979 resultados para Streptococcus thermophilus
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The vulnerability to infection of newborns is associated with a limited ability to mount efficient immune responses. High concentrations of adenosine and prostaglandins in the fetal and neonatal circulation hamper the antimicrobial responses of newborn immune cells. However, the existence of mechanisms counterbalancing neonatal immunosuppression has not been investigated. Remarkably, circulating levels of macrophage migration inhibitory factor (MIF), a proinflammatory immunoregulatory cytokine expressed constitutively, were 10-fold higher in newborns than in children and adults. Newborn monocytes expressed high levels of MIF and released MIF upon stimulation with Escherichia coli and group B Streptococcus, the leading pathogens of early-onset neonatal sepsis. Inhibition of MIF activity or MIF expression reduced microbial product-induced phosphorylation of p38 and ERK1/2 mitogen-activated protein kinases and secretion of cytokines. Recombinant MIF used at newborn, but not adult, concentrations counterregulated adenosine and prostaglandin E2-mediated inhibition of ERK1/2 activation and TNF production in newborn monocytes exposed to E. coli. In agreement with the concept that once infection is established high levels of MIF are detrimental to the host, treatment with a small molecule inhibitor of MIF reduced systemic inflammatory response, bacterial proliferation, and mortality of septic newborn mice. Altogether, these data provide a mechanistic explanation for how newborns may cope with an immunosuppressive environment to maintain a certain threshold of innate defenses. However, the same defense mechanisms may be at the expense of the host in conditions of severe infection, suggesting that MIF could represent a potential attractive target for immune-modulating adjunctive therapies for neonatal sepsis.
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BACKGROUND: Despite a low positive predictive value, diagnostic tests such as complete blood count (CBC) and C-reactive protein (CRP) are commonly used to evaluate whether infants with risk factors for early-onset neonatal sepsis (EOS) should be treated with antibiotics. STUDY DESIGN: We investigated the impact of imple- menting a protocol aiming at reducing the number of dia- gnostic tests in infants with risk factors for EOS in order to compare the diagnostic performance of repeated clinical examination with CBC and CRP measurement. The primary outcome was the time between birth and the first dose of antibiotics in infants treated for suspected EOS. RESULTS: Among the 11,503 infants born at 35 weeks during the study period, 222 were treated with antibiotics for suspected EOS. The proportion of infants receiving an- tibiotics for suspected EOS was 2.1% and 1.7% before and after the change of protocol (p = 0.09). Reduction of dia- gnostic tests was associated with earlier antibiotic treat- ment in infants treated for suspected EOS (hazard ratio 1.58; 95% confidence interval [CI] 1.20-2.07; p <0.001), and in infants with neonatal infection (hazard ratio 2.20; 95% CI 1.19-4.06; p = 0.01). There was no difference in the duration of hospital stay nor in the proportion of infants requiring respiratory or cardiovascular support before and after the change of protocol. CONCLUSION: Reduction of diagnostic tests such as CBC and CRP does not delay initiation of antibiotic treat- ment in infants with suspected EOS. The importance of clinical examination in infants with risk factors for EOS should be emphasised.
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Background: Community-acquired pneumonia is a leading cause of morbidity and mortality in children worldwide. New, rapid methods are needed to improve the microbiologic diagnosis of pneumonia in clinical practice. The increasing incidence of parapneumonic empyema in children accentuates the importance of the identification of the causative agent and clinical predictors of empyema. Aims and methods: Two prospective studies were conducted to find feasible diagnostic methods for the detection of causative agents of pneumonia. The usefulness of pneumolysin-targeted real-time PCR in the diagnosis of pneumococcal disease was studied in children with pneumonia and empyema, and the clinical utility of induced sputum analysis in the microbiologic diagnosis of pneumonia was investigated in children with pneumonia. In addition, two retrospective clinical studies were performed to describe the frequency and clinical profile of influenza pneumonia in children and the frequency, clinical profile and clinical predictors of empyema in children. Results: Pneumolysin-PCR in pleural fluid significantly improved the microbiologic diagnosis of empyema by increasing the detection rate of pneumococcus almost tenfold to that of pleural fluid culture (75 % vs. 8 %). In whole blood samples, PCR detected pneumococcus in only one child with pneumonia and one child with pneumococcal empyema. Sputum induction provided good-quality sputum specimens with high microbiologic yield. Streptococcus pneumoniae (46 %) and rhinovirus (29 %) were the most common microbes detected. The quantification results of the paired sputum and nasopharyngeal aspirate specimens provided support that the majority of the bacteria (79 %) and viruses (55 %) found in sputum originated from the lower airways. Pneumonia was detected in 14 % of children with influenza infection. A history of prolonged duration of fever, tachypnea, and pain on abdominal palpation were found to be independently significant predictors of empyema. Conclusions: Pneumolysin-targeted real-time PCR is a useful and rapid method for the diagnosis of pneumococcal empyema in children. Induced sputum analysis with paired nasopharyngeal aspirate analysis can be of clinical value in the microbiologic diagnosis of pneumonia. Influenza pneumonia is an infrequent and generally benign disease in children with rare fatalities. Repeat chest radiograph and ultrasound imaging are recommended in children with pneumonia presenting with clinical predictors of empyema and in children with persistent fever and high CRP levels during hospitalization.
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El estreptococo del grupo B (EGB) constituye la principal causa de morbimortalidad neonatal y de morbilidad materna durante el embarazo y el posparto. Coloniza el aparato digestivo y el genitourinario en un 10-30% de las gestantes, con una tasa de transmisión vertical del 50%. De entre los recién nacidos colonizados, un 1-2% desarrollará una sepsis grave precoz. Se ha realizado una revisión bibliográfica con el objetivo de conocer las estrategias de prevención de la infección neonatal por EGB. Los resultados ponen de manifiesto que las recomendaciones para su prevención consisten en el cribado universal prenatal de colonización por EGB mediante cultivo vaginorrectal a las 35-37 semanas, y la administración de profilaxis antibiótica intraparto a todas las embarazadas portadoras.
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El estreptococo del grupo B (EGB) constituye la principal causa de morbimortalidad neonatal y de morbilidad materna durante el embarazo y el posparto. Coloniza el aparato digestivo y el genitourinario en un 10-30% de las gestantes, con una tasa de transmisión vertical del 50%. De entre los recién nacidos colonizados, un 1-2% desarrollará una sepsis grave precoz. Se ha realizado una revisión bibliográfica con el objetivo de conocer las estrategias de prevención de la infección neonatal por EGB. Los resultados ponen de manifiesto que las recomendaciones para su prevención consisten en el cribado universal prenatal de colonización por EGB mediante cultivo vaginorrectal a las 35-37 semanas, y la administración de profilaxis antibiótica intraparto a todas las embarazadas portadoras.
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Probiotic lactobacilli and bifidobacteria in the mouth – in vitro studies on saliva-mediated functions and acid production Probiotics are viable bacteria which, when used in adequate amounts, are beneficial to the health of the host. Although most often related to intestinal health, probiotic bacteria can be found also in the mouth after consumption of products that contain them. This study aimed at evaluating the oral effects of probiotic bacteria already in commercial use. In a series of in vitro studies, the oral colonisation potential of different probiotic bacteria, their acid production and potential saliva-mediated effects on oral microbial ecology were investigated. The latter included effects on the salivary pellicle, the adhesion of other bacteria, and the activation of the peroxidase system. Streptococcus mutans, Streptococcus gordonii, Aggregatibacter actinomycetemcomitans and Helicobacter pylori were used as bacterial indicators of the studied phenomena. There were significant differences between the probiotic strains in their colonisation potential. They all were acidogenic, although using different sugars and sugar alcohols. However, their acid production could be inhibited by the peroxidase system. Based on the results, it can be suggested that probiotic bacteria might influence the oral microbiota by different, partly species or strain-specific means. These include the inhibition of bacterial adhesion, modification of the enamel pellicle, antimicrobial activity, and activation of the peroxidase system. To conclude, probiotic strains differed from each other in their colonisation potential and other oral effects as evaluated in vitro. Both positive and potentially harmful effects were observed, but the significance of the perceived results needs to be further evaluated in vivo.
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The phytochemical investigation of Erythroxylum pulchrum St. Hil. (Erythroxylaceae) led to the isolation of three known flavonoid glycosides quercetin-3-O-α-L-rhaminoside, ombuin-3-ruthinoside and ombuin-3-ruthinoside-5-glucoside. These flavonoids are being described for the first time in this E. pulchrum. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The methanolic extract of leaves from E. pulchrum inhibited the growth of the Bacillus subtilis CCT 0516, Escherichia coli ATCC 2536, Pseudomonas aeruginosa ATCC 8027, P. aeruginosa ATCC 25619, Staphylococcus aureus ATCC 6538, S. aureus ATCC 25925, Streptococcus sanguinis ATCC 15300, S. salivarius ATCC 7073, S. mutans ATCC 25175 and Streptococcus ATCC. S. aureus ATCC 25925 was the most sensitive among the other S. sanguinis while S. salivarius proved the most resistant.
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The phytochemical study of hexane extract from leaves of Salacia crassifolia resulted in the isolation of 3β-palmitoxy-urs-12-ene, 3-oxofriedelane, 3β-hydroxyfriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 28,29-dihydroxyfriedelan-3-one, 3,4-seco-friedelan-3-oic acid, 3β-hydroxy-olean-9(11):12-diene and the mixture of α-amirin and β-amirin. β-sitosterol, the polymer gutta-percha, squalene and eicosanoic acid were also isolated. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts and the triterpenes were tested against Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis and no activity was observed under the in vitro assay conditions. The hexane, chloroform, ethyl acetate and ethanol crude extracts, and the constituent 3,4-seco-friedelan-3-oic acid and 28,29-dihydroxyfriedelan-3-one showed in vitro antimicrobial activity against Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus sanguinis and Candida albicans.
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Tausta: Uloshengitysvaikeus on pienten lasten tavallinen sairaus. Monissa tutkimuksissa sen yleisimmäksi aiheuttajaksi on todettu respiratory syncytial virus infektio (RSV). Muiden virusten ja bakteereiden merkitys on vähemmän tunnettu. Pienten lasten uloshengitysvaikeuden hoito on vakiintumaton. Systeemisen prednisolonihoidon tehoa uloshengitysvaikeuksissa ei ole tutkittu muiden virusinfektioiden kuin RSV:n yhteydessä. Tavoitteet: Tutkimuksen tavoitteena oli selvittää lasten sairaalahoitoa edellyttäneen uloshengitysvaikeuden virusetiologia ja siihen liittyvät bakteeri-infektiot sekä systeemisen prednisolonihoidon teho suhteessa eri viruksiin. Lisäksi tavoitteena oli etsiä toistuvan uloshengitysvaikeuden riskitekijöitä ja selvittää prednisolonin teho riskiryhmiin kuuluvilla lapsilla. Menetelmät: Vuosien 2000–2002 aikana selvitettiin Turun yliopistollisessa keskussairaalassa uloshengitysvaikeuden vuoksi hoidetun 293 iältään 3 kuukauden - 16 vuotiaan lapsen tautietiologia. Nenänielun imulimanäytteestä tutkittiin viruksia viljelyn, antigeenin osoituksen sekä genomin monistustekniikan (PCR) avulla. Taudin akuutissa ja toipilasvaiheessa analysoitiin seeruminäytteistä vasta-ainepitoisuudet viruksia ja bakteereita vastaan. Bakteeri-infektioita etsittiin myös kliinisten, hematologisten ja radiologisten tutkimusten avulla. Satunnaistetulla, kaksoissokolla lumekontrolloidulla tutkimuksella selvitettiin prednisolonin kliinistä tehoa RSV- ja rinovirusinfektioissa alle 3 vuoden ikäisillä lapsilla. Toistuvan uloshengitysvaikeuden esiintymistä selvitettiin seuraamalla vuoden ajan 118 lasta, joilla oli ollut ensimmäinen uloshengitysvaikeuskohtaus. Tulokset: Todennäköinen uloshengitysvaikeuden aiheuttava virus löytyi 88 %:lta lapsista. Yleisimmät virukset olivat RSV (27 %) ja rinovirus (24 %). Kahden tai kolmen viruksen infektio todettiin 19 %:lla lapsista. Yleisin todennäköinen bakteeri-infektio oli akuutti välikorvatulehdus, joka todettiin 44 %:lla lapsista. Bakteeri-infektion serologinen osoitus saatiin 18 %:lla lapsista. Tavallisimmat bakteerit olivat Streptococcus pneumoniae (8 %) ja Mycoplasma pneumoniae (5 %). Nenän sivuontelotulehdus todettiin 17 %:lla ja alveolaarinen keuhkokuume 3 %:lla lapsista. Prednisolonihoito ei vaikuttanut lasten sairaalahoitoajan pituuteen, mutta se vähensi uusien kohtausten määrää lapsilla, joilla oli rinovirusinfektio ja sairaalaan tulohetkellä veren eosinofiilisten solujen määrä 0,2 • 109/l. Toistuvan uloshengitysvaikeuden riskitekijöitä olivat alle vuoden ikä, atopia ja äidin astma. Prednisoloni vähensi merkitsevästi toistuvan uloshengitysvaikeuden esiintymistä lapsilla, joilla oli rinovirusinfektio (HR = 0,19; 95 %:n LV, 0,05 – 0,71) tai lääkärin toteama ihottuma (0,15; 95 %:n LV, 0,04 – 0,63). Päätelmät: Lähes kaikilla lapsilla on todettavissa virusinfektio uloshengitysvaikeuden aikana. Tavallisin pienten lasten kliininen bakteerikomplikaatio on akuutti välikorvatulehdus. Prednisolonihoidolla ei ole vaikutusta sairaalahoidon pituuteen, mutta se näyttäisi vähentävän uusien kohtausten esiintymistä rinoviruspositiivisilla ja ihottumaisilla lapsilla.
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Rapid identification and resistance determination of pathogens in clinical specimens is vital for accurate treatment and monitoring of infectious diseases. Antimicrobial drug resistance is increasing globally and healthcare settings are facing this cost-intensive and even life-threatening problem. The incidence of resistant pathogens in Finland has remained relatively steady and manageable at least for the time being. DNA sequencing is the gold standard method for genotyping, mutation analysis, and identification of bacteria. Due to significant cost decrease in recent years, this technique is available to many research and clinical laboratories. Pyrosequencing technique, a rapid real-time DNA sequencing method especially suitable for analyzing fairly short stretches of DNA, was used in this study. Due to its robustness and versatility, pyrosequencing was applied in this study for identification of streptococci and detection of certain mutations causing antimicrobial resistance in different bacteria. Certain streptococcal species such as S. pneumoniae and S. pyogenes are significantly important clinical pathogens. S. pneumoniae causes e.g. pneumonia and otitis media and is one of the most important community-acquired pathogens. S. pyogenes, also known as group A streptococcus, causes e.g. angina and erysipelas. In contrast, the socalled alpha-haemolytic streptococci, such as S. mitis and S. oralis, belong to the normal microbiota, which are regarded to be non-pathogenic and are nearly impossible to identify by phenotypic methods. In this thesis, a pyrosequencing method was developed for identification of streptococcal species based on the 16S rRNA sequences. Almost all streptococcal species could be differentiated from one another by the developed method, including S. pneumoniae from its close relatives S. mitis and S. oralis . New resistance genes and their variants are constantly discovered and reported. In this study, new methods for detecting certain mutations causing macrolide resistance or extended spectrum beta-lactamase (ESBL) phenotype were developed. These resistance detection approaches are not only suitable for surveillance of mechanisms causing antimicrobial resistance but also for routine analysis of clinical samples particularly in epidemic settings. In conclusion, pyrosequencing was found to be an accurate, versatile, cost-effective, and rapid DNA sequencing method that is especially suitable for mutation analysis of short DNA fragments and identification of certain bacteria.
DPS-Like Peroxide Resistance Protein: Structural and Functional Studies on a Versatile Nanocontainer
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Oxidative stress is a constant threat to almost all organisms. It damages a number of biomolecules and leads to the disruption of many crucial cellular functions. It is caused by reactive oxygen species (ROS), such as hydrogen peroxide (H
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Objetivos: avaliar se o uso profilático da ampicilina pode evitar ou reduzir a morbidade infecciosa materna e perinatal decorrente da ruptura prematura das membranas (RPM) e prolongar a gestação em pacientes portadoras dessa complicação. Métodos: estudo prospectivo, randomizado e duplo-cego, avaliando 121 gestantes portadoras de RPM, divididas em dois grupos. O grupo tratado (61 gestantes) recebeu ampicilina e o grupo controle (60 gestantes) recebeu placebo, nas mesmas condições de horário, tempo de uso, embalagem e cor das cápsulas. Como parâmetros de infecção materna considerou-se a morbidade febril materna (índice térmico), presença de corioamnionite e/ou endometrite. Os parâmetros neonatais avaliados foram o índice de Apgar (1° e 5° minutos), colonização bacteriana do conduto auditivo e hemocultura. Para a análise estatística foram utilizados os testes: exato de Fisher, Wilcoxon e o chi². Resultados: o uso da ampicilina não prolongou a gestação, não reduziu a morbidade febril puerperal e nem as taxas de corioamnionite e/ou endometrite. Quanto à morbidade infecciosa perinatal também não foi possível demonstrar nenhuma redução decorrente do uso da ampicilina nem influência sobre as condições de nascimento. Estes dados foram consistentes em casos de RPM com até 72 horas de evolução, pois o limitado número de casos com tempo maior de evolução não permitiu uma análise estatística isenta de erro tipo II. Conclusões: com base nos resultados desse trabalho foi possível concluir que o uso profilático de ampicilina em gestantes com RPM com até 72 horas de evolução não reduz a morbidade infecciosa materna nem perinatal. No entanto, a presença de Streptococcus agalactiae do grupo B em hemocultura de recém-nascido do grupo controle indicou a necessidade imperiosa de antibioticoterapia para as gestantes colonizadas por esse microrganismo.
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Objetivo: avaliar as repercussões da infecção ascendente sobre a mãe, o feto e o recém-nascido (RN) nos casos de rotura prematura das membranas (RPM). Métodos: estudo prospectivo, avaliando 50 gestantes portadoras de RPM e seus RN. A corioamnionite clínica foi rastreada por meio de critérios clínicos (curva térmica, dor abdominal à palpação e/ou amolecimento uterino, odor e características da secreção vaginal) e subsidiários (leucograma e proteína C reativa). Por sua vez, a corioamnionite histológica foi avaliada com estudo macroscópico e microscópico da placenta, membranas e cordão umbilical. No estudo microscópico, utilizou-se a microscopia óptica com coloração pela hematoxilina-eosina. Os RN foram avaliados pela mensuração do peso e índice de Apgar no 1o e 5o minuto. O leucograma e a cultura do material colhido do ouvido e aspirado gástrico complementaram o estudo. Para análise estatística foram utilizados os testes exato de Fisher e t de Student, com nível de significância de 5% (p<0,05). Resultados: a taxa de corioamnionite clínica foi de 29,4% (15/50), ao passo que a de corioamnionite histológica foi de 40% (20/50). Todos os casos de corioamnionite clínica apresentaram período de latência (PL) superior a 24 horas. Os RN apresentaram sinais de infecção em 31,4% (16/51), todos com PL maior que 24 horas. Os principais microrganismos isolados do conduto auditivo e aspirado gástrico dos RN foram: Klebsiella pneumoniae, Staphylococcus aureus, cocos Gram positivos e Streptococcus agalactiae - Grupo B de Lancefield (SGB). Os RN infectados apresentaram menor escore de Apgar no 1o e 5o minuto, peso ao nascer inferior e maior morbidade e mortalidade perinatal quando comparados com os RN não infectados. Conclusões: baseados na análise dos resultados obtidos no presente estudo, foi possível concluir que o período de latência prolongado aumenta a chance de infecção ascendente, que, por sua vez, proporciona maior probabilidade de parto prematuro, aumentando portanto a morbidade materna (corioamnionite clínica), bem como a morbidade e mortalidade perinatal.
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OBJETIVO: verificar a prevalência de estreptococo do grupo B (EGB) em gestantes no terceiro trimestre da gravidez e explorar os fatores potencialmente associados à colonização. MÉTODOS: uma amostra de 273 gestantes no terceiro trimestre da gravidez, provenientes do ambulatório de pré-natal do Hospital Universitário do Sul do Brasil, foi investigada. Culturas de amostra vaginal e anorretal foram obtidas e inoculadas em meio seletivo de Todd-Hewitt suplementado com 10 µg/ml de colistina e 15 µg/ml de ácido nalidíxico e posteriormente subcultivadas em ágar sangue de carneiro desfibrinado. Todas as colônias suspeitas foram submetidas ao teste de aglutinação para detecção do antígeno específico do grupo B. O teste de Camp foi utilizado para identificação do EGB das variedades não hemolíticas. Analisaram-se também os dados demográficos, socioeconômicos, reprodutivos e clínico-obstétricos. A razão de prevalência (RP) foi utilizada como medida de risco. Considerou-se como significante o intervalo de confiança no nível de 95% (alfa=0,05). RESULTADOS: a prevalência de colonização pelo EGB foi de 21,6% (59), sendo que 9,9% (27) das gestantes tiveram positividade em ambos os sítios, 6,95% (19) foram positivas somente no sítio vaginal e 4,75% (13) da amostra tiveram positividade apenas no sítio anal. A prevalência de EGB foi ligeiramente mais alta nas gestantes com idade inferior a 20 anos, naquelas com menor escolaridade e nas gestantes primíparas, e o dobro entre aquelas que não relataram aborto espontâneo, porém sem significância estatística. Não foi encontrada diferença na prevalência de EGB de acordo com história de doenças sexualmente transmissíveis e tabagismo. Quando os dados foram analisados conjuntamente, os fatores detectados como potencialmente associados à colonização pelo EGB foram: primíparas com mais de 30 anos (RP=1,55) e mulheres com mais de um parceiro sexual e freqüência de atividade sexual aumentada (55,6 vs 20,5%; p<0,05). CONCLUSÃO: confirma-se a necessidade rotineira de cultura para EGB em ambos os sítios (vaginal e anal) de todas as gestantes no terceiro trimestre de gestação.