Orientador: Mirtha Nelly Uboldi Eiroa, Pilar Rodriguez Massaguer / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-20T04:29:11Z (GMT). No. of bitstreams: 1 Marenco_HebeAnaMariaCalettide_M.pdf: 3895198 bytes, checksum: 0906c8d66bfc0aeeb5f3229a41fed972 (MD5) Previous issue date: 1994 / Resumo: O forno de microondas vem sendo utilizado com freqüência crescente no descongelamento e preparação de refeições no âmbito doméstico bem como em centros de saúde e estabelecimentos comerciais, sendo a rapidez do processo um dos atributos mais apreciados. Por esta característica, foi conduzido um número significativo de pesquisas no campo da Microbiologia, visando obter informações a respeito da resposta dos microrganismos à ação das microondas. Este trabalho tem por objetivo avaliar o efeito das microondas sobre células vegetativas de Escherichia coli e esporos de Bacillus cereus e Clostridium sporogenes PA 3679 em sopa constituída de vegetais, margarina e ovos. As condições de trabalho no laboratório foram semelhantes às da operação de um forno de microondas doméstico. Amostras de sopa previamente esterilizadas foram inoculadas individualmente com cada um dos microrganismos citados nos níveis de 2 log UFC/ml ( unidades formadoras de colônias/ml), 4 log UFC/ml e 6 log UFC/ml e, a seguir, colocadas no centro do prato giratório do forno de microondas e aquecidas em potência alta por diferentes períodos de tempo. A intervalos de um minuto foram retiradas amostras para determinar a temperatura alcançada pela sopa e avaliar o número de microrganismos sobreviventes por inoculação em placa nos meios convenientes. A inativação total de E. coli foi observada após 3 minutos de aquecimento seguido de 3 minutos de tempo de espera. Populações de esporos de B. cereus da ordem de 2,1 log UFC/ml foram inativadas após 4 minutos de aquecimento seguido de 4 minutos de tempo de espera. Para populações da ordem de 4,1 log UFC/ml e 6,2 log UFC/ml, a inativação de esporos ocorreu após 5 minutos e 6 minutos de aquecimento seguido de 4 minutos de tempo de espera, respectivamente. Populações de C. sporogenes, nos três níveis de inoculação, não apresentaram evidências de injúria após 10 minutos de aquecimento / Abstract: The microwave oven is being increasingly used to defrost and reheat prepared meals for domestic consumption as well as in hospitals and commercial establishments, primarily because of the speed of operation. Due to the widespread usage of microwave ovens, much research has been conducted in the field of microbiology to obtain information on the influence of microwave radiation upon microorganisms. The present work has been conducted to evaluate the influence of microwaves upon Escherichia coli, Bacillus cereus spores and Clostridium sporogenes PA 3679 spores in soup composed of vegetables,eggs and margarine. The experiment was carried out at the laboratory simulating domestic use of the microwave oven. The samples of soup were sterilized and individually inoculated with each one of the microorganisms in concentrations of 2 log CFU/ml (colony formers units/ml), 4 log CFU/ml and 6 log CFU/ml. Afterwards, they were placed in the center of the giratory plate of a microwave oven and heated at high power for different periods of time. Samples were taken every minute to determine temperature, and to evaluate the number of survivors by plating. It was necessary to heat for 3 minutes followed by 3 minutes of resting time to inactivate completely E. coli. When the contamination level of B. cereus spores was 2,1 log CFU/ml the total inactivation was observed after 4 minutes of heating and 4 minutes of resting time. When the population was 4,1 log CFU/ml and 6,2 log CFU/ml the spores inactivation was observed after 5 minutes and 6 minutes of heating followed by 4 minutes of resting time respectively. Heating for 10 minutes showed no effect on spores of C. sporogenes / Mestrado / Mestre em Ciência de Alimentos

Orientador: Tomomasa Yano / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T06:09:15Z (GMT). No. of bitstreams: 1 Cordeiro_MelinaAparecida_M.pdf: 3889960 bytes, checksum: 3e92b071b7e108ebb8bff09fe751b180 (MD5) Previous issue date: 2015 / Resumo: O Resumo poderá ser visualizado no texto completo da tese digital / Abstract: The Abstract is available with the full electronic digital document / Mestrado / Microbiologia / Mestra em Genética e Biologia Molecular

Bibliography: pages 143-154. / This dissertation forms part of the study on the molecular biology of the aerobic, collagenolytic, halotolerant, gram-negative organism Vibrio alginolyticus. The cloning, expression and regulation of the v. alginolyticus sucrose utilization system in Escherichia coli is discussed and the results of a molecular analysis of the sucrase gene (scrA) are presented. The clone pVSlOO, containing a sucrose utilization system, was isolated from a genomic library of v. alginolyticus. Plasmid pVSlOO was mapped and the origin of its insert determined by Southern blotting and DNA hybridization. The number and sizes of the polypeptide products encoded by plasmid pVSlOO were determined by DNAdirected cell-free protein synthesis. The capsule, produced by transformed and untransformed E. coli JA221 cells, was shown to be independent of the presence of plasmid pVSlOO. The sucrase activity assay was optimized with respect to time, pH, temperature and salt requirements.

Purification of the phosphoroclastic system of Escherichia coli was undertaken. A 4-fold purification of the crude extract was obtained using heat precipitation and protamine sulfate. Some purification of Knappe's A fraction was obtained with ammonium sulfate and acetone. Evidence was obtained for the existence of two factors in the A fraction. Other purification techniques gave little success. Good evidence was obtained for the involvement of phosphotrans-acetylase in the reaction sequence. Phosphotransacetylase was purified 750-fold and characterized. The reversibility of the reaction was studied with carbon 14. Formate fixed readily into pyruvate only when pyruvate was present. Acetyl coenzyme A fixed into pyruvate also but to a much smaller degree. Better fixation without pyruvate was obtained after prior incubation and consumption of pyruvate. The dilution effect, inhibitors, effect of light, and a possible role of coenzyme B_12 were investigated. By using a deuterium label, it was shown that a hydrogen does not shift directly from the methyl group of pyruvate to formate in the reaction mechanism.

Objetivo General: Determinar la frecuencia de los agentes etiológicos bacterianos y su respectiva susceptibilidad antibiótica en las infecciones urinarias de los adultos atendidos ambulatoriamente, en consultorio externo y en emergencia, en el Hospital Nacional “Sergio E. Bernales” durante el periodo Enero-Diciembre 2014. Metodología: El estudio es de tipo descriptivo, observacional, retrospectivo y de corte transversal. La unidad de análisis fue cada resultado de urocultivo positivo cuya muestra perteneció a un paciente adulto (≥ 18 años) procedente de emergencia o consultorio externo del Hospital Nacional Sergio E. Bernales durante el periodo Enero – Diciembre 2014. Se registró la información proveniente de los urocultivos y sus respectivos antibiogramas mediante una ficha de recolección de datos, estos fueron analizados posteriormente utilizando el paquete estadístico SPSS 23. Resultados: Se incluyeron 327 urocultivos positivos de pacientes diferentes y sus respectivos antibiogramas. Se encontraron en total 15 agentes patógenos diferentes, de los cuales se halló en mayor proporción a Escherichia coli, quien presentó tasas de resistencia altas para ampicilina, ampicilina/sulbactam, cefazolina, cefepima, ceftazidima, ceftriaxona, ciprofloxacino, gentamicina y trimetoprima/sulfametoxazol; del mismo modo, en ambos sexos y en todos los rangos de edad se encontraron tasas de resistencia altas para los mismos antibióticos. Conclusiones: Los agentes etiológicos causantes de infección urinaria hallados con mayor frecuencia en el Hospital Nacional Sergio E. Bernales fueron Escherichia coli, Klebsiella pneumoniae ssp pneumoniae, Proteus mirabilis y Pseudomona aeruginosa, en ese orden; los cuales fueron altamente resistentes a ampicilina, ampicilina/sulbactam, cefazolina, cefepima, ceftazidima, ceftriaxona, ciprofloxacino, gentamicina y trimetoprima/sulfametoxazol. Palabras clave: Infección urinaria, susceptibilidad antibiótica, antibiograma, Escherichia coli / --- General Objective: To determine the frequency of bacterial etiologic agents and their respective antibiotic susceptibility in urinary tract infections in adults cared for outpatients, external clinic and emergency, at the National Hospital "Sergio E. Bernales" during the period January-December 2014. Methodology: The study is descriptive, observational, retrospective and cross-sectional. The unit of analysis was each result of positive urine culture whose sample belong to an adult patient (≥ 18 years) from emergency or outpatient clinic of the National Hospital Sergio E. Bernales during the period January - December 2014. Information was recorded from the urine cultures and their respective antibiogram by a data collection sheet, these were analyzed later using the statistical package SPSS 23. Results: 327 positive urine cultures of different patients and their respective antibiogram were included. Were isolated in total 15 different pathogens, which is found in greater proportion to Escherichia coli, who presented high rates of resistance to ampicillin, ampicillin/sulbactam, cefazolin, cefepime, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin and trimethoprim/sulfamethoxazole; in the same way, in both sexes and all age ranges were found high rates of resistance to the same antibiotics. Conclusions: Urinary tract infection-causing etiologic agents found most frequently in the Hospital Nacional Sergio E. Bernales were Escherichia coli, Klebsiella pneumoniae ssp. pneumoniae, Proteus mirabilis and Pseudomonas aeruginosa, in that order; which were highly resistant to ampicillin, ampicillin/sulbactam, cefazolin, cefepime, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin and trimethoprim/sulfamethoxazole. Keywords: urinary tract infection, antibiotic susceptibility, antibiogram, Escherichia coli. / Tesis

OBJETIVO: Determinar si la edad mayor de 60 años y el uso de antibióticos tres meses previos son factores de riesgo asociados a infección urinaria por Escherichia coli productora de betalactamasas de espectro extendido en pacientes hospitalizados de la Clínica Maison de Santé-Sede Este. MATERIALES Y MÉTODOS: Diseño transversal descriptivo de enfoque cuantitativo. La población estuvo conformada por todo paciente hospitalizado con diagnóstico principal de infección urinaria (ITU) con registro de cultivo de Escherichia coli durante el periodo enero-noviembre 2015. Se incluyeron en el estudio 120 pacientes, que fueron la totalidad de pacientes que tuvieron como motivo de hospitalización infección urinaria en el periodo citado. Se calculó la fuerza de asociación de la edad mayor de 60 años y el uso de antibiótico tres meses previos como factores de riesgo asociado a infecciones urinarias por Escherichia coli productora de betalactamasas de espectro extendido. Se describieron características generales de la población y perfil de sensibilidad antibiótica. Los resultados se analizaron y graficaron mediante el programa estadístico STATA 14 y hoja de cálculo de Microsoft Excel. RESULTADOS: Se encontró que quienes tenían edad mayor de 60 años tuvieron 3,26 veces más riesgo de ITU por E. coli BLEE comparado con quienes no tuvieron dicha exposición. El uso de antibiótico tres meses previos tuvo 2,62 más riesgo de producción de BLEE. Respecto a las características de los pacientes que tuvieron cultivo positivo para E. coli BLEE el 82.9% tenían más de 60 años, 68,4% eran de sexo femenino, 31,6% eran de sexo masculino, 13% tenían antecedente de uso de sonda urinaria y la enfermedad concomitante más frecuente fue la hipertensión arterial, 59,2%. En el perfil de sensibilidad Piperazilina/Tazobactam e Imipenem fueron antibiótico al que con más frecuencia eran sensibles los cultivos de E. coli BLEE. CONCLUSIONES: La infección urinaria por Escherichia coli productora de betalactamasas de espectro extendido en pacientes hospitalizados de la Clínica Maison de Santé-Sede Este durante enero-noviembre del 2015 tuvo asociación estadísticamente significativa con la edad mayor de 60 años y el uso de antibiótico 3 meses previos, lo cual es concordante con lo reportado en estudios similares. El perfil de sensibilidad antibiótica de los cultivos positivos a BLEE fue similar a los descritos por otros estudios de sensibilidad. PALABRAS CLAVE: Infección urinaria, Escherichia coli, BLEE / Tesis

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During entry into stationary phase, Escherichia coli expresses many genes which impart cellular resistance to numerous environmental stresses such as oxidative or acid stress. Many ofthese genes are regulated by the alternative sigma factor, RpoS To identify additional genes regulated by RpoS, a phenotype independent genetic screen was previously employed (L. Wei Masters thesis). The identities ofthe ten most highly RpoSdependent fusions were determined by DNA sequencing and subsequent sequence analysis using the BLAST algorithm Three fusions map to genes previously known to be RpoSdependent while the remaining seven represent new members ofthe regulon The expression of many ofthe RpoS-dependent fusions remained growth phase dependent even in the rpoS background This suggests that other growth phase regulatory factors in addition to RpoS may coordinate stationary phase gene expression Upon sequencing the remaining rsd fusions, three mutants mapped to narY which is part ofthe narZYWV operon encoding the secondary nitrate reductase Z (NRZ) This operon was selected for further investigation since NRZ has been previously reported to be constitutively expressed Expression studies using promoter lacZ fusions and nitrate reductase assays reveal that NRZ is induced ten-fold at the onset ofstationary phase and twenty-fold in the presence of nitrate Like other rsd fusions, growth phase dependent expression was observed in an rpoS background indicating that other regulatory factors may be involvedn the regulation of NRZ Northern analyses using probes specific to NRZ confirmed that transcription of NRZ is indeed dependent on RpoS. These results suggest that RpoS mediated regulation of NRZ may be an important physiological adaptation to reduced oxygen levels during transition to stationary phase / Thesis / Master of Science (MSc)

BiophotonicE. coli O157:H7(BEC) was evaluated for growth and stability to evaluate the effectiveness of BEC as a tool to validate pathogen reduction interventions. Escherichia coliO157:H7 containing Xen14 and pAK1 lux plasmids were monitored for growth and stability over 10 d at 2.2˚C and 37˚C. Concentration of BECat 2.2˚C remained constant (P> 0.05) but photonic emissions (RLU/s) changed (P<0.05), resulting in a positive correlation between RLU/s and CFU/mL (P< 0.01; r=0.5718). BEC grown at 37˚C yielded no change after a decrease on day 2 (P>0.05). In phase I, purge was monitored for photonic emission after trim was inoculated with BEC. BECwas found at 4 h in Combo C and D. Phase II purge collection used inoculated trim indicative of trim used currently in the beef industry stored in simulated combos. Neither photonic emission nor CFU’s were enumerated in phase II.