic. Intensified pig hunting, not pet keeping should be considered early domestication. Domestication carries with it detectable biometric markers, which seem to be rare in the Neolithic. The cross-cultural comparisons on traditional pig ‘low-intensity husbandry’ can attest to a human-pig relationship of hunter-gatherers keeping captive wild animals. The pig was not a staple food for the PWC and thus not intensively hunted, rather pigs were rare ritualistic commodities and likely highly praised. Perpetuating this human-pig relationship could have been maintained by PWC ‘big men’ that engaged in socio-political lavish giveaways at festivities and funerals, thus ‘hogging wealth’, but never domesticated the pig. / Studier i neolitiska zoo-arkeologiska sammanhang är undersökningar av tidig domesticering av djur i förhållande till mänsklighetens övergång till en mer stillasittande art. Forskning och dokumentation är avgörande för att rekonstruera mekanismerna bakom övergången. I denna uppsats har svintänder dokumenterats, analyserats och jämförts osteologiskt och tolkats tvärkulturellt. Studier i aDNA, isotop, pälsfärg och fysiska storleksfaktorer hos däggdjur presenteras också för att kontextualisera denna uppsats. Primära osteologiska metoder är tandslitage i underkäke (MWS), linjär emaljhypoplasi (LEH) och underkäkens tredje molar (M3) mätningar. Dessa metoder kan finna biometriska domesticeringsmarkörer. De analyserade svintänderna kommer ifrån den mellanneolitiska lokalen Ajvide, Eksta socken, Gotland. En samling moderna vildsvin agerar kontrollmaterial. Dessa tänder jämförs i första hand med kända domesticerade stenåldersvin från den Brittiska senneolitiska lokalen Durrington Walls, Wiltshire, Storbritannien. Resultaten indikerar på att den mellanneolitiska gropkeramiska kulturen (GRK), jagade på Gotland under vinterhalvåret och tog tillfånga ett begränsat antal svin som husdjur (totemdjur). Troligen togs svin tillfånga av olika ’hus’ till följd av att svinet var bundet till land och förfäder. En exakt rekonstruktion av GRKs svinhållningspraktik är dock osäkert på grund av att människo-svin relationer är dynamiska. Intensifierad svinjakt, inte tillfångatagandet av enstaka djur bör betraktas som tidig domesticering. Domesticering medför speciella biometriska markörer som är ovanligare i neolitisk tid. De tvärkulturella jämförelserna i traditionell "lågintensiv svinhållning" kan intyga på ett sådant förhållande mellan jägare-samlar grupper och vildsvin. Även om svinet inte var en basföda åt GRK, och därmed inte intensivt jagade, var svinen sällsynta ritualistiska handelsvaror och troligen högt värdesatta. Gropkeramiska "stormän" kan ha varit de drivande bakom denna praktik. Dessa ”stormän” engagerade sig i sociopolitiska aktiviteter, festligheter och begravningar, och därmed hade "hamstrat välstånd", men domesticerade aldrig svinet.

Les mycotoxines sont des métabolites secondaires des moisissures qui peuvent naturellement contaminer de nombreuses denrées alimentaires, notamment les céréales. Dans les travaux de thèse, nous nous sommes intéressés à deux mycotoxines majeures produites par des champignons du genre Fusarium, le Déoxynivalénol (DON) et la Fumonisine (FB). Les objectifs de la thèse ont été de déterminer les effets individuels et combinés d’une contamination en DON et FB chez le porc, une espèce cible et sensible aux mycotoxines. Les effets sur les fonctions immunitaires lors d’un challenge antigénique ainsi que sur les fonctions intestinales ont été évalués. Par ailleurs, dans le cadre d’un partenariat avec un industriel, nous avons évalué in vivo les effets de méthodes de détoxification par biotransformation et ciblant spécifiquement ces deux toxines. Chez le porc, l’ingestion d’aliments contaminés avec de faibles doses de mycotoxines (DON, 3 mg/kg ; FB, 6 mg/kg) a provoqué des lésions tissulaires (foie, reins et poumons) et a fortement altéré la mise en place d’une réponse immunitaire spécifique de l’antigène (expression des cytokines, prolifération des lymphocytes et anticorps spécifiques). Les animaux ont été significativement plus affectés après la consommation du régime co-contaminé, et l’interaction a pu être considérée comme additive. De plus, les paramètres intestinaux examinés ont révélé des changements dans la morphologie, dans le profil de sécrétion des cytokines et dans l’adhésion cellulaire. L’interaction des deux toxines a pu ici être caractérisée comme moins qu’additive. Les approches de détoxification biologique proposées par l’industriel étaient basées sur la transformation par voie enzymatique du DON et des FB, à partir d’un microorganisme entier et d’une enzyme respectivement. La stratégie d’élimination des FB a suscité un intérêt plus important étant donné que cette méthode est non commercialisée et en cours de développement. Ainsi, la toxicité du produit d’hydrolyse de la FB1 (mycotoxine principale de la famille des FB) obtenu initialement par traitement enzymatique, a été comparée in vivo à celle de la molécule mère la FB1. Les résultats ont montré que l’hydrolyse de la FB1 réduisait fortement la toxicité hépatique et intestinale chez les porcelets. L’expérimentation animale avec le DON et la FB, seuls ou en combinaison a ensuite été reproduite afin de déterminer l’efficacité d’hydrolyse de ce procédé chez le porc après incorporation de l’enzyme dans les aliments contaminés. Dans ces aliments, le microorganisme entier ciblant le DON avait également été inclus. La nette diminution du marqueur d’exposition des FB et la neutralisation partielle ou totale des effets ont suggéré que le procédé avait fortement réduit la biodisponibilité des FB dans le tractus gastro-intestinal. Cette observation a aussi été en partie confirmée pour l’approche de dégradation du DON. La biotransformation par voie enzymatique des mycotoxines représente ainsi une stratégie biotechnologique prometteuse dans la lutte contre ces contaminants. / Mycotoxins are secondary metabolites of fungi that are natural contaminants of several commodities, in particular cereals. In the present work, we focused on two major mycotoxins produced by the Fusarium genus, Deoxynivalenol (DON) and Fumonisin (FB). The main objectives of the thesis were to determine the toxic effects of individual and combined DON and FB contamination in pig, a target species highly sensitive to mycotoxins. The effects on the immune functions following an antigenic challenge and also on the intestinal functions were evaluated. Besides, within the framework of an industrial partnership, we evaluated in vivo the effects of detoxifying methods by biotransformation and targeting specifically these two toxins. In pigs, ingestion of contaminated feeds with low doses of mycotoxins (DON, 3 mg/kg ; FB, 6 mg/kg) triggered tissular lesions (liver, kidneys and lungs) and strongly impaired the establishment of the antigenic immune response (cytokines expression, lymphocytes proliferation and specific antibodies). Animals consuming the cocontaminated diet were more affected and the interaction could be considered as additive. In addition, changes in morphology, in profile of cytokines secretion and in cell adhesion were observed at intestinal level. The interaction here could be characterized as less than additive. The biological detoxification approaches proposed by the industrial were based on the transformation by enzymatic way of DON and FB, from intact microorganism and enzyme respectively. We paid a particular attention to the strategy of FB removal as this method is not marketed and still in development. Therefore, the toxicity of the hydrolysis product of FB1 (major mycotoxin in the FB group) initially obtained by enzymatic way, was compared in vivo to the toxicity of the parent compound FB1. Results showed that the hydrolysis of FB1 strongly reduced the toxicity in piglets at intestinal and hepatic levels. The animal experiment with DON and FB, alone or in combination was then repeated in order to determine in pigs the hydrolysis efficiency of this process when enzyme was incorporated in contaminated feeds. In these feeds, the intact microorganism toward DON was also included. The marked decrease of the biomarker of exposure to FB and the partial or total counteraction of the effects suggested that the process had greatly reduced the FB bioavailability in the gastrointestinal tract. This observation was also in part confirmed for the method degrading DON. The biotransformation method of mycotoxins by enzymatic way represents therefore a promising biotechnological strategy in the control of these contaminants.

O interesse por espécies animais não convencionais, para a suplementação de proteína animal, é crescente, particularmente nos países africanos e asiáticos, porém, a utilização dessas fontes de alimento ainda é pouco documentada e quase não se sabe sobre as condições microbiológicas das carnes disponíveis para consumo. Este estudo avaliou as condições microbiológicas das carnes de capivara (Hydrochaeris hydrochaeris), cateto (Tayassu tajacu) e javali (Sus scrofa scrofa) in natura comercializadas no Brasil, município de São Paulo. Um total de vinte e sete amostras de carne de capivara, cateto e javali foram analisadas em laboratório e verificado o grau de contaminação por mesófilos aeróbios totais, psicrotróficos, Staphylococcus aureus, Clostridium sulfito-redutores, coliformes totais e fecais e Salmonella. 22% das amostras de carne de cateto apresentaram-se impróprias para o consumo humano devido à presença de Salmonella. 11% das amostras das carnes de capivara e javali e 22% das amostras de cateto apresentaram contagens elevadas de S. aureus, maiores que o limite máximo estabelecido pela resolução RDC nº12 da Agência Nacional de Vigilância Sanitária (ANVISA) de 02 de janeiro de 2001, para produtos cárneos crus, resfriados ou congelados, uma vez que a resolução não cita tais padrões para carne in natura. Por apresentarem contagem de S. aureus superiores aos padrões estabelecidos, tais amostras são consideradas em condições higiênico-sanitárias insatisfatórias. A análise estatística descritiva apresentou um elevado coeficiente de variação entre as 9 amostras analisadas para cada tipo de carne. Esse alto grau de variação mostra que as condições microbiológicas das amostras não apresentaram uniformidade no decorrer das análises. / The interest for non-conventional animal species, for the supplementation of animal protein is growing, although this food source is little documented. This study has evaluated the microbiological conditions of capybara (Hydrochaeris hydrochaeris), collared peccary (Tayassu tajacu) and wild boar (Sus scrofa scrofa) raw meat sold in São Paulo city. A total of twenty-seven samples were evaluated in a laboratory to find out the contamination value by: mesophiles aerobic, psychrotrophs, Staphylococcus aureus, Clostridium sulfito-redutores, coliforms group and Salmonella. 22% of collared peccary meat samples were improper to human consumption due to the Salmonella presence. 11% of the samples of the capybara meats and boar and 22% of the collared peccary samples presented high counting of S. aureus, larger than the maximum limit established by the resolution RDC nº12 of the National Agency of Sanitary Surveillance (ANVISA) of January 02, 2001, for raw meat products, colds or frozen, once the resolution doesn't mention such patterns for raw meat. These samples showed unsatisfactory hygenic-sanitary conditions by presenting S. aureus counting higher than the maximum limit.