Les Bartonelles sont des bactéries hémotropes responsables de zoonoses émergentes. Ces Alphaprotéobactéries sont auxotrophes pour l'hème et doivent donc l'importer du milieu extérieur pour croître. Les Bartonelles possèdent un système complet de transport de l'hème permettant de transporter ce composé dans le cytoplasme. Chez Bartonella, il a été montré que l'hème pouvait être utilisé comme source de fer. Comme pour d'autres bactéries utilisant l'hème comme une source de fer, Bartonella doit dégrader l'hème pour libérer le fer. Chez Bartonella, un ensemble de gènes codant pour le système de transport de l'hème, contient un gène codant pour un polypeptide (HemS) présentant des homologies avec des protéines liant ou dégradant l'hème. En utilisant des expériences de complémentation de mutants d'E. coli incapables de dégrader l'hème, nous avons mis en évidence que HemS de Bartonella henselae permet la libération du fer de l'hème. HemS purifié lie l'hème et le dégrade en présence de donneurs d'électrons. La diminution du niveau de HemS chez B. henselae décroit sa capacité de survivre à une exposition à H2O2. Les Bartonelles expriment quatre ou cinq protéines de la membrane externe ayant la capacité de fixer l'hème. Les gènes de structure de ces protéines sont exprimés différemment en fonction de paramètres comme la température ainsi que la concentration en oxygène ou en hème. Ces protéines ont été proposées comme étant impliquées dans divers processus cellulaires étant donné leur profil d'expression. Dans ce manuscrit, nous montrons que ces protéines sont impliquées dans la défense contre le stress oxydatif, la colonisation des cellules endothèliales et la survie dans la puce

The arctic is currently experiencing some of the greatest rates of warming. Newly emerging diseases in the arctic are of particular interest due to the implications these may have at southern latitudes if temperatures continue to rise around the globe. It is important to document changes in pathogen populations, such as alterations in range, virulence, prevalence, and abundance, and the effect these may have on their host populations. Parasites influence the reproductive success of their hosts in some cases. Studies on impacts of ectoparasites on avian reproductive success have generally been focused on species with altricial young. I studied the abundance of an apparently newly emerging nest-parasite and the effects of this parasite on Rosss (<i>Chen rossii</i>) and lesser snow goose (<i>Chen caerulescens caerulescens</i>) reproductive success in the Karrak Lake goose colony, Nunavut, Canada from 2001 to 2004. <p>The nest parasite, identified as the flea <i>Ceratophyllus vagabundus vagabundus</i>, was associated with goose eggs covered with spots of blood. The proportion of goose egg-shells covered by blood was positively correlated with flea abundance in the nest. This relationship allowed the use egg blood-coverage as an index of flea abundance for remaining analyses. Flea abundance in goose nests was associated with variables associated with the host and the hosts habitat. I used general linear models in conjunction with Akaikes information criterion (AIC) to determine which factors were most important in influencing flea abundance in goose nests. The most parsimonious model to explain the relationship between egg blood coverage and flea abundance in goose nests included goose clutch size, age of nest bowl (new vs. old), history of nesting by geese on a specific plot within the colony, habitat within 0.5m of nest, and year. The best predictor of flea abundance was the age of the nest bowl, with nest bowls re-used by geese containing more fleas than new bowls. This relationship was expected as fleas over-wintered in goose nests at the Karrak Lake colony.<p> Logistic regression and AIC were used to determine whether egg blood-coverage was an important variable influencing nest success. All top five models included blood-coverage. Goose nest success was negatively influenced by fleas in most years. There was a threshold of egg blood-coverage at which nest success was affected, and this threshold varied, with >20% blood indicating a significant decline in nest success in two years, and >5% blood-coverage indicating a decrease in nest success in one year. To my knowledge, this is the first study that has examined the parasites of avian nests in an arctic ecosystem and was also the first to investigate the effect of nest parasites on birds with precocial young. More research is needed to determine what factors limit this flea population and whether fleas may become a regulating factor for geese in the Karrak Lake colony.

The arctic is currently experiencing some of the greatest rates of warming. Newly emerging diseases in the arctic are of particular interest due to the implications these may have at southern latitudes if temperatures continue to rise around the globe. It is important to document changes in pathogen populations, such as alterations in range, virulence, prevalence, and abundance, and the effect these may have on their host populations. Parasites influence the reproductive success of their hosts in some cases. Studies on impacts of ectoparasites on avian reproductive success have generally been focused on species with altricial young. I studied the abundance of an apparently newly emerging nest-parasite and the effects of this parasite on Rosss (<i>Chen rossii</i>) and lesser snow goose (<i>Chen caerulescens caerulescens</i>) reproductive success in the Karrak Lake goose colony, Nunavut, Canada from 2001 to 2004. <p>The nest parasite, identified as the flea <i>Ceratophyllus vagabundus vagabundus</i>, was associated with goose eggs covered with spots of blood. The proportion of goose egg-shells covered by blood was positively correlated with flea abundance in the nest. This relationship allowed the use egg blood-coverage as an index of flea abundance for remaining analyses. Flea abundance in goose nests was associated with variables associated with the host and the hosts habitat. I used general linear models in conjunction with Akaikes information criterion (AIC) to determine which factors were most important in influencing flea abundance in goose nests. The most parsimonious model to explain the relationship between egg blood coverage and flea abundance in goose nests included goose clutch size, age of nest bowl (new vs. old), history of nesting by geese on a specific plot within the colony, habitat within 0.5m of nest, and year. The best predictor of flea abundance was the age of the nest bowl, with nest bowls re-used by geese containing more fleas than new bowls. This relationship was expected as fleas over-wintered in goose nests at the Karrak Lake colony.<p> Logistic regression and AIC were used to determine whether egg blood-coverage was an important variable influencing nest success. All top five models included blood-coverage. Goose nest success was negatively influenced by fleas in most years. There was a threshold of egg blood-coverage at which nest success was affected, and this threshold varied, with >20% blood indicating a significant decline in nest success in two years, and >5% blood-coverage indicating a decrease in nest success in one year. To my knowledge, this is the first study that has examined the parasites of avian nests in an arctic ecosystem and was also the first to investigate the effect of nest parasites on birds with precocial young. More research is needed to determine what factors limit this flea population and whether fleas may become a regulating factor for geese in the Karrak Lake colony.

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Submitted by (edna.saturno@ufrpe.br) on 2016-11-08T16:41:32Z No. of bitstreams: 1 Wagner Mcklayton Alves de Souza.pdf: 1430165 bytes, checksum: 6865be14673aa551296e87905cdd469c (MD5) / Made available in DSpace on 2016-11-08T16:41:32Z (GMT). No. of bitstreams: 1 Wagner Mcklayton Alves de Souza.pdf: 1430165 bytes, checksum: 6865be14673aa551296e87905cdd469c (MD5) Previous issue date: 2012-02-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Lippia sidoides Cham (rosemary pepper) is a plant present in part of the semi-arid on Brazil northeastern. Their leaves have shown a high potential in the treatment of dermatitis in humans. This study aimed to evaluate the biological activity of the L. sidoides Cham oil on ectoparasites of domestic dogs (Canis familiares) and antimicrobial activities on Staphylococcus sp. isolated in these animals. To this end, were selected 20 dogs suffering from ectoparasites. In 40 samples of skin culture for bacterial growth it was found positive result in 09 samples analyzed, being Staphylococcus sp isolated, for in vitro evaluation of antimicrobial activity of oil L. sidoides they were subjected to MIC. The results also revealed the presence of flea C. felis felis, tick R. sanguineus. For in vitro evaluation of insecticidal activity against Ctenocephalides felis felis through the filter paper test, were used 150 adult fleas divided into three groups each with ten subjects. G 01 being distilled water + Tween 20, G 02 oil L. sidoides 5% with Tween 20 as a dispersant and G3 three spray fipronil, evaluating motility in time of 10 minutes 1, 3, 6, 12, 24 hours. In the in vivo test 20 pet dogs of both sexes parasitized by C. felis felis were divided into two groups G1 with shampoo of essential oil of L. sidoides 5% and G2 shampoo neutral, bathed twice a week for nine weeks. To in vitro acaricide evaluation against R. sanguineus were used 90 female ticks divided into three treatment groups, being G1 based on essential oil of L. siodoides Cham using Tween 20 as a dispersant at distilled water, G2 cypermethrin + Dichlorvos ® DDVP and in the negative control G3 distilled water and Tween 20. The results showed significant inhibition of bacterial growth at a concentration of 5% against S. sp. 100% mortality against R. sanguineus in the same concentrations. On in vivo tests against C. felis was a reduction of 100% in the number of fleas treated with L. sidoides and efficacy of 100% in the mortality in vitro of C. felis felis after 24 hours exposure to oil L. sidoides. It was concluded that the essential oil of Lippia sidoides Cham 5% presented insecticide effectiveness on the adult form of Ctenocephalides felis felis in both tests. Well as antimicrobial activity against Staphylococcus spp and acaricide against ticks of R. sanguineus. / A Lippia sidoides Cham (alecrim pimenta) é uma planta presente em parte do semi-árido do Nordeste Brasileiro. Suas folhas tem apresentado elevado potencial no tratamento de diversas dermatites em humanos. O presente trabalho objetivou avaliar a atividade biológica do óleo de L. sidoides Cham sobre ectoparasitos de cães domésticos (Canis familiares) e antimicrobiana sobre Staphylococcus sp isoladas destes mesmos animais. Para tal, foram selecionados 20 cães acometidos de ectoparasitoses. Em 40 amostras de cultura de pele para crescimento bacteriano foi verificado resultado positivo em 09 amostras analisadas, sendo isolada a bactéria Staphylococcus sp , para avaliação in vitro da atividade antimicrobiana do óleo de L. sidoides as mesmas foram submetidas ao MIC. Os resultados revelaram ainda a presença da pulga C. felis felis, e carrapato R. sanguineus. Para avaliação in vitro da atividade inseticida contra Ctenocephalides felis felis através do teste de papel filtro, foram utilizadas 150 pulgas adultas divididas em três grupos com dez indivíduos cada. Sendo G 01 água destilada + Tween 20, G 02 óleo de L. sidoides a 5% tendo como dispersante o Tween 20 e G3 fipronil spray, avaliando-se a motilidade em tempos de 10 minutos 1, 3, 6, 12, 24 horas. No teste in vivo 20 cães domiciliados de ambos os sexos parasitados por C. felis felis foram divididos em dois grupos G1 com shampoo de óleo essencial de L. sidoides a 5% e G2 shampoo neutro, banhados duas vezes por semana por nove semanas. Para avaliação acaricida in vitro contra R. sanguineus utilizou-se 90 fêmeas teleóginas divididas em três grupos de tratamento, sendo o G1 à base de óleo essencial de L. siodoides Cham a 5% utilizando-se tween 20 como dispersante em água destilada, G2 cipermetrina + Diclorvós® DDVP e no controle negativo G3 água destilada e tween 20. Os resultados revelaram inibição do crescimento bacteriano significativo na concentração de 5% frente a S. sp. mortalidade de 100% frente R. sanguineus nas mesmas concentrações. Nos testes in vivo contra C. felis houve uma redução de 100% no número de pulgas tratadas com L. sidoides bem como eficácia de 100% na mortalidade in vitro de C. felis felis após 24h de exposição ao óleo de L. sidoides. Conclui-se que o óleo essencial de Lippia sidoides Cham a 5% apresentou eficácia inseticida sobre a forma adulta de Ctenocephalides felis felis em ambos os testes. Bem como ação antimicrobiana frente a isolados de Staphylococcus spp e acaricida frente a teleóginas de R. sanguineus.

My diploma thesis, Kolbenova "flea market" - market as a space, market as an organism, searches what is the nature of such a place as perceived by its visitors. I claim that the market can be taken to be an organism continuously reacting to incentives from both the market surroundings and the market participants. The perception of the market is determined by four main elements - space, in which it is being held, temporal aspect of the market and its influence on the changes of the place, the products being marketed and the participants themselves. Based on the analysis of the data gained mostly by the participating observation and semistructured and random interviews, I have concluded that due to the interacting nature of the four aspects the Kolbenova flea market is not a fixed subject, but is a constantly changing and reacting mixture of the four aforementioned aspects.

Ctenocephalides felis est une espèce de puce cosmopolite parasitant majoritairement les carnivores domestiques. Elle est vectrice de nombreux agents pathogènes zoonotiques dont les bactéries du genre Bartonella, bactéries intracellulaires facultatives. La compétence vectorielle de cette puce a été investiguée pour B. henselae, B. quintana, B. clarridgeiae, B. tribocorum et B. birtlesii. Dans ces conditions expérimentales, utilisant un système de gorgement sur membrane, ces espèces ont persisté pendant les trois jours d'une première étude, et pour B. henselae durant les 13 jours de survie des puces, dans une seconde étude. Les cinq espèces de bartonelles ont été retouvées dans les fèces. Pour ces cinq espèces, nos résultats montrent une absence de transmission verticale transovarienne chez la puce et suggèrent une possibilité de contamination horizontale. Nous proposons enfin un protocole original d'évaluation de l'efficacité d'un traitement antiparasitaire chez le chat, pour prévenir sa contamination par Bartonella spp. / Ctenocephalides felis is a cosmopolitan flea species mainly parasitizing pets, transmitting several pathogens of veterinary and zoonotic importance including the facultative intracellular bacteria of the genus Bartonella. The vector competence of this flea was investigated for B. henselae, B. quintana, B. clarridgeiae, B. tribocorum and B. birtlesii, using an artificial feeding system. In these experimental conditions, these bartonellae proved to persist for three days, in a first study, while B. henselae persisted for the 13 days of its life span, in a second study. All five bartonellae were excreted in the flea's faeces. On the whole, these five species were not transmitted transovarially in the fleas, though horizontal transmission was suggested. Furthermore, we propose an original protocol allowing the evaluation of the efficacy of ectoparasiticidal products against Bartonella spp. infection in cats.

Anredera cordifolia (Basellaceae), Madeira vine, is a perennial, semi- succulent climber native from Paraguay to southern Brazil and northern Argentina. It has a history of weediness and difficulty of control once established. In South Africa Madeira vine has a wide range and distribution with altitudes ranging from 10-1800m above sea level. Described as a transformer species, its sheer weight is capable of breaking branches off trees, causing the potential collapse of forest canopies. Chemical and mechanical control methods are expensive, labour intensive and may provide only temporary relief. A biological control programme was therefore initiated in 2003. Cf Phenrica sp. 2 (Coleoptera: Chrysomelidae: Alticinae), was field collected from A. cordifolia in Brazil, SSW of Cascavel in the Paraná Province during a survey in November 2003. Eggs are laid in groups of 16 with the average fertility rate being 89%. After going though three larval instars, the larvae pupate in the soil with the adults eclosing after a period of 17 days. The total developmental time for a generation from egg to egg ranges between 7-8 weeks. Biological traits that favour the flea beetle as a possible biological control agent include long-lived adults (up to 5 months) and multiple generations during the summer period. Both adults and larvae feed extensively on leaves and stems and although developmental rates will slow down during the winter period, no indication of a definite diapause was found under the prevailing laboratory conditions. After completing the larval no-choice trials with twenty-six plant species from 14 plant families Phenrica sp. 2 proved to be adequately host specific, as larval development was only supported by 3 Basellaceae species (including the control A. cordifolia) and one Portulacaceae species. All of these are introduced species in South Africa. The only indigenous Basella species could not be tested as it has a very marginal distribution, and because it’s inconspicuous nature, it is seldom seen or collected. Adult multi-choice trials were restricted to species that could sustain larval development to give some indication of the acceptability of these species for adult feeding and oviposition. Although adult feeding was initially concentrated on B. alba, the oviposition preference was clear-cut as females only oviposited on A. cordifolia. In order to quantify the impact of Phenrica sp. 2 on plant biomass and to assess the incidence and intensity of foliar damage, a pair of adults was confined to the host plant, for 2 generations, with different levels of larval densities. The results indicated that the host plant, due to both larval and adult feeding, suffered leaf losses of up to 55%. Anredera cordifolia was however still capable of enlarging the root mass despite suffering huge leaf losses. This would imply that A. cordifolia has an effective re-growth capacity and it will only be vulnerable to attack of the storage organs that enable re-growth, or to repeated attack of other plant parts through which reserves are exhausted. Unfortunately the period of exposure (24 days) was too short to prove that Phenrica sp. 2 impacts on the below ground dry mass, but should the plant be completely defoliated, as was observed in the field, the host plant would be forced to deplete stored resources. Phenrica sp.2 has shown to be very host specific and although A.cordifoia loses its leaves during the winter period in most provinces in South Africa, the adults are long-lived and should be able to survive the leafless periods. Further more the relatively short life cycle, high fecundity and 3 generations per year should theoretically insure a strong population build-up that would improve the chances of establishment in the field. All indications are that Phenrica sp. 2 is an agent well worth considering for the biological control of A. cordifolia.

This study aimed to determine the applicability of western migration models to the movement patterns of foreign migrant traders at the Hartebeespoort Dam. After reflecting on theoretical dimensions of migration and the informal sector, an overview was provided of the historical development of migration patterns to and within South Africa. The complex nature of migration phenomena ensures the application of qualitative and quantitative research methodologies. A snowball sampling technique was used to select 30 respondents for the purpose of the questionnaire survey. Information obtained from this survey was supplemented by five in-depth interviews. Descriptive statistical techniques were used to analyse the information obtained from the survey. The study concluded that western migration models do not offer adequate explanation for the migration patterns observed among foreign migrant traders at the Hartebeespoort Dam. The study also established the merit of the combined use of qualitative and quantitative research methodologies in migration studies. / Geography / M.A. (Geography)

A thesis submitted to the Faculty of Humanities, University of the Witwatersrand, Johannesburg, to fulfil the requirements for the degree of Doctor of Philosophy. Johannesburg 2016 / Fordsburg, in central Johannesburg (Joburg) is a globally connected locality hosting 15-20 thousand visitors every month from all over the world. Fordsburg is a microcosm of Johannesburg’s cosmopolitanism and bears a distinctly South Asian flavour. With a growing south Asian and Indian presence, it has assumed the name ‘Indian market of Johannesburg’. The dedication of the shopkeepers to keep prices low and the options of good bargains for consumers has helped the area to develop its own identity. The passion to rise upwards among newly arrived south Asian migrants marks the mood throughout Fordsburg market.1 This thesis will provide insights on Fordsburg as an area for Indian businesses deriving stories of businessmen, and labourers from various backgrounds, professions and nationalities. [No abstract provided. Information taken from introduction] / MT2017