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Thesis (Master, Microbiology & Immunology) -- Queen's University, 2013-10-03 15:17:19.167

Autism spectrum disorder (ASD) is characterized by deficits in social communication and interaction as well as by repetitive patterns of behavior. It is thought to affect 1 in 68 children in the United States, yet researchers do not know what causes it and treatments are primarily focused on alleviating symptoms associated with ASD rather than treating any underlying cause. Various theories have been proposed over the years regarding what causes ASD in the hopes of finding effective treatment options. One of these theories, and the topic of this work, is that the intestinal bacteria play a role in the development of autism. The idea that gut bacteria may play a role in health and disease is one that has been gaining increased interest lately, and this has spread to the field of autism research. Reports of children with ASD suffering from gastrointestinal (GI) issues are widespread, and even the first reports of children with ASD mentioned that some of them experienced GI symptoms or had issues with feeding. While GI symptoms are uncomfortable for any child, they pose special circumstances for those with ASD because these children are likely unable to effectively communicate what they are experiencing. This thesis will first review the prevalence of GI issues in children with ASD as well as discuss studies that have examined if there is a difference between the gut bacteria of children with ASD compared to neurotypical children. As will be shown, many studies have in fact found a significant difference, but these differences vary across studies and a consensus has not been reached. Following this, the link between the gut bacteria and the brain, as well as how this relates to ASD will be discussed. Then, an overview of various treatment studies aimed at targeting the gut bacteria in animal models of ASD as well as in children with ASD will be analyzed. While this field of research is certainly exciting, there is still a lot of work to be done by researchers. For one, the wide range of methodologies used and populations studied introduces variables that could be skewing the results and contributing to the lack of agreement between researchers regarding what bacterial strains might be relevant to ASD. Additionally, just because there is a correlation between certain bacterial strains and ASD does not mean it can be assumed that this is causing the development of ASD in so many children. Nonetheless, the fact that some treatment studies have led to improvements in ASD-related behaviors when targeting the gut bacteria of children indicates that this field of research is worthy of attention and continued support.

Depuis la fin des années 1980, de nombreuses études épidémiologiques ont montré une association positive et indépendante entre les maladies cardiovasculaires et les maladies parodontales. Les maladies parodontales, responsables de bactériémies transitoires et répétées, ont la capacité d’initier ou d’aggraver les lésions d’athérosclérose. Deux mécanismes pathogéniques majeurs sont aujourd’hui avancés. L’un est indirect par augmentation des médiateurs de l’inflammation induite par les parodontites et l’autre est direct lié au microbiote oral. Cette hypothèse majeure repose sur deux mécanismes non exclusifs, la translocation des bactéries parodontales au sein des plaques d’athérosclérose par la circulation générale et sur la modification du microbiote intestinal. L’objectif de la thèse était d'explorer l'association entre l’exposition systémique aux bactéries parodontales et leur présence au sein des plaques d’athérosclérose sur les complications cardio- et neuro-vasculaires chez l’homme. Les résultats obtenus montrent que les bactéries parodontales sont associées à un phénotype vulnérable des plaques d’athérosclérose coronariennes et carotidiennes. Les lésions d’athérosclérose compliquées par des hémorragies intraplaques sont le siège d’une activation plus intense des neutrophiles. Les effets délétères des leucocytes sur les tissus vasculaires sont potentiellement augmentés et entretenus par les bactéries majorant la vulnérabilité à la rupture des plaques d’athérosclérose. La confirmation clinique de la relation biologique entre le microbiote parodontal et les complications cardio- et neuro-vasculaires de l’athérosclérose est une perspective importante de cette thèse. / Since the late 1980s, many epidemiological studies have shown a positive and independent association between cardiovascular disease and periodontal disease. Periodontal disease inducing transient bacteraemia, can initiate or worsen atherosclerotic lesions. Two major pathophysiologic mechanisms are supported by evidence. One is by indirect increase in inflammatory systemic periodontitis-induced mediators and the other is directly related to the oral microbiota. This major hypothesis is based on two non-exclusive mechanisms, the translocation of periodontal bacteria in atherosclerotic plaques by the general circulation and the impact on the gut microbiota.The aim of the thesis was to explore the association between systemic exposure to periodontal bacteria and their presence in atherosclerotic plaques on the cardiovascular and neurovascular complications in human.The results obtained show that periodontal bacteria are associated to a vulnerable phenotype of coronary and carotid atherosclerotic plaques. Atherosclerotic lesions complicated by intraplaque haemorrhage are the trigger of a super activation of neutrophils. The deleterious effects of leukocytes to the vascular tissues are potentially increased and maintained by the bacteria which increase the atherosclerotic plaques vulnerability to rupture.The clinical confirmation of the biological relationship between periodontal microbiota and cardio- and neurovascular complications of atherosclerosis is an important perspective of this thesis.

Ett av fem spädbarn drabbas av kolik under första tre levnadsmånaderna. I övrigt friska spädbarn skriker, gråter och är otröstbara minst tre timmar i sträck per dag mer än tre dagar i veckan. Trots att kolik är ett vanligt förekommande problem för både spädbarn och föräldrar finns det idag ingen effektiv behandling. Etiologin är oklar men rökning och mental ohälsa hos modern prepartum, födoämnesallergi och ett outvecklat magtarmsystem hos spädbarnet tros vara några bidragande faktorer. Denna litteraturstudie granskar åtta artiklar för att dels undersöka skillnaderna i tarmfloran mellan spädbarn med och utan kolik, om skillnaderna kan förklara kolik samt probiotikas effekt vid kolik. Granskade studier visar att förekomsten av Proteobacteria, koliforma bakterier och Escherichia coli är högre hos spädbarn med kolik. Till skillnad från spädbarn utan kolik uppvisar kolikbarn en mindre bakteriell mångfald, mindre kolonisation av Bacteroidetes och de gynnsamma bakteriesläkterna Lactobacillus och Bifidobacterium. Hos ammade kolikbarn som behandlades med den probiotiska bakteriestammen Lactobacillus reuteri DSM 17938 erhölls i två av tre studier  god effekt av probiotika utan några biverkningar där gråttiden reducerats till mer än hälften. Resultatet varierar geografiskt och evidensen kring probiotikas effekt hos flaskmatade spädbarn med kolik är fortfarande bristfällig. Det är oklart om en förändrad tarmflora kan orsaka kolik eller är ett resultat av koliken då tarmfloran är mycket komplex och fler studier inom området behövs. / One out of five infants suffer from colic during the first three months of life. Otherwise healthy infants suffer from severe crying and are unable to be comforted during at least three consecutive hours per day for more than three days a week. Although colic is a common problem for both babies and parents, there is currently no effective treatment. The etiology is unclear, but smoking and  prepartum maternal mental illness, allergies to foods and an undeveloped gastrointestinal system in infants are believed to be contributing factors. This study reviews eight articles that examine the differences in intestinal flora between infants with and without colic, to see if the differences can explain colic and probiotic effect in colicky infants. Reviewed studies show that the prevalence of Proteobacteria, coliforms and Escherichia coli is higher in infants with colic. Unlike infants without colic, colicky infants exhibit a minor bacterial diversity, reduced colonization of Bacteroidetes and the beneficial bacterial genus of Lactobacillus and Bifidobacterium. Breastfed colicky infants treated with the probiotic bacterial strain, Lactobacillus reuteri DSM 17938, obtained, in two out of three studies, a positive effect on colic symtoms without any side effects, where the crying time was reduced to less than half. Results vary geographically and evidence for a probiotic effect on bottle-fed infants with colic is still inadequate. It remains unclear whether an altered intestinal flora can cause colic or is a result of colic as the intestinal flora is very complex and more studies are needed in this area.

Recent 16S rRNA gene sequencing studies of the duodenal and fecal microbiota have revealed alterations in the abundance of specific bacterial groups in dogs with gastrointestinal (GI) disorders. The aim of this study was to establish a panel of quantitative real-time PCR (qPCR) assays for the evaluation of specific bacterial groups in fecal samples of healthy dogs, dogs with chronic enteropathies (CE), and dogs with acute hemorrhagic diarrhea (AHD). Fecal samples from 242 healthy dogs, 118 dogs with CE, and 57 dogs with AHD were analyzed using qPCR assays targeting Faecalibacterium spp., Turicibacter spp., Bifidobacterium spp., Lactobacillus spp., Streptococcus spp., Ruminococcaceae, C. perfringens, E. coli, gamma-Proteobacteria, Bacteroidetes, and Firmicutes). Differences in bacterial abundance among the three groups were evaluated using a Kruskal-Wallis test followed by a Dunn's post-test. A Bonferroni correction was used to correct for multiple comparisons and an adjusted p<0.05 was considered for statistical significance. Faecalibacterium spp., Turicibacter spp., and Ruminococcaceae were significantly decreased in CE and AHD compared to healthy dogs (p<0.001 for all). Lactobacillus spp. and Streptococcus spp. were significantly increased in dogs with CE (p<0.001 for both) when compared to the healthy dogs. In contrast, Lactobacillus spp. and Streptococcus spp. were significantly decreased in dogs with AHD compared to healthy dogs (p<0.01 and p<0.05, respectively) and also when compared to the dogs with CE (p<0.001 for both). C. perfringens and E. coli were significantly increased in dogs with AHD (p<0.001 and p<0.01, respectively), when compared to healthy dogs. E. coli was also significantly increased in dogs with CE when compared to the healthy dogs (p<0.001). Bacteroidetes were significantly lower in dogs with CE compared to healthy dogs (<0.001). Firmicutes were significantly higher in healthy dogs in comparison to dogs with AHD (p<0.05). Bifidobacterium spp. and gamma-Proteobacteria were not significantly different among all three groups of dogs. In conclusion, the qPCR panel employed here revealed a fecal dysbiosis in dogs with CE and AHD when compared to healthy dogs. These results are similar to recently reported findings using molecular sequencing approaches. Quantification of these bacterial groups by qPCR may be a useful adjunct for the diagnosis or monitoring of gastrointestinal disease in dogs.

Biological markers (“biomarkers”) may have applications in inflammatory bowel disease (IBD), a chronic disease of the gastrointestinal tract. Clinicians are presented with several challenges when treating IBD. Instead of performing expensive and invasive endoscopic procedures - if even possible, as resources for these procedures can be limited - biomarkers could be used to diagnose, assess disease activity and prognosis, and guide medical therapy, particularly in situations where novel biologics are involved. At this time, the use of biomarkers is limited, since few have been useful in predicting disease severity, prognosis and therapeutic response in IBD. Previous research cohorts studying biomarkers are limited due to varying heterogeneity between subjects that confounds the results since patients have variable disease courses. The main aim of this work was to evaluate the utility of biomarkers in IBD. To do this, biomarkers were included into a composite score with other patient reported outcomes (PRO) to predict endoscopic disease activity. Next, we examined the role of biomarkers in newly diagnosed IBD. Lastly, fecal calprotectin (FC) was evaluated in healthy pregnant and IBD patients, establishing reference values and practicality in this clinical group. We also studied the relationship between biomarkers and environmental factors, such as fecal microbiota. We hypothesized biomarker concentration would be elevated with increased clinical and endoscopic measures, and predictive of response to medical therapy in newly diagnosed patients. Additionally, we theorized the inclusion of biomarkers into composite scores would outperform existing scoring models in predicting endoscopic severity. Furthermore, FC levels would be below the limit of detection in healthy pregnancy and elevated in IBD pregnancy. The inclusion of biomarkers into composite scoring models outperformed existing clinical scores. In newly diagnosed patients, modest relationships were found between biomarkers and clinical and endoscopic markers of disease. Lastly, the presence of FC was elevated in pregnant IBD and not significant in healthy pregnancy; thus, FC is useful in IBD and pregnancy. Our work confirmed the significance of biomarkers in several clinical areas of IBD, along with the issues presented in recruiting newly diagnosed patients in small research centres. Future work will incorporate biomarkers into medical triage and as an endpoint in nutritional interventions.

Made available in DSpace on 2016-02-05T18:29:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-14. Added 1 bitstream(s) on 2016-02-05T18:33:31Z : No. of bitstreams: 1 000856560.pdf: 7026334 bytes, checksum: 187d889cf3bbf7e7012a8050b181befe (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Dos poços e plataformas de petróleo ao transporte e distribuição de petroquímicos, sempre há o risco de acidentes que resultam em incêndios. Nesses casos são muitas vezes utilizadas espumas formadoras de filme aquoso (AFFF), pois compostos fluorados em grandes quantidades nas misturas das AFFFs contribuem com a capacidade extintora de incêndio. Em situações de emergência, toneladas de AFFF são liberadas no ambiente e, portanto, podem afetar em longo prazo o ambiente mesmo depois do incêndio ser apagado, pois contém substâncias que escoam para corpos d'água. Os flúor-carbonados são altamente resistentes à biodegradação e, por isso, têm prolongada persistência ambiental. As vias de biodegradação dos organo-halogenados são bastante específicas e lentas. Nesse estudo foi determinado o potencial de biodegradação de diferentes microbiotas sobre misturas da AFFF em hidrocarbonetos, e estudado o processo de biotransformação dos compostos presentes na formulação da AFFF. Pela combinação de metodologias foi possível conhecer melhor sobre o impacto dos compostos flúor-carbonados no ambiente. Foram realizados estudos com a técnica de espectrometria de massa, para determinar as vias de biotransformação dos componentes perfluorcarbonados; técnicas respirométricas, para estudar a biodegradabilidade da AFFF em associação com hidrocarbonetos de petróleo; bioensaios com plantas, para determinar a toxicidade da AFFF; e técnicas de biologia molecular, para análise metagenômica de alteração no perfil da comunidade microbiana de solo após a introdução da AFFF ao meio. Os hidrocarbonetos de petróleo influenciaram, durante a aplicação de espumas de incêndio, o processo de transformação de fluorcarbonados, alterando o metabolismo de comunidades microbianas. Em geral, a biotransformação de fluorcarbonados foi mais lenta por uma interferência mútua entre BTEX e AFFF, mas a produção de CO2 foi maior pelo... / From oilrigs extraction to transport and distribution of petrochemicals, there is always the risk of accidents resulting in fires. In such cases, the release of aqueous film forming foams (AFFF) are a usual practice. These compounds are comprised of compounds containing fluorine-carbon, which contribute to their fire extinguishing capabilities when released in large amounts. Tons of AFFF are released into the environment during emergencies and thus causing long term harnessing of the environment even long after the fire is extinguished, since such substances end up in water bodies. Fluorine and carbon bonds are highly resistant to degradation and therefore have long environmental persistence. Biodegradation pathways of organic halogens are quite specific and slow. In this study, we determined the potential microbiota in different biodegradation AFFF mixtures of hydrocarbons, and studied the biotransformation of compounds in the formulation of AFFF. Thus, it was possible to better understand the impact of fluorinated compounds into the environment. A wide variety of techniques was applied, involving a combination of mass spectrometry techniques to determine the biotransformation pathways of perfluorcarbonados components; respirometric techniques to study the biodegradability of AFFF in association with petroleum hydrocarbons; bio-assays to determine the phyto-toxicity of AFFF; and molecular biology techniques for metagenomic analyzes evaluating changes in the profile of soil microbial communities after AFFF was introduced in the medium. It was observed that petroleum hydrocarbons during application of fire foams fluorocarbon influenced the overall biotransformation process, altering the metabolism of the microbial communities. In general, the fluorocarbon biotransformation is slower by a mutual interference between AFFF and BTEX, but the CO2 production is increased by the effect of the perfluorinated surfactant combined with the ...

Orientador: Ederio Dino Bidoia / Banca: Marcelo Henrique Otenio / Banca: Edson Aparecido Abdul Nour / Banca: Dejanira de Franceschi de Angelis / Banca: Maria Aparecida Marin Morales / Resumo: Dos poços e plataformas de petróleo ao transporte e distribuição de petroquímicos, sempre há o risco de acidentes que resultam em incêndios. Nesses casos são muitas vezes utilizadas espumas formadoras de filme aquoso (AFFF), pois compostos fluorados em grandes quantidades nas misturas das AFFFs contribuem com a capacidade extintora de incêndio. Em situações de emergência, toneladas de AFFF são liberadas no ambiente e, portanto, podem afetar em longo prazo o ambiente mesmo depois do incêndio ser apagado, pois contém substâncias que escoam para corpos d'água. Os flúor-carbonados são altamente resistentes à biodegradação e, por isso, têm prolongada persistência ambiental. As vias de biodegradação dos organo-halogenados são bastante específicas e lentas. Nesse estudo foi determinado o potencial de biodegradação de diferentes microbiotas sobre misturas da AFFF em hidrocarbonetos, e estudado o processo de biotransformação dos compostos presentes na formulação da AFFF. Pela combinação de metodologias foi possível conhecer melhor sobre o impacto dos compostos flúor-carbonados no ambiente. Foram realizados estudos com a técnica de espectrometria de massa, para determinar as vias de biotransformação dos componentes perfluorcarbonados; técnicas respirométricas, para estudar a biodegradabilidade da AFFF em associação com hidrocarbonetos de petróleo; bioensaios com plantas, para determinar a toxicidade da AFFF; e técnicas de biologia molecular, para análise metagenômica de alteração no perfil da comunidade microbiana de solo após a introdução da AFFF ao meio. Os hidrocarbonetos de petróleo influenciaram, durante a aplicação de espumas de incêndio, o processo de transformação de fluorcarbonados, alterando o metabolismo de comunidades microbianas. Em geral, a biotransformação de fluorcarbonados foi mais lenta por uma interferência mútua entre BTEX e AFFF, mas a produção de CO2 foi maior pelo... / Abstract: From oilrigs extraction to transport and distribution of petrochemicals, there is always the risk of accidents resulting in fires. In such cases, the release of aqueous film forming foams (AFFF) are a usual practice. These compounds are comprised of compounds containing fluorine-carbon, which contribute to their fire extinguishing capabilities when released in large amounts. Tons of AFFF are released into the environment during emergencies and thus causing long term harnessing of the environment even long after the fire is extinguished, since such substances end up in water bodies. Fluorine and carbon bonds are highly resistant to degradation and therefore have long environmental persistence. Biodegradation pathways of organic halogens are quite specific and slow. In this study, we determined the potential microbiota in different biodegradation AFFF mixtures of hydrocarbons, and studied the biotransformation of compounds in the formulation of AFFF. Thus, it was possible to better understand the impact of fluorinated compounds into the environment. A wide variety of techniques was applied, involving a combination of mass spectrometry techniques to determine the biotransformation pathways of perfluorcarbonados components; respirometric techniques to study the biodegradability of AFFF in association with petroleum hydrocarbons; bio-assays to determine the phyto-toxicity of AFFF; and molecular biology techniques for metagenomic analyzes evaluating changes in the profile of soil microbial communities after AFFF was introduced in the medium. It was observed that petroleum hydrocarbons during application of fire foams fluorocarbon influenced the overall biotransformation process, altering the metabolism of the microbial communities. In general, the fluorocarbon biotransformation is slower by a mutual interference between AFFF and BTEX, but the CO2 production is increased by the effect of the perfluorinated surfactant combined with the ... / Doutor

Submitted by Heitor Rapela Medeiros (heitor.rapela@ufpe.br) on 2015-03-06T14:20:41Z No. of bitstreams: 2 Dissertacao_Tatiana_Silva_SEM_ASSINATURA_04_DE_MAIO_DE_2012.pdf: 845827 bytes, checksum: 19ffcad3fdcf3c9f86b9b8ff26ad5fc0 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-06T14:20:41Z (GMT). No. of bitstreams: 2 Dissertacao_Tatiana_Silva_SEM_ASSINATURA_04_DE_MAIO_DE_2012.pdf: 845827 bytes, checksum: 19ffcad3fdcf3c9f86b9b8ff26ad5fc0 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-02-29 / Devido a grande importância da microbiota no desenvolvimento de parasitas nos invertebrados, muitos estudos vêm sendo desenvolvidos para o melhor entendimento desta interação. Desta forma, a associação entre microrganismos e seus hospedeiros invertebrados, vetores de doenças, está se tornando cada vez mais evidente. Com base nisto, o objetivo do presente estudo foi caracterizar a microbiota bacteriana de caramujos da espécie Biomphalaria glabrata, principal hospedeiro intermediário do Schistosoma mansoni. Para isto, um grupo de caramujos selvagens, provenientes da Vila Sotave em Jaboatão dos Guararapes, PE/Brasil, e um grupo não selvagem, mantido em laboratório, tiveram a sua microbiota caracterizada através da: técnica de coloração de Gram, análise morfológica das colônias em ágar sangue e em ágar Eosina Azul de Metileno, sendo a caracterização confirmada pelo sistema de identificação bacteriana VITEK 2. Foram realizados testes de susceptibilidade aos antimicrobianos, com base no método de difusão em disco. Os antimicrobianos empregados pertencem à classe de ß-lactâmicos, aminoglicosídeos, quinolonas, inibidores da via folato, fenicóis e tetraciclinas. Os resultados mostraram que todas as bactérias foram gram negativas, incluindo 11 gêneros bacterianos, sendo Enterobacter cloacae a espécie predominante em caramujos selvagens, enquanto que, Citrobacter freundii e Aeromonas sobria predominaram no grupo não selvagem. Quanto à susceptibilidade aos antimicrobianos, todos os isolados mostraram-se resistentes ao ß-lactâmico amoxicilina e sensíveis ao meropenem. A partir destes resultados, novas estratégias de controle biológico da esquistossomose podem ser propostas.