Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 140-150). Also available in electronic version.

Errata sheet has been pasted onto the front end-paper. Bibliography: leaves 208-217. Outlines a systematic synthesis and testing of continual sterilization design. Principal aim is to evaluate and develop mathematical models for sterilization, undertake experimental studies for determining thermal inactivation effects on continuous processing of a liquid containing contaminant bacteria and compare the data obtained with those predicted by a selected model.

Background: Voluntary HIV counselling and testing (VCT) is considered one of the key strategies in the prevention and control of HIV/AIDS in South Africa. However its role in modifying risky sexual behaviour among patients tested as HIV-negative (primary prevention) is controversial. Objective: This study was intended to demonstrate the likelihood of VCT reducing risky sexual practices among patients testing sero-negative for HIV infection. Methods: This is a quantitative cross-sectional survey that took place over a period of 3½ months in a district hospital in rural South Africa. A self-administered questionnaire was completed by 54 patients who had VCT and tested sero-negative for HIV infection during the previous 12 months (Study Group). The same questionnaire was filled in by 61 patients who had never received VCT before (Control Group). Both groups consisted of women and men aged 18 years or older. Socio-demographic information, sexual behaviour, willingness to disclose the HIV sero-status with the sexual partner, and readiness to have VCT were asked in the survey. To compare differences between two independent proportions the Pearson Chi-square test was used. Significant results were regarded as a p-value of less than 0, 05, which was taken as an indication of association between VCT and the variable being measured. Results: The median age of our sample was 29 years (Interquartile Range 24-40), with most of the respondents (38 %) between the ages of 26 and 35 years. More than 90 % of patients in both groups reported being sexually active. Sexual intercourse with more than one partner was significantly lower in the Study group (p=0,003). Those who had never received VCT before had a higher (although not significant) incidence of episodes of unprotected sexual intercourse and symptoms of sexually transmitted infections (STIs) (81, 9 % and 42, 6 % respectively) when compared to the study group (77, 7 % and 35, 1 %). Most of the participants in both groups did not consider the disclosing of their sero-status an issue of concern for their sexual partner(s). Readiness to receive VCT was significantly higher in the study group (p=0, 02). Conclusions: In this study, people who tested sero-negative for HIV through VCT showed a significant decrease in the number of sexual partners as compared to the control group who did not undergo VCT. The VCT group had less unprotected sexual intercourse and less symptoms of STIs than the control group.

Orientador: Fernando Antônio de Ávila / Banca: Patrícia Amoroso / Banca: Branca Maria de Oliveira Santos / Banca: Ruben Pablo Schocken-Iturrino / Banca: José Moacir Marin / Resumo: Este trabalho objetivou trazer uma contribuição aos estudos relacionados à infecção cruzada, por Staphylococcus spp, dentro do ambiente dos consultórios odontológicos, destacando as principais fontes de contaminação e o provável risco a que os profissionais e pacientes estão expostos. Foram coletadas 160 amostras de água, 300 amostras de fômites e 360 amostras das mãos (direita e esquerda) e da cavidade nasal de dentistas, auxiliares e pacientes em 40 consultórios. A determinação da contagem de Staphylococcus spp na água, pelo método de filtração em Millipore® ,mostrou que 28% não atenderam ao padrão de potabilidade estabelecidos pela American Dental Association. Dentre os consultórios estudados, os de atendimento de convênio apresentaram a maior contaminação da água (62,5%) e os consultórios particulares (36%) e de convênios (35%) apresentaram maior contaminação em relação aos fômites pesquisados. As regiões de fômites mais contaminadas foram: assento (90%), maçaneta (80%), aparelho de Rx (76%) e caneta de alta rotação (70%). A área anatômica mais contaminada foi à cavidade nasal (66%) seguido da mão esquerda (57%) e mão direita (42%). A correlação entre os isolados de Staphylococcus spp nos fômites, água e áreas anatômicas significativa, podendo ser sugerido que houve infecção cruzada nos consultórios odontológicos estudados. As cepas de Staphylococcus spp, isoladas das águas de abastecimento do equipamento odontológico, foram sensíveis aos antibióticos ciprofloxacina (97%) e vancomicina (91%) e resistentes a oxacilina (78%), enquanto, as cepas, isoladas de fômites, das mãos e cavidade nasal foram sensíveis ao antibiótico ciprofloxacina (85%) e resistentes a oxacilina (88%). / Abstract: This work aimed at making a contribution to studies related to cross infection by Staphylococcus spp in the environment of dental offices, focusing on main contamination sources and possible risk for professionals and patients. There have been collected 160 samples of water, 300 samples of fomites, and 360 samples from hands (right and left) and nasal cavities of dentists, assistants, and patients in 40 dental offices. The count determination of Staphylococcus spp in water, through the Millipore® filtering method, has shown that 28% did not meet the standard of potability established by the American Dental Association. Among studied dental offices, dental care plan offices have presented the highest rate of contamination of water (62,5%), and private offices (36%) and dental care plan offices (35%) have presented the highest rate of contamination as to researched fomites. The most contaminated fomites areas were: chair (90%), door knob (80%), Rx device (76%), and high-speed handpiece (70%). The most contaminated anatomical area was the nasal cavity (66%), followed by left (57%) and right hands (42%). The correlation among isolated Staphylococcus spp in fomites, water, and anatomical areas was significant, therefore, it might be suggested that there has been cross infection in the studied dental offices. Strains of Staphylococcus spp, which had been isolated from dental equipment water, were sensible to antibiotics ciprofloxacin (97%) and vancomycin (91%), and they were resistant to oxacillin (78%); on the other hand, strains isolated from fomites in hands and nasal cavities were sensible to antibiotics ciprofloxacin (85%) and oxacillin (88%). / Doutor

Humans are subject to infection with a wide range of commensal and pathogenic organisms. Each pathogen requires an appropriate immune response to eliminate or control the invading organism and minimise pathology. Many pathogens have evolved strategies to subvert or manipulate the immune response and establish on-going infections. Similarly acute respiratory infection with virulent strains of influenza A virus are often poorly controlled by the immune system and can cause severe immunopathology and even fatality as a result of an inappropriate and excessive inflammatory response called a ‘cytokine storm’. Morbidity due to influenza infection and exacerbation by the immune response can vary greatly between individuals. The effect of underlying infection on the immune system could contribute to the variation in response. The aim of this project was therefore to determine if co-infection with two pathogens that establish on-going infections could alter the immune response to influenza A and impact the outcome of infection. Persistent infections with filarial helminths can cause debilitating disease and significantly impact the immune response toward a skewed TH2 or regulatory phenotype in order to control pathology. In contrast, infection with gammaherpesviruses in an immunocompetent host causes an initial inflammatory ‘anti-viral’ response before becoming an asymptomatic, latent infection. In an immunocompromised host, gammaherpesviruses can reactivate and lead to clinical presentation of disease. This suggests that these viruses require an on-going immune response to control all stages of infection. Both filarial helminths and gammaherpesviruses are common infections in human populations and therefore mouse models of these infections provide relevant systems to study their potential role in influenza virus infections. In a BALB/c murine co-infection model, latent infection with the rodent gammaherpesvirus MHV-68 led to significantly decreased weight loss and clinical signs following high dose infection with A/WSN/33, (a H1N1 influenza A virus). This was coupled with decreased immunopathology in the lung and fewer infiltrating lymphocytes in the alveolar spaces and around larger airways, although infectious virus titres were not significantly reduced. This response was coupled with a decreased production of inflammatory cytokines and chemokines in co-infected mice 6 days post infection which correlated with the amelioration of pathogenesis in these animals. A repeat of the study in 129Sv/Ev IFNγR knock out mice showed the same protective effect in the co-infected mice, suggesting IFNγ is not critical for the protective phenotype. Mice infected with latent MHV-68 alone showed a significant increase in expression of T cell chemokines in the lung and alveolar macrophages had a significantly increased production of suppressor of cytokine signalling (SOCS-1) suggesting latent MHV-68 infection may impact the phenotype of macrophages in the lung, modulating the response to influenza co-infection. A co-infection model with a persistent rodent filarial helminth, Litomosoides sigmodontis and A/WSN/33 was also established in BALB/c mice. The L4 developmental stage of L. sigmodontis infection had no impact on co-infection with A/WSN/33. Adult stage worms, however, appeared to have a protective effect against A/WSN/33 pathogenesis. Co-infected mice had significantly delayed weight loss and clinical signs 3-5 days post infection. CD4+ and CD8+ T cells in the lung draining lymph nodes had significantly reduced TH1 and TH2 phenotypes (measured by cytokine production) compared with singly infected controls. IFNγ secreting CD4+ T cells in the lungs of co-infected mice also secreted increased levels of IL-10, suggesting an increase in regulation of the inflammatory response to A/WSN/33. At the full patent stage of L. sigmodontis infection, co-infection with A/WSN/33 led to increased clinical signs and significantly exacerbated weight loss. CD4+ and CD8+ T cells in the lung draining lymph nodes were inflammatory in L. sigmodontis infected mice alone as well as co-infected mice and there were no differences in the percentage of CD4+ T cells in the lung secreting IL-10 and IFNγ between co-infected and influenza infected mice. A loss in regulatory responses during the patent stage of L. sigmodontis infection may therefore contribute to the loss of protection against A/WSN/33 at this time point within the co-infection model. Understanding the impact of an underlying infection on the immune system could provide immune mechanisms that could be exploited to increase vaccine efficacy against influenza and similarly help to provide better treatment for individuals infected with influenza A. These results may also help predict the outcome of influenza A infection in individuals already infected with highly immunogenic, on-going infections.

Made available in DSpace on 2016-04-01T17:54:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-03. Added 1 bitstream(s) on 2016-04-01T18:00:38Z : No. of bitstreams: 1 000860382.pdf: 1242104 bytes, checksum: 3320d53e62cee7f801cf9af5273b9dc1 (MD5) / A erliquiose em cães, causada pela bactéria Ehrlichia canis, é uma hemoparasitose com distribuição mundial, de natureza multissistêmica e com reflexos clínico-hematológicos diversos e importantes, que pode causar o óbito, tanto por suas alterações hematológicas quanto por possíveis alterações imuno-inflamatórias, oxidativas e hormonais consequentes. Tendo em vista a importância da manutenção do equilíbrio dos mecanismos hormonais e oxidativos na saúde animal, é de interesse clínico conhecer o comportamento dos eixos hipotálamo-hipófise-adrenocortical e hipotálamo-hipófise-tireoide em doenças multissistêmicas, como é o caso da infecção naturalmente adquirida por E. canis em cães, assim como da possibilidade do estresse oxidativo contribuir para a gravidade dos sinais clínicos. Assim, foram conduzidas avaliações das concentrações séricas de cortisol e de sulfato de dehidroepiandrosterona (DHEA-S) pré e pós-estimulação com hormônio adrenocorticotrópico (ACTH) sintético; do hormônio estimulador da tireoide (TSH), de T4 total (tetraiodotironina), T4 livre e de autoanticorpos anti-tireoglobulina séricos; do óxido nítrico (NOx), produto proteico de oxidação avançada (AOPP) e poder redutor de íons ferro (FRAP). As avaliações foram realizadas em soro de cães com infecção naturalmente adquirida por Ehrlichia canis no momento do diagnóstico e após o tratamento com hiclato de doxiciclina [5mg/kg (grupo II; n=6) e 10mg/kg (grupo III; n=6) a cada 12 horas, por 30 dias]. Amostras de soro obtidas de cães (n=6) saudáveis, provenientes do canil do Hospital Veterinário da FCAV/Unesp, Jaboticabal, foram utilizadas como controle (grupo I). A análise de variância de medidas repetidas foi utilizada para avaliar as respostas e a comparação de médias aos pares foi feita usando o teste de Tukey entre os grupos I, II e III, e pelo teste T-Student com correção de Welch entre o grupo I e os grupos... / Canine ehrlichiosis, caused by the bacterium Ehrlichia canis, is a disease with worldwide distribution with important hematological and clinical aspects, that may lead to death, both for its hematological disturbances and for possible consequent immune and inflammatory, oxidative and hormonal changes. Considering the importance in maintaining the balance of hormonal and oxidative mechanisms for animal health, it may be important to assess the hormonal behavior of hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axis in multissystemic disorders, as naturally acquired infection by E. canis, as well as the possibility of oxidative stress improves the severity of the clinical signs. Thus, cortisol and dehydroepiandrosterone sulfate (DHEA-S) pre and post-synthetic adrenocorticotropic hormone (ACTH) levels; thyroid-stimulating hormone (TSH), total T4 (tetraiodothyronine), free T4 and antithyroglobulin antibody; nitric oxide (NOx), advanced oxidation protein product (AOPP) and ferric reducing antioxidant power (FRAP) were measured. The assessments were performed from sera of dogs naturally infected with E. canis at baseline and after treatment with doxycycline hyclate [5mg/kg (group II; n=6) and 10mg/kg (group III; n=6) every 12 hours, for 30 days]. Serum samples of healthy dogs (n=6) from the kennel of the Veterinary Teaching Hospital of FCAV/Unesp, Jaboticabal, were used as control (group I). Repeated measures analysis of variance of was used in order to evaluate responses, and mean comparison was performed with Tukey's test between groups I, II and III. T-Student test followed by Welch's correction was used to compare group I with groups II and III. P value was set at 5%. Dogs naturally infected with E. canis have shown adequate capacity in secreting cortisol before ACTH stimulation, and have presented greater DHEA-S levels than healthy dogs at baseline moment of the study. Dogs with ehrlichiosis have shown greater ...

Made available in DSpace on 2014-06-11T19:25:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T20:13:38Z : No. of bitstreams: 1 paro_mlc_me_araca.pdf: 3376248 bytes, checksum: 3cb7c10029858de2655c594466804a68 (MD5) / As doenças infecciosas representam uma das principais causas de perda precoce dos dentes, podendo levar a seqüelas graves. Os microrganismos normalmente envolvidos nessas patologias quase sempre pertencem a microbiota autóctone da cavidade bucal e, quase invariavelmente, são de baixa virulência. Assim, o objetivo desse estudo foi avaliar a susceptibilidade a antimicrobianos de bactérias anaeróbias obrigatórias e anaeróbias facultativas isoladas de processos infecciosos da cavidade bucal, procurando verificar a existência de padrões de susceptibilidade à fármacos nas diferentes espécies e gêneros microbianos. As amostras microbianas foram obtidas de 4 casos de osteomielite crônica da mandíbula, 3 lesões periapicais refratárias ao tratamento endodôntico, 30 infecções endodônticas, 7 casos de periodontite agressiva localizada e 2 casos de periodontite agressiva generalizada. O isolamento dos microbiano foi realizado em meios de cultura seletivos e a identificação dos isolados foi realizada de acordo com suas características morfológicas e bioquímico-fisiológicas. Os isolados, uma vez identificados, foram mantidos em nitrogênio líquido (- 196 oC). Nos testes de susceptibilidade, empregou-se o método de diluição em ágar e o meio de cultura empregado foi o ágar infuso de cérebro coração acrescido de extrato de levedura. Os resultados evidenciaram resistência natural dos anaeróbios facultativos ao metronidazol e níveis moderados de resistência às penicilinas, enquanto a cefoxitina, a associação de amoxicilina/ácido clavulânico e imipenem foram quase que universalmente eficazes. A lincomicina e a clindamicina também se mostraram eficazes, particularmente sobre os anaeróbios obrigatórios. O principal mecanismo de resistência aos b-lactâmicos foi a produção de compostos capazes de degradar essas drogas. / Infections diseases represent one of the major causes of early tooth loss, and they can lead to sequels. The microorganisms involved oftenly in these pathologies belong to oral microflora and almost all of them are of virulence potential. Thus, the objective of this study was to evaluate the susceptibility to antimicrobials of obligate and facultative anaerobes recovered from infections in head and neck area, trying to verify the existence of susceptibility patterns to those drugs the different species and microbial goods. Microbials samples were obtained of 4 cases of chronic osteomyelitis, 3 refractary periapical lesions, 30 endodontics infections, 7 cases of localized aggressive periodontitis, 2 cases of generalized aggressive periodontitis. The isolation microbial was accomplished in selective culture means and the identification of the isolated ones was accomplished in agreement with its morphologic and biochemical-physiologic characteristics. The isolates, after identification, were maintained in liquid nitrogen (- 196°C). The susceptibility tests, were carried out throught na agar dilution method and the culture medium employed was brain heart infusion agar supplemented with yeast extract. The results evidenced natural resistance of facultative anaerobes to metronidazole and moderate levels of resistance to penicillin, while cefoxitin, amoxycillin/clavulanic acid and imipenem were almost universally effective, particularly on obligate anaerobes. The main mechanisms of resistance to b-lactams was the production of compounds capable to destroy these drugs.

Submitted in fulfillment of the requirements for the degree of Doctor of Technology: Health Sciences, Durban University of Technology, Durban, South Africa, 2018. / Soil-transmitted helminths are a major health concern, especially in tropical and sub-tropical regions. Poor sanitation and poverty are major pre-disposing factors contributing to increase in infections. Infection with STH is mainly through exposure to water, soil and food contaminated with the eggs of these parasites. Accurate detection and quantification of STH eggs in environmental samples is therefore critical for the determination of infection risks from exposure. Accurate detection of these eggs is also important in the adoption of risk reduction strategies. This thesis presents the development of a revised method for the accurate detection and quantification of STH eggs in different environmental matrices, such as wastewater, sludge etc. It further presents the application of this method in the comparative determination of STH egg reduction efficiencies of centralized wastewater treatment plants and decentralized wastewater treatment (DEWATS) plants in Durban, South Africa and Maseru, Lesotho. The concentration of viable STH eggs in dried sludge from Durban, South Africa and Dakar, Senegal was also determined and compared with both WHO guidelines and South African national standards for sludge reuse. The risks of infection with STHs for different populations exposed (directly and indirectly) to wastewater, wastewater contaminated surface water and sludge were determined using both quantitative microbial risks assessment and epidemiological approaches. Despite the plethora of methods available for the detection and quantification of STH eggs in the environment there is no internationally accepted method, however the most commonly used methods are based on the principles of sedimentation, differential flotation and microscopy. These are mainly adaptations of the WHO and USEPA methods. These methods were found to be similar with a few differences which affected the recovery rates reported. However, the major challenges with the conventional methods are the time needed for sample analysis and the use of reagents that could possibly affect the recovery of viable STH eggs. A new revised method was developed based on review of literature and laboratory experiments. In this method the heterogeneity of environmental samples was accounted for by the development of different pre-processing steps, involving the use of detergents to aid in the separation of eggs from particles in samples such as sludge, UD waste and untreated wastewater. Additionally, the use of sieves of different pore sizes ensured that the number of debris on the microscope slides was reduced considerably. The use of these sieves also reduced the time need for sample analysis, due to the elimination of the spontaneous sedimentation step, which is commonly used. This spontaneous sedimentation step takes between 12-24 hours therefore prolonging the time needed for sample analysis. Reagents such as acetoacetic acid and ethyl acetate were found to result in considerable loss of egg viability after just 5 minutes of exposure. This new method therefore does not involve their usage. The elimination of the use of acetoacetic acid and ethyl acetate step also reduces the number of steps involved in sample analysis. This reduces room for error as well as helping in fast analysis of samples. In addition to a much faster sample analysis the method has recovery percentages of 80.25% to 97.63% in sludge and wastewater samples respectively, with sensitivity of 2-3 eggs per liter in wastewater samples and 5-7 eggs per 20 gram of sludge. Exposure to STH eggs in the environment is mainly through wastewater, either treated or untreated, this exposure could therefore be eliminated through wastewater treatment. Centralized wastewater treatment systems are the most favored treatment options globally. These centralized treatment systems incur high cost of construction, maintenance and operations which may hamper the robustness in developing countries and rural areas. One of the most widely used alternative means of wastewater treatment is the anaerobic baffled reactors (ABRs) and planted gravel filters (PGFs) (collectively referred to as DEWATS in this thesis), which have been considered as low cost, effective wastewater treatment options. However, there is lack of comparative assessment of the STH egg removal efficiency of these two different wastewater treatment approaches. Eggs of Ascaris spp, hookworm, Trichuris spp, Taenia spp and Toxocara spp were the commonly recorded STH eggs in the untreated wastewater at the inlets of the centralized wastewater treatment plants as well as the DEWATS plants (except for Toxocara spp). There was variation in STH egg concentrations between and within the study areas, indicating difference in STH infections among the populations both in Durban and Maseru. STH egg removal varied between and within the different wastewater treatment plants as well. The DEWATS plants achieved 95-100% STH egg removals as compared to the 67 to 100% in the centralized wastewater treatment plants. This could be attributed to the difference in treatment processes. Among the different STHs, reduction in Ascaris spp eggs was significantly higher, irrespective of the type of treatment, which is attributed to the high relative density of the egg resulting in a higher settling velocity than the other STH eggs. Reduction or elimination of STH eggs through wastewater treatment is achieved by removing the eggs from the wastewater into the sludge. STH egg concentration in sludge is therefore mostly higher than in the wastewater. Sludge from Durban and Dakar after 60 days of drying under ambient environmental conditions contained very high concentration of viable STH eggs. Ascaris spp, hookworm, Trichuris spp, Taenia spp and Toxocara spp were the commonly recorded STH eggs, except for Dakar were Taenia spp and Toxocara spp were not detected in the sludge. STH egg concentrations were higher in Dakar than in Durban, with viable STH egg concentrations exceeding both the USEPA regulatory value (≤0.25 eggs/g TS) and the WHO guideline value (≤1 eggs/g TS). This variation in egg concentration could be attributed to the difference in prevalence and intensity of STH infections in the two study areas. Over a ten-month study period concentration of viable eggs in the sludge from Durban varied considerably, probably influenced by the environmental conditions. A decay rate of 0.0056 per day was calculated for egg die-off during drying. The rate of decay is low therefore drying alone cannot produce sludge meeting both local and international standards and guidelines for sludge reuse. Determination of STH infection risks due to exposure to wastewater and sludge either directly or indirectly is critical in the prevention of infection. Exposure to the effluents during wastewater irrigation is one major route of infection. STH egg concentrations in the final effluents from the centralized and DEWATS wastewater treatment plants were consistently higher than the WHO recommended guideline for unrestricted agricultural use (≤ 1 helminth egg/L), whereby the direct reuse of the effluents for agriculture was found to pose a higher risk than the WHO tolerable risk of infection (1 ×10-2 pppy) for farmers and consumers. Annually the use of effluents from the DEWATS plants poses the least risk of infection (1.9 ×10-2 (±2.4×10-4)), which is marginally higher than the WHO tolerable risk value. Well maintained DEWATS plants are more efficient in removing or reducing the concentration of STH eggs in wastewater and therefore pose the least risks of infection compared to centralized wastewater treatment plants. Consumers of vegetables from these farms are also at considerable risks of STH infections. Probabilistic assessment of the STH infection risks showed that farmers applying sludge from Durban and Dakar without adequate protective measures had risks of infections higher than the WHO tolerable risks figure (1×10-2 pppy). Based on the estimated risks of infection after decay, exposure to farm soil after 40-50 days of sludge application may reduce the risks of infection to levels lower the WHO tolerable risks value. However, this may not be practical due to the need for farmers to attend to their crops frequently. Incorporation of the decay of the eggs into the risks assessment also indicated that, using lettuce as a representative vegetable, harvesting of vegetables in Dakar could be done after 40 days of sludge application to reduce the risks of infection to the WHO tolerable value but in Durban harvesting after 30 days ensures that consumers are protected. Therefore, to protect both the farmers and consumers exposed to STH eggs through wastewater/sludge reuse in agriculture the implementation of the WHO multi-barrier approach to risk reduction is required. Risks of STH infections could be directly estimated using epidemiological approaches. By using this approach, the concept of STH infection risks for farmers using wastewater was assessed through direct measurements of the concentration of STHs both in wastewater used for irrigation and the farm soil, as well as the actual load of STHs ova in the stool of farmers and their family members. In Kumasi, Ghana, wastewater used for irrigation of vegetables and the farm soil contained high concentration of STH eggs. There was positive correlation between STH concentrations in the wastewater/soil and STH eggs load in stool of the exposed farmers. Stool analysis after 3 months, following deworming, showed a fast re-infection rate. Farmers exposed to the wastewater were three times more likely as compared to the control group of non-farmers to be infected with Ascaris spp (OR = 3.9, 95% CI, 1.15-13.86) and hookworm (OR = 3.07, 95% CI, 0.87-10.82). These risks of infection were higher in the rainy season than the dry season. This corresponds to a higher egg concentration in wastewater used for irrigation during this period. This indicates a relationship between STH infection and egg concertation in the environment. This study therefore contributes to the evidence-based conclusion that wastewater irrigation contributes to a higher incidence of STHs infection for farmers. In conclusion, this thesis therefore presents a new revised method that can be used to determine the STH egg concentration in different environmental samples. The development of this method also provides an opportunity to comparatively assess the STH egg reduction/removal efficiency of the more commonly used centralized wastewater treatment plants and DEWATS plants. The accurate quantification of viable STH eggs provide inputs for the probabilistic assessment of STH infection risks for different populations exposed to effluents from these two wastewater treatment approaches. This assessment of risks provides a public health perspective to the wastewater treatment. Additionally, it was concluded with the used of this method that drying of sludge for 60 days in Durban or Dakar does not produce sludge of good quality for agricultural application. This was confirmed by the estimates of STH infection risks determined using quantitative microbial risks assessment. This thesis therefore shows the importance of accurate quantification of STH eggs in the determination of infection risks either though QMRA or epidemiological approache / D

Made available in DSpace on 2014-06-11T19:29:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-18Bitstream added on 2014-06-13T20:19:23Z : No. of bitstreams: 1 camossi_lg_me_botfmvz.pdf: 3533496 bytes, checksum: 60945d70b81603efb8f19a414a05e3a3 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A toxoplasmose em ovinos é uma doença parasitária de grande importância médica veterinária, zootécnica e de saúde pública, uma vez que acarreta prejuízos na criação animal, gerado pelas perdas reprodutivas e econômicas, além de sua implicação na saúde humana, já que o consumo de carne e leite contaminados podem facilitar a transmissão zoonótica. Este estudo tem como propósito maior investigar a resposta imunológica das infecções naturais por Toxoplasma gondii em ovelhas, pela análise seqüencial de imunoglobulinas, objetivando a diferenciação entre os estágios agudo e crônico da doença, bem como a pesquisa do DNA do agente no leite pela técnica de PCR. Para realização do estudo utilizaram-se ovelhas em lactação, naturalmente infectadas por T. gondii, divididas em dois grupos: G1, com sorologia positiva, e G2, sorologicamente negativo, composto por 20 ovelhas cada um. A diferenciação dos estágios da infecção toxoplásmica, agudo ou crônico foi realizada pela técnica de aglutinação direta modificada (MAT) com antígeno fixado com formalina (MAT-AF) e metanol (MAT-AM) e pela Reação de Imunofluorescência Indireta para pesquisa de imunoglobulinas IgM e IgG. Os resultados sorológicos evidenciaram que as ovelhas demonstravam perfil sorológico de cronicidade da infecção. A detecção do parasito no leite foi realizada pela reação em cadeia pela polimerase (PCR), detectando-se o DNA do T. gondii em sete amostras de leite, provenientes de cinco ovelhas soropositivas, sendo que em duas ovelhas o DNA foi detectado no leite por duas vezes. A identidade molecular dos produtos amplificados foi confirmada pelo sequenciamento., obtendo-se de 97 a 100% de identidade com T. gondii, constituindo-se em resultado relevante quanto aos aspectos de saúde pública. / Toxoplasmosis is a major parasitary disease in sheep, due its importance in veterinary medicine and animal science and in public health, causing reproductive and economic losses to the herd, and also the prejudice to human health for the consumption of contaminated meat and milk, which can facilitate the zoonotic transmission. This study aims to investigate the immune response of natural infections by Toxoplasma gondii in sheep by sequence analysis of immunoglobulins, aiming to compare the acute and chronic stages of disease as well as DNA research agent in milk by the technique PCR. To accomplish the goal of this study, naturally infected by T. gondii lactating ewes were used, divided in two groups: G1, serologically positive, and G2, serologically negative, each group were composed by 20 ewes. The differentiation between the acute and chronic stages of the illness was made by the modified direct agglutination test (MAT) with antigens fixed with formaline (MAT-AF) and methanol (MAT-AM) and by the indirect fluorescent antibody test searching for IgM and IgG immunoglobulins. The serological results showed that the sheep showed serological profile of chronic infection. The detection of the parasite in milk was performed by polymerase chain reaction (PCR), detecting the DNA of T. gondii in seven milk samples from five seropositive sheep, and in two sheep DNA was detected in milk twice. The molecular identity of the amplified products was confirmed by sequencing, getting up for 97 to 100% identity with T. gondii, constituting an important result regarding the public health aspects

Orientador: Mirela Tinucci Costa / Banca: Marcos Rogério André / Banca: Marcio Antonio Brunetto / Banca: Ângela Merice de Oliveira Leal / Banca: Ana Silvia Dagnone / Resumo: A erliquiose em cães, causada pela bactéria Ehrlichia canis, é uma hemoparasitose com distribuição mundial, de natureza multissistêmica e com reflexos clínico-hematológicos diversos e importantes, que pode causar o óbito, tanto por suas alterações hematológicas quanto por possíveis alterações imuno-inflamatórias, oxidativas e hormonais consequentes. Tendo em vista a importância da manutenção do equilíbrio dos mecanismos hormonais e oxidativos na saúde animal, é de interesse clínico conhecer o comportamento dos eixos hipotálamo-hipófise-adrenocortical e hipotálamo-hipófise-tireoide em doenças multissistêmicas, como é o caso da infecção naturalmente adquirida por E. canis em cães, assim como da possibilidade do estresse oxidativo contribuir para a gravidade dos sinais clínicos. Assim, foram conduzidas avaliações das concentrações séricas de cortisol e de sulfato de dehidroepiandrosterona (DHEA-S) pré e pós-estimulação com hormônio adrenocorticotrópico (ACTH) sintético; do hormônio estimulador da tireoide (TSH), de T4 total (tetraiodotironina), T4 livre e de autoanticorpos anti-tireoglobulina séricos; do óxido nítrico (NOx), produto proteico de oxidação avançada (AOPP) e poder redutor de íons ferro (FRAP). As avaliações foram realizadas em soro de cães com infecção naturalmente adquirida por Ehrlichia canis no momento do diagnóstico e após o tratamento com hiclato de doxiciclina [5mg/kg (grupo II; n=6) e 10mg/kg (grupo III; n=6) a cada 12 horas, por 30 dias]. Amostras de soro obtidas de cães (n=6) saudáveis, provenientes do canil do Hospital Veterinário da FCAV/Unesp, Jaboticabal, foram utilizadas como controle (grupo I). A análise de variância de medidas repetidas foi utilizada para avaliar as respostas e a comparação de médias aos pares foi feita usando o teste de Tukey entre os grupos I, II e III, e pelo teste T-Student com correção de Welch entre o grupo I e os grupos... / Abstract: Canine ehrlichiosis, caused by the bacterium Ehrlichia canis, is a disease with worldwide distribution with important hematological and clinical aspects, that may lead to death, both for its hematological disturbances and for possible consequent immune and inflammatory, oxidative and hormonal changes. Considering the importance in maintaining the balance of hormonal and oxidative mechanisms for animal health, it may be important to assess the hormonal behavior of hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axis in multissystemic disorders, as naturally acquired infection by E. canis, as well as the possibility of oxidative stress improves the severity of the clinical signs. Thus, cortisol and dehydroepiandrosterone sulfate (DHEA-S) pre and post-synthetic adrenocorticotropic hormone (ACTH) levels; thyroid-stimulating hormone (TSH), total T4 (tetraiodothyronine), free T4 and antithyroglobulin antibody; nitric oxide (NOx), advanced oxidation protein product (AOPP) and ferric reducing antioxidant power (FRAP) were measured. The assessments were performed from sera of dogs naturally infected with E. canis at baseline and after treatment with doxycycline hyclate [5mg/kg (group II; n=6) and 10mg/kg (group III; n=6) every 12 hours, for 30 days]. Serum samples of healthy dogs (n=6) from the kennel of the Veterinary Teaching Hospital of FCAV/Unesp, Jaboticabal, were used as control (group I). Repeated measures analysis of variance of was used in order to evaluate responses, and mean comparison was performed with Tukey's test between groups I, II and III. T-Student test followed by Welch's correction was used to compare group I with groups II and III. P value was set at 5%. Dogs naturally infected with E. canis have shown adequate capacity in secreting cortisol before ACTH stimulation, and have presented greater DHEA-S levels than healthy dogs at baseline moment of the study. Dogs with ehrlichiosis have shown greater ... / Doutor