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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Epidémiologie et transmission mère-enfant des entérobactéries productrices de bêta-lactamases à spectre étendu (E-BLSE) à Madagascar. / Epidemiology and mother-to-child transmission of Extended-spectrum ß-lactamase-producing Enterobacteria (ESBL-PE) in Madagascar.

Herindrainy, Perlinot 19 November 2018 (has links)
L’émergence et la dissémination des bactéries résistantes aux antibiotiques sont préoccupantes. L’infection causée par les bactéries multi-résistantes (BMR) aggrave le pronostic des malades infectés et augmente les dépenses liées à leur prise en charge. Parmi les BMR, les bactéries à Gram négatif (BGN), plus particulièrement les entérobactéries productrices de béta-lactamase à spectre étendu (E-BLSE) sont les plus fréquemment isolées. La résistance aux antibiotiques pourrait avoir un impact sur la morbidité et la mortalité dans les pays à revenu faible ou intermédiaire (PRFI) en raison du potentiel d’émergence et de diffusion de bactéries résistantes aux antibiotiques, et du fardeau des infections bactériennes dans ces pays. Cependant, les données sur la résistance bactérienne sont rares et très majoritairement hospitalières dans les PRFI. De plus, dans ces pays, les infections bactériennes néonatales sévères (septicémies, pneumonies et méningites) représentent encore les principales causes de décès chez les nouveau-nés. Les entérobactéries sont majoritairement responsables de ces infections néonatales. Ainsi, investiguer la transmission d'E-BLSE chez le nouveau-né permettrait de proposer des stratégies de prévention. Ce travail de recherche s’est appuyé sur le programme BIRDY (Bacterial Infections and antibiotic Resistant Diseases among Young children in low-income countries). Le premier objectif était d’estimer la prévalence de la colonisation par des E-BLSE chez les femmes enceintes à Madagascar ainsi que les facteurs favorisant cette colonisation. Les résultats ont montré une prévalence globale de colonisation de 18.5% [IC à 95% 14.5-22.6]. Des facteurs reflétant un niveau socioéconomique plus élevé comme l’accès privatif à l’eau de boisson et avoir une maison individuelle sont associés à la colonisation. Le second objectif de ce travail était d'étudier l'incidence de la première colonisation par des E-BLSE chez les nouveau-nés en milieu communautaire et d'identifier les facteurs de risque d'acquisition. Les résultats révèlent une incidence globale d'acquisitions d'E-BLSE de 10.4 pour 1000 nouveau-nés-jours [IC à 95% : 8.0; 13.4]. Par ailleurs, nous avons mis en évidence que le faible poids à la naissance HR ajusté 2.7 [IC à 95% 1.2 ; 5.9], l'accouchement par césarienne HR ajusté 3.4 [IC à 95% 1.7 ; 7.1], la prise maternelle d'antibiotique à l'accouchement HR ajusté 2.2 [IC à 95% 1.1 ; 4.5] étaient des facteurs de risque d'acquisition d'E-BLSE. Le troisième objectif était de documenter les infections néonatales. Nous avons trouvé une incidence d'infections néonatales de 30.6 cas pour 1000 naissances vivantes [IC à 95%: 23.4 ; 40.1].Nos résultats montrent que les mesures de santé publique devraient axer sur l’amélioration de la prise en charge de la grossesse et sur le diagnostic précoce des infections néonatales. / The emergence and spread of antibiotic-resistant bacteria is a concern. Infection caused by multidrug-resistant bacteria (MDR) worsens the prognosis of infected patients and increases the costs associated with their management. Among the MDRs, Gram-negative bacteria (GNB), especially extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) are the most frequently isolated. Antibiotic resistance may have an impact on morbidity and mortality in low- and middle-income countries (LMICs) because of the potential for emergence and spread of antibiotic-resistant bacteria, and the burden of bacterial infections in these countries. However, data on bacterial resistance are scarce or came from the hospital, for the great majority, in LMICs. In these settings, severe neonatal bacterial infections (sepsis, pneumoniae and meningitis) still represent the leading causes of death in newborns. Enterobacteriaceaeare responsible for a great part of these neonatal infections. Thus, investigating the transmission of ESBL-PE in newborns would make it possible to propose prevention strategies. This work was based on the BIRDY program (Bacterial Infections and Antibiotic Resistant Diseases among Young Children in Low-Income Countries). The first objective was to estimate the prevalence of colonization by ESBL-PE in pregnant women in Madagascar as well as the risk factors of this colonization. The results showed an overall colonization prevalence of 18.5% [95% CI 14.5-22.6]. Factors reflecting a higher socioeconomic level such as private access to drinking water and having a house are associated with colonization. The second objective of this work was to study the incidence of ESBL-PE colonization in community-based infants and to identify acquisition risk factors. The results reveal an overall incidence of ESBL-PE acquisition of 10.4 per 1000 newborn-days [95% CI: 8.0; 13.4]. In addition, we found that low birth weight adjusted HR 2.7 [95% CI 1.2; 5.9], cesarean section delivery adjusted HR 3.4 [95% CI 1.7; 7.1], maternal intake of antibiotic at delivery adjusted HR 2.2 [95% CI 1.1; 4.5] were risk factors for the acquisition of ESBL-PE. The third objective was to document neonatal infections. We found an incidence of neonatal infections of 30.6 cases per 1000 live births [95% CI: 23.4; 40.1]. Our results suggest that public health measures should focus on the improvement of pregnancy follow-up and early diagnosis of neonatal infections.
132

Nectin-1 is Degraded in <em>Chlamydia trachomatis</em>-Infected Genital Epithelial Cells and is Required for Herpes Simplex Virus Co-Infection-Induced <em>C. trachomatis</em> Persistence.

Sun, Jingru 09 May 2009 (has links) (PDF)
The obligate intracellular bacterium Chlamydia trachomatis is the most common bacterial STD agent in the US. This bacterium has a unique biphasic developmental cycle in which the infectious elementary body (EB) infects a host mucosal epithelial cell and differentiates into the replicative form (the reticulate body or RB) within a modified vacuole called an inclusion. The RB later divides and develops back into an EB and is released, perpetuating the infectious cycle. When developing chlamydiae are exposed to unfavorable environmental conditions, they deviate from the normal developmental cycle into a non-infectious but viable state termed persistence. Previous data from our laboratory indicate that i) during C. trachomatis/HSV co-infection, the chlamydiae become persistent and ii) HSV gD interaction with host cell surface is sufficient to induce this response. During viral entry, HSV gD interacts with one of four host co-receptors, one of which is the host adhesion molecule nectin-1. Interestingly, Western blotting demonstrated that nectin-1 is significantly decreased in C. trachomatis-infected HeLa cells. Additional studies indicated that active C. trachomatis replication is required for nectin-1 down-regulation and nectin-1 is likely down-regulated post-translationally. CPAF, a chlamydia-secreted protease, is responsible for degrading several host proteins. Both in vivo experiments using CPAF-specific chemical inhibitors and cell-free cleavage assays using recombinant CPAF indicate that nectin-1 is degraded by CPAF in C. trachomatis-infected cells. Further studies suggest that nectin-1 is the most likely candidate involved in triggering HSV-induced chlamydial persistence. Co-infection experiments using nectin-1-specific HSV-1 mutants suggest that nectin-1 is, indeed, required for persistence induction. Additional studies in single co-receptor-expressing CHO cells demonstrate that, despite the fact that HSV-1 enters both HVEM- and nectin-1-expressing cells, viral co-infection reduces chlamydial infectivity only in the CHO-nectin-1 cell line. These data confirm that HSV/nectin-1 interaction is sufficient for chlamydial persistence induction. Although nectin-1 ligation is known to activate Cdc42, pull-down assays indicate that Cdc42 is not activated in co-infected HeLa cells. Taken together, these data suggest that: i) HSV gD-nectin-1 binding activates a novel host epithelial cell pathway that restricts chlamydial development and ii) the chlamydiae may degrade nectin-1 to evade this inhibitory host response.
133

Cryptococcus neoformans Serotype Groups Found in Clinical and Environmental Isolates

Clauson, John 01 May 1993 (has links)
Cryptococcus neoformans is an encapsulated yeast responsible for severe meningoencephalitis. The importance of epidemiological studies on cryptococcosis has increased since the beginning of the AIDS epidemic. C. neoformans exists in two varieties containing four serotypes, C. neoformans var. neoformans (serotypes A and D) and C. neoformans var. gattii (serotypes B and C). Locally C. neoformans var. neoformans has been associated with pigeon feces during those months having an average temperature of 64.2°F j(17.8°C) and above. Clinical and environmental isolates of C. neoformans obtained from regional hospitals and environmental samplings, respectively, have been grouped into their variety status utilizing canavanine-glycine-bromthymol blue agar. Polyclonal antisera against C. neoformans serotypes A, B, C and D were isolated from challenged rabbits. Serotyping C. neofromans isolates using the polyclonal antisera resulted in 57% (20 of 35) of the serotypes confirmed with a direct immunofluorescent assay utilizing a single monoclonal antibody (E1). Data from the immunofluorescence assay suggest all C. neoformans obtained from regional hospitals (26 of 26) and those isolated from the environment (9 of 9) belong to the A serotype group. These data have provided information leading to the origin of infection for cryptococcosis in our region, which may be beneficial to immunocompromised individuals.
134

Orientia tsutsugamushi secretes two ankyrin repeat-containing effectors via a type 1 secretion system to inhibit host NF-κB function

Evans, Sean M. 01 January 2017 (has links)
Scrub typhus is a potentially fatal infection that threatens one billion persons in the Asia-Pacific region and is caused by the obligate intracellular bacterium, Orientia tsutsugamushi. How this organism facilitates its intracellular survival and pathogenesis is poorly understood. Intracellular bacterial pathogens utilize the Type 1 (T1SS) or Type 4 secretion system (T4SS) to translocate ankyrin repeat-containing proteins (Anks) into the host cell to modulate host cell processes. The O. tsutsugamushi genome encodes one of the largest known bacterial Ank libraries as well as Type 1 and Type 4 secretion systems (T1SS and T4SS), which are expressed during infection. In silico analyses of the Anks’ C-termini revealed that they possess characteristics of T1SS secretion signals. Escherichia coli expressing a functional T1SS was able to secrete chimeric hemolysin proteins bearing the C-termini of 19 of 20 O. tsutsugamushi Anks. In addition to infecting endothelial cells, O. tsutsugamushi infects professional phagocytes. To better understand why these innate immune cells are unable to eliminate O. tsutsugamushi, we addressed the activity of host NF-κB proinflammatory transcription factor. Screening of O. tsutsugamushi infected cells at an MOI of 1 revealed inhibition of NF-κB nuclear accumulation as early as 8 hours in HeLa and bone-marrow derived macrophage cells. When stimulating infected cells with TNF-α, IκBα degradation still occurs, however NF-κB dependent gene transcription remains downregulated. Immunofluorescence microscopic analysis of TNF-α treated cells ectopically expressing all O. tsutsugamushi Anks revealed that two nuclear trafficking Anks, Ank1 and Ank6, result in a significant decrease in NF-κB nuclear accumulation. Additionally, these Anks also significantly inhibited NF-κB dependent gene transcription. Co-immunoprecipitation experiments revealed that both Anks interact with importin-β1, exportin-1, and the p65 NF-κB subunit. Treating cells with importazole significantly reduces the nuclear accumulation of Ank1 and Ank6. Finally, treating infected cells or cells ectopically expressing Ank1 or Ank6 with leptomycin B resulted in restoration of NF-κB nuclear accumulation. With these data, we propose that O. tsutsugamushi secretes Ank1 and Ank6 to initially interact with importin-β1, which permits their nuclear entry where they then interact with NF-κB and subsequently exportin-1 to prevent NF-κB nuclear accumulation.
135

Ispitivanje primenjivosti međunarodnih smernica za lečenje infektivnih bolesti bakterijske etiologije / Testing applicability of international guidelines in the treatment of bacterial infections

Petrić Vedrana 11 July 2016 (has links)
<p>Uvod: U na&scaron;oj zemlji nema smernica za lečenje bakterijskih infekcija u tercijarnim zdravstvenim ustanovama. Odabir antibakterijskih lekova je empirijski, &scaron;to nije uvek u skladu sa preporučenom terapijom prema međunarodnim smernicama. Zbog toga su na Klinici za infektivne bolesti Kliničkog centra Vojvodine u januaru 2013. godine usvojeni međunarodni protokoli i primenjivani za lečenje infektivnih bolesti bakterijske etiologije. Cilj istraživanja bio je da se ispita i uporedi efikasnost lečenja pojedinih antibiotskih tretmana za lečenja infektivnih bolesti bakterijske etiologije prema kliničkom iskustvu ordinirajućeg lekara, prema međunarodno prihvaćenim protokolima i prema modifikovanim međunarodnim protokolima na osnovu stanja lokalne rezistencije. Materijal i metode: Ispitivanje je bilo retrospektivno-prospektivno u trajanju od tri godine od&nbsp; 01.01.2012-31.12.2014.godine, sprovedeno je na Klinici za infektivne bolesti Kliničkog centra Vojvodine. U studiju je uključeno 1147 pacijenata sa dijagnozom infektivne bolesti bakterijske etiologije (sepsa, infekcija urinarnog trakta, bakterijski meningitis, infekcije kože i mekih tkiva, bakterijski tonzilofaringitisi, pneumonija, febrilni gastroenteritis i spondilodiscitis). U retrospektivnom delu, tokom 2012. godine ustanovljena je efikasnost lečenja prema kliničkom iskustvu ordinirajućeg lekara, kod 459 pacijenata. U drugom delu ispitivanja koje je bilo prospektivno, tokom 2013. godine, kod 487 pacijenata, ustanovljena je efikasnost lečenja prema međunarodnim protokolima i upoređena sa lečenjem prema kliničkom iskustvu ordinirajućeg lekara. Tokom 2012. i 2013. godine, ustanovljena je struktura uzročnika i rezistencija na antimikrobne lekove, i prema stanju lokalne rezistencija modifikovani su međunarodni protkoli i primenjivani su tokom 2014. godine. U trećem delu ispitivanja koje je bilo prospektivno, tokom 2014. godine, kod 201 pacijenta ustanovljena je efikasnost lečenja prema modifikovanim međunarodnim protokolima i upoređena sa lečenjem prema usvojenim međunarodnim protokolima. Efikasnost lečenja praćena je na osnovu vrednosti telesne temperature i na osnovu laboratorijskih parametara (leukocita, C reaktivnog proteina, fibrinogena, sedimentacije eritrocita i prokalcitonina), prvog i sedmog dana hospitalizacije. Za upoređivanje efikasnosti terapijskih režima napravljen je sistem skorovanja telesne temperature i laboratorijskih parametara. Za statističku obradu podataka kori&scaron;ćen je programski paket Statistical Package for Social Sciences - SPSS 21. Statistički značajnim se smatraju vrednosti nivoa značajnosti p&lt;0.05. Rezultati: Praćenjem rezistencija bakterija u na&scaron;oj sredini modifikovani su međunarodni protokoli za lečenje infekcija izazvanih E.coli i S aureus-om. Rezistencija E. coli iz urinokultura tokom 2012. i 2013. godine na ciprofloksacin (koji je preporučen prema međunarodnim protokolima za lečenje infekcija urinarnog trakta) je bila u 2012. godini 38,8% i u 2013. godini 57,1%, a na levofloksacin 27,7% u 2012. godini i u 2013. godini 28,6%. Rezistencija S. aureus-a izolovanog iz brisa rana na cefazolin (koji je preporučen prema međunarodnim protokolima za lečenje infekcija kože i mekih tkiva) u prve dve godine ispitivanja bila je 25% a na klindamicin nije zabeležena rezistencija. Rezistencija S. aureus-a na cefazolin (koji je preporučen prema međunarodnim protokolima za lečenje bakterijskih tonzilofaringitisa) iz brisa grla bila je u 2012. godini 18,1%, u 2013. godini 14,2% a na klindamicin u ovom periodu nije zabeležena rezistencija. Tako da je preporuka u modifikovanom kliničkom protokolu za lečenje infekcija urinarnog trakta levofloksacin, za lečenje bakterijskih tonzilofaringitisa i lečenje infekcija kože i mekih tkiva izazvanih S aureus-om klindamicin.Poredeći ukupan skor kliničkih i laboratorijskih parametara, lečenje pacijenata prema usvojenim međunarodnim protokolima, statistički značajno je efikasnije u odnosu na lečenje prema kliničkom iskustvu lekara kod lečenja pacijenata sa infekcijom urinarnog trakta (p=0,034) i infekcijom kože i mekih tkiva (p=0,032). U lečenju ostalih ispitivanih bakterijskih infekcija prema kliničkom iskustvu lekara i usvojenim međunarodnim protokolima nema statički značajne razlike (p&gt;0,05). Lečenje pacijenata sa infekcijom urinarnog trakta, prema modifikovanim međunarodnim protokolima je statistički značajno efikasnije u odnosu na efikasnost lečenja prema usvojenim međunarodnim protokolima (p=0,025) poredeći ukupan skor kliničkih i laboratorijskih parametara. Lečenje pacijenata sa tonzilofaringitisima i infekcijama kože i mekih tkiva prema modifikovanim međunarodnim protokolima podjednako je efikasno u odnosu na lečenje prema usvojenim međunarodnim protokolima (p=0,100) poredeći ukupan skor kliničkih i laboratorijskih parametara. Zaključak: Upoređivanjem dobijenih rezultata, omogućeno je određivanje najoptimalnijeg načina lečenja bolesti bakterijske etiologije, uvažavajući preporuke prema međunarodnim smernicama. Dobijeni rezultati ukazuju na to da je praćenjem lokalne strukture uzročnika i stanja lokalne rezistencije omogućeno određivanje optimalnijeg načina lečenja infekcija urinarnog trakta i infekcije kože i mekih tkiva, uvažavajući međunarodne preporuke i modifikaciju međunarodnih smernica prema stanju rezistencija bakterija na antimikrobne lekove u na&scaron;oj sredini</p> / <p>Introduction:In our country,there are noguidelines for the treatment of bacterial infections in tertiary health institutions. The choice of antibiotic is empirical and it does not always comply with the recommended treatment according to international guidelines. For this reason, international protocols were adopted at the Clinic for infectious diseases of the Clinical Center of Vojvodinain January 2013. and implemented in therapy of infectious diseases caused by bacteria. The aim of the study was to compare different regimens and to evaluate their effectiveness in therapy of the bacterial infections: one based on the clinical experience of the prescribing physician, another based on international guidelines and the third, modified international protocoladapted to comply with the local antibacterial resistance. Material and methods: Thisretrospective-prospective study was conducted at the Clinic for Infectious Diseases of the Clinical Center of Vojvodina and it covered the period of three years, from 01.01.2012.-31.12.2014. 1,147 patients diagnosed with infectious diseases of bacterial etiology (sepsis, urinary tract infections, bacterial meningitis, skin and soft tissue infections, bacterial tonsillopharyngitis, pneumonia, febrile gastroenteritis and spondylodiscitis) were included in the study. In the first, retrospective part of the study, the efficacy of therapy based on the clinical experience of the prescribing physician was analyzed from medical records of 459 patients treated in 2012. In 2013, during the second, prospective part of the study, the efficacy of treatment according to the international guidelines was evaluated in 487 patients and the results were compared to the data obtained from the patients treated according to the clinical experience of the prescribing physician. The types of organism isolated in 2012/2013 were analyzed as well as their resistance to antimicrobials, the international protocols were subsequently modified according to the state of local resistance and implemented during 2014. In 2014, during the third, prospective part of the study, the efficacy of therapy according to modified international protocols was established in 201 patients, and the results were compared to the ones obtained by therapy according to original international protocols. The efficacy of the treatment was estimated by body temperature measurements and laboratory parameters (leukocytes, C-reactive protein, fibrinogen, erythrocyte sedimentation rate and procalcitonin) on day 1 and day 7 of hospitalization. The scoring system for body temperature and laboratory parameters was designed to compare therapeutic regimes efficiency. For statistical analysis, we used a software package Statistical Package for Social Sciences- SPSS 21. The values of p&lt;0.05were considered statistically significant. Results.Monitoring of antibiotic resistance patterns in our community led to modification international protocols for treating infections caused by E. coli and S aureus. Resistance of E.coli to ciprofloxacin (recommended for the treatment of urinary tract infectionsby international protocols) from urine culture in 2012 and 2013 was 38.8% and 57.1% respectively, while resistance to levofloxacin in 2012 and 2013 was 27.7% and 28.6%, respectively. Resistance of S. aureus to cefazolin (recommended by international protocols for the treatment of the skin and soft tissue infections) from wound cultures in 2012 and 2013 was 25% while the resistance to&nbsp; clindamycin was not present. Resistance to cefazolin (recommended for the treatment of bacterial tonsillopharyngitisby international protocols) from throat culture in 2012 and 2013 was 18,1% and 14,2%, respectively,and the resistance to clindamycin was not present in the same period. Accordingly, clinical therapeutic protocols were modified, levofloxacin was recommended for urinary tract infections and clindamycin was recommended for treatment of tonsillopharyngitis and skin and soft tissues infections caused by S. aureus. Comparing the total score of clinical and laboratory parameters, the treatment of patients according to the adopted international protocols was statistically significantly more effective compared to the one based on clinical experience of physicianin urinary tract infections (p = 0.034) and skin and soft tissue infections(p = 0.032). No statically significant difference (p&gt;0.05) was observed in efficiency of treatment options for other studied bacterial infections. In therapy of urinary tract infections, modified international protocols proved to be significantly more efficient than the adopted international protocols (p = 0.025) when the total score of clinical and laboratory parameters was compared.&nbsp; Comparing the total score of clinical and laboratory parameters, both adopted international protocols and modified international protocols proved to be equally efficient (p=0,100) in therapy of bacterial tonsillopharyngitis and skin and soft tissue infections. Conclusion:Comparison of the obtained results made possible to develop the optimal way of treating diseases of bacterial etiology, taking into account recommendations by international guidelines.The results suggest that the monitoring of the local structure of pathogens and their resistance pattern enabled the determination of optimal treatment options for urinary tract infections and skin and soft tissue infections, respecting international recommendations and modifying the international guidelines to match bacterial resistance pattern in our community.</p>
136

Characterization of a Novel Protease in Staphylococcus aureus

Johnson, Adam L 01 January 2015 (has links)
A newly discovered cysteine protease, Prp, has been shown to perform an essential, site-specific cleavage of ribosomal protein L27 in Staphylococcus aureus. In Firmicutes and related bacteria, ribosomal protein L27 is encoded with a conserved N-terminal extension that must be removed to expose residues critical for ribosome function. Uncleavable and pre-cleaved variants were unable to complement an L27 deletion in S. aureus, indicating that this N-terminal processing event is essential and likely plays an important regulatory role. The gene encoding the responsible protease (prp) has been shown to be essential, and is found in all organisms encoding the N-terminal extension of L27. Cleavage of L27 by Prp represents a new target for potential antibiotic therapy. In order to characterize this protease, Prp has been overexpressed and purified. Using an assay we have developed, based on cleavage of a fluorogenic peptide derived from the conserved L27 cleavage sequence, we have undertaken an analysis of the enzyme kinetics and substrate specificity for Prp cleavage and tested predictions made based on a structural model using active-site mutants.
137

Papel das citocinas e quimiocinas na resposta imunológica murina na infecção por Leptospira interrogans sorovar Copenhageni. / The role of cytokines and chemokines in the murine immune response in infection by Leptospira interrogans serovar Copenhageni.

Silva, Josefa Bezerra da 15 May 2012 (has links)
A leptospirose é uma zoonose causada por bactérias do gênero Leptospira. A patogênese da doença em humanos é observada principalmente no pulmão, fígado e rins. Neste trabalho, foi avaliado o papel da resposta imune inata na proteção contra a leptospirose usando camundongos como modelo experimental. Os animais foram infectados com L. interrogans e o desenvolvimento da doença foi acompanhado, observando-se a morte de animais C3H/HeJ, enquanto C3H/HePas apresentou icterícia e BALB/c não apresentou sintomas. O perfil de mRNA foi medido por qPCR nas amostras de rim, fígado e pulmão e as concentrações de proteinas TNF-<font face=\"Symbol\">&#945;, TGF-<font face=\"Symbol\">b, MCP-1, MIP-1<font face=\"Symbol\">&#945;, MIP-2 e IL-8 foram analisadas por ELISA em extratos dos tecidos e no soro. Os resultados demonstraram que L. interrogans estimula a expressão prematura de TNF-<font face=\"Symbol\">&#945;, TGF-<font face=\"Symbol\">b, MCP-1, MIP-1<font face=\"Symbol\">&#945;, MIP-2 e IL-8 na linhagem BALB/c resistente à infecção. A análise histológica indica que estes mediadores podem estar relacionados com o influxo de diferentes células do sistema imune desempenhando importantes funções na proteção contra leptospirose. / Leptospirosis is a worldwide zoonosis caused by Leptospira. The pathogenesis in humans is mainly observed in lungs, livers and kidneys. In this work the role of innate immune response in protection against leptospirosis is being studied using different mice models. The animals were infected intraperitoneally with virulent cells of L. interrogans serovar Copenhageni and the development of the disease was followed, being observed mortality of C3H/HeJ mice, whereas C3H/HePas presented jaundice and BALB/c mice remained asymptomatic. Samples of liver, kidney, lungs and sera were analyzed following the profiles of mRNA and protein of the cytokines TNF-<font face=\"Symbol\">&#945; and TGF-<font face=\"Symbol\">b and chemokine MCP-1, MIP-1<font face=\"Symbol\">&#945;, MIP-2 and CXCL1/IL-8. We showed that Leptospira infection stimulates early expression of cytokine TNF-<font face=\"Symbol\">&#945; and TGF-<font face=\"Symbol\">b and chemokine MCP-1, MIP-1<font face=\"Symbol\">&#945;, MIP-2 and IL-8 in the resistant mice strain BALB/c. Histological analysis indicates that the expression of those molecules can be related to the influx of distinct immune cells, which play a role in the naturally acquired protective immunity.
138

Caracterização imunológica e genética da deficiência do componente C5 do sistema complemento humano. / Immunological and genetic characterization of the deficiency of the component C5 of the human complement system.

Ramirez, Priscilia Aguilar 22 June 2007 (has links)
A deficiência da proteína C5 do sistema complemento humano é rara com 38 casos relatados na literatura e freqüentemente associada a severas infecções provocadas por bactérias Neisseria. O objetivo do trabalho é caracterizar imunológica e geneticamente esta deficiência encontrada pela primeira vez em brasileiros. Por imunodifusão dupla obtivemos níveis expressivos de C3, C4, C6, C7, C8, C9, Fator B, Fator H e Fator I em todos os membros desta família, a proteína C5 não foi detectada no soro de três irmãos: II:9, II:4 e II:5. Por ELISA a concentração de C5 nestes indivíduos foi (0,9; 1,0; 1,3 µg/ml, 45- 190 µg/ml). Soros destes probandos não apresentam atividade hemolítica mediada pelo sistema complemento. O cDNA de C5 dos indivíduos I:1, I:2, II:4 e II:9 apresenta a deleção do éxon 30. Causada pela substituição de GAG4028 por GAA4028 no último nucleotídeo deste éxon que leva a um erro no splicing. Este defeito provavelmente produz uma proteína incompleta e destinada à degradação. / The deficiency of the C5 component of the complement system is rare with 38 described cases in the literature. This deficiency is frequently associated with severe infections, especially caused by Neisseria. Our objective is to characterize immunologically and genetically this deficiency, the first of its type described in the Brazilian population.We noted that C3, C4, C6, C7, C8, C9, Factor B, Factor H and Factor I have expressive levels in all the individuals sera of this family. C5 was absent in individuals II:4, II:5 and II:9. By ELISA a C5 concentration in this individuals were 0,9; 1,0; 1,3 µg/ml (normal: 45 - 190 µg/ml). Their serum doesn´t present hemolytic activity mediated by complement system. The C5 cDNA from individuals I:1, I:2, II:4 and II:9 has éxon 30 deleted. Caused by the substitution of GAG4028 for a GAA4028 in the last codon of exon 30. This defect was responsible for the deficiency of C5 in this family and this deletion would probably produce an unstable protein destined for degradation.
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Aquisição passiva de anticorpos IgG maternos reativos com os lipopolissacarídeos de enterobactérias incidentes em infecções neonatais por recém-nascidos pré-termos e a termo. / Passive acquisition of maternal IgG antibodies reactive to lipopolysaccharide from enterobacteria incident in neonatal infections by preterm and term neonates.

Marques, Ana Lúcia Silveira Lessa 24 March 2009 (has links)
As espécies Klebsiella pneumoniae, Escherichia coli e Pseudomonas aeruginosa são responsáveis por infecções neonatais hospitalares. Lipopolissacarídeo (LPS) é o principal indutor de respostas inflamatórias. Os objetivos foram avaliar a transferência placentária de IgG reativa ao LPS de K. pneumoniae, E. coli O111, O26 e O6 e P. aeruginosa empregando ELISA para dosar IgG em soro materno e de cordão de 29 neonatos pré-termos e 32 a termo; analisar IgM total e específica no soro materno; e investigar a influência das patologias apresentadas pelas mães na transferência placentária. Concentrações de IgG total foram reduzidas em pré-termos como esperado, porem índices de transferência placentária de IgG total e IgG anti-LPS foram sistematicamente reduzidos quando comparados aos neonatos a termo. Níveis de IgM total e anti-LPS foram equivalentes em mães de ambos os grupos. As patologias das mães influenciaram os níveis de IgM no grupo de mães de pré-termos. Estes resultados indicam uma imunidade adquirida deficiente pelo grupo pré-termo aumentando os riscos de infecção. / Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa species are responsible for neonatal nosocomial infections. Bacterial lipopolysaccharide (LPS) is the major inducer of the inflammatory responses. The aims were to evaluate the placental transfer of IgG reactive to LPS present in K. pneumoniae, in E. coli O111, O26 and O6 and in P. aeruginosa employing ELISA to detect IgG in maternal and cord sera from 29 preterm and 32 term neonates; to analyze total and specific IgM on the mothers sera; and to investigate the influence of the pathologies presented by some mothers in the placental transfer. Total IgG concentrations were reduced in preterm neonates as expected, but placental transfer indexes of total and anti-LPS IgG were systematically reduced when compared with term neonates. Total and anti-LPS IgM levels were equivalent on mothers of both groups. The mothers pathologies influenced only the IgM levels in the preterm mothers group. These results indicate a deficient acquired immunity by the preterm group increasing the risk of infection.
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Flora bacteriana e citoquínas pró-inflamatórias no trato digestório exclusivo após cirurgia de derivação em Y de Roux para obesidade mórbida / Microbial flora and proinflammatory cytokines in excluded digestive tract after Roux en-Y gastric bypass for morbid obesity

Ishida, Robson Kiyoshi 10 October 2007 (has links)
Introdução: Em estudo prospectivo, os efeitos da gastroplastia redutora com reconstrução em Y de Roux sobre a flora bacteriana e produção de citoquinas nas câmaras gástricas proximal e excluída foram estudados. Métodos: pacientes bariátricos (n=37) foram submetidos à avaliação endoscópica em ambos reservatórios gástricos,7,3+-1,4 anos após a gastroplastia. Idade foi de 42,4+-9,9 anos (70,2% sexo feminino), IMC pré-operatório de 53,5+-10,6, e IMC atual de 32,6+-7,8kg/m2. TNFalfa e TGF-beta foram medidos pelo método ELISA em biópsias da mucosa gástrica., assim como cultura quantitativa da secreção gástrica, com pH gástrico e teste respiratório lactulose/hidrogênio.Resultados: Nenhum dos pacientes apresentou queixas sugestivas de supercrescimento bacteriano gastrointestinal. Todavia, contagens elevadas de bactérias e fungos foram identificadas nas duas câmaras, principalmente no estômago proximal. Gram-positivos representaram a maioria dos isolados. O pH foi neutro na câmara proximal, enquanto que também na câmara distal nem sempre conservou-se em níveis esperados. Conclusões: 1)Produção elevadas de TNF-alfa e TGF-beta, com a colonização de aeróbios, anaeróbios e fungos em ambas câmaras gástricas foram identificadas; 2)O pH gástrico como a contagem bacteriana foram maiores no estômago proximal funcionante; 3)Teste respiratório foi positivo para supercrescimento bacteriano em 40,5% dos pacientes,entretanto não foram identificadas manifestações clínicas de supercrescimento bacteriano gastrointestinal. / Background: In a prospective study, the effect of Roux-en-Y gastric bypass (RYGBP) on bacterial flora and cytokines production in the used (proximal pouch) and unused (large bypassed) gastric chamber was analysed. Methods: Bariatric subjects (n=37) were submitted to endoscopic examination of both gastric reservoirs, 7.3 ± 1.4 years after RYGBP. Age was 42.4 ± 9.9 years (70.2% females), preoperative BMI was 53.5 ± 10.6, and current BMI was 32.6 ± 7.8 kg/m2.TNF-alpha and TGF-beta were meausured by enzyme-linked immunosorbent assay (ELISA) from gastric mucosal biopsies. Quantitative culture of gastric secretion along with gastric pH and actulose/hydrogen breath test were also investigated.Results: None of the subjects displayed complaints suggestive of GI bacterial overgrowth. Elevated counts of bacteria and fungi were identified in both chambers, mostly in the proximal stomach. Gram-positives represented the majority of the isolates. Gastric pH was neutral in the proximal pouch, whereas the distal chamber mostly but not always onserved the expected acidity. Conclusions: 1)Increased TNF-alpha and TGFbeta production, as aerobes, anaerobes and fungi colonization of both gastric chambers was detected; 2) Gastric pH as well as bacterial count was higher in the functioning proximal stomach; 3) Breath test was positive for bacterial overgrowth in 40.5% of the subjects, however clinical manifestation of GI bacterial overgrowth were not demonstrated

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