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Orientadores: Angelica Zaninelli Schreiber, Plinio Trabasso Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas Resumo: Bacteriemias são ocorrências relacionadas a diferentes processos patológicos e em grande parte associadas a infecções hospitalares. Podem ser causadas por diferentes tipos de microrganismos, sendo os Gram negativos, em especial, os bacilos, responsáveis por grande número destas. O diagnóstico laboratorial envolve coleta de hemoculturas, isolamento e identificação do agente e avaliação de sua sensibilidade aos antimicrobianos. Com o aumento da sobrevida de pacientes com doenças de base muito graves e o uso indiscriminado de antimicrobianos de amplo espectro, são crescentes os relatos de desenvolvimento de resistência dos microrganismos aos antimicrobianos em uso. Trata-se este de estudo retrospectivo que buscou avaliar a prevalência e o perfil de resistência dos principais bacilos Gram negativos isolados a partir de hemoculturas de pacientes adultos, internados no HC-UNICAMP frente a antimicrobianos selecionados e correlação da tendência da resistência aos antimicrobianos com a estimativa de utilização destes antibióticos durante o período de 2000 a 2004. Neste período, os bacilos Gram negativos mais prevalentes foram Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa e Acinetobacter baumanii. Foi possível observar ao longo do período estudado uma alteração no perfil de freqüência dos bacilos Gram negativos encontrados nas hemoculturas, havendo permuta de Enterobacter cloacae por cepas de Klebsiella pneumoniae ao longo do tempo. O consumo aumentado de cefalosporinas de terceira e quarta geração no HC-UNICAMP pôde ser correlacionado de forma significativa a uma maior taxa de resistência de Klebsiella pneumoniae resistente. O aumento no consumo de quinolonas pôde ser correlacionado de forma significativa com aumento de resistência dos bacilos Gram negativos até o ano de 2002, excetuando a Klebsiella pneumoniae que manteve os níveis de resistência até 2004 Abstract: Bacteriemias are events related to different diseases, mostly hospital infections. They can be caused by many different microorganisms, but the Gram negative bacilli are often responsible for them. The laboratory diagnosis includes blood sampling, isolation and identification of the microorganism, and evaluation of its susceptibility to the available antibiotics. Increases in prevalence of these resistant pathogens in hospitals are frequently related to high selective pressure commonly used in hospitalized patients, almost always represented by older and debilitated individuals. This is a retrospective study of the prevalence and resistance of pathogens isolated from the blood of patients in the Hospital das Clínicas UNICAMP, during the years 2000-2004, and the correlation of the intensive use of some proposed antibiotics. During this period the most commonly isolated microorganisms were: Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa and Acinetobacter baumanii. We observed an alteration of this profile during the study, having Klebsiella pneumoniae replaced the Enterobacter cloacae 's score. The increasing utilization of broad expect rum cephalosporin's in HC UNICAMP was related to the highest resistance of Klebsiella pneumoniae to these drugs. The ever increasing use of quinolones could be related in a very considerable way to the increasing resistance of all Gram negative bacilli until the year of 2002, when it declined but not for Klebsiella pneumoniae which was prolonged during all the time of the study Mestrado Patologia Clínica Mestre em Ciências Médicas

The complement C3-like protein TEP1 of the mosquito Anopheles gambiae is required for defense against malaria parasites and bacteria. Two forms of TEP1 are present in the mosquito hemolymph, the full-length TEP1-F and the proteolytically processed TEP1cut that is part of a complex including the leucine-rich repeat proteins LRIM1 and APL1C. Here we show that the non-catalytic serine protease SPCLIP1 is a key regulator of the complement-like pathway. SPCLIP1 is required for accumulation of TEP1 on microbial surfaces, a reaction that leads to lysis of malaria parasites or triggers activation of a cascade culminating with melanization of malaria parasites and bacteria. We also demonstrate that the two forms of TEP1 have distinct roles in the complement-like pathway and provide the first evidence for a complement convertase-like cascade in insects analogous to that in vertebrates. Our findings establish that core principles of complement activation are conserved throughout the evolution of animals., Author Summary Mosquitoes are vectors of numerous human diseases including malaria. Disease transmission requires that microbes overcome the robust mosquito immune system. In the African malaria mosquito, the TEP1 protein that is homologous to mammalian complement factor C3 is shown to play a central role in mosquito immunity to malaria parasites and bacteria. In this study, we report that another mosquito protein belonging to a class of non-catalytic enzymes that are specific to arthropods is a core component of the mosquito complement-like immune pathway. We found that this new protein, named SPCLIP1, regulates the accumulation of TEP1 on malaria parasites and bacteria, and show that this can lead to distinct defense reactions including lysis and melanization of the pathogen. This work is valuable because it reveals novel insight into the regulation of mosquito complement on microbial surfaces such as those of the malaria parasites. Unraveling the molecular mechanisms regulating these defense responses may ultimately lead to the design of novel disease blocking strategies in the vector.