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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Tobacco Use and Impact of Tobacco-Free Policy on University Employees in an Environment of High Tobacco Use and Production

Veeranki, Sreenivas P., Mamudu, Hadii M., He, Yi 01 March 2013 (has links)
Objective: To assess occupational tobacco use and the impact of a tobacco-free policy in the Central Appalachia, an environment characterized by high tobacco use and production. Methods: This study was an Internet-based survey conducted on 2,318 university employees. Descriptive, chi-square, and logistic regression statistics were performed. Unadjusted and adjusted odds ratios (AOR) with respective 95 % confidence intervals (CI) were reported. Results: The survey response rate was 50.8 %; of the respondents, 9.0 % were current smokers. Smoking prevalence among faculty, administrators/professionals, and clerical/support staff was 6.1, 8.1, and 13.1 %, respectively. While those respondents aged 30-39 years showed a significantly increased likelihood of being a current smoker (AOR 5.64, 95 % CI 1.31-9.26), knowledge that secondhand smoke is harmful (AOR 0.22, 95 % CI 0.07-0.70) and support for tobacco-free policy (AOR 0.11, 95 % CI 0.04-0.27) decreased the likelihood. Conclusion: Low tobacco use among faculty and administrators confirmed the relationship between tobacco use and socio-economic status, even in a tobacco-producing environment. Disaggregation of tobacco use data assists the public health community in the efficient allocation of efforts and resources for cessation programs to reduce tobacco use in such environments.
152

Tobacco Use and Impact of Tobacco-Free Policy on University Employees in an Environment of High Tobacco Use and Production

Veeranki, Sreenivas P., Mamudu, Hadii M., He, Yi 01 March 2013 (has links)
Objective: To assess occupational tobacco use and the impact of a tobacco-free policy in the Central Appalachia, an environment characterized by high tobacco use and production. Methods: This study was an Internet-based survey conducted on 2,318 university employees. Descriptive, chi-square, and logistic regression statistics were performed. Unadjusted and adjusted odds ratios (AOR) with respective 95 % confidence intervals (CI) were reported. Results: The survey response rate was 50.8 %; of the respondents, 9.0 % were current smokers. Smoking prevalence among faculty, administrators/professionals, and clerical/support staff was 6.1, 8.1, and 13.1 %, respectively. While those respondents aged 30-39 years showed a significantly increased likelihood of being a current smoker (AOR 5.64, 95 % CI 1.31-9.26), knowledge that secondhand smoke is harmful (AOR 0.22, 95 % CI 0.07-0.70) and support for tobacco-free policy (AOR 0.11, 95 % CI 0.04-0.27) decreased the likelihood. Conclusion: Low tobacco use among faculty and administrators confirmed the relationship between tobacco use and socio-economic status, even in a tobacco-producing environment. Disaggregation of tobacco use data assists the public health community in the efficient allocation of efforts and resources for cessation programs to reduce tobacco use in such environments.
153

University Personnel's Attitudes and Behaviors Toward the First Tobacco-Free Campus Policy in Tennessee

Mamudu, Hadii M., Veeranki, Sreenivas P., He, Yi, Dadkar, Sumati, Boone, Elaine 01 August 2012 (has links)
In 1994, Tennessee, the third largest tobacco-producing state in the U.S., preempted tobacco regulation. However, in 2005, higher educational institutions were exempted from this preemption and the 2007 Non-Smoker Protection Act required educational facilities to create smoke-free environment. To this date, while all higher educational institutions have some sort of smoke-free policy, East Tennessee State University is the only public institution with a tobacco-free policy. We investigated attitudes and behaviors of the university personnel, the most stable segment of the population, toward the policy and compliance with it using an internet-based survey. All employees (2,318) were invited to participate in a survey; 58% responded. Bivariate analyses found 79% of the respondents favored the policy. Multiple variable logistic regression analyses found support for the policy was higher among females [OR = 3.14; 95% CI (1.68, 5.86)], administrators/professionals [OR = 3.47; 95% CI (1.78, 6.74)], faculty [OR = 2.69; 95% CI (1.31, 5.53)] and those affiliated with the College of Medicine [OR = 4.14; 95% CI (1.45, 7.85)]. While only 67 employees (5.6% of sample) reported they have not complied with the policy, around 80.8% reported observing someone engaged in non-compliance. The high level of support for the policy suggests it should be promoted throughout the higher education system and nationwide. At the same time, in preemptive states, higher educational institutions should be targeted as venues for strong tobacco-free policies. The gap in compliance, however, implies in tobacco-friendly environments, a tobacco-free campus policy with no reporting and enforcement mechanisms could lead to high levels of non-compliance.
154

Temperature-dependent Regulation of Sugar Metabolism During Cold Stress Responses

Zhao, Lu 07 July 2017 (has links)
No description available.
155

Functional Scaffolding for Musical Composition: A New Approach in Computer-Assisted Music Composition

Hoover, Amy K. 01 January 2014 (has links)
While it is important for systems intended to enhance musical creativity to define and explore musical ideas conceived by individual users, many limit musical freedom by focusing on maintaining musical structure, thereby impeding the user's freedom to explore his or her individual style. This dissertation presents a comprehensive body of work that introduces a new musical representation that allows users to explore a space of musical rules that are created from their own melodies. This representation, called functional scaffolding for musical composition (FSMC), exploits a simple yet powerful property of multipart compositions: The pattern of notes and rhythms in different instrumental parts of the same song are functionally related. That is, in principle, one part can be expressed as a function of another. Music in FSMC is represented accordingly as a functional relationship between an existing human composition, or scaffold, and an additional generated voice. This relationship is encoded by a type of artificial neural network called a compositional pattern producing network (CPPN). A human user without any musical expertise can then explore how these additional generated voices should relate to the scaffold through an interactive evolutionary process akin to animal breeding. The utility of this insight is validated by two implementations of FSMC called NEAT Drummer and MaestroGenesis, that respectively help users tailor drum patterns and complete multipart arrangements from as little as a single original monophonic track. The five major contributions of this work address the overarching hypothesis in this dissertation that functional relationships alone, rather than specialized music theory, are sufficient for generating plausible additional voices. First, to validate FSMC and determine whether plausible generated voices result from the human-composed scaffold or intrinsic properties of the CPPN, drum patterns are created with NEAT Drummer to accompany several different polyphonic pieces. Extending the FSMC approach to generate pitched voices, the second contribution reinforces the importance of functional transformations through quality assessments that indicate that some partially FSMC-generated pieces are indistinguishable from those that are fully human. While the third contribution focuses on constructing and exploring a space of plausible voices with MaestroGenesis, the fourth presents results from a two-year study where students discuss their creative experience with the program. Finally, the fifth contribution is a plugin for MaestroGenesis called MaestroGenesis Voice (MG-V) that provides users a more natural way to incorporate MaestroGenesis in their creative endeavors by allowing scaffold creation through the human voice. Together, the chapters in this dissertation constitute a comprehensive approach to assisted music generation, enabling creativity without the need for musical expertise.
156

Impacts of low-water activity food type on inactivation kinetics and models of foodborne pathogens treated with low-temperature, vacuum-assisted steam processing

Acuff, Jennifer Claire 29 April 2020 (has links)
Low water activity foods (LWAF), specifically nuts and dried fruits, have been generally considered safe because they do not support the growth of foodborne pathogens. However, many pathogens have been noted to survive in LWAF for considerable periods of time, and a number of recent outbreaks and recalls have implicated various types of nuts and dried fruits. The Food Safety Modernization Act requires food processors to develop preventive control plans that make ready-to-eat LWAF safer for consumers. The presented research was designed to investigate several aspects of LWAF safety by evaluating a steam process as a strategy to remove pathogen contamination from LWAF, modeling the inactivation of such treatments, and studying the thermal resistances of two E. coli strains in low-water activity solutions. Low-temperature, vacuum-assisted steam (vacuum-steam) was evaluated as a potential intervention and preventive control to remove pathogens from the surface of LWAF without using high-heat treatments that could damage product quality. The presented work examined the efficacy of vacuum-steam (<85°C) as a means to decontaminate the surface of whole macadamia nuts, dried apricot halves, and raisins from Salmonella spp., Listeria monocytogenes, and Shiga toxin-producing Escherichia coli (STEC) contamination. The low-temperature steam treatments successfully reduced all pathogens by >4 log CFU/g from the surfaces of the foods. Additionally, Pediococcus acidilactici, proved to be a surrogate organism for these pathogens and could be used to challenge and validate similar treatments within processing plants. The data were fit to models, which showed that food type significantly impacted the fit, with the Weibull model best describing bacterial inactivation kinetics on raisins and macadamia nuts, and the Gompertz model best describing reductions on the apricot halves. The models were challenged for validation of their abilities to predict times required for 3-log reductions using internal and external datasets, determining the usefulness to industry members who wish to design similar thermal treatments for LWAF. Comparing predicted values from internally constructed models to observed values generated from external data, models were shown to be limited in scope and application and could only be applied to pathogen inactivation on different LWAF or thermal processes in certain circumstances. First-order and Weibull model predictions of bacterial reductions on dried apricots had varied success in predicting times for 3-log reductions on other thermally treated LWAF. However, the models of bacterial reductions on thermally treated macadamia nuts frequently overestimated the times required for 3-log bacterial reductions for other LWAF. In an effort to understand the effect that reduced water activity has specifically on STEC, two strains were investigated for induced thermal resistance due to osmotic stress. Thermal resistance of STEC strains (O121:H19 and O157:H7) were evaluated on the basis of strain variation, culture preparation, and water activity (D- and z-values). At the lowest treatment temperature (56°C), O121 displayed greater heat resistance than O157, and the broth-grown samples exhibited greater heat resistance than the lawn-grown cells, but significant differences were not observed at higher temperatures. Samples in reduced-water activity solutions displayed reduced thermal resistance at 56°C, but the z-values were 29-43% higher than those of high-water activity samples. While water activity has been shown to impact thermal resistance of pathogens, comparisons of STEC thermal resistance according to the D- and z-values revealed that other factors also play roles in pathogen thermal resistance on LWAF. Results from the collection of experiments conclude that efficacy of thermal treatments is impacted by the physiological state of the cells, stress experienced in the food matrix, and characteristics of the food, including water activity and composition. / Doctor of Philosophy / Consumers expect foods they purchase to be safe to consume by themselves and family members, particularly those that are ready-to-eat with no additional cooking requirements. Many of these foods are low-water activity foods (LWAF), like nuts and dried fruits, with very little water content that could be used by bacteria. These foods may be preferred snack foods due to their affordability, long shelf lives, and health benefits over other types of snack foods. Until recently, LWAF were generally considered safe because they do not support the growth of foodborne pathogens due to the lack of moisture or water within the food. However, a number of recent outbreaks related to various types of nuts and dried fruits have proven that many pathogens can survive in dried foods, even if not actively growing, for considerable amounts of time. Designed to address these types of food safety issues, the Food Safety Modernization Act recognizes risks associated with foods and responded with regulations requiring food processors to take steps to make ready-to-eat LWAF, like nuts and dried fruits, safer for consumers. A popular strategy is to treat foods with heat to destroy pathogens, however the quality attributes of some nuts and dried fruits could be damaged by high-heat treatments like roasting. An alternative process uses a vacuum to form steam at lower temperatures, allowing for efficient heat transfer through water droplets to the surface of the foods, thus causing less damage to the foods without introducing too much moisture. This research evaluated how this process could be used by food processors to remove harmful bacteria from the surfaces of whole macadamia nuts, dried apricot halves, and raisins. Results indicated that the low-temperature steam treatments successfully reduced Salmonella, Listeria monocytogenes, and Shiga toxin-producing Escherichia coli (STEC) by >4 log CFU/g (>99.99%) from the surfaces of the foods. Additionally, a nonpathogenic lactic acid bacterium, Pediococcus acidilactici, exhibited similar or greater heat tolerance, which would allow food processors to use it as a substitute, or surrogate, for in-plant studies without introducing harmful bacteria into the food processing environment. Mathematical models were used to describe the trends of bacterial death due to the steam treatments, and the results indicated that the type of food significantly impacted the reduction of bacteria. The models were tested using additional data collected within our own laboratory, as well as others. Results indicated that some of the models could be used as predictors of bacterial death for similar LWAF but can only be applied with caution and consideration for the type of food and process. Additionally, two different E. coli strains associated with outbreaks (O121:H19 and O157:H7) were investigated to understand impacts of strain variation, growth method, and water activity on thermal resistance. Some differences in heat resistance were observed between the strains and between the growth methods. Additionally, the reduced water activity seemed to decrease the bacteria's ability to withstand some heat treatments. Overall, thermal resistance studies indicated that several factors, in addition to water activity, impact pathogens' development of resistance to heat treatments. The experiments' results show that there are complex relationships between bacteria and the food they inhabit. Food processors must consider these relationships in order to design the best thermal processes to make LWAF safe for consumers.
157

Guide lines for educational psychologists in the therapeutical application of the medical hypnoanalysis with anxiety clients

Roets, Susanna 06 1900 (has links)
People's inability to cope with the demands of modern life, has led to a significant increase in the incidence of anxiety being experienced by people from all walks of life. People are suffering from anxiety without knowing the root cause of it and it was found from the anxiety cases studied that its origin can in many cases be traced to the birth experience where specific negative suggestions were imprinted on the subconscious. In this study the influence of the birth experience as the underlying cause of anxiety and the effect of it on the formation of the self-concept and self-actualisation have been explored. The research shows that a subconscious origin exists in the development of anxiety. In the research for this study, Medical Hypnoanalysis, which is based on a process of diagnosis and therapy, was used as therapeutic method with several clients suffering from anxiety symptoms. In this research the perceptions formed in the subconscious during the birth experience were examined and related to the anxiety experienced during childhood and later life. The case studies, their diagnoses and the follow-up therapeutic sessions relating to the birth experience were investigated and discussed. Educational Psychologists show a specific interest in and a tendency to get involved with, or implement Medical Hypnoanalysis in therapy. It became obvious from this study that Medical Hypnoanalysis supplements the needs of the Educational Psychologist as a tool in therapy. In this study guide lines have been presented to the Educational Psychologist for the treatment of anxiety originating from the birth trauma by regressing the client back to this traumatic experience. Suggestions on how to conduct the birth regression sessions have also been presented and clarified. Through the case studies the identification and removal of the highly charged emotional and negative beliefs that were responsible for the anxiety symptom have been demonstrated. The case studies have furthermore demonstrated the successful utilisation of positive and healing suggestions to achieve the therapeutic goals. The results of this study show that Medical Hypnoanalysis can be used effectively in the treatment of the root causes of anxiety. / Psychology of Education / D. Ed. (Psychology of Education)
158

Soviet Oil Politics and the Middle East

Abbas, Ehsan A. R. 12 1900 (has links)
This investigation, covering the past two decades, attempts to determine what benefits the Soviets have sought to gain in their relationships with Middle Eastern oil-producing nations. Chapter I surveys the U.S.S.R.'s oil industry and its tentative prospects for the 1980's. Chapter II discusses Soviet involvement in the Middle East since 1950, including nationalization and oil embargoes. In Chapter III, developments less favorable to the U.S.S.R. are, analyzed: the growing influence of conservative, anti -Soviet oil-producing states and the deradicalization of other Middle Eastern nations. Chapter IV concludes that the Soviets have met with varying success in their Middle Eastern involvements. The future of their oil industry remains uncertain.
159

Diferenciação de células-tronco embrionárias murinas (mESCs) em células produtoras de insulina (IPCs) e caracterização funcional do gene Purkinje cell protein 4 (Pcp4) neste processo / Differentiation of murine embryonic stem cells (mESCs) into insulin-producing cells (IPCs) and functional characterization of the Purkinje Cell Protein 4 (Pcp4) gene in this process

Kossugue, Patricia Mayumi 28 May 2013 (has links)
Fontes alternativas de células &#946; têm sido estudadas para o tratamento de Diabetes mellitus tipo 1, dentre as quais a mais promissora consiste das células-tronco diferenciadas em células produtoras de insulina (IPCs). Alguns trabalhos demonstram a capacidade de células-tronco embrionárias murinas (mESCs) de formarem estruturas semelhantes a ilhotas pancreáticas, porém, os níveis de produção de insulina são insuficientes para a reversão do diabetes em camundongos diabetizados. Este trabalho visa desenvolver um protocolo adequado para geração de IPCs e contribuir para a identificação e caracterização funcional de novos genes associados à organogênese pancreática. Logo no início da diferenciação das mESCs em IPCs, foi possível verificar o surgimento de células progenitoras, evidenciado pela expressão de marcadores importantes da diferenciação beta-pancreática. Ao final do processo de diferenciação in vitro, ocorreu a formação de agrupamentos (clusters) semelhantes a ilhotas, corando positivamente por ditizona, que é específica para células &#946;-pancreáticas. Para avaliar seu potencial in vivo, estes clusters foram microencapsulados em Biodritina® e transplantados em camundongos diabetizados. Apesar dos níveis de insulina produzidos não serem suficientes para estabelecer a normoglicemia, os animais tratados com IPCs apresentaram melhores condições, quando comparados ao grupo controle, tendo melhor controle glicêmico, ganho de massa corpórea e melhor aparência da pelagem, na ausência de apatia. Além disso, análise dos clusters transplantados nestes animais indicou aumento da expressão de genes relacionados à maturação das células &#946;. Porém, quando estes clusters foram microencapsuladas em Bioprotect® e submetidos à maturação in vivo em animais normais, ocorreu um aumento drástico na expressão de todos os genes analisados, indicando sua maturação completa em células beta. O transplante destas células completamente maturadas em animais diabetizados, tornou-os normoglicêmicos e capazes de responder ao teste de tolerância à glicose (OGTT) de forma semelhante aos animais normais. A segunda parte do trabalho visou analisar genes diferencialmente expressos identificados em estudo anterior do nosso grupo, comparando, através de DNA microarray, mESCs indiferenciadas e diferenciadas em IPCs. Um dos genes diferencialmente expressos é aquele que codifica para a Purkinge cell protein 4 (Pcp4), sendo 3.700 vezes mais expresso em IPCs. Para investigar o possível papel do gene Pcp4 em células &#946; e no processo de diferenciação &#946;-pancreática, adotou-se o enfoque de genômica funcional, superexpressando e inibindo sua expressão em células MIN-6 e mESCs. Apesar da alteração na expressão de Pcp4 em células MIN-6 não ter interferido de forma expressiva na expressão dos genes analisados, quando inibido, modificou o perfil da curva de crescimento celular, aumentando seu tempo de dobramento de forma significativa e diminuindo da viabilidade celular em ensaios de indução de apoptose. Já na diferenciação de mESCs em IPCs, a superexpressão de Pcp4 interferiu de forma positiva apresentando uma tendência a aumentar a expressão dos genes relacionado à diferenciação&#946;-pancreática. Concluindo, desenvolvemos um novo protocolo de diferenciação de mESCs em IPCs as quais foram capazes de reverter o diabetes em camundongos diabetizados e descrevemos, pela primeira vez, o gene Pcp4 como sendo expresso em células &#946;-pancreáticas, podendo estar relacionado à manutenção da viabilidade celular e maturação destas células. / New cellular sources for type 1 Diabetes mellitus treatment have been previously investigated, the most promising of which seems to be the insulin producing cells (IPCs), obtained by stem cells differentiation. Some reports show that murine embryonic stem cells (mESCs) are able to form islet-like structures, however, their insulin production is insufficient to render diabetic mice normoglycemic. This work aims at developing an adequate protocol for generation of IPCs and searching for new genes which could be involved in the pancreatic organogenesis process. Early on during mESCs differentiation into IPCs, we observed the presence of progenitor cells, which were able to express pancreatic &#946;-cell markers. At the end of the differentiation process, the islet-like clusters positively stained for the insulin-specific dithizone. These clusters were microencapsulated in Biodritin® microcapsules, and then transplanted into diabetized mice. Although the levels of insulin production were insufficient for the animals to achieve normoglycemia, those which received IPCs displayed improved conditions, when compared to the control group, as judged by a better glycemic control, body weight gain and healthy fur appearance, in the absence of apathy. In addition, when these transplantated clusters were retrieved, high levels of expression of the genes related to &#946;-cell maturation were detected. IPCs were also microencapsulated in Bioprotect® and subjected to in vivo maturation in normal animals. A dramatic increase of the analyzed genes expression was observed, indicating complete maturation of the differentiated cells. When these cells were transplanted into diabetized mice, these animals achieved normoglycemia and were able to display glucose tolerance test (OGTT) response very similar to that of normal mice. In the second part of this work, we analyzed upregulated genes described in previous work from our group, comparing undifferentiated mESCs to IPCs using a microarray platform. One of these genes is that coding for the Purkinje cell protein 4 (Pcp4), which is 3,700 more expressed than in undifferentiated mESC cells. We adopted a functional genomics approach to investigate the role played by the Pcp4 gene in &#946;-cells and in &#946;-cell differentiation, by inducing overexpression and knocking down this gene in MIN-6 and mESC cells. Although the differential expression of Pcp4 in MIN-6 was not able to interfere with the expression of the genes analyzed, we observed different cell growth rates, with increased doubling time and decreased cell viability when its expression was knocked down. In addition, overexpression of Pcp4 in mESCs subjected to differentiation into IPCs apparently increases the expression of genes related to &#946;-cell differentiation. In conclusion, we developed a new protocol for ESCs differentiation into IPCs, which is able to revert diabetes in diabetized mice, and we also describe here, for the first time, the Pcp4 gene as being expressed in pancreatic &#946;-cells and possibly being related to maintenance of cell viability and &#946;-cell maturation.
160

Molecular epidemiology of livestock-associated staphylococcus aureus in animal and human populations in Belgium

Vandendriessche, Stien 13 December 2012 (has links)
Staphylococcus aureus is a major opportunistic pathogen causing a wide range of infections in humans and animals. Methicillin-resistant S. aureus (MRSA) has traditionally been regarded as a strictly human problem, initially confined to the healthcare settings and later a matter of concern in the general community too. All this changed in 2005 with the isolation of a specific MRSA clone, assigned to Clonal Complex (CC)398, from pigs and pig farmers in the Netherlands. These findings triggered worldwide investigation, showing the presence of this livestock-associated (LA)-MRSA clone in a variety of farm animals and in persons in contact with affected animals. Furthermore, the capacity of LA-MRSA CC398 to cause infections in humans and animals has been well documented. Recently, MRSA with a divergent mecA-homologue gene variant has been discovered in bovines and humans. Together, these emerging MRSA strains from animal sources have raised new questions as to their origin and inter-host transmission, as well as raised global concern in both veterinary and human medicine about health risks posed by MRSA prevailing in livestock.<p>In the present work, we aimed to investigate the extent and molecular epidemiology of the LA-MRSA reservoir in animal and human populations, including on livestock farms and in acute-care hospitals in Belgium. As a secondary objective, the presence of methicillin susceptible S. aureus (MSSA) CC398, from which MRSA CC398 could locally emerge by acquisition of the Staphylococal Cassette Chromosome mec (SCCmec) element, was assessed. To this end, we undertook an extensive and systematic cross-sectional survey of S.aureus and MRSA carriage among humans and animals on pig, veal calf, dairy cattle, beef cattle, broiler and horticulture farms. A questionnaire, completed by all farm residents, was used to assess occupational risk factors for human MRSA CC398 carriage. Bacterial genetic characterisation was done by spa typing, SCCmec typing and multi-locus sequence typing (MLST). Antimicrobial susceptibility profiles were determined; the presence of resistance genes and toxin genes were determined by PCR. A second set of S. aureus clinical isolates from two national surveys organised in 2005 and 2008 were characterised using the same methods.<p>Carriage of MRSA CC398 was highly prevalent in animals and humans on pig and veal calf farms and to a significantly lesser extent on beef, dairy, broiler and horticulture farms (Chapter 5.1). Persons who work with pigs or veal calves on a daily basis are at significantly higher risk for MRSA CC398 carriage compared to farm-exposed persons who work with them less regularly or never. In accordance with the results from the present work as well as those from others, it appears important to assess the impact of interventions at farm-level that aim to reduce the MRSA carriage rate in animals, as this would also reduce the risk for MRSA carriage in farmers and relatives.<p> MRSA CC398 isolates, especially those from veal calf farms, were frequently multi-resistant and thereby represent a reservoir of antimicrobial resistance determinants that could be transferred to other, more human-adapted staphylococci or other micro-organisms (Chapter 5.1). Additionally, this multi-resistance phenotype should be considered when applying empiric treatment of human staphylococcal infections in livestock-exposed persons. Only very few major “human-associated” virulence factors were detected, indicating a limited virulence capacity of LA-MRSA CC398 isolates. MRSA strains with the mecA homologue mecC, which is difficult to detect using conventional diagnostic methods, were found in beef and dairy cattle, but not in humans. <p>MSSA CC398 strains from which MRSA CC398 might locally emerge were frequently detected in humans and animals on pig, veal and broiler farms, all of which are commonly known to be affected by MRSA CC398 (Chapter 5.2). Three porcine MSSA CC398-t011 isolates harbored remnant DNA of a composite SCCmec V(5C2&5)c element, from which the mec gene complex was lacking. These findings indicate that the strains were previously involved in SCCmec recombination events. Processes similar to the one described here likely contribute to the enormous diversity of SCCmec elements observed in staphylococci. <p>Although LA-MRSA CC398 strains were frequently detected in livestock and livestock-exposed persons, they only represented a minority (~1%) of the MRSA strains from hospitalised patients. This suggests that this specific MRSA clone has not yet spread among Belgian patients without livestock contact (Chapter 5.3). However, similar to what has been seen in other countries, we observed a recent emergence of severe infections, caused by a human-adapted subclone of MSSA CC398, in hospitalised patients without livestock contact (Chapter 5.4). <p>Once more has S. aureus proven its versatility: it has optimally adapted to the selective pressure exerted by intensive animal farming by acquisition of mobile genetic elements, such as resistance determinants. Clearly MRSA is no longer a strictly human problem. Working across the human and veterinary health sectors will be essential to tackle the dissemination and pathogenic evolution of MRSA in livestock. <p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

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