The rate at which bacterial pathogens are becoming resistant to antibiotics is quite alarming, and therefore much attention has been focussed on this area. The mechanism whereby the bacterial cells acquire resistance is studied in order to determine how this process works as well as to determine if any future resistance mechanisms can be circumvented. In this study three different genera and the antibiotics that are resistant to them were used, namely, penicillin resistant Streptococcus, vancomycin resistant Enterococcus and methicillin resistant Staphylococcus. The results prove that the active sites SXXK, SXN and KT(S) G in the penicillin resistance Streptococcus plays a major role in resistance. It is seen in this study that the SXXK active site is found in all the resistant and most of the intermediate strains, therefore proving to be an important component of the cell wall resistance. It was subsequently noticed the greater the number of mutations found in the sequences the higher the resistance. Three dimensional structures showed the actives sites and their binding pockets. The results also show the change in conformation with a mutation in the active site. The results also proved that the Penicillin Binding Protein (PBP) genes essential for resistance are PBP Ia, PBP 2b and PBP 2x. The results obtained, for the vancomycin resistance in Enterococcus study, proved that the VanC and VanE cluster are very much alike and VanE could have evolved from VanC. There is also close similarity between the different ligase genes. The VanX 3D structure shows the position of the critical amino acids responsible for the breakdown of the D-Ala-D-Ala precursors, and the VanA ligase 3D structure shows the amino acids responsible the ligation of the D-Ala-D-Lac precursors. The analysis performed on the methicillin resistance in Staphylococcus study showed that the genes used to confer resistance are very similar between different strains as well as different species. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Biology

Background: Modern culture has stereotyped the divine female body as one that is continually getting leaner, with the internalization of the “thin” ideal possibly resulting in body dissatisfaction, disturbances in body image and exploitation of extreme weight control measures. These shoddy eating behaviours/attitudes may involve body mass and figure anxiety, sub-optimal nutrition or insufficient energy intake (possibly even a combination of both) and use of pathogenic weight control measures (PWCM). Furthermore, low energy availability can be a consequence of disordered eating (DE) behaviour, but can also inadvertently emerge in the absence of clinical eating disorders, DE behaviours and/or restricted dietary intake. Various researchers have concluded that dancers are overly-concerned about dieting and their body mass, and tend to be discontented with their bodies. Every organ system in the body may potentially be negatively affected as a result of the ensuing undernourishment and/or weight loss related to poor nutritional behaviour. The aim of the study was to investigate the DE behaviour, PWCM use, body image and energy status of a group of University female dancers Methods: Fifty two volunteer (18-30 years) dancers (n=26) matched by controls (n=26) of the same race, and comparable age and body mass index were recruited. DE behaviour was assessed with the Eating disorder inventory-3 (EDI3), Cognitive dietary restraint (CDR) subscale of the Three-factor eating questionnaire (TFEQ) and EDI3 referral form (EDI3-RF) behavioural questions. Body image was assessed using the Body Silhouette Assessment Scale. Energy status was assessed using a 5-day weighed food record to measure energy intake and Actiheart® monitor to measure energy expenditure. Results: Dancers presented with significantly higher EDI3-Drive for thinness, EDI3-Body dissatisfaction and TFEQ-CDR raw subscale scores when compared to controls. Furthermore, the majority of dancers scored above the designated cut-off scores for the EDI3-Drive for thinness (46.2%), EDI3-Body dissatisfaction (61.5%), EDI-Bulimia (53.9%) and TFEQ-CDR (52.0%) subscales. Bingeing was the most common PWCM used by both dancers and controls (19.2% vs. 23.1%), followed by weight loss ≥ 9kg within the preceding 6 months (11.5% vs. 15.4%). Vomiting (7.7%), laxatives (11.5%) and excessive exercise (19.2%) for weight loss were used only by the dancers. Current body weight was significantly different to desired body weight for the dancers only (p=0.0004). The discrepancy between current and ideal body image, also termed Feel Minus Ideal Discrepancy (FID), was significantly different between dancers and controls, and indicated that controls were content with their body silhouette while dancers were inclined to want to lose weight. A negative energy balance was found in 80.8% of both dancers and controls. The energy availability of 48.0% of dancers and 52.0% of controls was between 30 and 45 kcal/kg fat-free mass/day. A total of 65.4% of dancers and 38.5% of controls reported to be currently trying to lose weight. Conclusion: Irrespective of the limitations of this study, noteworthy observations were made pertaining to the DE behaviour, body image, and energy status of a group of South African student women dancers. This group of South African university women dancers were vulnerable to DE behaviour, had a propensity to be greatly displeased with their body image, and possessed a low energy status possibly because they were trying to lose weight. / Thesis (MSc (Nutrition))--North-West University, Potchefstroom Campus, 2013.

Background: Modern culture has stereotyped the divine female body as one that is continually getting leaner, with the internalization of the “thin” ideal possibly resulting in body dissatisfaction, disturbances in body image and exploitation of extreme weight control measures. These shoddy eating behaviours/attitudes may involve body mass and figure anxiety, sub-optimal nutrition or insufficient energy intake (possibly even a combination of both) and use of pathogenic weight control measures (PWCM). Furthermore, low energy availability can be a consequence of disordered eating (DE) behaviour, but can also inadvertently emerge in the absence of clinical eating disorders, DE behaviours and/or restricted dietary intake. Various researchers have concluded that dancers are overly-concerned about dieting and their body mass, and tend to be discontented with their bodies. Every organ system in the body may potentially be negatively affected as a result of the ensuing undernourishment and/or weight loss related to poor nutritional behaviour. The aim of the study was to investigate the DE behaviour, PWCM use, body image and energy status of a group of University female dancers Methods: Fifty two volunteer (18-30 years) dancers (n=26) matched by controls (n=26) of the same race, and comparable age and body mass index were recruited. DE behaviour was assessed with the Eating disorder inventory-3 (EDI3), Cognitive dietary restraint (CDR) subscale of the Three-factor eating questionnaire (TFEQ) and EDI3 referral form (EDI3-RF) behavioural questions. Body image was assessed using the Body Silhouette Assessment Scale. Energy status was assessed using a 5-day weighed food record to measure energy intake and Actiheart® monitor to measure energy expenditure. Results: Dancers presented with significantly higher EDI3-Drive for thinness, EDI3-Body dissatisfaction and TFEQ-CDR raw subscale scores when compared to controls. Furthermore, the majority of dancers scored above the designated cut-off scores for the EDI3-Drive for thinness (46.2%), EDI3-Body dissatisfaction (61.5%), EDI-Bulimia (53.9%) and TFEQ-CDR (52.0%) subscales. Bingeing was the most common PWCM used by both dancers and controls (19.2% vs. 23.1%), followed by weight loss ≥ 9kg within the preceding 6 months (11.5% vs. 15.4%). Vomiting (7.7%), laxatives (11.5%) and excessive exercise (19.2%) for weight loss were used only by the dancers. Current body weight was significantly different to desired body weight for the dancers only (p=0.0004). The discrepancy between current and ideal body image, also termed Feel Minus Ideal Discrepancy (FID), was significantly different between dancers and controls, and indicated that controls were content with their body silhouette while dancers were inclined to want to lose weight. A negative energy balance was found in 80.8% of both dancers and controls. The energy availability of 48.0% of dancers and 52.0% of controls was between 30 and 45 kcal/kg fat-free mass/day. A total of 65.4% of dancers and 38.5% of controls reported to be currently trying to lose weight. Conclusion: Irrespective of the limitations of this study, noteworthy observations were made pertaining to the DE behaviour, body image, and energy status of a group of South African student women dancers. This group of South African university women dancers were vulnerable to DE behaviour, had a propensity to be greatly displeased with their body image, and possessed a low energy status possibly because they were trying to lose weight. / Thesis (MSc (Nutrition))--North-West University, Potchefstroom Campus, 2013.

Some yeast strains under certain conditions secrete into the medium polypeptide toxins which are inhibitory to sensitive cells. These yeast strains are termed as killer yeasts and their toxins are designated as killer proteins or killer toxins. Killer proteins are classified into 11 typical types (K1-K11). These toxins have different killing mechanisms on sensitive cells. Some of them hydrolyze major cell wall component &amp / #946 / -1,3- glucans. As mammalian cells lack cell walls research and development of novel highly selective antifungals are mostly focused on the agents which target the components of the fungal cell wall. We have previously characterized the K5 type killer protein. This protein is an exo &amp / #946 / -1,3-glucanase which is stable at pH&rsquo / s and temperatures appropriate for its medical usage. &amp / #946 / -1,3- glucan hydrolyzing activity of the K5 type killer protein highlighted the potential use of this protein as a selective antimycotic agent. Antifungal activity of the K5 type yeast killer protein was tested against 26 human pathogenic yeast and 9 dermathophyte strains and found to be affective on all of the tested strains. Toxin MIC50, MIC100 and MFC values were found to be between 0.25-4, 0.5-8, 1-8 &micro / g/ml respectively except Candida krusei isolates. Cell killing analysis revealed that toxin activity starts within first 2 hours and complete cell death time differs due to the susceptibility of strains to the K5 type yeast killer protein. K5 type yeast killer protein would be used as a novel and selective agents with the results obtained from this study.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted. Includes bibliographical references.

La présence de micro-organismes pathogènes dans les produits alimentaires représente un risque important de santé publique. La réglementation régit leur contrôle en imposant, dans la majorité des cas, la recherche d’une faible quantité de ces bactéries. Les méthodes de détection de référence sont simples à mettre en œuvre mais chronophages et nécessitent un temps d’analyse de plusieurs jours. Aussi, un des enjeux majeurs dans le domaine du contrôle alimentaire, est la mise au point de méthodes sensibles et rapides pour la détection d’un ou plusieurs pathogènes dans des matrices alimentaires. Ces nouvelles technologies ont pour but de réduire le nombre de toxi-infections alimentaires tout en augmentant la durée de commercialisation des produits et en limitant les impacts économiques négatifs pour les industries (longues périodes de stockage, rappels de lot, etc.).Dans ce contexte, nous nous sommes intéressés à la mise au point d’une méthode alternative aux méthodes de références, basée sur un biocapteur présentant une transduction de type résonance des plasmons de surface (SPR). Cette technologie présente de multiples avantages : simplicité de mise en œuvre, analyse en temps réel, absence de marquage, etc. Des preuves de concept de son utilisation, pour la détection de bactéries pathogènes ont été présentées dans la littérature, utilisant principalement des récepteurs de type anticorps.Au cours des travaux présentés dans cette thèse nous nous sommes intéressés à la détection de bactéries pathogènes alimentaires majeures en termes de prévalence ou de gravité de l’infection, qu’elles soient Gram positif ou Gram négatif. La production d’anticorps performants a également été optimisée pour obtenir des anticorps polyclonaux sensibles et spécifiques de plusieurs genres bactériens. Les cinétiques de croissance bactérienne ont été analysées par SPR afin d’identifier les principaux phénomènes impactant la détection. Des techniques en haute résolution ont permis une meilleure compréhension des événements se produisant à la surface du biocapteur. Ces études ont menés à l’obtention d’un système permettant la détection multiplexe d’un faible inoculum de bactéries pathogènes dans des matrices alimentaires (salade et poudre de lait infantile) en moins de 24h. / The presence of pathogenic micro-organisms in foodstuff is a major concern for health safety. Regulations impose, in most cases, the research of low levels of these bacteria. Although reference methods are simple, they are time-consuming and can require several days before obtaining results. This is why one of the major challenges in food hygiene science is the development of sensitive and rapid methods, for the detection of one or more pathogens. These new technologies aim to decrease the occurrence of foodborne infections, while improving both the shelf life of food products and industrial production costs (long storage times, recalls …).In this context, the development of an alternative method has been carried out in this work, using a biosensor with a transduction based on surface plasmon resonance (SPR). Such optical technology offers multiple benefits: ease-of-use, real-time analysis, label-free process… Proofs of concept for the use of this technology in basic conditions, for the detection of model bacteria, have been described in the literature, mostly using antibodies as receptors, but the full operation in "real" conditions encountered in industrial facilities still has to be tested and optimizedThis manuscript thus describes the detection of foodborne pathogenic bacteria playing a major role in terms of prevalence and/or severity of the caused infection, whether Gram positive or negative. The production of efficient antibodies was optimized, resulting in polyclonal antibodies sensitive and specific for multiple bacterial genera. Dynamics of bacterial growths were analysed by SPR in an effort to identify the main factors having an impact on the detection. High resolution SPR was used for a better understanding of reactions occurring at the surface of the biosensor. These studies lead to the development of a system capable of multiplex detection of low bacterial inoculum in food samples (lettuce and powdered infant formula) within less than 24 hours.

abstract: Systemic lupus erytematosus (SLE) is an autoimmune disease where the immune system is reactive to self antigens resulting in manifestations like glomerulonephritis and arthritis. The immune system also affects the central nervous system (known as CNS-SLE) leading to neuropsychiatric manifestations such as depression, cognitive impairment, psychosis and seizures. A subset of pathogenic brain-reactive autoantibodies (BRAA) is hypothesized to bind to integral membrane brain proteins, affecting their function, leading to CNS-SLE. I have tested this BRAA hypothesis, using our lupus-mouse model the MRL/lpr mice, and have found it to be a reasonable explanation for some of the manifestations of CNS-SLE. Even when the MRL/lpr had a reduced autoimmune phenotype, their low BRAA sera levels correlated with CNS involvement. The correlation existed between BRAA levels to integral membrane protein and depressive-like behavior. These results were the first to show a correlation between behavioral changes and BRAA levels from brain membrane antigen as oppose to cultured neuronal cells. More accurate means of predicting and diagnosing lupus and CNS-SLE is necessary. Using microarray technology I was able to determine peptide sets that could be predictive and diagnostic of lupus and each specific CNS manifestation. To knowledge no test currently exists that can effectively diagnose lupus and distinguish between each CNS manifestations. Using the peptide sets, I was able to determine possible natural protein biomarkers for each set as well as for five monoclonal BRAA from one MRL/lpr. These biomarkers can provide specific targets for therapy depending on the manifestation. It was necessary to investigate how these BRAA enter the brain. I hypothesized that substance P plays a role in altering the blood-brain barrier (BBB) allowing these BRAA to enter and affect brain function, when bound to its neurokinin-1 receptor (NK-1R). Western blotting results revealed an increase in the levels of NK-1R in the brain of the MRL/lpr compared to the MRL/mp. These MRL/lpr with increased levels of both NK-1R and BRAA displayed CNS dysfunction. Together, these results demonstrate that NK-1R may play a role in CNS manifestations. Overall, the research conducted here, add to the role that BRAA are playing in CNS-lupus. / Dissertation/Thesis / Ph.D. Molecular and Cellular Biology 2011

Made available in DSpace on 2016-08-12T19:15:31Z (GMT). No. of bitstreams: 1 ShamyraGAS_Dissert.pdf: 1345668 bytes, checksum: 408f47b3e8a408dc7702858d04d13fc8 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Silk Flower [Calotropis procera (Aiton) W.T. Aiton] is a plant that has been highlighted by the case of a species that has several features such as animal feed, traditional medicine, agriculture, environment, cosmetics and textile industry, and may also act to combat pests, fungi and viruses through mechanisms defense associated with your latex. This study aimed to evaluate latex fluid from Silk Flower in inhibiting the development of pathogenic fungi of Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae and Monosporascus cannonballus and study the genetic diversity from Silk Flower genotypes using the RAPD and ISSR molecular markers. Twenty samples of species of leaves were collected in the Grossos/RN and Mossoró/RN cities (ten plants from each city). The plants latex were tested on four different types of phytopathogenic fungi, Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae and Monosporascus cannonballus with two different methods (adding latex to the culture medium before and after polymerization middle), and with two different concentration level (neat and diluted 1:1). For molecular analysis, DNA of each plant was extracted with 11 RAPD primers and 10 ISSR primers. For latex analyzes, it was observed that there was no inhibitory effect for any of Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae and Monosporascus cannonballus isolates in any of the concentrations tested under the conditions studied. Molecular results showed a good standard for both amplification of DNA markers, showing the formation of different groups, and the presence of genetic variability has been detected. For the analysis with molecular markers there was the formation of the four distinct groups, and in the ISSR marker was observed the formation of six groups. When it was analyzed the two markers in a corresponding manner it was possible to detect the formation of seven distinct groups showing the existence of variability. The difference in the results of both markers can be explained by the case of two markers that covered different regions of the genome / Flor de Seda [Calotropis procera (Aiton) W.T. Aiton] é uma planta que tem recebido destaque por se tratar de uma espécie que possui diversas funcionalidades como alimentação animal, medicina tradicional, agricultura, meio ambiente, indústria cosmética e têxtil, podendo também atuar no combate à pragas, fungos e vírus através de mecanismos de defesa associados ao seu látex. Objetivou-se nesse estudo avaliar fluidos laticíferos da Flor de Seda na inibição do desenvolvimento de fungos fitopatogênicos de Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae e Monosporascus cannonballus e estudar a divergência genética de genótipos de Flor de Seda por meio de marcadores moleculares RAPD e ISSR. Vinte amostras de folhas da espécie foram coletadas na cidade de Grossos/RN e na cidade de Mossoró/RN no Campus Leste da UFERSA (dez plantas para cada local de coleta). O látex das plantas foram testados em quatro diferentes tipos de fungos fitopatogênicos, Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae e Monosporascus cannonballus com duas diferentes metodologias (adicionando o látex ao meio de cultura antes e após a polimerização do meio) e com dois níveis diferentes de concentração (puro e diluído 1:1). Para as análises moleculares, o DNA de cada uma das plantas foi extraído com 11 primers RAPD e 10 primers ISSR. Para as análises do látex, foi observado que não houve efeito inibitório para nenhum dos isolados de Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae e Monosporascus cannonballus em nenhuma das concentrações testadas nas condições estudadas. Os resultados moleculares obtidos revelaram um bom padrão de amplificação para ambos os marcadores de DNA, mostrando à formação de grupos distintos, tendo sido detectada a presença de variabilidade genética. Para as análises com os marcadores RAPD houve a formação de quatro grupos distintos, e para o marcador ISSR foi possível observar a formação de seis grupos. Quando se analisou os dois marcadores de forma correlacionada foi possível detectar a formação de sete grupos distintos demonstrando a existência de variabilidade. A diferença encontrada nos resultados de ambos marcadores pode ser explicada por se tratar de dois marcadores que cobriram diferentes regiões do genoma

Made available in DSpace on 2016-08-12T19:18:49Z (GMT). No. of bitstreams: 1 ShamyraGAS_Dissert.pdf: 1345668 bytes, checksum: 408f47b3e8a408dc7702858d04d13fc8 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Silk Flower [Calotropis procera (Aiton) W.T. Aiton] is a plant that has been highlighted by the case of a species that has several features such as animal feed, traditional medicine, agriculture, environment, cosmetics and textile industry, and may also act to combat pests, fungi and viruses through mechanisms defense associated with your latex. This study aimed to evaluate latex fluid from Silk Flower in inhibiting the development of pathogenic fungi of Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae and Monosporascus cannonballus and study the genetic diversity from Silk Flower genotypes using the RAPD and ISSR molecular markers. Twenty samples of species of leaves were collected in the Grossos/RN and Mossoró/RN cities (ten plants from each city). The plants latex were tested on four different types of phytopathogenic fungi, Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae and Monosporascus cannonballus with two different methods (adding latex to the culture medium before and after polymerization middle), and with two different concentration level (neat and diluted 1:1). For molecular analysis, DNA of each plant was extracted with 11 RAPD primers and 10 ISSR primers. For latex analyzes, it was observed that there was no inhibitory effect for any of Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae and Monosporascus cannonballus isolates in any of the concentrations tested under the conditions studied. Molecular results showed a good standard for both amplification of DNA markers, showing the formation of different groups, and the presence of genetic variability has been detected. For the analysis with molecular markers there was the formation of the four distinct groups, and in the ISSR marker was observed the formation of six groups. When it was analyzed the two markers in a corresponding manner it was possible to detect the formation of seven distinct groups showing the existence of variability. The difference in the results of both markers can be explained by the case of two markers that covered different regions of the genome / Flor de Seda [Calotropis procera (Aiton) W.T. Aiton] é uma planta que tem recebido destaque por se tratar de uma espécie que possui diversas funcionalidades como alimentação animal, medicina tradicional, agricultura, meio ambiente, indústria cosmética e têxtil, podendo também atuar no combate à pragas, fungos e vírus através de mecanismos de defesa associados ao seu látex. Objetivou-se nesse estudo avaliar fluidos laticíferos da Flor de Seda na inibição do desenvolvimento de fungos fitopatogênicos de Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae e Monosporascus cannonballus e estudar a divergência genética de genótipos de Flor de Seda por meio de marcadores moleculares RAPD e ISSR. Vinte amostras de folhas da espécie foram coletadas na cidade de Grossos/RN e na cidade de Mossoró/RN no Campus Leste da UFERSA (dez plantas para cada local de coleta). O látex das plantas foram testados em quatro diferentes tipos de fungos fitopatogênicos, Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae e Monosporascus cannonballus com duas diferentes metodologias (adicionando o látex ao meio de cultura antes e após a polimerização do meio) e com dois níveis diferentes de concentração (puro e diluído 1:1). Para as análises moleculares, o DNA de cada uma das plantas foi extraído com 11 primers RAPD e 10 primers ISSR. Para as análises do látex, foi observado que não houve efeito inibitório para nenhum dos isolados de Macrophomina phaseolina, Rhizoctonia solani, Colletotrichum musae e Monosporascus cannonballus em nenhuma das concentrações testadas nas condições estudadas. Os resultados moleculares obtidos revelaram um bom padrão de amplificação para ambos os marcadores de DNA, mostrando à formação de grupos distintos, tendo sido detectada a presença de variabilidade genética. Para as análises com os marcadores RAPD houve a formação de quatro grupos distintos, e para o marcador ISSR foi possível observar a formação de seis grupos. Quando se analisou os dois marcadores de forma correlacionada foi possível detectar a formação de sete grupos distintos demonstrando a existência de variabilidade. A diferença encontrada nos resultados de ambos marcadores pode ser explicada por se tratar de dois marcadores que cobriram diferentes regiões do genoma