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Alexandrium tamarense is a harmful algal species that can produce saxitoxins, a suite of powerful neurotoxins that bioaccumulate up the food chain and can have severe economic and health impacts. With harmful algal blooms increasing temporally and spatially, it is important for us to understand the relationship between harmful algal blooms and nutrients, particularly nitrogen from anthropogenic sources. To this end, the stable nitrogen isotopic composition (δ¹⁵N) of medium nitrate, algal cells and toxin in both nitrogen-replete and nitrogen-limited batch cultures of A. tamarense were measured in order to assess the potential for using the δ¹⁵N of the toxin as a tracer of the nitrogen source used for growth. A. tamarense cells grown under nitrate-replete conditions were depleted by 1.5‰ relative to the growth medium, and saxitoxin was depleted by 1.5‰ relative to the whole cells. Under nitrate-limiting conditions, the isotopic difference between cells and saxitoxin changed as nitrate in the growth medium was depleted, indicating uncoupling of toxin synthesis and cell growth rates under changing external nutrient conditions. Determination of the absolute magnitude of the isotopic differences between the medium nitrate and either the cells or the saxitoxin was confounded by 1) using two different nitrate sources – one nitrate source was used to grow the inoculum and a different nitrate source was used for the experimental medium - with different ‰ values and 2) the presence of an unidentified, isotopically-light, nitrogen blank in the low-nitrate medium samples. I conclude that STX nitrogen isotope values have the potential to be used as nitrogen source indicators. However, overall fractionation between whole cells and STX is unknown due to the uncoupling between cell growth and STX synthesis observed during my nitrogen-limited experiment. Based on previous research on cell growth and toxin production dynamics under different nutrient regimes, it is also reasonable to assume that the observed results here may differ if a different nitrogen source was utilized by the cells for STX production. Further research could include isotope analysis of cultures grown on different nitrogen sources, such as ammonium and urea; isotopic analysis of additional compounds, such as amino acids; or use of additional stable isotopes, such as C or O. / text

Contexte : L’organisme en développement est très sensible à son environnement. Plusieurs études épidémiologiques ont suggéré la toxicité développementale d’une dizaine de polluants suite à des expositions prénatales. L’objectif général de cette thèse est d’évaluer les conséquences des expositions à des polluants chimiques (consommation de produits de la mer comme vecteur de contamination, solvants organiques et insecticides organophosphorés) pendant la grossesse sur le développement de l’enfant à 2 ans en se focalisant sur le développement neuro-comportemental, le développement respiratoire et immunitaire et le développement staturo-pondéral. Matériel et méthodes : Ce travail s’est appuyé sur la cohorte mère-enfant PELAGIE, mise en place en Bretagne entre 2002 et 2006. Près de 3500 femmes ont été incluses en début de grossesse et environ 1500 couples mère-enfant ont été suivis à 2 ans. Les expositions ont été évaluées en début de grossesse à partir de questionnaires, de matrices emplois-expositions ou de dosage de biomarqueurs d’exposition. Les indicateurs de santé ont été mesurés lors du suivi à 2 ans par questionnaire permettant de recueillir des éléments sur le comportement, les manifestations respiratoires à type de sifflement, les maladies allergiques et la croissance entre la naissance et 2 ans. Résultats : L’exposition professionnelle prénatale aux solvants organiques était associée à des déficits de l’attention/hyperactivité et des niveaux d’agressivité plus importants chez l’enfant à 2 ans. Cette exposition n’était pas associée avec les manifestations respiratoires et allergiques. Nous avons aussi montré que la consommation maternelle de coquillages et crustacés pendant la grossesse était associée à une augmentation du risque d’allergie alimentaire chez l’enfant. Enfin, l’exposition prénatale aux insecticides organophosphorés a été associée à une diminution de la vitesse de croissance en taille à 2 ans. Conclusion : Ce travail renforce l’hypothèse de l’implication de l’exposition prénatale aux polluants chimiques de l’environnement, y compris à faible dose, dans l’origine développementale de la santé et des maladies. / Background: The organism is very sensitive to environment during its developmental period. Number of epidemiological studies has suggested the developmental toxicity of about ten chemical pollutants after prenatal exposure. The general objective of the thesis is to explore the effect of prenatal exposure to certain chemical pollutants (organic solvents, organophosphates pesticides and maternal consumption of fish and shellfish (vectors of pollutants)) on child development at age 2. Methods: This thesis is based on the PELAGIE mother-child cohort that was set up in 2002, in Brittany (FRANCE). In total, 3421 women were included in this cohort at the beginning of pregnancy and 1500 mother- child pairs were followed when the child was 2 years old. Exposures were evaluated at the beginning of pregnancy from questionnaires, job-exposure matrices or measurement of biomarkers of exposure. Health indicators were measured at the 2 years follow-up. At follow-up, questionnaires allowed to obtain information on child behaviour, respiratory manifestations like wheezing, allergies (eczema and food allergy) and growth between birth and the age of two. Results: Prenatal occupational exposure to solvents was associated with higher level of hyperactivity and attention deficit at age 2. This exposure was not associated neither with respiratory nor with allergic manifestations. We also observed that maternal shellfish consumption during pregnancy was associated with a higher risk of food allergy in preschoolers. Finally, higher prenatal exposure to organophosphate pesticides was associated with a decrease height growth velocity at age 2. Conclusion: The present thesis based on the PELAGIE study supported for the hypothesis that prenatal exposure to environmental chemicals may be implicated in the developmental origin of health and diseases.

La Polynésie française et la Nouvelle-Calédonie, îles du Pacifique, ont l’un des taux de cancer de la thyroïde les plus élevés au monde. A l’exception des rayonnements ionisants, aucun autre facteur de risque n’est clairement établi pour ce cancer. Deux études cas-témoins sur le cancer de la thyroïde ont été réalisées en Polynésie française et Nouvelle-Calédonie afin d’étudier les facteurs de risque qui sont encore peu connus. L'objectif de ce travail de thèse est d’étudier le rôle des facteurs anthropométriques et de l’alimentation sur le risque de cancer de la thyroïde dans les îles du Pacifique.En Polynésie française, 229 cas de cancer de la thyroïde diagnostiqués entre 1979 et 2004 et 371 témoins appariés sur l’âge et le sexe ont été inclus. En Nouvelle-Calédonie, 331 cas de cancer de la thyroïde diagnostiqués entre 1993 et 1999 et 412 témoins appariés également sur l’âge et le sexe ont été inclus.Dans l’analyse poolée des deux études cas-témoins, un peu plus de la moitié des Polynésiens et Néo-calédoniens étaient en surpoids ou obèses. Une augmentation du risque de cancer thyroïdien a été mise en évidence avec une taille, un poids, un indice de masse corporelle, et une surface corporelle élevés. Parmi ces facteurs anthropométriques, la surface corporelle joue un rôle dominant dans le risque de cancer de la thyroïde, en particulier à l’âge de 18 ans.Ensuite, nous nous sommes intéressés à l’alimentation des Polynésiens uniquement. Nous avons identifié deux régimes (ou patterns) alimentaires : l’un occidental et l’autre polynésien traditionnel. Le régime « occidental » n’était pas associé à un risque de cancer thyroïdien, alors que le régime « polynésien traditionnel » était faiblement associé à une diminution du risque. Par ailleurs, les résultats ont montré que les Polynésiens avaient une alimentation carencée en iode. Une consommation élevée de poissons et fruits de mer, ainsi qu’un apport alimentaire en iode élevé étaient associés à une diminution du risque de cancer de la thyroïde. Enfin, une consommation élevée de manioc, aliment goitrigène, diminuait le risque de cancer thyroïdien. / French Polynesia and New Caledonia, Pacific Islands, have one of the world’s highest thyroid cancer incidence rates. Except ionizing radiation, no other risk factor is clearly established for this cancer. Two case-control studies on thyroid cancer were conducted in French Polynesia and New Caledonia to investigate the risk factors not still understood. The objective of this thesis is to study the role of anthropometric and dietary factors in the risk of thyroid cancer in the Pacific Islands.In French Polynesia, 229 cases of thyroid cancer diagnosed between 1979 and 2004 and 371 controls matched on age and sex were included. In New Caledonia, 331 cases of thyroid cancer diagnosed between 1993 and 1999 and 412 controls matched also on age and sex were included.In the pooled analysis of the two case-control studies, half of Polynesians and Melanesians were overweighed or obese. An increased risk of thyroid cancer was shown with a high height, weight, body mass index, and body surface area. Among anthropometric factors, BSA plays a dominant role in thyroid cancer risk, in particular at 18 years old.Then, we are interested in the diet only of Polynesians. We have identified two dietary patterns: Western and traditional Polynesian. The pattern “Western" was not associated with a risk of thyroid cancer, while the pattern "traditional Polynesian" was weakly associated with a decreased risk. Moreover, results showed that Polynesians had a diet deficient in iodine. A higher consumption of fish and shellfish, and a higher dietary iodine intake are significantly associated with a decreased risk of thyroid cancer. Lastly, high cassava consumption decreased the thyroid cancer risk.

INTRODUÇÃO: A alergia a camarão é causa comum e potencialmente grave de alergia alimentar IgE mediada, incluindo anafilaxia. Ao contrário de outras alergias alimentares, a alergia a camarão afeta predominantemente adultos e geralmente é vitalícia. Até o momento, não existe terapia específica para a alergia a camarão. Os pacientes necessitam excluir o crustáceo de sua dieta e portar adrenalina auto-injetável, para uso em reações por exposição acidental. A complexidade do perfil alergênico do camarão tem sido cada vez mais reconhecida nos últimos dez anos. A proteína muscular tropomiosina foi o primeiro alérgeno do camarão identificado e é considerada o seu principal alérgeno. Alguns estudos indicam que a tropomiosina apresenta alta especificidade na alergia a camarão, sendo apontada como uma possível e importante ferramenta diagnóstica. OBJETIVO: O objetivo deste estudo foi avaliar sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo da tropomiosina em pacientes brasileiros em restrição alimentar por suspeita de alergia a camarão. MÉTODOS: Selecionou-se 32 indivíduos com suspeita de alergia a camarão, os quais foram submetidos a testes cutâneos de leitura imediata para camarão (extrato) e \"in natura\" (cru e cozido), ácaros e barata. Também foram realizadas dosagens séricas de IgE específica para camarão, tropomiosina de camarão, ácaros e barata americana. Avaliou-se reatividade clínica a camarão através de testes de provocação oral. O camarão utilizado nos testes cutâneos e nos testes de provocação oral foi o Xiphopenaeus kroyeri (sete barbas). Foi realizado Western Blot 1 D dos pacientes alérgicos. Foram realizados cálculos de valor de corte para teste cutâneo de leitura imediata e IgE sérica específica através da utilização da curva ROC. RESULTADOS: Alergia a camarão foi confirmada em 17 pacientes. A IgE sérica específica para tropomiosina de camarão neste estudo apresentou sensibilidade de 58,8%, especificidade de 60%, valor preditivo positivo de 62,5% e valor preditivo negativo 56%. Em comparação com a IgE especifica para camarão e os testes cutâneos para camarão com extrato e \"in natura\", a IgE específica para tropomiosina apresentou a menor sensibilidade e menor valor preditivo positivo. Em sete pacientes alérgicos, a tropomiosina não foi detectada, apontando a importância de outros alérgenos do camarão, avaliados no Western blot. Os testes cutâneos apresentaram diferença estatística significativa entre alérgicos e não alérgicos e foi possível definir um ponto de corte, útil na distinção entre ambos. Os resultados dos valores de corte do teste cutâneo (média) para extrato comercial foram 5,75 mm, para camarão cru 6,75 mm e para camarão cozido 5,00 mm. Todos os pacientes são atópicos. CONCLUSÃO: A IgE específica para tropomiosina neste estudo não apresentou superioridade diagnóstica quando comparada aos testes cutâneos com camarão \"in natura\" e extrato, e a IgE específica para o camarão. Outros alérgenos, além da tropomiosina, devem ser considerados na avaliação diagnóstica para a alergia a camarão / INTRODUCTION: Shrimp allergy is a common and potentially serious cause of food allergy-mediated IgE, including anaphylaxis. Unlike other food allergies, shrimp allergy affects predominantly adults and is usually lifelong. To date, there is no specific therapy for shrimp allergy. Patients need to exclude the crustacean from their diet and carry selfinjectable adrenaline to be used if the reaction begins after accidental exposure. The complexity of the allergenic profile of shrimp has been increasingly recognized in the last ten years. The tropomyosin muscle protein was the first identified shrimp allergen and is considered its main allergen. Some studies indicate that tropomyosin presents high specificity in shrimp allergy, being pointed out as a possible and important diagnostic tool. OBJECTIVE: The objective of this study was to evaluate sensitivity, specificity, positive predictive value and negative predictive value of tropomyosin in Brazilian patients under food restriction due to the suspicion of allergy to shrimp. METHODS: Thirty-two individuals with suspected allergy to shrimp were selected, who underwent immediate skin tests for shrimp (extract) and \"in natura\" (raw and cooked), mites and cockroaches. Serum dosages of IgE specific for shrimp, shrimp tropomyosin, mites and American cockroach were also performed. Clinical reactivity to shrimp was assessed by oral challenge tests. Shrimp used in skin tests and oral challenge tests was Xiphopenaeus kroyeri (seabob). Western Blot 1 D of the allergic patients was performed. Cut-off calculations were performed for immediate-reading skin test and specific serum IgE using the ROC curve. RESULTS: Shrimp allergy was confirmed in 17 patients. Serum IgE specific for shrimp tropomyosin in this study showed sensitivity of 58.8%, specificity of 60%, positive predictive value of 62.5% and negative predictive value of 56%. Compared to shrimp-specific IgE and cutaneous shrimp skin tests with extract and \"in natura\", tropomyosin was not detected, indicating the importance of other shrimp allergens evaluated in the Western blot. The skin tests presented a statistically significant difference between allergic and non-allergic and it was possible to define a cutoff point, useful in distinguishing between both. The results of the cutoff values of the skin test (average) for commercial extract were 5.75 mm, for raw shrimp 6.75 mm and for cooked shrimp 5.00 mm. All patients are atopic. CONCLUSION: The tropomyosin-specific IgE in this study did not present diagnostic superiority when compared to cutaneous tests with in natura shrimp and extract, and shrimp specific IgE. Other allergens, in addition to tropomyosin, should be considered in the diagnostic evaluation for shrimp allergy

Στα πλαίσια αυτής της διδακτορικής εργασίας μελετήθηκαν οι εμπορικά σημαντικότερες περιοχές καλλιέργειας και συγκομιδής οστρακοειδών του Ελλαδικού χώρου. Κατά τη διάρκεια περιόδου 18 μηνών πραγματοποιήθηκε μηνιαία συλλογή δειγμάτων στρειδιών (Οstrea edulis) και μυδιών (Mytilus galloprovincialis), τα οποία συλλέχθηκαν από έξι (6) διαφορετικά σημεία του Ελλαδικού χώρου και αναλύθηκαν για τους εντεροϊούς (EV), τους αδενοϊούς (Adv), τον ιό της ηπατίτιδας Α (HAV), τους ιούς Noro I και II (NLVI και NLVII), για το βακτήριο Ε. coli, καθώς και για σωματικούς κολιφάγους, τους F-sperific RNA βακτηριοφάγους και τους βακτηριοφάγους του Β. fragilis. Επιπλέον αναπτύχθηκαν μέθοδοι τόσο για την ανίχνευση παθογόνων ιών ανθρώπινης προέλευσης στα οστρακοειδή, όσο και για την ανίχνευση των "πιθανών δεικτών" αυτών των ιών. Οι μέθοδοι εξετάστηκαν προκειμένου να αξιολογηθεί η απόδοση καλής ποιότητας από όλα τα εργαστήρια μέσω διεργαστηριακών αναλύσεων. Η μέθοδος που εφαρμόστηκε σε αυτή τη μελέτη για την ανίχνευση των ιών στα οστρακοειδή βασίζεται στην εξαγωγή και την ομογενοποίηση του πεπτικού αδένα με χρήση διαλύματος γλυκίνης, pH 10, απομόνωση των νουκλεϊνικών οξέων και ενίσχυση του γονιδιώματος των ιών που αναλύονται. Για την ανίχνευση του βακτηρίου E. coli χρησιμοποιήθηκε η μέθοδος των πολλαπλών σωλήνων, ενώ για την ανίχνευση των βακτηριοφάγων χρησιμοποιήθηκε η μέθοδος καλλιέργειας διπλοστιβάδας. Για το βακτήριο E. coli, σε σύνολο 138 δειγμάτων, 110 δείγματα (ποσοστό 79,7%) βρέθηκαν να ανήκουν στην κατηγορία Α (MPN/100g σάρκας = <20 έως 220), δηλαδή χαρακτηρίζονται σαν δείγματα χαμηλής μόλυνσης, 25 δείγματα (ποσοστό 18,1%) βρέθηκαν να ανήκουν στην κατηγορία Β (MPN/100g σάρκας = 220 έως 3500), οπότε χαρακτηρίζονται σαν δείγματα μεσαίας μόλυνσης, ακατάλληλα προς κατανάλωση χωρίς να προηγηθεί διαδικασία εξυγίανσης, ενώ μόνο 3 δείγματα (ποσοστό 2,2%) βρέθηκαν να ανήκουν στη κατηγορία C (MPN/100g σάρκας =3500 έως >18000), δηλαδή είναι δείγματα υψηλής μόλυνσης. Οι ιοί που εμφανίζονται με μεγαλύτερη συχνότητα στα οστρακοειδή της Ανατολικής Μεσογείου είναι οι αδενοϊοί (34% των δειγμάτων βρέθηκαν θετικά για τους αδενοϊούς) και ακολουθούν οι εντεροϊοί (16,7% των δειγμάτων βρέθηκαν θετικά για τους εντεροϊούς). Αντίθετα, ο ιός της ηπατίτιδας Α (ποσοστό θετικών δειγμάτων = 4,34%), καθώς και οι ιοί Noro I (ποσοστό θετικών δειγμάτων = 2,1%) και Noro II (ποσοστό θετικών δειγμάτων = 1,47%%) εμφανίζονται σε μικρό ποσοστό δειγμάτων. Τέλος, 80 δείγματα (58%) βρέθηκαν θετικά (παρουσία πλακών βακτηριοφάγων) για τους σωματικούς κολιφάγους, με τον αριθμό των πλακών να κυμαίνεται από 71,4 έως 584800 pfp/100g, 52 δείγματα (37,7%) βρέθηκαν θετικά για τους F-specific RNA βακτηριοφάγους (αριθμός των πλακών από 76,2 έως 17051 p100g) και 33 δείγματα (24%) βρέθηκαν θετικά για τους βακτηριοφάγους του Bacteroides fragilis (αριθμός των πλακών από 194.5 έως 5266,25 pfp/100g). Τόσο για το βακτήριο E. coli όσο και για τους βακτηριοφάγους πραγματοποιήθηκαν διεργαστηριακές αναλύσεις προτύπων, οι οποίες οδήγησαν στο συμπέρασμα ότι οι αντίστοιχες μέθοδοι χαρακτηρίζονται ως αξιόπιστες. Η στατιστική ανάλυση έδειξε ότι το βακτήριο E. coli παρουσιάζει θετική συσχέτιση με τους σωματικούς κολιφάγους, αλλά δεν δείχνει στατιστικά σημαντική συσχέτιση ούτε με τους F-specific RNA βακτηριοφάγους, ούτε με κανέναν από τους ιούς εντερικής προέλευσης. Επίσης, θετική συσχέτιση παρουσίασαν οι αδενοϊοί με τους εντεροϊούς, καθώς και οι σωματικοί κολιφάγοι με τους βακτηριοφάγους του B. fragilis. Η μοναδική συσχέτιση μεταξύ ιών εντερικής προέλευσης και βακτηριοφάγων βρέθηκε για τους αδενοϊούς και τους βακτηριοφάγους του B. fragilis. Εάν αυτό επιβεβαιωθεί σε περαιτέρω μελέτες, τότε η συγκεκριμένη κατηγορία βακτηριοφάγων θα μπορούσε να αποτελέσει έναν καλό δείκτη πρόβλεψης της παρουσίας αδενοϊών σε δείγματα οστρακοειδών. Επιπλέον μελετήθηκε η σχέση που μπορεί να υπάρχει μεταξύ των φυσικοχημικών παραμέτρων και των μικροοργανισμών που εξετάστηκαν. Η επεξεργασία αυτή οδήγησε στο συμπέρασμα ότι το βακτήριο E. coli ανιχνεύεται σε μεγαλύτερα ποσά όταν το διαλυμένο οξυγόνο και η περιεκτικότητα σε άλας του ύδατος είναι αυξημένα. Αντίθετα, αύξηση της θερμοκρασίας οδηγεί σε μείωση της ανίχνευσης του βακτηρίου. Επίσης, η περιεκτικότητα σε άλας φαίνεται να επηρεάζει θετικά και τον ιό της ηπατίτιδας Α, αν και ο μικρός αριθμός θετικών δειγμάτων γι’αυτόν τον ιό δεν μπορεί να επιτρέψει την εξαγωγή ασφαλών συμπερασμάτων. Το pH και το διαλυμένο οξυγόνο των υδάτων οδηγεί σε αύξηση της ανίχνευσης των βακτηριοφάγων του B. fragilis, χωρίς όμως να μπορούμε να ισχυριστούμε ότι κάτι τέτοιο ισχύει, λόγω του μικρού αριθμού θετικών δειγμάτων γι’αυτούς τους βακτηριοφάγους. Τέλος, η αύξηση της θερμοκρασίας των υδάτων φαίνεται να οδηγεί και σε αύξηση της παρουσίας των F-specific RNA βακτηριοφάγων, και το ίδιο παρατηρήθηκε και με την αύξηση του διαλυμένου οξυγόνου στο νερό. Η παρούσα μελέτη αποτελεί την πρώτη διεξοδική έρευνα για την ιογενή κοπρανώδη μόλυνση τον οστρακοειδών στην Ελλάδα. Επιπλέον, αντιπροσωπεύει την πρώτη μελέτη σχετικά με τη αποτελεσματικότητα των οργανισμών - δεικτών ιϊκής μόλυνσης, καθώς και για τη συσχέτιση της μικροβιολογικής επιβάρυνσης των οστρακοειδών με τις φυσικοχημικές παραμέτρους του περιβάλλοντος ύδατος. Η μελέτη κατάλληλων δεικτών που σχετίζονται με την παρουσία εντερικών ιών στα οστρακοειδή οδήγησε σε χρήσιμα συμπεράσματα για τη χρήση της ανίχνευσης των βακτηριοφάγων ως δεικτών ιϊκής μόλυνσης. Εντούτοις, απαιτείται περαιτέρω μελέτη προκειμένου να προσδιοριστεί και η χρήση των βακτηριοφάγων ως δεικτών που θα μαρτυρούν την προέλευση (ανθρώπινη ή ζωική) των εντερικών ιών που ανιχνεύονται στα οστρακοειδή. / In this doctorate investigation, important shellfish growing areas of Greece have been defined and studied. Oysters (Ostrea edulis) and mussels (Mytilus galloprovincialis) were obtained on a monthly basis over an 18 month sampling period. These samples were collected by six (6) different points of Greece and were analyzed for enteroviruses (EV), adenoviruses (Adv), virus of hepatitis A (HAV), Noro viruses I and II (NLVI and NLVII ), bacterium E. coli, as well as for somatic coliphages, F-sperific RNA bacteriophages and bacteriophages of B. fragilis. Moreover, methods were developed for the detection of pathogenic viruses of human origin in the shellfish, as well as for the detection of potential "viral indicators". The methods were examined in order to validate the good quality performance from all the laboratories via interlaboratory analyses. The method that used in this study for the detection of human enteric viruses in the shellfish is based on the export and homogenisation of digestive gland with glycine buffer at pH 10, viral nucleic acid extraction and amplification of the genomes of the analysed human viruses. The procedure applied for detection of E. coli consists on a five tube, three dilution most probable number (MPN) method, while the method for the detection of bacteriophages was the double-agar-layer method. For E. coli analysis, in a total number of 138 samples, 110 samples (79,7%) were found to belong in category A (MPN / 100 g of flesh = < 20 until 220), that it means these samples are characterized as samples of low pollution, 25 samples (18,1%) were found to belong in category B (MPN / 100 g of flesh = 220 until 3500), therefore are characterized as samples of intermediate pollution, inadequate to consumption without precedes process of cleansing, while only 3 samples (2,2%) were found to belong in category C (MPN / 100 g of flesh = 3500 until > 18000), that it means they are samples of high pollution. The viruses that are presented with higher frequency in the shellfish of Eastern Mediterranean are the adenoviruses (34% of samples were found positive for adenoviruses) and follow enteroviruses (16,7% samples they were found positive for enteroviruses). On the contrary, virus of hepatitis A (percentage of positive samples = 4,34%), as well as the Noro I viruses (percentage of positive samples = 2,1%) and Noro II viruses (percentage of positive samples = 1,47%%) are presented in small number of samples. Finally, 80 samples (58%) were found positive (presence of plaques of bacteriophages) for somatic coliphages, with the number of plaques between 71,4 and 584800 pfp / 100 g, 52 samples (37,7%) were found positive for F - specific RNA bacteriophages (number of plaques from 76,2 to 17051 pfp/ 100 g) and 33 samples (24 %) were found positive for the bacteriophages of B. fragilis (number of plaques from 194,5 to 5266,25 pfp / 100 g). Interlaboratory studies involved the testing of reference materials of E. coli and bacteriophages were used as part of the good quality performance assessment program to be applied all over the study, and led to the conclusion that the corresponding methods are characterized by good reliability. According to the statistical analysis of the results, the presence of E. coli seems to be significantly related with the presence of somatic coliphages. However, E. coli do not present significant statistical relation neither with F - specific RNA bacteriophages, nor with all of the viruses of intestinal origin. Also, adenoviruses were significantly related with enteroviruses, as well as somatic coliphages with the bacteriophages of B. fragilis. The unique significant relation between viruses of intestinal origin and bacteriophages was found for the adenoviruses and bacteriophages of B. fragilis. If this is confirmed in further studies, then this category of bacteriophages could constitute a good indicator of forecast of presence adenoviruses in samples of shellfish. Moreover, we studied the relation that can exist between the physic-chemical parameters and the micro-organisms that were examined. This analysis led to the conclusion that E. coli is detected in higher levels when the dissolved oxygen and the salinity of water are increased. On the contrary, increase of temperature leads to reduction of detection of E. coli. Also, the salinity appears to influence positively also virus of hepatitis A, even if the small number of positive samples of this virus cannot allow the export of sure conclusions. The pH and the dissolved oxygen of waters lead to increase of detection of bacteriophages of B. fragilis, but the small number of positive samples for these bacteriophages can’t give safe conclusions. Finally, the increase of temperature of waters appears to lead also to increase of presence of F - specific RNA of bacteriophages, and the same was also observed with the increase of dissolved oxygen in water. This study constitutes the first extensive research for the fecal viral pollution of shellfish in Greece. Moreover, it represents the first study with regard to the effectiveness viral indicators, as well as for the correlation of microbiological parameters of shellfish with the physical-chemical parameters of water. The study of suitable indicators that are related with the presence of enteric viruses in the shellfish led to useful conclusions on the use of detection of bacteriophages as indicators of viral pollution. Nevertheless, further study is required in order to determine also the use of bacteriophages as indicators that will testify the origin (human or animal) of the enteric viruses that are detected in the shellfish.

Norovirus (NoV) is a significant cause of gastroenteritis globally, and the consumption of oysters is frequently linked to outbreaks. Depuration is the principle means employed to reduce levels of potentially harmful agents or toxins in shellfish. The aim of this thesis is to construct mathematical models which can describe the depuration dynamics of water-borne pathogens, and specifically examine the dynamics of NoV during depuration for a population shellfish. Legislation is currently under consideration within the EU by the Directorate-General for Health and Consumers (DG SANCO) to limit the maximum level of NoV that consumers are exposed to via this route. Therefore it is important to the utility of the thesis that any models constructed should incorporate control measures which could be used to implement minimum NoV levels. Doing so allowed calculation of minimum depuration times that would be required to adhere to the control measures incorporated into the models. In addition to modelling the impact on pathogens during the depuration, we wished to gain some insight into how the variability, and not just the mean levels, of water-borne pathogens can be as important with respect to the length of depuration required to minimise any food safety risks to the consumer. This proved difficult in the absence of any data sets that can be used to calculate variability measures, as little data is currently available to inform these values for NoV. However, our modelling techniques were able to calculate an upper limit on the variability of water-borne pathogens that can be well approximated by lognormal distributions. Finally we construct a model which provided linkage between the depuration process and the accretion of pathogens by shellfish while still within farming waters. This model proposed that the pulses of untreated waste waters released by sewage treatment works due to high levels of rainfall would be transmitted into shellfish whilst filter-feeding.

La Lyonnaise est la province gauloise la plus maritime, avec un trait de côte s’étendant sur plus de 3000 km de long. Ce travail de recherche concerne l’habitat dispersé (villae, fermes, ateliers) sur son littoral, du Ier au Vème siècle. Son objectif est de comprendre comment cette forme d’occupation et de gestion de l’espace rural a été adaptée au milieu géographique particulier qu’est le littoral. La question de la diffusion sur la façade Atlantique du phénomène des villae maritimes se pose également. Tout d’abord, les questions de typologie, de configuration et d’architecture des ensembles bâtis sont abordées. Ensuite, l’économie de ces établissements et en particulier l’exploitation des ressources maritimes est analysée. Bien que la documentation disponible soit ancienne et peu détaillée, des opérations archéologiques récentes ont contribué à renouveler les connaissances scientifiques sur le sujet, notamment sur les ateliers de salaisons et de sauces de poissons en Gaule et leurs productions. / With a coastline of at least 3000 kilometers, the Roman province of Lugdunensis is the most maritime area of the Gallic territories. This thesis deals with the occupation of the coastal countryside, dotted with villae, farms and craft workshops, between the 1st and 5th centuries AD. The main objective is to understand how the rural areas were managed and how roman society adapted to and transformed this landscape. This study also addresses the question of the dissemination of “villae maritimae” along the Atlantic coast. Themes covered included the organisation of Roman coastal settlements and their architectural influences, the role of farms in the management and exploitation of marine resources, and lastly, the types of products produced. The archaeological information available for use is extensive although dated, difficult to exploit, and as a such the analysis suffers. However, several recent surveys and excavations have allowed for the collection of new data about Roman salting and fish sauce workshops in western Gaul. Atlantic Coast and English Channel

A pesca é uma atividade desenvolvida há muito tempo, principalmente por comunidades ribeirinhas e costeiras. A atividade pesqueira é considerada masculina por parte do grupo que a desenvolve, devido à exigência da força física no manuseio dos instrumentos e à imprevisibilidade no que se refere à segurança do pescador. No que tange às mulheres, estas ficaram responsáveis, por muito tempo, pelos serviços domésticos e pela extração de mariscos nas proximidades de suas residências. Porém, as mulheres começaram a participar cada vez mais do setor e passaram a lutar por seu reconhecimento perante a comunidade como pescadoras, fato concretizado a partir de seu registro nas colônias e associações de pesca. Nessa perspectiva, a pesquisa teve como objetivo principal analisar a (re) produção social e a dinâmica ambiental do espaço da pesca sob a ótica do trabalho feminino, tendo como foco a territorialidade reconstruída no cotidiano das atividades das marisqueiras da Taiçoca de Fora/SE. Destarte, a relevância da temática está calcada na possibilidade de tornar em evidência grupos e fenômenos que, por muito tempo, foram negados nas discussões acadêmicas e político-sociais. No método fenomenológico, o espaço geográfico é analisado enquanto espaço das experiências vividas, como fenômeno experienciado por homens que nele vivem. Com base nos procedimentos técnicos utilizados, a pesquisa contemplou as seguintes etapas: a) levantamento bibliográfico e documental e b) pesquisa de campo, com a aplicação de entrevistas semiestruturadas, registro fotográfico, observação participante e a aplicação de entrevista em profundidade. O presente trabalho está estruturado em cinco capítulos: O primeiro apresenta a sistematização do projeto de pesquisa. O capítulo dois traz aspectos a respeito da comunidade, evidenciando o uso e manejo do ambiente pelos pescadores da localidade e o conhecimento tradicional como um instrumento de manutenção da atividade. O capítulo três explana a compreensão da participação da mulher no setor pesqueiro. O capítulo quatro retrata as territorialidades das marisqueiras a partir da análise das suas vivências na terra e na água. Por fim, as principais considerações a respeito do trabalho feminino na pesca, buscando responder as questões norteadoras da pesquisa. Portanto, os desafios das mulheres na atividade pesqueira não são poucos, pois ainda são revestidos de preconceitos e pelo pouco espaço na produção científica. É preciso desconstruir e evidenciar onde estão estas mulheres pescadoras e marisqueiras que fazem de seu trabalho verdadeiras lições de vida.

Seafood permits the transmission of many bacterial pathogens. In order to reconcile consumer demands with important safety standards, traditional means of regulating microbial spoilage and safety hazards in foods are combined with novel technologies. These include biological antimicrobial systems, such as the use of lactic acid bacteria (LAB) and/or their bacteriocins, such as Carnobacterium maltaromaticum CS526 and its bacteriocin piscicocin CS526. The aims of this study were to investigate the presence of Listeria monocytogenes in temperate seafood, namely fresh and smoked salmon, fresh and smoked haddock, and fresh mussels and oysters. Additionally, there was an aim to recover, characterise and use bacteriocin-like-substance to control Listeria monocytogenes in cold smoked haddock. Vibrio spp., Enterobacteriaceae representatives, total aerobic heterotrophic counts and Listeria monocytogenes were isolated from commercially prepared smoked and fresh Atlantic salmon, smoked and fresh haddock, live mussels and oysters using selective media and tryptone soya agar (TSA). Vibrio spp. occurred in high densities (>106 CFU gˉ1) in mussels and Enterobacteriaceae representatives were recorded at >106 CFU gˉ1 in fresh salmon. Total aerobic heterotrophic counts in fresh salmon, live mussels and oysters reached 107, > 107, and > 106 CFU gˉ1, respectively. Listeria monocytogenes was recorded at 5.0 x 104 CFU gˉ1 in mussels. In total sixty one bacterial isolates were recovered from the seafood examined. The results revealed 19 genera of bacteria, i.e. Acinetobacter, Aerococcus, Aeromonas, Bacillus, Brochothrix, Carnobacterium, Citrobacter, Corynebacterium, Enterobacter, Escherichia coli, Moraxella, Micrococcus, Pseudomonas, Psychrobacter, Serratia, Shewanella, Staphylococcus, Vibrio and Listeria. The prominent characteristics of fish spoilage isolates were demonstrated by the ability of the isolates to reduce trimethylamine oxide (TMAO) to trimethylamine, and to produce H₂S. Sh. baltica OS185, Aeromonas spp. HB-6, Sh. baltica, Sh. putrefaciens, A. hydrophila HX201006-3, A. salmonicida subsp. achromogenes, A. hydrophila, C. freundii, Enterobacter cloacae were strong producers of TMA and H₂S. The spoilage microorganisms were tested for potential pathogenicity. The result revealed that 6/15 of the spoilage microorganisms produced proteolytic, lecithinase, blood (β and α haemolysin) and elastinase activity, respectively, whereas 7/15 of the spoilage microorganisms showed lipolytic activity. Cell free supernatants, ammonium sulphate precipitated supernatants and semi-purified bacteriocin-like substances of Carnobacterium maltaromaticum MMF-32 and KOPRI 25789 producing strains isolated from commercially prepared smoked salmon were investigated for their potential antimicrobial activity against potentially pathogenic and food spoilage microorganisms. Generally, a broad spectrum of activity was revealed against potentially pathogenic and food spoilage microorganisms in vitro. Cold-smoked haddock treated with bacteriocin producing C. maltaromaticum MMF-32, C. piscicola A9b bacˉ phenotype nonbacteriocin producing strain a mutant of C. piscicola A9b bac+, cell free supernatants, ammonium sulphate precipitated supernatants and semi-purified bacteriocin-like substances was challenged with L. monocytogenes ATCC 19114 up to 103 CFU gˉ1, respectively. Samples were stored at 4 °C for 10 days. L. monocytogenes and total bacterial counts were determined along with changes in total volatile base nitrogen (TVBN) and biogenic amines production as well as texture, colour and odour. Although the study on anti-listerial effects of C. maltaromaticum MMF-32 was not successful, this organism did have a positive effect on retention of firmness and sensory perception in cold smoked haddock.