Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-17T13:18:52Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_IncidenciaInfeccaoHospitalar.pdf: 1290455 bytes, checksum: b987e2dd281d83e5bd2516f53119f227 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-10-17T14:09:11Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_IncidenciaInfeccaoHospitalar.pdf: 1290455 bytes, checksum: b987e2dd281d83e5bd2516f53119f227 (MD5) / Made available in DSpace on 2017-10-17T14:09:11Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_IncidenciaInfeccaoHospitalar.pdf: 1290455 bytes, checksum: b987e2dd281d83e5bd2516f53119f227 (MD5) Previous issue date: 2008 / Pacientes portadores do HIV/AIDS podem ser expostos aos mesmos riscos para aquisição de Infecção Hospitalar (IH) que os não infectados. Contudo, fatores relacionados à imunodepressão desses pacientes, representam papel importante na patogênese relacionada ao desenvolvimento da infecção nosocomial. O estudo investigou e comparou a incidência de infecções entre pacientes portadores do HIV e pacientes admitidos com outras doenças que não HIV/AIDS, internados na Clínica de Doenças Infecciosas e Parasitárias do Hospital Universitário João de Barros Barreto, e relacionou-o aos procedimentos invasivos (ventilador mecânico, sonda vesical de demora e cateter vascular central). A metodologia utilizada baseou-se em estudo analítico, observacional, prospectivo, realizado no período de fevereiro a dezembro de 2007, mediante visitas diárias aos pacientes desde a sua internação até a alta, na busca de infecções. Dentre as 1.130 saídas e 20.276 pacientes-dia, 40 pacientes evoluíram com IH, sendo 17 (42,5%) pacientes não-HIV e 23 (57,5%) pacientes HIV positivos, na qual desenvolveram 19 (39,6%) e 29 (60,4%) infecções hospitalares, respectivamente. 11 (55%) pacientes HIV positivos apresentaram contagem de células TCD4<100cél/mm3 e 15 (65,22%) evoluíram a óbito associado à IH. A incidência de infecção hospitalar foi maior para os pacientes HIV positivos, com 3,09 episódios por 1000 pacientes-dia, que para os pacientes não-HIV (1,74 episódios por 1000 pacientes-dia), assim como a pneumonia, topografia mais freqüente, a qual teve uma incidência de 1,6 episódios por 1000 pacientes-dia. Quanto à influência do procedimento invasivo, a infecção do trato urinário (ITU) foi maior nos pacientes não-HIV com 12,11 episódios de ITU relacionada à sonda vesical de demora (SVD) por 1000 SVD-dia. Os resultados deste estudo sugerem que os pacientes HIV positivos são mais predispostos a evoluir com IH, provavelmente pelo seu estado imunológico associado aos procedimentos invasivos, o que justifica a necessidade de medidas preventivas direcionadas para esta população. / HIV/AIDS patients may be exposed to the same risks for acquisition of nosocomial infections than non-HIV/AIDS patients, however, factors related to the immune suppression of former patients represent important paper in the pathogenesis for the development of nosocomial infections. This study investigated and compared the incidence of infections between HIV infected inpatients and non-infected inpatients in the Infectious Diseases Service of Hospital Universitário João de Barros Barreto. Nosocomial infections were related to invasive procedures (mechanical ventilation, urinary and central vascular catheter). It was an analytical, observational and prospective study, accomplished from February to December, 2007. Daily visits were performed by infection control team and the researcher from the first day in the Hospital to his discharge. There were reported 1.130 exits and 20.276 patients-day; 40 patients developed nosocomial infections and 17 (42,5%) non-HIV patients had 19 (39,6%) infections and 23 (57,5%) HIV patients developed 29 (60,4%) infections; eleven (55%) of these 23 patients had T4 cells counts less than 100cells/mm3 and 15 (65,22%) deaths were related to nosocomial infections. Hospital infections rates in HIV patients were higher than in non-HIV patients (3.09 versus 1.74 infections by 1000 patients-day). Pneumonia was the most frequent infection site an its incidence was 1,6 episodes for 1000 patients-day. Urinary tract infection in non-HIV patients was 12,11 episodes by 1000 urinary catheters-day compared to 4,41 episodes by 1000 urinary catheters-day in HIV positive patients. In conclusion, HIV patients are more susceptible to acquire nosocomial infections probably because of immune suppression related to HIV infection and invasive procedures and preventive and control measures should be directed to this patient population.

Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-18T15:55:51Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PrevalenciaPneumoniaUnidade.pdf: 2308365 bytes, checksum: 00d2b3ad3bcd519d7d2de9783c94ebc6 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-11-14T15:30:13Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PrevalenciaPneumoniaUnidade.pdf: 2308365 bytes, checksum: 00d2b3ad3bcd519d7d2de9783c94ebc6 (MD5) / Made available in DSpace on 2017-11-14T15:30:13Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PrevalenciaPneumoniaUnidade.pdf: 2308365 bytes, checksum: 00d2b3ad3bcd519d7d2de9783c94ebc6 (MD5) Previous issue date: 2012-09-12 / A pneumonia constitui um importante problema de saúde pública contribuindo com altas taxas de morbidade e mortalidade no mundo principalmente nos países em desenvolvimento. Este estudo tem como objetivo avaliar a prevalência de pneumonia em crianças hospitalizadas em Unidade de Terapia Intensiva pediátrica, bem como estimar a incidência destas crianças, com diagnostico de pneumonia e quais variáveis estão associadas com o desenvolvimento da pneumonia, determinar qual a incidência da mortalidade infantil nesta Unidade de Terapia Intensiva por pneumonia. Trata-se de um estudo de caráter descritivo com delineamento transversal e abordagem retrospectiva a partir de revisão de prontuários de crianças que estiveram hospitalizadas em uma Unidade de Terapia Intensiva pediátrica de um hospital público municipal de Imperatriz no Maranhão, durante o período de janeiro a dezembro de 2011. Os dados foram obtidos inicialmente através dos registros contidos em livro de admissão das crianças na Unidade de Terapia Intensiva Pediátrica, onde se constatou 230 admissões. Em um segundo momento, foram selecionados e incluídos na pesquisa prontuários de crianças de ambos os sexos na faixa etária de um mês a 12 anos de idade, internados Unidade de Terapia Intensiva pediátrica com diagnóstico de pneumonia hospitalar, perfazendo uma amostra de 60 prontuários, dos quais realizou-se coleta dos dados contidos nos mesmos utilizando-se formulário previamente estruturado. Dos 230 pacientes internados na Unidade de Terapia Intensiva do referido hospital, no período de janeiro a dezembro de 2011 26%(n=60) desenvolveram pneumonia nosocomial, faixa etária que compreende entre 1 a 12 meses 63% (n=38), seguidos das idades entre 13 e 36 meses com 36%(n= 13 ), o diagnóstico de pneumonia foi de 26%. Observou-se que a pneumonia relacionada a assistência à saúde no Hospital Infantil de Imperatriz representou uma complicação frequente em pacientes pediátricos sob cuidados intensivos, sendo um fator agravante para ocorrência de óbitos, com importante relação a procedimentos invasivos em especial ventilação mecânica invasiva, bem como a terapêutica utilizada. / Pneumonia is an important public health problem contributing to high rates of morbidity and mortality in the world especially in developing countries. This study aims to evaluate the prevalence of pneumonia in children hospitalized in the pediatric intensive care unit, as well as to estimate the incidence of these children, with diagnosis of pneumonia and identify variables associated with the development of pneumonia, which determine the incidence of infant mortality this ICU for pneumonia. This is a descriptive study with cross-sectional and retrospective approach from a review of medical records of children who were hospitalized in a pediatric intensive care unit of a Municipal Hospital in Imperatriz Maranhão, during the period January to December 2011. data were initially obtained through the records contained in the admission book of children in the Pediatric Intensive Care Unit, where they found 230 admissions. In a second stage, were selected and included in the records of children of both sexes aged one month to 12 years of age, hospitalized pediatric intensive care unit with a diagnosis of nosocomial pneumonia research, making a sample of 60 medical records of which held the collection of the data contained therein using previously structured form. Of the 230 patients admitted to the Intensive Care Unit of the hospital, in the period January-December 2011 26% (n = 60) developed nosocomial pneumonia, age between 1 to 12 months 63% (n = 38), followed ages between 13 and 36 months with 36% (n = 13), the diagnosis of pneumonia was 26%. It was observed that pneumonia related to health care at the Children's Hospital the Imperatriz represented a common complication in pediatric patients under intensive care, being an aggravating factor for the occurrence of deaths, with important relationship to invasive procedures particularly invasive mechanical ventilation as well as therapy used.

Pseudomonas aeruginosa est un pathogène opportuniste responsable de pneumonies. Il est particulièrement impliqué dans la mortalité des patients sous ventilation mécanique et des patients atteints de la mucoviscidose. Ces infections sont difficiles à traiter en raison de l’existence de nombreuses résistances aux antibiotiques chez cette bactérie et des alternatives thérapeutiques s’avèrent donc nécessaires. Nous avons ainsi émis l’hypothèse qu’une application oropharyngée de lactobacilles pourrait permettre de limiter les infections à P. aeruginosa et leurs effets chez les patients concernés. L’objectif principal de ce travail était d’évaluer les effets d’un mélange de lactobacilles dans un modèle murin de pneumonie à P. aeruginosa. Les effets de lactobacilles isolés dans les cavités orales de volontaires sains sur la formation de biofilm et l’activité élastolytique de P. aeruginosa PAO1 ont été mesurés in vitro. Les effets des lactobacilles sélectionnés ont ensuite été évalués dans un modèle d’infection de cellules épithéliales respiratoires(A549) par P. aeruginosa PAO1 puis dans un modèle murin de pneumonie à P. aeruginosa PAO1. Les effets de 87 lactobacilles sur la formation de biofilm et l’activité élastolytique de P. aeruginosa PAO1 ont été déterminés in vitro,aboutissant à la sélection de 3 et 5 souches ayant respectivement inhibé la formation de biofilm et l’activité élastolytique de P. aeruginosa PAO1. Parmi ces souches, L. fermentum K.C6.3.1E, L. paracasei ES.D.88 et L. zeae Od.76,qui étaient les souches les plus actives contre la formation de biofilm ou l’activité élastolytique et les plus acidifiantes lors de croissances dans une salive artificielle, ont été associées dans un mélange testé dans un modèle cellulaire d’infection à P. aeruginosa PAO1. Ce mélange n’a pas eu d’effet cytotoxique et a démontré un effet cytoprotecteur vis-à-vis de l’infection à P. aeruginosa PAO1. In vivo, l’administration intratrachéale de ces mêmes bactéries de façon prophylactique a permis d’une part de réduire les charges pulmonaires en P. aeruginosa PAO1 et d’autre part de réduire ses effets pro-inflammatoires au niveau pulmonaire (IL-6, TNF-α). Ces résultats prometteurs laissent entrevoir la possibilité de nouvelles applications thérapeutiques pour les probiotiques. / Pseudomonas aeruginosa is an opportunistic pathogen that causes pneumonia and which is involved in themortality of mechanically-ventilated or cystic fibrosis patients.These infections are difficult to treat because of the existence of many antibiotic resistances in P. aeruginosa and therapeutic alternatives are needed. Our hypothesis was that the use of probiotics could be an alternative to antibiotic therapy in order to reduce P. aeruginosa infections and its injurious and pro-inflammatory effects in lungs.The main goal of this work was to evaluate the effects of lactobacilli in a murine model of P. aeruginosa pneumonia.The first step of this work was to screen lactobacilli isolated from oral cavities of healthy volunteers against biofilmformation and elastolytic activity of P. aeruginosa PAO1. The effects of selected lactobacilli were then evaluated in amodel of infection of lung epithelial cells by P. aeruginosa PAO1 and in a murine model of P. aeruginosa PAO1pneumonia. Eighty-seven lactobacilli were tested in vitro, leading to the selection of 3 and 5 strains respectively active against biofilm formation and elastolytic activity. The most active strains (L. fermentum K.C6.3.1E, L. paracasei ES.D.88and L. zeae Od.76) toward biofilm formation and elastolytic activity were chosen to be tested in vitro, in a cell model of P. aeruginosa PAO1 infection. This mix showed cytoprotective effect against P. aeruginosa PAO1. Finally, the prophylactic intratracheal administration of the mix of lactobacilli in mice allowed to reduce the pulmonary loads in P.aeruginosa PAO1. In the same time, the pro-inflammatory effects(IL-6 and TNF- α) of the infection were reduced. These promising results suggest the possibility of new therapeutic applications for probiotics.

Submitted by Ana Rosa Silva (arosa@ufpa.br) on 2012-07-31T13:51:13Z No. of bitstreams: 2 Tese_PesquisaEpidemiologicaMolecular.pdf: 2189674 bytes, checksum: 71e01a2190e47150066bfdf839a116bc (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2012-07-31T13:51:50Z (GMT) No. of bitstreams: 2 Tese_PesquisaEpidemiologicaMolecular.pdf: 2189674 bytes, checksum: 71e01a2190e47150066bfdf839a116bc (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2012-07-31T13:51:50Z (GMT). No. of bitstreams: 2 Tese_PesquisaEpidemiologicaMolecular.pdf: 2189674 bytes, checksum: 71e01a2190e47150066bfdf839a116bc (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2011 / FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas / IEC - Instituto Evandro Chagas / A pneumonia e a bronquiolite na infância são as principais causas de morbidade e mortalidade no mundo, sendo o Vírus Respiratório Sincicial Humano (VSRH) o principal agente viral. O VSRH está associado a surtos anuais de doenças respiratórias, onde a co-infecção bacteriana tem sido relatada. Este foi o primeiro estudo do VRSH em crianças hospitalizadas com Pneumonia Adquirida na Comunidade (PAC) em Belém, Pará (Norte do Brasil), que teve como objetivo determinar a prevalência da infecção pelo VSRH e avaliar as características clínicas e epidemiológicas dos pacientes. Métodos. Foi realizado um estudo prospectivo em oito hospitais no período de novembro de 2006 a outubro de 2007. Foram testadas 1.050 amostras de aspirado nasofaríngeo para o VRSH, obtidas de crianças hospitalizadas com até três anos de idade com diagnóstico de PAC, pelo método da imunofluorescência direta e da reação em cadeia por polimerase após transcrição reversa (RT-PCR) para identificação do subtipo viral. Foram obtidos resultados da dosagem de proteína C-reativa (PCR) e da cultura bacteriana. Resultados. A infecção pelo VSRH foi diagnosticada em 243 (23,1%) crianças. A idade média do grupo VRSH-positivo foi menor do que a do grupo VRSH-negativo (12,1 meses versus (vs) 15,5 meses, ambos com variância de 1-36 meses, p<0,001), enquanto que a distribuição por genero foi similar. O grupo VRSH-positivo apresentou menor dosagem (PCR) quando comparados ao grupo VRSH-negativo (15,3 vs 24.0 mg/dL, p<0,05). Os achados radiológicos confirmaram que 54,2% do grupo VRSH-positivo e 50,3% do grupo VRSH-negativo apresentavam infiltrado intersticial. A infecção bacteriana foi identificada predominantemente no grupo VRSH-positivo (10% vs 4,5%, p<0,05). Rinorréia e obstrução nasal foram predominantemente observadas no grupo VRSH-positivo. A co-circulação dos subtipos A e B foi observada, com predominância do subtipo B (209/227). A análise multivariada revelou que a idade de 1 ano (p<0,015), os níveis de PCR inferior a 48 mg/dL (p<0,001) e a co-infecção bacteriana (p<0,032) foram independentemente associados com a presença do VRSH em oposição ao grupo VRSH-negativo, e na análise dos sintomas, a obstrução nasal foi independentemente associada com o grupo VRSH-positivo (p<0,001). Conclusão. O presente estudo destaca a relevância da infecção por VSRH em casos hospitalizados de PAC em nossa região; nossos resultados justificam a realização de investigações adicionais que possam ajudar a elaborar estratégias para o controle da doença. / Childhood pneumonia and bronchiolitis is a leading cause of illness and death in young children worldwide with Respiratory Syncytial Virus (RSV) as the main viral cause. RSV has been associated with annual respiratory disease outbreaks and bacterial co-infection has also been reported. This study is the first RSV study in young children hospitalized with community-acquired pneumonia (CAP) in Belém city, Pará (Northern Brazil). It had the objective of determining the prevalence of RSV infection and evaluating the patients’ clinical and epidemiological features. Methods. We conducted a prospective study across eight hospitals from November 2006 to October 2007. In this study, 1,050 nasopharyngeal aspirate samples were obtained from hospitalized children up to the age of three years with CAP, and tested for RSV antigen by direct immunofluorescence assay and by Reverse Transcription Polymerase Chain Reaction (RT-PCR) for RSV subtype identification. Levels of C-reactive protein (CRP) and results of bacterial infection were also obtained. Results. RSV infection was diagnosed in 243 (23.1%) children. The mean age of the RSV-positive group was lower than the RSV-negative group (12.1 months vs 15.5 months, both ranged 1-36 months, p<0.001) whereas gender distribution was similar. The RSV-positive group showed lower CRP mean levels when compared to the RSV-negative group (15.3 vs 24.0 mg/dL, p<0.05). Radiological findings showed that 54.2% of RSV-positive group and 50.3% of RSV-negative group had interstitial infiltrate. Bacterial infection was identified predominantly in the RSV-positive group (10% vs 4.5%, p<0.05). Rhinorrhea and nasal obstruction were predominantly observed in the RSV-positive group. A co-circulation of subtypes A and B was noted, with a predominance of subtype B (209/227). Multivariate analysis revealed that age under 1 year (p<0.015), CRP levels under 48 mg/dL (p<0.001) and bacterial co-infection (p<0.032) were independently associated with the presence of RSV as opposed to RSV-negative group, and in analyze of symptoms, nasal obstruction were independently associated with RSV-positive group (p<0.001). Conclusion. The present study highlights the relevance of RSV infection in hospitalized cases of CAP in our region; our findings warrant the conduct of further investigations which can help design strategies for controlling the disease.

Pulse oximeters are low-cost, easy to use, and effective at detecting hypoxemia (low blood oxygen levels), a common complication of bronchiolitis, asthma, and pneumonia, the leading infectious cause of death in children worldwide. However, pulse oximeters are often unavailable in lowincome settings, and if available, often underused, yet little research investigates why. In this thesis, I examine pulse oximeter implementation in low-income settings, focusing on Kenyan hospitals as a case study, and using a mixed-methods approach. I conducted a systematic literature review, examining how pulse oximeter use with children at admission to hospital impacts health outcomes; I then conducted quantitative analyses of 28,000 children admitted to seven Kenyan hospitals to determine with which children pulse oximeters are used, and pulse oximetry's impact on treatment provision; these analyses informed the qualitative research component, for which I conducted interviews with 30 healthcare workers (HCWs) and staff in 14 Kenyan hospitals and employed theoretical frameworks to determine how HCWs decide whether to use pulse oximeters, and the barriers to pulse oximetry. I found that pulse oximeter use varies substantially between and within Kenyan hospitals over time. After adjusting for case-mix and signs of illness severity, HCWs were most likely to use pulse oximeters with children with a very high respiratory rate, indrawing and/or who were not alert; children who obtained a pulse oximeter reading were more likely to be prescribed oxygen than if a pulse oximeter was not used; and children with a reading below 90% were more likely to be prescribed oxygen than those with higher readings, suggesting that HCW decision-making is influenced by international and national guidelines. However, HCWs sometimes cannot use pulse oximeters when they intend to, because of insufficient pulse oximeter availability, largely due to inefficient and confusing procurement processes and repair delays. Furthermore, HCWs sometimes use pulse oximeters incorrectly or misinterpret their results, because of insufficient training. Pulse oximeter promotion programme planners can use the recommendations I provide to effectively target barriers to pulse oximeter uptake in low-income settings. Increased pulse oximetry implementation could enable early detection of hypoxemia, improving accurate diagnosis, and supporting prompt, effective treatment, which could help reduce mortality in children needing oxygen, in line with Sustainable Development Goal 3.

Orientador: Magda Adelaide Lombardo / Coorientador: Sandra Elisa Contri Pitton / Banca: José Bueno Conti / Banca: Ana Tereza Cáceres Cortez / Banca: Sílvia Aparecida Guarnieri Ortigoza / Banca: Tânia Maria de Campos Leite / Resumo: Esta pesquisa, realizada no campo da Geografia Médica, tem como objetivo estabelecer interface entre o clima e a saúde. Nessa ótica, buscou-se analisar a variabilidade dos elementos climáticos nas ocorrências de casos de internação por pneumonia, relacionando-os com os fatores de risco dos grupos dos pacientes e riscos socioeconômicos da população em estudo. Tomou-se a cidade de Rio Claro como exemplo de caso, para estimar a associação existente entre os totais diários de internação por pneumonia, obtidos pelo Sistema de Informação Hospitalar (AIH/SUS), e os dados meteorológicos (temperatura, precipitação e umidade), obtidos junto a Estação Metereológica do Centro de Análise e Planejamento Ambiental (CEAPLA) e pelo Laboratório de Análise Metereológica e Climatologia Aplicada da UNESP-campus de Rio Claro-SP no período compreendido entre janeiro de 2000 e dezembro de 2009. Foi evidenciado que o número de ocorrência de internação por pneumonia sofreu acréscimo durante os meses de outono e inverno, época em que foram registradas baixas temperaturas e período de estiagem. Com relação à distribuição espacial, verificou-se que as áreas de concentração de domicílios dos pacientes se localizaram na zona central, onde há uma grande concentração de pessoas e a frota de veículos é mais numerosa, gerando mais poluentes na atmosfera, e nos bairros periféricos, onde as moradias têm menor qualidade de acabamento e a população se torna mais vulnerável. Pelas evidências, foi possível concluir que as condições climáticas têm influência sobre a morbidade respiratória / Abstract: This research made in Medical Geography field aims to establish an interface between climate and health. In this viewpoint, the climatic factor variability had been analyzed on the hospital stay for pneumonia, correlating with the risk factors of risk patient groups and the population's socioeconomic study. The city of Rio Claro, Sao Paulo State, Brazil, had been taken as the geographical study place to estimate the linking between daily totals of hospital stay for pneumonia, got by the Hospital Information System (AIH/SUS), and the meteorological data - temperature, precipitation, moisture - which had been gotten from the Climatology Laboratory of Geography Department, Unesp (Sao Paulo University) - Rio Claro campus and Climatological Station to the Center of Analysis and Environmental Planning (CEAPLA), during the period between January 2000 and December 2009. The number of hospitalization for pneumonia had been increased during autumn and winter months due to the low temperature and dry periods which had been recorded. Related to special distribution, it had been shown that the patient housing area concentration had been located in the central area as well peripheral ones such as Mae Preta and Chervezon. In the central areas there as been a large concentration of people and a high number of vehicles which results in more pollutants in the atmosphere. Therefore, in the peripheral region houses have been presenting low housing finishing, becoming such population more vulnerable to this health problem. However, it is possible to conclude that the climate has influence on respiratory morbidity / Doutor

Mycoplasma hyopneumoniae est l’agent causal de la pneumonie enzootique. On le retrouve dans plusieurs élevages de porcs à travers le monde. Même si ce micro-organisme est présent dans plusieurs troupeaux canadiens, peu d’informations sont présentement disponibles sur les isolats québécois. Un total de 160 poumons de porcs possédant des lésions de pneumonie ont été récupérés à l’abattoir, mis en culture et testés par PCR pour M. hyopneumoniae et Mycoplasma hyorhinis. D’autres pathogènes bactériens communs du porc et les virus du syndrome reproducteur et respiratoire porcin (VSRRP), de l’influenza et le circovirus porcin de type 2 (CVP2) ont été également testés. Quatre-vingt-dix pourcent des échantillons étaient positifs pour M. hyopneumoniae et 5.6% l’étaient seulement pour M. hyorhinis. Dans ces échantillons positifs pour M. hyopneumoniae, la concentration de ce mycoplasme variait de 1.17 x 105 à 3.37 x 109 génomes/mL. Vingt-cinq poumons positifs en culture ou par PCR en temps réel pour M. hyopneumoniae ont été sélectionnés, parmi ceux-ci 10 étaient en coinfection avec Pasteurella multocida, 12 avec Streptococcus suis, 9 avec CVP2 et 2 avec le VSRRP. Les analyses des nombres variables de répétitions en tandem à de multiples loci (MLVA) et PCR-polymorphisme de longueur de fragments de restriction (PCR-RFLP) de M. hyopneumoniae ont démontré une forte diversité des isolats de terrain. Par contre, il semble y avoir plus d’homogénéité à l’intérieur d’un même élevage. L’analyse MLVA a également démontré que près de la moitié des isolats possédaient moins de 55% d’homologie avec les souches vaccinales et de référence utilisées dans la présente étude. L’absence d’amplification du locus 1 de M. hyopneumoniae en MLVA a été significativement associée à une baisse de la concentration de bactérie et de la sévérité des lésions. Pour tous les isolats de M. hyopneumoniae, des concentrations minimales inhibitrices (CMI) de faibles à intermédiaires ont été obtenues envers tous les antimicrobiens testés. Les isolats possédant des CMI intermédiaires envers les tétracyclines, les macrolides et les lincosamides ont été testés pour la présence des gènes de résistance tetM, ermB et pour des mutations ponctuelles dans les gènes des protéines L4, L22 et de l’ARNr 23S. Aucun de ces gènes n’a été détecté mais la mutation ponctuelle G2057A a été identifiée. Cette mutation est responsable de la résistance intrinsèque de M. hyopneumoniae face aux macrolides à 14 carbones. Ces résultats indiquent qu’il ne semble pas y avoir de résistance acquise aux antimicrobiens parmi ces isolats. En conclusion, cette recherche a permis d’obtenir de nouvelles données scientifiques sur les isolats québécois de M. hyopneumoniae. / Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, is present in swine herds worldwide. However, little is known about the prevalence of this microorganism in Quebec and Canadian herds. A total of 160 swine lungs with lesions suggestive of enzootic pneumonia were recovered from two slaughterhouses. They were cultured and tested by PCR for M. hyopneumoniae and Mycoplasma hyorhinis and for the porcine reproductive and respiratory syndrome virus (PRRSV), the influenza virus, and the porcine circovirus type 2 (PCV2). Samples were also cultured for other commonly encountered swine pathogenic bacteria. Ninety percent of the samples were positive for M. hyopneumoniae (Real-time PCR) whereas 5.6% were positive only for M. hyorhinis (PCR). The concentration of M. hyopneumoniae in these positive samples varied between 1.17 x 105 and 3.37 x 109 genomes/mL Among 25 selected M. hyopneumoniae positive lungs (culture or real-time PCR), 10 demonstrated a co-infection with Pasteurella multocida, 12 with Streptococcus suis, 9 with PCV2 and 2 with the PRRS virus. Multiple loci variable number of tandem repeats analysis (MLVA) and PCR-restriction fragments length polymorphism (PCR-RFLP) analyses showed a high diversity among field M. hyopneumoniae isolates. However, there seemed to be greater homogeneity within the same herd. The MLVA analysis also demonstrated that almost half of the field isolates presented less than 55% homology with the vaccine and reference strains used in our study. The absence of amplification of one locus (locus 1) of M. hyopneumoniae was significantly associated with a lower number of bacteria and a lower severity of lung lesions. All M. hyopneumoniae isolates showed low to intermediate MICs against the antimicrobials tested. Cultures with intermediate MICs for tetracyclines, macrolides and lincosamides were tested for the presence of previously described resistance genes tetM, ermB and L4, L22 and 23S rRNA point mutations. None of these genes were found, although one point mutation, G2057A, was identified. This mutation is responsible for the intrinsic resistance of M. hyopneumoniae against 14-membered macrolides. These results indicate that there is probably no acquired antimicrobial resistance within these isolates. This research provides new scientific data on M. hyopneumoniae isolates from Canada.

Le métapneumovirus humain (hMPV) est un virus responsable d'infections aiguës des voies respiratoires telles que des bronchiolites, des bronchites ou des pneumonies, principalement chez les populations à risques que sont les jeunes enfants de moins de 5 ans, ainsi que les personnes âgées ou immunodéprimées. Découvert en 2001, ce virus et sa pathogénèse ne restent encore aujourd'hui que partiellement caractérisés. De ce fait et malgré les besoins, il n'y a aucun vaccin ou traitement thérapeutique spécifique et efficace contre le HMPV disponible sur le marché. Dans ce contexte, mon projet de thèse s'est articulé autour de deux axes principaux : (i) L'étude de la protéine de fusion F du virus hMPV, protéine majeure antigénique de surface et responsable de l'entrée du virus dans la cellule cible. Elle a pour particularité d'induire de manière autonome la fusion membranaire in vitro et d'être associée à des effets cytopathiques variable selon les souches virales. De par son rôle clé pour le virus hMPV, la protéine F a déjà fait l'objet de plusieurs études structurales et fonctionnelles mais les déterminants de cette activité fusogénique ne sont pas encore entièrement caractérisés. Nous nous sommes donc intéressés à l'identification de déterminants du phénotype viral hyperfusogénique, localisés dans les domaines heptad repeats de la protéine F du hMPV. (ii) L'atténuation de deux souches virales cliniques (CAN98-75 et C-85473) par délétion de gènes accessoires dans le but de développer des candidats vaccinaux adaptés aux enfants en bas âge. Différents virus ont été générés par génétique inverse et les délétions des gènes accessoires SH et G dans les deux fonds génétiques viraux ont été étudiées pour leur impact sur l'infectivité, la réplication et la pathogénèse virale in vitro et in vivo ainsi que leur contribution pour le développement de virus atténués candidats vaccinaux / Human metapneumovirus (hMPV) is a major pathogen responsible of acute respiratory tract infections, such as bronchiolitis or pneumonia, affecting especially infants, under five years old, elderly individuals and immunocompromised adults. Identified since 2001, this virus and its pathogenesis still remain largely unknown and no licensed vaccines or specific antivirals against hMPV are currently available. In this context, my research project was built over two main subjects: (i) The study of the fusion F glycoprotein which is the major antigenic protein of hMPV and is responsible of viral entry into host cell. By its crucial role for the virus, the F protein has already been characterized in several structural and/or functional studies. Thus, it has been described that the hMPV F protein induces membrane fusion autonomously, resulting in variable cytopathic effects in vitro, in a strain-dependent manner. However, as the determinants of the hMPV fusogenic activity are not well characterized yet, we focused on identification of some of these, located in heptad repeats domains of the protein. (ii) The evaluation of hMPV SH and G gene deletion for viral attenuation. Liveattenuated hMPV vaccine candidates for infants’ immunization has been constructed thank to this deletion approach at the beginning of hMPV vaccine development efforts. Despite encouraging results, these candidates have not been further characterized and the importance of the viral background has not been evaluated

No description available.

Mycoplasma hyopneumoniae est l’agent causal de la pneumonie enzootique. On le retrouve dans plusieurs élevages de porcs à travers le monde. Même si ce micro-organisme est présent dans plusieurs troupeaux canadiens, peu d’informations sont présentement disponibles sur les isolats québécois. Un total de 160 poumons de porcs possédant des lésions de pneumonie ont été récupérés à l’abattoir, mis en culture et testés par PCR pour M. hyopneumoniae et Mycoplasma hyorhinis. D’autres pathogènes bactériens communs du porc et les virus du syndrome reproducteur et respiratoire porcin (VSRRP), de l’influenza et le circovirus porcin de type 2 (CVP2) ont été également testés. Quatre-vingt-dix pourcent des échantillons étaient positifs pour M. hyopneumoniae et 5.6% l’étaient seulement pour M. hyorhinis. Dans ces échantillons positifs pour M. hyopneumoniae, la concentration de ce mycoplasme variait de 1.17 x 105 à 3.37 x 109 génomes/mL. Vingt-cinq poumons positifs en culture ou par PCR en temps réel pour M. hyopneumoniae ont été sélectionnés, parmi ceux-ci 10 étaient en coinfection avec Pasteurella multocida, 12 avec Streptococcus suis, 9 avec CVP2 et 2 avec le VSRRP. Les analyses des nombres variables de répétitions en tandem à de multiples loci (MLVA) et PCR-polymorphisme de longueur de fragments de restriction (PCR-RFLP) de M. hyopneumoniae ont démontré une forte diversité des isolats de terrain. Par contre, il semble y avoir plus d’homogénéité à l’intérieur d’un même élevage. L’analyse MLVA a également démontré que près de la moitié des isolats possédaient moins de 55% d’homologie avec les souches vaccinales et de référence utilisées dans la présente étude. L’absence d’amplification du locus 1 de M. hyopneumoniae en MLVA a été significativement associée à une baisse de la concentration de bactérie et de la sévérité des lésions. Pour tous les isolats de M. hyopneumoniae, des concentrations minimales inhibitrices (CMI) de faibles à intermédiaires ont été obtenues envers tous les antimicrobiens testés. Les isolats possédant des CMI intermédiaires envers les tétracyclines, les macrolides et les lincosamides ont été testés pour la présence des gènes de résistance tetM, ermB et pour des mutations ponctuelles dans les gènes des protéines L4, L22 et de l’ARNr 23S. Aucun de ces gènes n’a été détecté mais la mutation ponctuelle G2057A a été identifiée. Cette mutation est responsable de la résistance intrinsèque de M. hyopneumoniae face aux macrolides à 14 carbones. Ces résultats indiquent qu’il ne semble pas y avoir de résistance acquise aux antimicrobiens parmi ces isolats. En conclusion, cette recherche a permis d’obtenir de nouvelles données scientifiques sur les isolats québécois de M. hyopneumoniae. / Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, is present in swine herds worldwide. However, little is known about the prevalence of this microorganism in Quebec and Canadian herds. A total of 160 swine lungs with lesions suggestive of enzootic pneumonia were recovered from two slaughterhouses. They were cultured and tested by PCR for M. hyopneumoniae and Mycoplasma hyorhinis and for the porcine reproductive and respiratory syndrome virus (PRRSV), the influenza virus, and the porcine circovirus type 2 (PCV2). Samples were also cultured for other commonly encountered swine pathogenic bacteria. Ninety percent of the samples were positive for M. hyopneumoniae (Real-time PCR) whereas 5.6% were positive only for M. hyorhinis (PCR). The concentration of M. hyopneumoniae in these positive samples varied between 1.17 x 105 and 3.37 x 109 genomes/mL Among 25 selected M. hyopneumoniae positive lungs (culture or real-time PCR), 10 demonstrated a co-infection with Pasteurella multocida, 12 with Streptococcus suis, 9 with PCV2 and 2 with the PRRS virus. Multiple loci variable number of tandem repeats analysis (MLVA) and PCR-restriction fragments length polymorphism (PCR-RFLP) analyses showed a high diversity among field M. hyopneumoniae isolates. However, there seemed to be greater homogeneity within the same herd. The MLVA analysis also demonstrated that almost half of the field isolates presented less than 55% homology with the vaccine and reference strains used in our study. The absence of amplification of one locus (locus 1) of M. hyopneumoniae was significantly associated with a lower number of bacteria and a lower severity of lung lesions. All M. hyopneumoniae isolates showed low to intermediate MICs against the antimicrobials tested. Cultures with intermediate MICs for tetracyclines, macrolides and lincosamides were tested for the presence of previously described resistance genes tetM, ermB and L4, L22 and 23S rRNA point mutations. None of these genes were found, although one point mutation, G2057A, was identified. This mutation is responsible for the intrinsic resistance of M. hyopneumoniae against 14-membered macrolides. These results indicate that there is probably no acquired antimicrobial resistance within these isolates. This research provides new scientific data on M. hyopneumoniae isolates from Canada.