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Chen, Pei-Chun. "Improvement of detection method and heat resistance study among strains of Enterobacter sakazakii." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/p-c_chen_111407.pdf.
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Nazarowec-White, Maria. "Biological characterization of Enterobacter sakazakii." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ36785.pdf.
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Schütz, Anja. "Untersuchungen zur Struktur und zum Katalysemechanismus der Indolpyruvatdecarboxylase aus Enterobacter cloacae." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97412088X.
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Hall, Amanda, Steven Pribanich, and Sean Fox. "Analysis of Reciprocal Inhibition Between Candida albicans and Opportunistic Pathogens Enterobacter aerogenes and Enterobacter cloacae." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/asrf/2020/presentations/51.
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The fungal pathogen Candida albicans and the opportunistic bacterial pathogens Enterobacter aerogenes and Enterobacter cloacae are common sources of human disease. The colonization of proximal anatomical locations by these pathogens suggests that interspecies polymicrobial interactions between Candida albicans and Enterobacter species occur. In order to understand mechanisms of diseases caused by these pathogens and to further the study of disease prevention, analyzation of their combined activities was conducted in this study. Changes in fungal morphology, cellular viability, and colony density were investigated using fungal and bacterial co-cultures. The effects of the Candida secreted quorum sensing molecule farnesol on Enterobacter aerogenes and Enterobacter cloacae was studied to observe changes in Enterobacter viability and colony density. The effects of the presence of Enterobacter species on Candida albicans was studied by observing changes in Candida morphology and colony density. The mutant strain of Candida albicans AlS6-/- was also cultured with Enterobacter to determine if the presence of the ALS6 surface glycoprotein gene affected Candida viability and colony density in the presence of Enterobacter species. Statistically significant decreases were observed in all studied metrics between experimental and control groups. This indicated that the interactions observed between Candida albicans and Enterobacter species represent reciprocal inhibitions of cellular functionalities. As Candida albicans is the primary cause of human fungal infections and Enterobacter species are common causes of opportunistic infections, the study of polymicrobial interactions between Candida and Enterobacter species as conducted in this study is important to furthering efforts of human disease inhibition.
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CABRAL, Adriane Borges. "Caracterização genética de isolados clínicos de Enterobacter aerogenes e Enterobacter cloacae: determinantes de resistência e virulência." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17748.
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Previous issue date: 2016-02-26<br>FACEPE<br>Enterobacter aerogenes e Enterobacter cloacae são importantes patógenos causadores de Infecções relacionadas à Assistência à Saúde (IRAS), podendo apresentar diferentes genes de virulência e de resistência a antimicrobianos. O objetivo desse estudo foi caracterizar e comparar genomicamente isolados de E. aerogenes e E. cloacae multidrogas resistentes (MDR), provenientes de um Hospital público de Recife-PE entre 2011 e 2013, através da investigação de genes relacionados à resistência a antimicrobianos e à virulência, como também analisar o perfil plasmidial e relação clonal dos isolados. Portanto, este estudo foi dividido em três etapas: (1) caracterizar fenotipicamente e genotipicamente 51 isolados de E. aerogenes e E. cloacae provenientes de infecção ou colonização em pacientes de um hospital público de Recife-PE, Brasil, através de perfil de susceptibilidade a antimicrobianos, análises de genes de β-lactamase por PCR e sequenciamento de DNA, perfil plasmidial e ERIC-PCR; (2) realizar o primeiro sequenciamento genômico de 2 isolados de E. aerogenes, blaKPC-2 positivos, provenientes de colonização (Ea5A) e de infecção (Ea7A) em pacientes internados na Unidade de Terapia Intensiva (UTI) de um mesmo hospital, além de análise comparativa com 2 cepas de E. aerogenes sequenciadas anteriormente e (3) realizar sequenciamento genômico de 2 isolados de E. cloacae, blaCTX-M-15 positivos, provenientes de infecções: Ec2A (secreção ocular) e Ec7A (hemocultura) em pacientes internados na Unidade de Terapia Intensiva neonatal (UTI neo) de um mesmo hospital, além de análise comparativa com cepas de E. cloacae sequenciadas anteriormente. Em ambas as espécies houve detecção de altas taxas para ESBL (41%) e carbapenemases (18% para E. cloacae e 88% para E. aerogenes), com identificação das variantes: blaTEM-1, blaCTX-M-15 e blaKPC-2. Os isolados apresentaram disseminação clonal, com E. cloacae blaCTX-M positivo disseminado na UTI neonatal e E. aerogenes blaKPC positivo na UTI e em outros setores do hospital. Foi visto que apesar dos isolados apresentarem relação clonal pela ERIC-PCR apresentaram diferentes perfis plasmidiais e de resistências, além de, diferentes genes de resistência. O sequenciamento genômico permitiu a detecção de: (1) vasto arsenal de genes de resistência a beta-lactâmicos, assim como, genes de resistência a outras classes de antimicrobianos, (2) diversos genes de virulência relacionados a adesinas fimbriais, sideróforos, cápsula e biofilme e (3) cinco tipos de sistemas de efluxo e quatro tipos de sistemas de secreção, relacionados pricipalmente à resistência e virulência, respectivamente. Em relação à análise comparativa dos genomas, foi visto que apesar de serem clones pela ERIC-PCR e provenientes do mesmo setor hospitalar, ambas as espécies apresentaram diferenças sutis no quantitativo de genes totais, genes de resistência, genes de virulência, sistemas de efluxo e secreção, além de características exclusivas de cada isolado. Também foi possível detectar que dentre os isolados de E. aerogenes, foi visto que o isolado proveniente de colonização (Ea5A), apresentou genes de virulência potenciais para estabelecer a infecção, além de elementos genéticos móveis capazes de transmitir diversos genes para outras bactérias presentes na microbiota entérica do paciente, o que reforça a importância da colonização no contexto de IRAS. Considerando os isolados de E. cloacae sequenciados genomicamente, o isolado proveniente de hemocultura (Ec7A) mostrou maior número de determinantes de resistência (beta-lactamases e sistemas de efluxo) que o isolado proveniente de secreção ocular, o que pode dificultar o tratamento e consequentemente favorecer a evolução para estágios mais severos como sepse e choque séptico. Os resultados aqui apresentados evidenciam o vasto arsenal de genes de resistência e virulência albergados pelos isolados de E. aerogenes e E. cloacae o que pode facilitar o estabelecimento da infecção e dificultar o tratamento.
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Iversen, Carol. "Isolation and characterisation of Enterobacter sakazakii." Thesis, Nottingham Trent University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442091.
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Enterobacter sakazakii is a bacterial contaminant of powdered infant formula milk that has been associated with necrotising enterocolitis, bacteraemia and a rare form of infant meningitis. The presence, persistence and growth of the organism in infant formula milk needs to be better understood to limit the occurrence of infection, and improved isolation methods need to be developed in order for companies to implement appropriate food safety management systems. A collection of E. sakazakii isolates from diverse clinical, food and environmental sources was compiled. Isolates identified biochemically as E. sakazakii formed four genomic clusters when housekeeping gene sequences (165 rONA and hsp60 loci) were compared. The reliability of presumptive isolate identification using commercial biochemical galleries was investigated in comparison to identification by 165 sequencing. The Biolog GN2 system appeared to be the most reliable identification gallery. A novel chromogenic medium, based on the a-glucosidase reaction, was developed to improve the efficiency of E. sakazakii isolation methods and is commercially available as Chromogenic Enterobacter sakazakii medium, Oruggan-Forsythe-Iversen formulation (OFI), CM1055, Oxoid ltd. The sensitivity and specificity of the OFI medium was compared with other proposed media. Also 486 food samples were tested for the presence of E. sakazakii. The organism was isolated from 67 samples using the OFI medium compared with only 19 using the conventional method. A novel enrichment medium was also investigated to improve recovery of E. sakazakii. Preliminary investigation of factors that may be associated with increased risk of acquiring E. sakazakii infection from contaminated infant formula indicated that E. sakazakii strains are able to survive in a desiccated state for over 6 months. They are also able to form biofilms on infant feeding equipment, can attach and invade human epithelial (CaCO-2) cells in vitro and can survive in human serum. Some strains may persist in macrophages, and many produce exopolysaccharide capsules which enhance biofilm formation and may contribute to evasion of host immune defences.
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Guérin, François. "Facteurs d'opportunisme chez enterobacter cloacae complexe." Caen, 2016. http://www.theses.fr/2016CAEN2014.
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Enterobacter cloacae, bactérie commensale du tube digestif de l’homme, est devenu un pathogène opportuniste majeur en particulier chez les patients hospitalisés dans les unités de soins continus. Dans cette étude, nous nous sommes intéressés aux facteurs d’opportunisme chez le complexe Enterobacter cloacae, susceptibles d’expliquer son émergence. La mise au point d’une stratégie d’analyse par « Transposon sequencing », nous a permis dans une première approche de mettre en évidence des gènes potentiellement impliqués dans la colonisation par cette bactérie. Par la construction de souches mutantes, 3 gènes (fliI codant pour ATP synthétase transportant la flagelline, ECL_00056 codant pour un régulateur TetR et ECL_01421 codant pour une protéine hypothétique de 49 acides aminés) semblent être impliqués dans le processus de colonisation. Parallèlement, nous nous sommes intéressés à 3 mécanismes de résistance aux biocides qui constituent également des facteurs d’opportunisme. I) Nous avons décrypté la régulation de l’expression de la céphalosporinase chromosomique (ampC) en s’inspirant du modèle de Pseudomonas aeruginosa. Ii) Nous avons caractérisé le rôle de 11 gènes codant pour les pompes d’efflux de type RND pour lesquelles nous avons réalisé l’étude de la sensibilité à 36 biocides et le rôle de la virulence de E. Cloacae dans le modèle Galleria mellonella. Iii) Pour finir, nous nous sommes intéressés à l’hétéro-résistance à la colistine, antibiotique de recours, caractérisant la grande majorité des clusters, à l’exception des C-III et C-VI majoritairement retrouvés en clinique<br>Enterobacter cloacae, a commensal bacteria of the human gastrointestinal tract, has become a major opportunistic pathogen in hospitalized in the intensive care units. In this study, we were interested to the opportunism factors of complex Enterobacter cloacae, that may explain its emergence. The development of a “Transposon sequencing” strategy, allowed us to highlight genes potentially involved in colonization of E. Cloacae. By the construction of mutant strains, 3 genes (fliI coding for ATP synthetase transporting the flagelline, ECL_00056 coding for a regulator TetR and ECL_01421 coding for a hypothetical protein of 49 amino acids) seem to be involved in the process of colonization. In parallel, we were interested in 3 mechanisms of resistance to biocides. I. We deciphered the regulation of the expression of chromosomal cephalosporinase (ampC) that also constitute opportunistic traits by comparison with the model of Pseudomonas aeruginosa. Ii) We characterized the role of 11 genes encoding for coded for RND-type transporters, which were tested for their role in antimicrobial susceptibility to 36 compounds and their virulence in the invertebrate Galleria mellonella model of infection. Iii) we were interested to the hetero-resistance of colistine (one of the constitutive opportunistic traits) characterizing the great majority of clusters of E. Cloacae, with the exception of the C-III and C-VI that are mainly found in clinical strains
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Rosa, Juliana Ferraz. "Caracterização molecular dos mecanismos de resistência aos carbapenêmicos de isolados clínicos de Enterobacter aerogenes e Enterobacter cloacae." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/5/5134/tde-11012016-142655/.
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INTRODUÇÃO: Nas últimas três décadas E. aerogenes e E. cloacae vem sendo reportado como importante patógeno de infecção relacionada a assistência à saúde e vem cada vez mais apresentando resistência a vários antibióticos incluindo os carbapenêmicos. Poucos estudos, entretanto, avaliaram os mecanismos de resistência aos carbapenêmicos em espécies de Enterobacter no Mundo e no Brasil. OBJETIVO: Avaliar a presença de genes codificadores de carbapenemases, genes de ?- lactamases de espectro estendido e de bomba de fluxo AcrAB-TolC e alteração de proteínas de membrana externa de 44 isolados de E. aerogenes e 8 isolados de E. cloacae resistentes aos carbapenêmicos de 03 hospitais brasileiros. MATERIAL E MÉTODOS: Para determinar a Concentração Inibitória Mínima (CIM), foi realizado o teste de microdiluição em caldo, com os antibióticos: Imipenem, Meropenem, Ertapenem, Cefepima, Tigeciclina e Polimixina B e para Fosfomicina foi realizado o teste de diluição em ágar, segundo CLSI. Foi realizado PCR para identificar os genes codificadores de Serino Beta-lactamase da Classe A de Ambler (blaKPC, blaIMI e blaGES), de Metalo-beta-lactamase da Classe B de Ambler (bla IMP, blaVIM, blaGIM, blaSIM, blaSPM e blaNDM), de Oxacilinases da Classe D de Ambler (bla OXA-48), as ESBL (blaTEM, blaCTX e blaSHV) e da bomba de efluxo AcrAB-TolC. A tipagem molecular foi feita pela técnica de PFGE, as proteínas de membrana externa pelo método de SDS-PAGE e a atividade da bomba de efluxo por meio da determinação da CIM dos carbapenêmicos com e sem inibidor Carbonyl cyanide mchlorophenylhydrazone (CCCP). RESULTADOS: No período de 2005 a 2011, foram analisados, 130 isolados de Enterobacter spp, 105 (80,8%) dos isolados foram identificados como Enterobacter aerogenes, destes 44 (41,9%) apresentaram resistência ao Imipenem, Ertapenem ou Meropenem e 25 (19,2%) foram identificados como Enterobacter cloacae, destes 8 (32,0%) apresentaram resistência aos carbapenêmicos. Os isolados de E. aerogenes apresentaram CIMs que variaram de 2 a 128ug/mL para Imipenem, 4 a 64ug/mL para Meropenem e para Ertapenem 1 a >=128 ug/mL e os isolados de E. cloacae apresentaram CIMS que variaram de 8 a 64?g/mL para Imipenem, 2 a 16ug/mL para Meropenem e 8 a 64 ug/mL para Ertapenem. Todos isolados foram sensíveis a Fosfomicina, Polimixina B e Tigeciclina. A única carbapenemase identificada foi KPC, que estava presente em ambos isolados e em todos hospitais estudados. Os 39 isolados de E. aerogenes apresentaram 5 clones diferentes, sendo o clone A predominante. Os 5 isolados de E. aerogenes do Hospital de Itapecerica da Serra pertenciam ao mesmo clone. Os 8 isolados de E. cloacae apresentaram 2 clones diferentes. E a maioria dos isolados analisados apresentarou mecanismos de resistência aos carbapenêmicos como: gene blaKPC associado com o gene blaTEM e/ou blaCTX, associado com diminuição ou ausência de proteína 35-36kDa e 39 kDa. CONCLUSÃO: Em nosso estudo foi observado alta resistência aos carbapenêmicos nos isolados de E. aerogenes e E. cloacae nos 3 hospitais estudados. Os mecanismos observados que contribuíram para a resistência aos carbapenêmicos foram: a presença de KPC, ESBL e impermeabilidade da membrana para os isolados de E. aerogenes e para os isolados de E. cloacae foi observado também como mecanismo o gene da bomba de efluxo AcrART. Para os isolados de E. aerogenes, não foi observado o gene da bomba de efluxo, mas todos isolados analisados apresentaram atividade da bomba de efluxo para os carbapenêmicos, possivelmente nos indicando a presença de outra bomba de efluxo ainda não identificada<br>INTRODUCTION: In the last three decades, E. aerogenes and E. cloacae have been reported as important opportunistic pathogens in humans. They have been showing an increase resistance to multiple antibiotics including carbapenem. Few studies, however, evaluated the mechanisms of resistance to carbapenem in Enterobacter species in the world and in Brazil. OBJECTIVES: To evaluate the presence of genes encoding carbapenemases, genes of beta- lactamases of extended spectrum and AcrAB TolC- efflux pump and amendment of outer membrane proteins of 44 isolates of E. aerogenes and 8 isolates of E. cloacae carbapenems resistant of 03 Brazilian hospitals. METHODS: To determine the minimum inhibitory concentration (MIC), microdilution broth test was performed for the followings antibiotics: Imipenem, Meropenem, Ertapenem, Cefepima, Tigecycline and Polymyxin B and agar dilution for Fosfomycin, according to CLSI. PCR was performed to identify the genes encoding Serino Beta-lactamase Class A Ambler (blaKPC, blaIMI and blaGES) of Metallo-beta-lactamase Class B Ambler (blaIMP, blaVIM, bla GIM, blaSIM, blaSPM and blaNDM) of Oxacilinases Class D Ambler (blaOXA-48), the ESBL (blaTEM, blaSHV and blaCTX) and efflux pump AcrAB-TolC. Molecular typing was performed by PFGE, outer membrane proteins by SDS-PAGE method and the activity of the efflux pump by carbapenem´s MIC by agar diluition with and without inhibitor Carbonyl cyanide m-chlorophenylhydrazone (CCCP). RESULTS: In the period from 2005 to 2011, 130 isolates of Enterobacter spp were analyzed, 105 (80.8%) isolates were identified as Enterobacter aerogenes, of these 44 (41.9%) were resistant to Imipenem, Meropenem or Ertapenem and 25 (19.2%) were identified as Enterobacter cloacae, and 8 (32.0%) showed resistance to carbapenems. The isolated E. aerogenes presented MIC ranging from 2 to 128?g /ml for Imipenem, 4 to 64ug /ml for Meropenem and Ertapenem 1 to >= 128 mg /mL. E. cloacae isolated showed MIC ranged from 8 to 64ug / ml for Imipenem, 2 to 16ug / ml for Meropenem and 8 to 64 mg / mL to Ertapenem. All isolates were susceptible to fosfomycin, polymyxin B and tigecycline. The only carbapenemase identified was KPC, which was present in both isolated and in all hospitals studied. The 39 isolates of E. aerogenes presented five different clones, the clone A being predominant. The five isolates of E. aerogenes in the Hospital of Itapecerica da Serra belong to same clone. Eight isolates of E. cloacae showed two different clones. Most of the isolates analyzed showed resistance mechanisms to carbapenems like: blaKPC gene associated with blaTEM gene and / or blaCTX associated with a decreased or absent protein 35- 36kDa and 39 kDa. CONCLUSION: In our study, we observed high carbapenem resistance in isolates of E. aerogenes and E. cloacae in the three studied hospitals. The observed mechanisms that contributed to resistance to carbapenems were: the presence of KPC, ESBL and impermeability of the membrane in E. aerogenes and in E. cloacae isolates. E. cloacae presented also that gene of the efflux pump AcrART. Among E. aerogenes, the gene wasn´t observed, but all isolates analyzed demonstrated active efflux pump to carbapenems possibly indicating the presence of other efflux pump still unidentified
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Gillio, Cintia de Moraes. "Enterobacter sakazakii em fórmulas lácteas infantis desidratadas, para bebês de 0-6meses." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-07032007-104637/.
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Enterobacter sakazakii é uma bactéria Gram-negativa, em forma de bastonete, pertencente a família Enterobacteriaceae e que não faz parte da microbiota normal do trato gastrointestinal humano ou animal. É reconhecida como um patógeno emergente de origem alimentar e já foi relacionada a diversos surtos e casos esporádicos de doenças envolvendo neonatos debilitados. A população de risco à infecção é composta por bebês prematuros ou bebês nascidos a termo até atingirem quatro a seis semanas de idade, bebês imunocomprometidos de qualquer idade e bebês que necessitem de cuidados especiais (UTI neonatal). Apesar do reservatório e do modo de transmissão de E. sakazakii não estarem claramente identificados, relatos mostraram que fórmulas infantis desidratadas, a base de leite, foram a fonte e o veículo de infecções para a população de risco. Os objetivos deste estudo foram avaliar a eficiência do meio cromogênico DFI na identificação do E. sakazakii; verificar a eficiência das metodologias ISO (TC 34/SC 5N) e FDA empregadas na enumeração de E. sakazakii e avaliar a população de Enterobacter sakazakii e de Enterobacteriaceae em fórmulas lácteas infantis, desidratadas, importadas ou nacionais, específicas para a faixa 0-6 meses de idade comercializadas na cidade de São Paulo, Brasil. Para tanto, foram examinadas 150 amostras de fórmulas lácteas infantis desidratadas, de diferentes lotes e marcas comerciais, adquiridas no comércio varejista da cidade de São Paulo. Para enumeração de E. sakazakii empregou-se o método preconizado pela ISO (TC 34/SC 5 N) com modificação. A enumeração de Enterobacteriaceae foi realizada empregando-se placas PetrifilmTM contagem de enterobactérias (3MTM). Todas as amostras examinadas, independente de marca comercial ou origem, apresentaram população de Enterobacter sakazakii < 0,03 NMP/100g e de Enterobacteriaceae < 5 UFC/g. O ágar DFI foi eficiente na identificação de colônias de E. sakazakii, mesmo na presença de Escherichia cloacae e Enterobacter aerogenes. E a metodologia ISO (TC 34/SC 5N) foi mais eficiente na enumeração de E. sakazakii que o método preconizado pelo FDA.<br>Enterobacter sakazakii is a Gram-negative rod from the Enterobacteriaceae family. This microorganism is not part of the normal microbiota of the human or animal gastrointestinal tract. It is recognized as an emergent pathogen of food origin and has already been related to outbreaks and sporadic cases of illnesses mainly involving weak in neonates. The population at risk of infection is composed by premature babies or newborn till they reach four to six weeks of age, immunocompromised babies of any age and babies in need of special care (neonatal ICU). Although the reservoir and the form of transmission of E. sakazakii is not clearly identified yet, studies have shown that milk-based dried-infant formula have been the source and the vehicle of infections for the at risk population. The objectives of this study were to evaluate the efficiency of DFI agar in the identification of E. sakazakii; to verify the efficiency of the methodologies proposed by ISO (TC 34/SC 5N) and FDA for the enumeration of E. sakazakii and to evaluate the population of Enterobacter sakazakii and Enterobacteriaceae in dehydrated infant milk formula, imported or domestic, specific for 0-6 months of age commercialized in the city of Sao Paulo, Brazil. 150 dehydrated milk infant formula samples from different commercial brands, acquired at retail level in the city of Sao Paulo, SP, Brazil were examined. For enumeration of E. sakazakii a modification of the method recommended by ISO (TC 34/SC 5N) was used. The enumeration of Enterobacteriaceae was carried out using PetrifilmTM Enterobacteriaceae count plate (3MTM). All the examined samples, independent of commercial brand or origin, presented population of Enterobacter sakazakii < 0,03 MPN/100g and < 5 CFU/g of Enterobacteriaceae. The DFI agar was efficient in the identification of colonies of E. sakazakii, even in the presence of Escherichia cloacae or Enterobacter aerogenes. The methodology ISO (TC 34/SC 5N) was more efficient for the enumeration of E. sakazakii that the one recomended by FDA.
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Manickan, Lakshmy. "Proteomics of bacteroides fragilis and enterobacter cancerogenus." Thesis, Northumbria University, 2010. http://nrl.northumbria.ac.uk/1253/.
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Bacteroides fragilis NCTC 9343 is a Gram-negative anaerobic bacterium with genomic DNA of 5205 Kb and a GC ratio of 43%. It is a commensal organism that can act as an opportunistic pathogen and is commonly present on the mucous membranes. It causes a variety of infections including intra abdominal infections, perirectal abscesses and decubitus ulcers. Enterotoxigenic forms are capable of causing diarrhoea in children and animals. Enterobacter cancerogenus ATCC 35316 is also a Gram-negative facultatively anaerobic bacterium with genomic DNA of 4602 Kb and a GC ratio of 55%. It is a naturally occurring human gut symbiont known to exhibit resistance to antibiotics like aminopenicillins. It has also been reported in cases of severe osteomyelitis and infections of bones and joints. This study aims to analyse the differential expression of proteins in the presence of mucin since it serves as the first site of adherence for the bacteria. The E. cancerogenus and B. fra gilis proteins were extracted and separated by two dimensional electrophoresis from logarithmic phase cultures grown in semi-defined media enriched with or without porcine gastric mucin Types II and III. The gel images were analysed using Bio-Rad PDQuest, Ludesi Redfin and Nonlinear Dynamics SameSpots softwares. It was observed that the presence of mucin in the media affected the expression of a number of proteins in E. cancerogenus and B. fragilis cells. The protein spots of interest were excised, hydrolysed using trypsin and subjected to electrospray ionisation based LC-MS analysis in order to determine the identity of the digested proteins and obtain a better understanding of the interactions of B. fra gilis and E. cancero genus with mucin. The outer membrane protein surface antigen X was found to be up-regulated in both mucin Type II and III enriched media in E. cancerogenus. Some of the other proteins that were differentially regulated in both E. cancerogenus and B. fra gilis included the elongation factor Ts, malate dehydrogenase, triose phosphate isomerase and thiol peroxidase proteins indicating that these proteins may be associated with the ability of bacteria to grow in mucin and may be potential virulence factors. Genes encoding the proteins CAH06598 and CAH09443 from the glycoside hydrolase families 95 and 97 in B. fra gilis strain NCTC9343 were cloned, overexpressed and purified using nickel affinity and gel filtration chromatography. The enzymes were found to be active by performing fluorimetric assays using methyl-umbelliferyl sugar substrates. Diffracting crystals of CAH09443 were obtained from the PACT ANION screens containing polyethylene glycol and sodium malonate as a precipitant. Structure determination was achieved via molecular replacement using the glycoside hydrolase Family 97 α-galactosidase, BtGH97b, from Bacteroides thetaiotaomicron as a starting model. The structure of CAH09443 was shown to be composed of a N-terminal β-super-sandwich domain and a canonical (β/α)₈ barrel, similar to the two other glycoside hydrolase family 97 enzyme structures reported.
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Hopkins, J. M. "Mechanisms of cefotaxime resistance in Enterobacter SPP." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384328.
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Boyer, Mariotte Sophie. "Caractérisation d'une beta-lactamase hydrolysant l'imipénème chez entérobacter sp." Paris 11, 1995. http://www.theses.fr/1995PA114839.
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Silva, Ane Elise Bruhn da. "Avaliação da heteroresistência a carbapenêmicos em isolados do complexo Enterobacter cloacae." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/149463.
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Os isolados do complexo Enterobacter cloacae estão entre os principais patógenos causadores de infecções hospitalares. Embora os carbapenêmicos sejam considerados a última opção terapêutica no tratamento de infecções graves por Enterobacter spp, existem evidências indicando o aumento da resistência deste gênero aos carbapenêmicos. Esta resistência é normalmente mediada pela hidrólise dos carbapenêmicos por β-lactamases (carbapenemases). A resistência aos carbapenêmicos se apresenta de forma homogênea numa população bacteriana, no entanto, eventualmente a resistência pode ocorrer em apenas parte da população. Heteroresistência pode ser definida como a expressão de resistência de uma subpopulação dentro de uma população considerada sensível em testes de susceptibilidade in vitro e pode ser considerada um estágio precursor, o qual pode ou não levar a emergência de uma população homogeneamente resistente. A não detecção destas subpopulações resistentes pode levar ao fracasso no tratamento. O objetivo deste trabalho foi avaliar a heteroresistência aos carbapenêmicos em isolados do complexo Enterobacter cloacae. Trinta e um isolados foram selecionados de acordo com seu perfil de suscetibilidade aos carbapenêmicos (imipenem e meropenem sensíveis e ertapenem resistente) e a presença de OXA-370 (5 positivas para blaOXA-370). A heteroresistência foi avaliada por análise de perfil populacional (PAP). Isolados com subpopulações que apresentaram crescimento em concentrações de carbapenêmicos ≥ 4μg/ml foram considerados heteroresistentes e isolados contendo subpopulações que cresceram em concentrações de carbapenêmicos pelo menos duas vezes maior do que o MIC original, mas < 4 μg/ml foram considerados heterogêneos. A estabilidade da heteroresistência foi determinada por sub-cultivo sete dias em meio isento de antibiótico. Um total de 6 (19,4%) isolados apresentaram subpopulações heteroresistentes e 15 (48,4%) subpopulações heterogêneas ao imipenem. Em relação ao meropenem foi encontrado apenas 1 (3,2%) isolado heteroresistente e 5 (16,13%) isolados com subpopulações heterogêneas. Todos os isolados positivos para blaOXA-370 foram classificados como heteroresistentes ou heterogêneos ao imipenem. Apenas 2/21 (9,5%) e 2/6 (33,3%) subpopulações heterogêneos/heteroresistentes para imipenem e meropenem, respectivamente, mantiveram os mesmos MICs após sete dias de sub-cultivo em meio isento de antibiótico. Nossos resultados indicam que subpopulações heterogêneas/heteroresistentes ao imipenem são comuns entre isolados do complexo Enterobacter cloacae (21/31; 67,7%). Os isolados de OXA-370 foram classificados como heterogêneo/heteroresistente e, portanto, a presença de blaOXA-370 pode estar associada ao aumento de heteroresistência a imipenem. Já a estabilidade da heteroresistência e heterogeneidade aos carbapenêmicos demonstrou-se baixa.<br>Enterobacter cloacae complex isolates are major pathogens in hospital infections. Although carbapenems are considered the last resort in the treatment of severe infections caused by Enterobacter spp, there are several reports indicating increase of resistance to carbapenems among isolates of this genus. This resistance is usually mediated by hydrolysis of carbapenems by β-lactamases (carbapenemases). Carbapenem-resistance is usually a homogeneous feature in a bacterial population but, eventually, the resistance may occur in only a small proportion of the population. Heteroresistance can be defined as resistance to certain antibiotics expressed by a subset of a microbial population that is generally considered to be susceptible to these antibiotics according to traditional in vitro susceptibility testing. Lack to detect heteroresistance may lead to the therapeutic failure. The aim of this study was to evaluate the heteroresistance to carbapenems among Enterobacter cloacae complex isolates. Thirty-one isolates of Enterobacter cloacae complex were selected according to their susceptibility profile as follow: resistance to ertapenem and susceptibility to imipenem and meropenem. Among these, five isolates presented the blaOXA-370 gene. Heteroresistance was evaluated by population analysis profile (PAP). Isolates that grew at concentrations ≥4μg/mL of carbapenem were considered heteroresistant, while those that grew at concentration with at least two dilutions higher than the original MIC, but <4μg/mL were considered heterogeneous. Heteroresistance stability was determined after seven day sub-culture in antibiotic-free medium. A total of 6 (19.4%) isolates presented heteroresistant subpopulations and 15 (48.4%) heterogeneous subpopulations to imipenem. Only 1 (3.2%) isolate was heteroresistant and 5 (16.1%) heterogeneous to meropenem. All positive isolates for blaOXA-370 were classified as heteroresistant or heterogeneous to imipenem. Only 2/21 (9.5%) and 2/6 (33.3%) heterogeneous/heteroresistant subpopulations to imipenem and meropenem, respectively, kept the same MIC of the subpopulation after seven days in antibiotic free medium. Our results indicate that heterogeneous/heteroresistant subpopulations were common among Enterobacter cloacae complex (21/31 - 67.7%) to imipenem and less common to meropenem. Noteworthy, that all OXA-370 producing isolates were classified as heterogeneous/heteroresistant. Therefore, the presence of blaOXA-370 may be associated with increase heteroresistance to imipenem. The stability of heteroresistance was low in antibiotic-free medium after seven days.
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Liu, Wing-yee, and 廖泳怡. "Discovery and genome analysis of the plant growth-promoting endophyticbacterium Enterobacter cloacae ENHK." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B49858750.
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Enterobacter cloacae strain ENHK is a Gram-negative endophyte belonging to the family Enterobacteriacae. Initially considered as an unknown bacterium, E. cloacae ENHK was first isolated from a diseased pepper (Capsicum annuum) plant infected by the bacterial plant pathogen Ralstonia solanacearum in Hong Kong in 2010.
A pure isolate was obtained for whole genome sequencing. De novo shortgun and paired-end sequencing by 454 GS Junior platform were applied to obtain a draft genome sequence of E. cloacae ENHK containing 36 contigs in one scaffold. Gaps were closed by PCR and primer walking using Sanger sequencing to produce the first complete genome sequence of a plant-associated strain of E. cloacae. The genome size of E. cloacae ENHK consists of a single chromosome of 4,726,582kb, with a GC content of 55.1%. Gene annotation and analysis was performed using NCBI Prokaryotic Genomes Automatic Annotation Pipeline (PGAAP) and further annotation and comparative genome analysis was performed by the SEED-based automated annotation system provided by the RAST server.
Comparative genome analysis indicated that E. cloacae ENHK shares major genomic features with Enterobacter sp.638 that is characterized for its plant-growth promoting and endophytic behaviors. Further genome analysis revealed antagonistic potentials of E. cloacae ENHK against other microbes by possessing antagonistic mechanisms which involve microbial competition, production of antimicrobial compounds and induction of plant defense response. Candidates of Chitinases and type VI secretion system associated rhs-related genetic element were identified and their potential antibacterial activity were investigated. E. cloacae ENHK was further demonstrated to suppress the growth of several plant pathogenic fungal species Alternaria sp., Choanephora infundibulifera, Colletotrichum capsici, Didymella bryoniae, Fusarium oxysporum, Sclerotinia sclerotiorum and Sclerotinia rolfsii and a plant pathogenic bacterial species Ralstonia solanacearum.
Among the publicly available completed genome sequences of the Enterobacter species complex, E. cloacae ENHK is most closely related to E. cloacae subsp. cloacae ATCC13047, an opportunistic human pathogen. A comparative genome analysis showed that critical factors involving human pathogenesis in terms of virulence and specific adhesion were identified in the variable genomic regions in E. cloacae subsp. cloacae ATCC 13047 and are absent in E. cloacae ENHK. In addition, two microbial competition related type VI secretion systems (T6SS) were found conserved in both E. cloacae strains. Phylogenetic analysis revealed that the two systems were associated with other plant-associated and human/animal-associated species respectively in the Enterobacteriaceae. The results indicated that T6SSs may provide the E. cloacae strains fitness advantages for microbial competition in the microflora of a diverse environment. In short, comparative genome analysis suggested that the conserved chromosomal regions retain the general physiological and survival of the species, while variable genomic regions play a critical role in determining the functional differences of the pathogenic E. cloacae subsp. cloacae ATCC13047 and the endophytic E. cloacae ENHK.
Finally, significant findings derived from the current thesis research are summarized and potential applications of E. cloacae ENHK in agricultural, medical and industrial areas, as well as future prospectus are discussed.<br>published_or_final_version<br>Biological Sciences<br>Doctoral<br>Doctor of Philosophy
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Sampaio, Jorge Luiz Mello. "Caracterização de betalactamases de espectro ampliado e KPC em Enterobacter cloacae e Enterobacter aerogenes isoladas de casos de infecções relacionadas aos cuidados com a saúde em pacientes atendidos em hospitais da cidade de São." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/5/5134/tde-30112011-183431/.
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INTRODUÇÃO: O tratamento das infecções relacionadas à assistência à saúde, causadas por enterobactérias, representa um desafio crescente, em função do aumento da prevalência de resistência aos betalactâmicos, em particular às cefalosporinas de terceira e quarta gerações e carbapenêmicos. Os mecanismos de resistência mais relevantes a essas classes de antimicrobianos, em enterobactérias, é a produção de betalactamases de espectro ampliado e carbapenemases. Os objetivos do estudo foram: (1) determinar a frequência e caracterizar betalactamases de espectro ampliado (ESBL); (2) determinar a frequência e caracterizar o gene blaKPC-2; (3) avaliar a relação clonal entre isolados produtores de ESBL ou KPC, uma coleção de isolados do gênero Enterobacter cultivadas de casos de infecções relacionadas aos cuidados com a saúde diagnosticadas em pacientes atendidos em hospitais da cidade de São Paulo. MÉTODOS: Foram estudadas 141 isolados do gênero Enterobacter quanto à produção de ESBL pelo método de Jarlier e colaboradores, concentrações inibitórias mínimas para cefotaxima, cefepima e ceftazidima pelo método da diluição em ágar, halo de inibição para ertapenem pelo método de Kirby-Bauer e presença de genes que codificam ESBL ou KPC, por PCR. RESULTADOS: A frequência de isolados produtores de ESBL, quando utilizado o método de Jarlier e colaboradores foi de 22,7%. Os genes que codificam cefotaximases foram detectados em 34,4% dos isolados com teste fenotípico positivo para ESBL, e houve predomínio do grupo da CTX-M-8, enquanto os genes que codificam variantes SHV foram detectados em 18,7% dos produtores de ESBL. Os genes blaTEM-1 e blaOXA-1 foram detectados em 62,5%; 12,5% dos isolados com teste fenotípico positivo para ESBL, mas não são ESBLs. Não houve detecção do gene que codifica a enzima BES-1 na amostragem. O gene blaKPC-2 foi detectado em três dos 15 isolados produtores de ESBL e resistentes ao ertapenem. Os perfis obtidos por ERIC-PCR sugerem a disseminação de um clone de E. aerogenes entre instituições hospitalares. CONCLUSÕES: Os determinantes genéticos de ESBLs predominantes na amostragem analisada são derivados de blaCTX-M. A presença de grupos clonais em instituições hospitalares distintas, evidencia disseminação entre hospitais. A presença de KPC em Enterobacter é reportada pela primeira vez em São Paulo<br>INTRODUCTION: The treatment of healthcare associated infections caused by enterobacteria represents a growing challenge due to the increasing prevalence of beta-lactam resistance, particularly to third and fourth generations cephalosporins and carbapenems. The main mechanisms of resistance to these antimicrobial classes are the production of extended spectrum beta-lactamases and carbapenemases. The objectives of this study were: (1) determine the frequency and characterize extended spectrum beta-lactamases; (2) determine the frequency and characterize blaKPC; (3) evaluate the clonal relation among ESBL or KPC producers, in a collection of Enterobacter isolates cultivated from cases of healthcare associated infections in patients from hospitals located in the city of São Paulo. METHODS: A total of 141 Enterobacter isolates were studied concerning ESBL production using the method from Jarlier and colleagues, minimum inhibitory concentrations for cefotaxime, ceftazidime and cefepime by agar dilution method, inhibition zone for ertapenem by by Kirby-Bauer method and the presence of genes coding for ESBLs or KPCs, by PCR. RESULTS: The frequency of ESBL producers using Jarlier´s method was 22.7%. Genes coding for cefotaximases were detected in 34.4% of isolates with a positive test for ESBl and CTX-M-8 group was predominant, but blaSHV variants were also detected in 18.7% of the ESBL producres. blaTEM-1, and blaOXA-1 genes were detected in 62.5%; 12.5% of all isolates with a positive phenotypic test for ESBL, but there are not ESBLs. The blaKPC-2 gene was detected in three among 15 ESBL producers that were also resistant to ertapenem. ERIC-PCR profiles suggest the dissemination of an E. aerogenes clone among hospitals. CONCLUSIONS: The predominant ESBL determinants in the sample analyzed derive from blaCTX-M. The presence of the same clonal groups in different hospitals indicates inter-hospital dissemination. The presence of KPC producing Enterobacter is reported for the first time in São Paulo
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Häusler, Sebastian Franz Martin. "Charakterisierung des putativen Transkriptionsfaktors Roh von Enterobacter cloacae." kostenfrei, 2008. http://www.opus-bayern.de/uni-regensburg/volltexte/2009/1168/.
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Demarquilly-Henquell, Cécile. "Résistance des entérobactéries aux béta-lactamines : résistance des Enterobacter aerogenes aux carbapénèmes, résistance des Escherichia coli aux associations de béta-lactamines et inhibiteurs de béta-lactamases." Clermont-Ferrand 1, 1995. http://www.theses.fr/1995CLF1MM04.
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Santos, Rosana Francisco Siqueira dos. "Avaliação de diferentes métodos para detecção de Cronobacter spp (Enterobacter sakazakii) em alimentos." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254598.
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Orientadores: José Luiz Pereira, Valéria Christina Amstalden Junqueira<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos<br>Made available in DSpace on 2018-08-18T21:41:27Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011<br>Resumo: Cronobacter spp (Enterobacter sakazakii) é uma bactéria patogênica oportunista, que tem sido associada a surtos e casos esporádicos de meningite, enterocolite necrosante e sepse em recém nascidos. Em 2008 as cepas dessa espécie foram divididas em várias novas espécies e transferidas para o novo gênero Cronobacter spp. Um dos métodos mais recentes para sua detecção é o da ISO 22964 (2006), que inclui duas etapas de enriquecimento, o isolamento de colônias típicas (alfa-glicosidase positivas) no meio seletivo diferencial ESIA (Enterobacter sakazakii Isolation Agar) e a confirmação das culturas através de testes bioquímicos. Há, entretanto, necessidade de métodos e meios de cultura alternativos para o isolamento de Cronobacter spp (Enterobacter sakazakii), objetivo desse trabalho. Para isso, 83 amostras foram analisadas usando a técnica de PCR através do sistema BAX® (Dupont Qualicon), em comparação com o método cultural ISO/TS 22964:2006. Dois meios de cultura seletivos diferenciais foram usados para isolamento de culturas típicas: o Ágar de Isolamento de E.sakazakii (ESIA) e o Ágar Druggan-Forsythe-Iversen (DFI). Cronobacter spp (Enterobacter sakazakii) foi isolado em 13,25% das amostras analisadas, sendo mais freqüente em amostras de soja em grãos (destinada à preparação de bebidas à base de soja), em leite em pó e em amido de milho. Nas fórmulas infantis em pó o micro-organismo foi encontrado em 6% das amostras. A unidade analítica de 25g não se mostrou adequada para o isolamento das cepas, porque a contagem encontrada nas amostras positivas (unidade analítica de 500g) foi muito baixa (variando de <0,22 a >1,61NMP/100g). Em 27% das amostras positivas, Cronobacter spp só foi isolado de colônias atípicas (alfa-glicosidase negativas) no ESIA e/ou no DFI. Em 9% das amostras as cepas isoladas também não apresentaram pigmentação amarela no TSA. Os resultados mostraram desempenho equivalente do ESIA e do DFI, no protocolo de ensaio da ISO/TS 22964 (2006). O método do Sistema BAX® apresentou desempenho inferior ao método ISO/TS 22964 (2006), com uma alta porcentagem de resultados falsos positivos no PCR (73,33%) e uma porcentagem significativa de resultados falsos negativos na confirmação cultural (53,85%). Os resultados indicaram que, a pesquisa de Cronobacter spp (Enterobacter sakazakii) em produtos destinados à alimentação de recém nascidos, deve ser feito com unidade analítica de pelo menos 500g, preferencialmente maior, porque a contagem encontrada nas amostras positivas foi muito baixa<br>Abstract: Cronobacter spp (Enterobacter sakazakii) is an opportunist pathogenic bacterium, which has been associated to outbreaks and sporadically cases of meningitis, necrotizing enterocolitis and sepses in newborns. In 2008, strains of this species was divided in some new species and transferred to the new genus Cronobacter spp. One of the most recent method used to determine the microorganisms is ISO 22964 (2006), that includes two stages of enrichment, isolation of typical colonies (positive a- glycosidase) in the differential media selective ESIA (Enterobacter sakazakii Isolation Agar) and biochemical tests for confirmation. However, it already exists alternative and rapid methods for the isolation of Cronobacter spp (Enterobacter sakazakii), which were the aim of this study. For this, 83 samples were analyzed using the Polymerase Chain Reaction method (PCR) by BAX® System (DuPont Qualicon), in comparison with ISO/TS 22964:2006 method. Two differential selective media were used to isolation of typical colonies: Agar of Isolation for E. sakazakii (ESIA) and Agar Druggan-Forsythe-Iversen (DFI). Cronobacter spp (Enterobacter sakazakii) was isolated in 13.25% of the analyzed samples being more frequent in bean (designated to prepare soy base drink), powered milk and corn flour samples. In powered infantile formula, 6% of the samples were contaminated. The analytical unit of 25g was not adequate for the isolation this microorganism, where the count detected in the positive samples (analytical unit of 500g) was very low (among of <0.22 and >1,61MPN/100g). In 27% of positive samples, Cronobacter spp (Enterobacter sakazakii) was only isolated from atypical colonies (alpha-glycosidase negative) in ESIA and/or DFI. Nine per cent (9%) of the strains isolated from samples did not show yellow pigment in the TSA. Results showed equivalent performance of both ESIA and DFI medias, following the of ISO/TS 22964 (2006) assay protocol. The PCR method (BAX® System) showed lower performance when compared with ISO/TS 22964 (2006) method. A high percentage of false positive results (73.33%) and a significant percentage of false negative results in the cultural confirmation (53.85%) were observed with PCR method. The results indicated that the research of Cronobacter spp (Enterobacter sakazakii) in products destined to the feeding of just born, must be made with analytical unit of at least 500g (or major quantity) due to the counting found in the positive samples was very low<br>Doutorado<br>Ciência de Alimentos<br>Doutor em Ciência de Alimentos
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Kemp, Francisca. "Detection of Enterobacter sakazakii in South African food products." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1064.
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Sanjaq, Suhad. "Enterobacter sakazakii : Risikoprofil und Untersuchungen zum Nachweis in Säuglingsnahrungen /." Giessen : VVB Laufersweiler, 2008. http://d-nb.info/989046907/34.
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Barrantes, Palomino Celia, and Bohórquez Celia Rojas. "Enterobacter sakazakii en fórmulas infantiles reconstituidas en ambientes hospitalarios." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2010. https://hdl.handle.net/20.500.12672/16197.
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Publicación a texto completo no autorizada por el autor<br>Evalúa la contaminación con Enterobacter sakazakii en fórmulas infantiles reconstituidas en ambientes hospitalarios. En total se analizaron 140 muestras de las cuales, 80 fueron de fórmula infantil recostituida, 60 muestras de utensilios, recipientes y superficies, siendo analizadas según la norma ISO/TS 22964 IDF/RM 210. En las fórmulas infantiles reconstituidas se aisló e identificó Enterobacter sakazakii en un 1.4% (2/80) y otras enterobacterias en un 15% (12/80), en esta última se aisló e identificó Klebsiella pneumoniae y Enterobacter cloacae. Entre las muestras de utensilios, recipientes y superficies se aisló e identificó Klebsiella pneumoniae (66.66%, 16/24), Enterobacter sp. (20.83%, 5/24), Enterobacter aerogenes (4.17%, 1/24), Enterobacter cloacae (4.17%, 1/24), y Escherichia coli (4.17%, 1/24). Según los resultados obtenidos se demostró la presencia de Enterobacter sakazakii.
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FIRMO, Elza Ferreira. "Pesquisa de genes de resistência a aminogliosídios em isolados de colonização e infecção de Klebsiella pneumoniae e enterobacter aerogenes portadores do gene blaKPC provinentes de hospitais de Recife-PE." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17747.
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Previous issue date: 2016-02-24<br>CAPEs<br>Klebsiella pneumoniae e Enterobacter aerogenes têm se destacado como importantes agentes de infecções relacionadas à assistência à saúde (IRAS), causando principalmente infecções de feridas, dos tratos urinário e respiratório, além de sepse. Essas infecções são causadas por linhagens bacterianas geralmente multirresistentes. Genes que codificam as enzimas modificadoras de aminoglicosídeos (EMAs) e metiltransferases 16S RNAr podem estar presentes em isolados de enterobactérias também produtores de Klebsiella pneumoniae carbapapenemase (KPC). Portanto, o objetivo deste estudo foi investigar genes que codificam resistência aos aminoglicosídeos em 30 isolados de E. aerogenes e em 28 isolados de K. pneumoniae portadores do gene blaKPC resistentes a amicacina, tobramicina e/ou gentamicina, oriundos de colonização e infecção em pacientes de diferentes hospitais em Recife-PE, Brasil. A investigação dos genes armA, rmtB, rmtD, aac(3)Ia, aac(3)IIa, aac(6´)Ib, ant(2´)Ia e aph(3’)-VI foi realizada através de PCR, seguida de sequenciamento de DNA. Nos isolados de K. pneumoniae observou-se uma maior ocorrência dos genes ant(2´)Ia, seguidos de aac(3)IIa, aph(3’)-VI e aac(6´)Ib. O gene mais encontrado em E. aerogenes foi o aph(3’)-VI, seguidos de aac(3)-IIa e ant(2”)-Ia. Esse é o primeiro relato de aph(3’)-VI em E. aerogenes no Brasil. Os genes aac(3)-Ia, armA, rmtB e rmtD não foram encontrados. Esses achados ressaltam para a gravidade da alta ocorrência de isolados de K. pneumoniae e E. aerogenes portadores de genes para EMAs e gene blaKPC principalmente colonizando pacientes, visto que essas bactérias podem atuar na disseminação de mecanismos de resistência dentro da unidade hospitalar e limitar as opções de tratamento.<br>Klebsiella pneumoniae and Enterobacter aerogenes have been highlighted as important agents of healthcare-associated infections (HAIs), primarily causing wound, urinary and respiratory tracts infections, and sepsis. These infections are often caused by multiresistant bacterial strains. Genes encoding aminoglycoside modifying enzymes (AMEs) and 16S RNAr methyltransferases can also be present in Enterobacteriaceae isolates producing Klebsiella pneumoniae carbapapenemase (KPC). Therefore, the aim of this study was to investigate genes encoding resistance to aminoglycosides in 30 isolates of E. aerogenes and 28 K. pneumoniae isolates carrying the blaKPC gene and resistant to amikacin, tobramycin and / or gentamicin, from colonization and infection in patients from different hospitals in Recife-PE, Brazil. The investigation of the genes armA, rmtB, rmtD, aac(3)Ia, aac(3)IIa, aac(6´)Ib, ant(2´)Ia e aph(3’)-VI was performed by PCR followed DNA sequencing. In K. pneumoniae isolates there was a higher incidence of genes ant(2´)Ia, followed by aac(3)IIa, aph(3’)-VI e aac(6´)Ib. The gene most frequently found in E. aerogenes was aph(3’)-VI, followed by aac(3)-IIa e ant(2”)-Ia . This is the first report of aph (3 ') - VI in E. aerogenes in Brazil. The genes aac(3)-Ia, armA, rmtB e rmtD were not found. These findings points to the seriousness of the high incidence of isolates of K. pneumoniae and E. aerogenes carriers of AMEs and blaKPC gene, mainly colonizing patients, since these bacteria can act in the dissemination of resistance mechanisms within the hospital and to limit treatment options.
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Nascimento, Alessandra Karisa Costa Lima do. "Desenvolvimento de um veto bifuncional para a bactéria endofítica Enterobacter agglomerans e Escherichia coli." Universidade Federal do Amazonas, 2006. http://tede.ufam.edu.br/handle/tede/2241.
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Previous issue date: 2006-08-28<br>Fundação de Amparo à Pesquisa do Estado do Amazonas<br>Endophytic microorganisms can be utilized in distinct ways in Biotechnology science. Among them, one of most interesting uses is as heterologue gene carriers into plants, allowing the development of new Biotechnologic processes, which makes relevant the development of vectors from native plasmids from the endophytic bacterias itselves for genetic transformation of this kind of bacteria. Studies involving Enterobacter agglomerans, a endophytic bacteria isolated from Copaifera multijuga (copaiba tree), demonstrated the presence of a small, cryptic plasmid named pEA1. Based on this plasmid, the pEA1.0 and pEA2.4 plasmids were developed. pEA1.0 was built from a fragment of PstI (1000 bp), cloned in pUC18. pEA2.4 was developed from an amplified fragment (2415 bp), cloned in the vector pCR2.1TOPO (Invitrogen), which allowed, by primer walking, the determination of the complete sequence of the original plasmid (2545 bp), which had been previously recorded in GenBank (access DQ659147). The sequence analysis showed a GC level of 34% and an AT level of 66%. The restriction map was determined using NEBCutter2.0. Comparison between pEA1 sequence and the data bank revealed high similarity (62%) with the sequence of the pIGMS31 plasmid (2520 bp) from Klebsiella pneumoniae. Using the BlastX and ORF finder softwares, the result demonstrated the presence of two ORFs, one of them similar (E value=-98) to ORF2 of pIGMS31 (AY543072.1) isolated from K. pneumoniae. The pEA2.4 plasmid was used to genetically transform Escherichia coli and E. agglomerans by the Tris-calcium/thermal shock method. Besides the capability of pEA2.4 to genetically transform E. coli cells, it has showed itself capable of transforming E. agglomerans as well, which can actually acquire resistance to kanamicine. This reflects the bifunctional chacter of pEA2.4. The transformation efficacy of E. agglomerans using pEA2.4 extracted from E. coli was about 5 x 104 T/μg, while the same process with pEA2.4 extracted from E. agglomerans itself showed a ten times higher efficacy (5,1 x 105 T/μg), probably because of the avoidance of host restriction. The pEA2.4 plasmid will be used as foundation for the development of heterologue gene expression vectors in E. agglomerans.<br>Microrganismos endofíticos podem ser utilizados de diversas formas em biotecnologia. Dentre estas, se destaca o uso como carreadores de genes heterólogos para o interior de plantas possibilitando o desenvolvimento de novos processos biotecnológicos, o que torna relevante o desenvolvimento de vetores a partir de plasmídeos nativos das próprias bactérias endofíticas para transformação genética desse tipo de bactérias. Estudos envolvendo a Enterobacter agglomerans, uma bactéria endofítica isolada de Copaifera multijuga (copaíba) demonstraram a presença de um pequeno plasmídeo críptico denominado pEA1. Com base neste plasmídeo foram desenvolvidos os plasmídeos pEA1.0 e pEA2.4. O pEA1.0 foi construído a partir do fragmento de PstI (1000 pb) clonado em pUC18. O plasmídeo pEA2.4 foi desenvolvido a partir de um fragmento amplificado (2415 pb) clonado no vetor pCR2.1TOPO (INVITROGEN), o qual por primer walking permitiu a determinação da seqüência completa do plasmídeo original (2545 pb), que foi depositada no GenBank (acesso DQ659147). A análise da seqüência mostrou um índice GC de 34% e AT de 66%, e o mapa de restrição foi determinado utilizando a ferramenta NEBCutter2.0. Comparando a seqüência do pEA1 com o banco de dados, observou-se alta similaridade (62%) com a seqüência do plasmídeo pIGMS31 (2520 pb) de Klebsiella pneumoniae. Utilizando as ferramentas BlastX e ORF finder, o resultado demonstrou a presença de duas ORFs, sendo uma delas similar (E value = -98) à ORF2 do plasmídeo pIGMS31 (AY543072.1) isolado de K. pneumoniae. O plasmídeo pEA2.4 foi utilizado para transformar geneticamente bactérias Escherichia coli e E. agglomerans pelo método Tris-Cálcio/choque térmico. O pEA2.4 além de ser capaz de transformar geneticamente células de E. coli, mostrou-se também capaz de transformar geneticamente a E. agglomerans tornando-a resistente a canamicina, evidenciando seu caráter bifuncional. A eficiência de transformação da E. agglomerans com pEA2.4 extraído de E. coli foi de 5 x 104 T/μg, enquanto que a transformação desta bactéria com o pEA2.4 extraído da própria E. agglomerans, apresentou eficiência 1 ordem de grandeza maior (5,1 x 105 T/μg) provavelmente por ter sido, desta forma, evitado o processo de restrição da hospedeira. O plasmídeo pEA2.4 será utilizado como base para o desenvolvimento de vetores de expressão de genes heterólogos em E. agglomerans.
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Shek, Hoi-leong. "Detection and characterization of extended-spectrum beta-lactamases among blood isolates of enterobacters in Hong Kong." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31972159.
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McCarroll, Matthew G. "Application of the BIOLOG microplate system to monitor the physiological response of heat-stressed bacteria." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5545.
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Thesis (M.S.)--West Virginia University, 2008.<br>Title from document title page. Document formatted into pages; contains ix, 111 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 104-110).
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Shek, Hoi-leong, and 石海亮. "Detection and characterization of extended-spectrum beta-lactamases among blood isolates of enterobacters in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31972159.
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Neitzke, Thaís Luft da Silva. "Agrupamento de rizobactérias nativas da região oeste do Paraná por estudo de congruência genética e bioquímica." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3877.
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Previous issue date: 2018-04-20<br>Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Estado do Paraná (FA)<br>In the search for agronomic alternatives that are less aggressive to the environment, the substitution of mineral fertilizers by biofertilizers based on plant-beneficial micro-organisms was initiated, among them plant growth promoting bacteria. The objective of this work was to characterize rhizobacteria isolated from soils with different crop managements, grouping the samples based on their genetic characteristics (16S rDNA sequencing, amplification of the ITS 16–23S rDNA region, feoB, entC and entF genes) and biochemical (indole-acetic acid (IAA) production, acetoin production and phosphate solubilization), and verify their diversity within groups. Based on the results, the presence of the genes feoB, entF and entC was verified in 81.5%, 48.1% and 81.5% of the samples, respectively. Most of the strains (96.3%) had the capacity to produce IAA, 59.2% were able to produce acetoin and 81.5% of them to solubilize phosphate. By the analysis of congruence and grouping, there was similarity of genetic or biochemical patterns between the groups; however, there was great diversity among the isolates within each group. In general, it was observed that the conservationist managements presented the best performances. The study revealed that strains 130, 219, 302 and 326 presented biotechnological potential for at least two of the characteristics evaluated.<br>Na busca por alternativas agronômicas que sejam menos agressivas ao
meio ambiente, iniciou-se a substituição do fertilizante mineral por biofertilizante
a base de microrganismos benéficos às plantas, entre estes as bactérias
promotoras do crescimento vegetal. O objetivo deste trabalho foi caracterizar
rizobactérias isoladas de solos com diferentes manejos de cultivo, agrupando as
amostras com base em suas características genéticas (sequenciamento 16S
rDNA, amplificação da região ITS 16-23S rDNA, genes feoB, entC e entF) e
bioquímicas (produção de ácido-indol-acético (AIA), produção de acetoína e
solubilização de fosfato), e verificar a sua diversidade dentro dos grupos.
Baseado nos resultados, foi verificada a presença do gene feoB, entC e entF em
81,5%,48,1% e 81,5% das amostras, respectivamente. A maioria (96,3%) das
estirpes apresentou a capacidade de produzir AIA, 59,2% foi capaz de produzir
acetoína e 81,5% delas à solubilizar fosfato. Pela análise de congruência e
agrupamento, verificou-se semelhança de padrões genéticos ou bioquímicos
entre os grupos, no entanto, apresentaram grande diversidade entre os isolados
dentro de cada grupo. De forma geral, observou-se que os manejos
conservacionistas apresentaram os melhores desempenhos. O estudo revelou
que as estirpes 130, 219, 302 e 326 apresentaram potencial biotecnológico para
pelo menos duas das características avaliadas.
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Wanke, Christoph Martin. "The UDP-N-acetylglucosamine 1-carboxyvinyltransferase (enolpyruvyltransferase) from Enterobacter cloacae /." [S.l.] : [s.n.], 1993. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10364.
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Chollet, Renaud. "Régulation génétique de la multirésistance aux antibiotiques chez Enterobacter aerogenes." Aix-Marseille 2, 2004. http://www.theses.fr/2004AIX20659.
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Enterobacter aerogenes est devenu, ces dernières années, un pathogène incontournable du milieu hospitalier. Le caractère clonal des isolats et leur phénotype de résistance élevé aux antibiotiques représentent les deux caractéristiques principales de son épidémiologie. A côté des mécanismes d'inactivation enzymatique efficaces, sont maintenant décrits des processus générant une imperméabilité membranaire et un efflux actif. De telles souches sont considérées comme présentant un phénotype de " Multidrug-Resistance " (MDR). Face à cette situation, il est indispensable de caractériser les systèmes génétiques contrôlant l'apparition de la MDR. Notre travail a montré que E. Aerogenes regroupe sur son génome deux systèmes de régulation de la MDR : l'opéron marRAB et le gène ramA. Les deux régulateurs RamA et MarA permettent à E. Aerogenes de contrôler finement les systèmes d'échange avec le milieu extérieur et de répondre efficacement contre les agressions. Ces régulateurs peuvent fonctionner aussi bien indépendamment que simultanément et l'expression de l'un régule celle de l'autre. MarA et RamA entraînent, chez E. Aerogenes, une régulation négative des porines, voie d'entrée des antibiotiques hydrophiles, créant une imperméabilité membranaire, et l'expression de la pompe d'efflux AcrAB-TolC permettant d'éjecter hors de la cellule les composés intracellulaires toxiques. L'imperméabilité membranaire est également responsable de la résistance à l'imipénème et nous avons montré, in vitro, qu'un traitement par cet antibiotique active l'opéron marRAB. Les isolats MDR présentent ainsi des modulations de perméabilité de l'enveloppe bactérienne jouant un rôle important dans la résistance aux antibiotiques ; ces modifications relèvent d'un schéma général de régulation<br>Enterobacter aerogenes is a nosocomial pathogen associated with high mortality rate in intensive care units. Besides the presence of an extended b-lactamase (ESBL) and a chromosomal derepressed cephalosporinase, 5% of clinical isolats show a MultiDrug Resistant (MDR) phenotype. Our work showed that E aerogenes gathers on its genome two systems of MDR regulation: the marRAB and the ramA gene. The two regulators RamA and MarA allow E aerogenes to control exchanges with the external medium and to answer effectively against aggressions. MarA and RamA are able to negatively down-regulate porin expression and to activate the expression of the AcrAB-TolC efflux pump
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ARROYO, VINCENT. "Etude epidemiologique des enterobacter aerogenes resistants aux cephalosporines par ribotypage." Lyon 1, 1994. http://www.theses.fr/1994LYO1M146.
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Barasa, Nathaniel W. "Proteomic characterization of selenite resistance in a strain of Enterobacter cloacae /." Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1221154755.
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BELTRÃO, Elizabeth Maria Bispo. "Caracterização de grupos de incompatibilidade plasmidial e ambiente genético de blaKPC-2, blaSCO-1, sul2 e aph (3')-VIi em isolados clínicos de Enterobacter aerogenes." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/25360.
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Previous issue date: 2017-02-23<br>CAPES<br>Enterobacter aerogenes é uma enterobactéria frequentemente envolvida em Infecções Relacionadas a Assistência à Saúde, que pode apresentar resistência às diferentes classes de antimicrobianos. Há evidências de que a aquisição de resistência nessa espécie, se deve à disseminação plasmidial, juntamente com transposons, entre bactérias gram-negativas. Portanto, o objetivo deste trabalho foi realizar a caracterização de grupos de incompatibilidade plasmidiais (Incs) e determinar o ambiente genético de blaKPC-2 e outros genes de resistência presentes em plasmídeos de isolados clínicos de E. aerogenes provenientes de um hospital público de Recife-PE. Foram selecionados 17 isolados clínicos de E. aerogenes, carreadores do gene blaKPC, e os mesmos foram submetidos a PCR para os grupos Incs A/C, L/M e HI-2. Foram selecionados dois isolados de E. aerogenes para o sequenciamento do DNA plasmidial, por serem provenientes de septicemia em pacientes de UTI e portadores do gene blaKPC. Todos os 17 isolados foram positivos na PCR para os Incs A/C e L/M, enquanto o Inc HI-2 não foi detectado. Na análise do sequenciamento plasmidial além da confirmação da presença do gene blaKPC-2, também foram encontrados os genes de resistência, blaSCO-1, sul2 e aph (3')-VIi. O gene blaKPC-2 foi encontrado inserido no transposon Tn4401 com uma deleção da sequência de inserção ISKpn7 e dos genes istA, istB e transposase (TnpA). Próximo ao gene blaKPC-2 também foi encontrado o gene aph (3')-VIi. Com relação ao gene blaSCO-1, este foi encontrado próximo a uma transposase tnpAtnpR, sendo este o primeiro relato do gene blaSCO-1 em isolados de E. aerogenes. A presença de diferentes genes de resistência, inseridos em plasmídeos Inc A/C₂ e L/M, confirmam a importância de se monitorar a circulação dos plasmídeos e analisar as sequências gênicas dessas estruturas. Deve-se destacar que embora o gene blaKPC-2 tenha sido codificado dentro do elemento Tn4401, foram encontradas diferentes características estruturais, notadamente a perda de tnpA e ISKpn7, indicando uma nova versão do Tn4401 (a ser denominada Tn4401i). Essas características podem fazer com que o transposon Tn4401 perca sua capacidade de transposição, pois as sequências de inserção são essenciais para a sua mobilidade. Estes achados enfatizam ainda a continuada recombinação e evolução de plasmídeos e do elemento Tn4401 que contém o gene blaKPC-2, e o potencial de disseminação plasmidial de diferentes genes de resistência por E. aerogenes no ambiente hospitalar.<br>Enterobacter aerogenes is a frequently enterobacterium involved in healthcare-associated infections, it may be resistant to different antimicrobials agents classes. There is evidence of resistance acquisition in this species, due to plasmid propagation, along with transposons between gram-negative bacteria. This study aimed to characterize Plasmid Incompatibility Groups (Incs) and to determine the genetic region of blaKPC-2 and other resistance genes present in plasmids from clinical isolates of E. aerogenes from a public hospital in Recife/PE. Seventeen clinical isolates of E. aerogenes carriers of the blaKPC gene were selected and subjected to PCR for the Incs A/C, L/M and HI-2 groups. Only two E. aerogenes isolates were selected for the sequencing of the plasmid DNA by carriers blaKPC-2 gene and from septicemia in ICU patients. All seventeen strains were PCR positive for Incs A/C and L/M, while Inc HI-2 was not detected. Plasmid sequencing confirmed the presence of the blaKPC-2 gene, and resistance genes, blaSCO-1, sul2 and aph (3')-Vi were also found. blaKPC-2 gene was found inserted in Tn4401 transposon with deletion of the ISKpn7 insertion sequence and the istA, istB gene and a transposase (TnpA). Next to the blaKPC-2 gene was also found the aph (3')-VIi gene. Related to the blaSCO-1 gene, it was found next to a tnpAtnpR transposase, which is the first report of the blaSCO-1 gene in E. aerogenes isolates. Presence of different resistance genes inserted in Inc A/C₂ and L/M plasmids confirm the importance of monitoring the circulation of plasmids and analyzing their gene sequences. It is important to note that although the blaKPC-2 gene was encoded within the Tn4401 element, different structural characteristics were found; noting that the loss of tnpA and ISKpn7 indicated a new version of Tn4401 (will be called Tn4401i). These characteristics may do the transposon Tn4401 to lose its transposing ability, since the insertion sequences are essential for its mobility. These findings emphasize the continuous recombination and evolution of plasmids and Tn4401 element that contains the blaKPC-2 gene, in addition to the potential for plasmidial dissemination of different resistance genes by E. aerogenes in the hospital environment.
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Funk, Anne Edith. "Molekularbiologischer Nachweis von Enterobacter sakazakii (Cronobacter spp.) in Säuglings-und Kleinkindernahrung." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-115781.
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Sandrini, Gustavo Bonagamba [UNESP]. "Caracterização cinética da fosfatase ácida de Enterobacter sp. isolada de orquídea." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/94877.
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sandrini_gb_me_jabo.pdf: 333023 bytes, checksum: 103aefb6c00d464c83f63b4a78d2cb4c (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Bactérias do gênero Enterobacter sp. são conhecidas por produzir ácidos orgânicos e solubilizar fosfato inorgânico presente no solo. O objetivo do trabalho foi caracterizar a enzima fosfatase ácida ligada à membrana de Enterobacter sp. isolada de raízes de orquídeas Cyrtopodium paludicolum. A enzima ligada à membrana foi purificada por centrifugação a 100.000 x g durante uma hora a 4ºC. A atividade da p-nitrofenilfosfatase (PNFFásica) foi determinada descontinuamente a 37°C. A bactéria foi inoculada em meio de cultura líquido e a enzima foi estritamente regulada pelo fósforo, atingindo expressão máxima a 5 mM, em pH ótimo aparente de 3,5. Em relação aos inibidores avaliados, verificouse que o cobre apresentou inibição não-competitiva. Já o arsenato, vanadato e fosfato inibiram competitivamente a enzima, demonstrando que são análogos estruturais. A enzima exibiu comportamento “michaeliano” para a hidrólise do PNFF (atividade específica de 30,67 U/mg, Km = 0,55 mM e n = 1). Interações sítio-sítio foram observadas para a hidrólise do ATP (atividade específica de 11,2 U/mg, Km = 0,62 mM e n = 1,8) e para a hidrólise do pirofosfato (atividade específica de 15,64 U/mg, Km = 0,89 mM e n = 2,8). Os valores obtidos pela inativação térmica demonstraram que a enzima manteve-se estável a 45°C e a atividade enzimática diminuiu com o aumento da temperatura. Os resultados sugerem que a produção da fosfatase ácida promove aumento na disponibilidade dos nutrientes para as plantas, solubilizando minerais insolúveis através da produção de enzimas, sendo um dos mecanismos que esses microrganismos utilizam para solubilização de fosfato mineral<br>Bacteria of the genus Enterobacter sp. are known as organic acid producers and are able to solubilize inorganic phosphate which is present in soil. The aim of this work was to characterize the cell-wall associated acid phosphatase of Enterobacter sp. symbionts of plants and were isolated from roots of orchid Cyrtopodium paludicolum. The enzyme was obtained by centrifugation at 100.000 x g, for one hour at 4ºC and the activity from p-nitrophenilphosphatase (PNPPase) was determined at 37°C Culture medium was inoculate d with bacteria and supplemented with phosphorus. Under optimal conditions (5mM phosphorus, pH 3.5) the enzyme was expressed. The activity from p-nitrophenylphosphatase (PNPPase) was determined at 37°C. The enzyme presen ted Michaelis behavior for the hydrolysis of PNPP (specific activity of 30.67 U/mg, Km = 0.55 mM and n = 1). Besides site-site interactions were observed for ATP hydrolysis (specific activity of 11.2 U/mg, Km = 0.62 mM and n = 1.8) and pyrophosphate hydrolysis (specific activity of 15.64 U/mg, Km = 0.89 mM and n = 2.8). It was observed that enzyme activity decreased with increasing temperature. Inhibition studies revealed that copper inhibited the enzyme in a non-competitive manner. In contrast arsenate, and vanadate which are structural analogues of phosphate presented a competitive inhibition. The results suggest that plants expressing acid phosphatase are able to solubilize mineral phosphate and are able to hydrolyse insoluble minerals thereby increasing the availibilty of nutrients which can be used by the plant
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Jitrwung, Rujira. "Optimized continuous hydrogen production by «Enterobacter aerogens» from glycerol-containing waste." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95168.
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ABSTRACT Glycerol is the main by-product of biodiesel production. Enterobacter aerogenes has a known ability to convert glycerol (GL) in a fermentative process to yield hydrogen and ethanol. To demonstrate the potential of a continuous fermentative process to valorize crude-glycerol, hydrogen yield was optimized by determining the optimal cultivation conditions in serum bottles, which were then applied to the optimization of the operation of a 3.6-L continuous bioreactor for maximum hydrogen yield. Conditions optimized in bottles were grouped and tested using a Box-Behnken response surface methodology to determine the optimal concentration of inoculum volume (18%), O2 in transfer step (7.5% O2), Na2HPO4 (12 g/L), NH4NO3 (1.5 g/L) and FeSO4.7H2O (6.25 mg/L). Two levels of full factorial design with a middle point were used to optimize the concentration of trace salts including Na2EDTA (3.5 mg/L), CaCl2.2H2O (0 mg/L) and MgSO4.7H2O (200 mg/L) while a parametric study was used to determine the optimal amounts of two phosphate salts (Na2HPO4, KH2PO4). After a scale-up of 30x in batch mode, the optimal operating conditions of the 3.6-L bioreactor (50% working volume) were determined to be: fresh feed rate (0.44 mL/min), liquid recycle ratio (33%), pH (6.4), glycerol concentration (15 g/L), mixing speed (500 rpm), and waste reuse (0%). Using the optimized conditions we demonstrated the stability of the system over time and obtained the highest yields ever reported in CSTR, 0.86 mole hydrogen/mole GL and 0.74 mole ethanol/mole GL, and this at a significantly reduced media cost of $ 0.91 CAD/L (77% lower than previous studies).<br>ABRÉGÉ Le glycérol est le principal sous-produit de la production de biodiesel. Enterobacter aerogenes a une capacité connue à convertir le (glycérol) en hydrogène et en éthanol au cours d'une fermentation. Afin de démontrer le potentiel d'un procédé en continu de valorisation du glycérol, les conditions optimales de culture ont été déterminées dans des bouteilles afin d'optimiser le rendement en hydrogène et puis appliquées à un bioréacteur de 3.6 L. Les conditions de culture optimales, déterminées à l'aide de la méthodologie de réponse de surface de Box-Behnken, sont un volume d'inoculation de 18%, une concentration d'oxygène de 7.5% lors du transfert, et les concentrations suivantes de Na2HPO4 (12 g/L), NH4NO3 (1.5 g/L) et FeSO4.7H2O (6.25 mg/L). Un plan factoriel complet à deux niveaux avec point central a aussi été utilisé afin de déterminer les concentrations optimales de Na2EDTA (3.5 mg/L), CaCl2.2H2O (0 mg/L) et MgSO4.7H2O (200 mg/L) alors qu'une étude paramétrique a permis de déterminer la quantité optimale de deux sels de phosphate (Na2HPO4, KH2PO4). Suite à la mise à l'échelle 30x dans le bioréacteur opéré en mode batch, les conditions optimales du CSTR ont été identifiées comme étant un débit d'alimentation de 0.44 mL/min, un ratio de recyclage de liquide de 33%, un pH de 6.4, une concentration de glycérol de 15 g/L, une vitesse de mélange de 500 rpm ainsi qu'une réutilisation nulle du résidu liquide. En utilisant ces conditions optimales de culture et d'opération du bioréacteur opéré en continu, la stabilité du procédé sur une période prolongée d'opération a été confirmée. Dans ces conditions, les plus hauts rendements en hydrogène et en éthanol jamais rapportés dans un tel système, ont été obtenus, 0.86 mole hydrogène/mole GL and 0.74 mole éthanol/mole GL, et ce, à un coût en média de 75% inférieur aux études antérieures.
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Ridley, Helen. "Purification and characterisation of oxyanion reductases from Enterobacter cloacae SLD1a-1." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446195.
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Jacobs, D. "Type II restriction-modified systems in Enterobacter aerogenes and Herpetosiphon giganteus." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379680.
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Rottman, Martin. "Phylogenie et variabilite des cephalosporinases chromosomiques au sein du genre enterobacter." Paris 5, 2001. http://www.theses.fr/2001PA05N004.
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Bornet, Charléric. "Perméabilité membranaire et mécanismes de résistance aux antibiotiques chez Enterobacter aerogenes." Aix-Marseille 2, 2004. http://www.theses.fr/2004AIX20654.
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Zook, Dana M. "Molecular basis of group A colicin/TolA recognition in Enterobacter species." Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1300564452.
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Barasa, Nathaniel Wafula. "Proteomic Characterization of Selenite Resistance in a strain of Enterobacter cloacae." Youngstown State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1221154755.
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Curtis, Christine. "Development of a Recombineering System in Enterobacter sp. YSU." Youngstown State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1452363978.
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Ford, Kelsey L. "Knockout of the lacZ gene in Enterobacter sp. YSU." Youngstown State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1534337870735813.
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Konda, Venkataramana. "Identification of Metal Resistance Genes in a Strain of Enterobacter cloacae." Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1219421291.
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Lamm, Katelyn Amber. "Distribution and evolution of the palatinose (pal) operon in Enterobacter sakazakii." College Park, Md. : University of Maryland, 2008. http://hdl.handle.net/1903/8324.
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Thesis (M.S.) -- University of Maryland, College Park, 2008.<br>Thesis research directed by: Dept. of Nutrition and Food Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Sandrini, Gustavo Bonagamba. "Caracterização cinética da fosfatase ácida de Enterobacter sp. isolada de orquídea /." Jaboticabal : [s.n.], 2011. http://hdl.handle.net/11449/94877.
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Orientador: João Matins Pizauro Júnior<br>Coorientador: Cecília Maria Costa do Amaral<br>Banca: Jesus Aparecido Ferro<br>Banca: Luís Henrique Souza Guimarães<br>Resumo: Bactérias do gênero Enterobacter sp. são conhecidas por produzir ácidos orgânicos e solubilizar fosfato inorgânico presente no solo. O objetivo do trabalho foi caracterizar a enzima fosfatase ácida ligada à membrana de Enterobacter sp. isolada de raízes de orquídeas Cyrtopodium paludicolum. A enzima ligada à membrana foi purificada por centrifugação a 100.000 x g durante uma hora a 4ºC. A atividade da p-nitrofenilfosfatase (PNFFásica) foi determinada descontinuamente a 37°C. A bactéria foi inoculada em meio de cultura líquido e a enzima foi estritamente regulada pelo fósforo, atingindo expressão máxima a 5 mM, em pH ótimo aparente de 3,5. Em relação aos inibidores avaliados, verificouse que o cobre apresentou inibição não-competitiva. Já o arsenato, vanadato e fosfato inibiram competitivamente a enzima, demonstrando que são análogos estruturais. A enzima exibiu comportamento "michaeliano" para a hidrólise do PNFF (atividade específica de 30,67 U/mg, Km = 0,55 mM e n = 1). Interações sítio-sítio foram observadas para a hidrólise do ATP (atividade específica de 11,2 U/mg, Km = 0,62 mM e n = 1,8) e para a hidrólise do pirofosfato (atividade específica de 15,64 U/mg, Km = 0,89 mM e n = 2,8). Os valores obtidos pela inativação térmica demonstraram que a enzima manteve-se estável a 45°C e a atividade enzimática diminuiu com o aumento da temperatura. Os resultados sugerem que a produção da fosfatase ácida promove aumento na disponibilidade dos nutrientes para as plantas, solubilizando minerais insolúveis através da produção de enzimas, sendo um dos mecanismos que esses microrganismos utilizam para solubilização de fosfato mineral<br>Abstract: Bacteria of the genus Enterobacter sp. are known as organic acid producers and are able to solubilize inorganic phosphate which is present in soil. The aim of this work was to characterize the cell-wall associated acid phosphatase of Enterobacter sp. symbionts of plants and were isolated from roots of orchid Cyrtopodium paludicolum. The enzyme was obtained by centrifugation at 100.000 x g, for one hour at 4ºC and the activity from p-nitrophenilphosphatase (PNPPase) was determined at 37°C Culture medium was inoculate d with bacteria and supplemented with phosphorus. Under optimal conditions (5mM phosphorus, pH 3.5) the enzyme was expressed. The activity from p-nitrophenylphosphatase (PNPPase) was determined at 37°C. The enzyme presen ted Michaelis behavior for the hydrolysis of PNPP (specific activity of 30.67 U/mg, Km = 0.55 mM and n = 1). Besides site-site interactions were observed for ATP hydrolysis (specific activity of 11.2 U/mg, Km = 0.62 mM and n = 1.8) and pyrophosphate hydrolysis (specific activity of 15.64 U/mg, Km = 0.89 mM and n = 2.8). It was observed that enzyme activity decreased with increasing temperature. Inhibition studies revealed that copper inhibited the enzyme in a non-competitive manner. In contrast arsenate, and vanadate which are structural analogues of phosphate presented a competitive inhibition. The results suggest that plants expressing acid phosphatase are able to solubilize mineral phosphate and are able to hydrolyse insoluble minerals thereby increasing the availibilty of nutrients which can be used by the plant<br>Mestre
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Santos, Rosana Francisco Siqueira dos. "Ocorrencia de Enterobacter sakazakii em formulas infantis para lactentes em hospitais e maternidades da região de Campinas/SP." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254599.
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Orientador: Jose Luiz Pereira, Valeria Chritina Amstalden Junqueira<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos<br>Made available in DSpace on 2018-08-07T20:30:44Z (GMT). No. of bitstreams: 1
Santos_RosanaFranciscoSiqueirados_M.pdf: 1367464 bytes, checksum: 1f8a0a9b0f9ec558cd3f583d15def385 (MD5)
Previous issue date: 2006<br>Mestrado<br>Mestre em Ciência de Alimentos
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Lee, Eun-Hee. "Perméabilité membranaire d'"Enterobacter cloacae" aux bêta-lactamines : rôle des porines et identification de gènes régulant leur expression." Paris 11, 1994. http://www.theses.fr/1994PA114814.
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Castro, Luis Fernando. "Inactivation of Cronobacter (Enterobacter) sakazakii using different antimicrobial agents and the effect of sanitizers on biofilm formation properties." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/l_castro_102709.pdf.
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Thesis (M.S. in food science)--Washington State University, December 2009.<br>Title from PDF title page (viewed on Jan. 20, 2010). "School of Food Science." Includes bibliographical references (p. 55-59).
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Jacobs, Cécile. "Vorkommen und Bedeutung von Enterobacter sakazakii in einem Milchtrocknungsbetrieb - Betriebsepidemiologie und Prozesssicherheit." Doctoral thesis, Universitätsbibliothek Leipzig, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:15-20100223-115909-0.
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Enterobacter sakazakii führt in seltenen Fällen bei Neu- und Frühgeburten zu Sepsis, Meningitis und nekrotisierender Enterocolitis. In zahlreichen Fällen konnte kontaminierte, auf Milchpulver basierende Säuglingsnahrung als Infektionsquelle nachgewiesen werden. Im Hinblick auf die oben dargestellte Problematik, wurde ein Milchtrocknungswerk auf das Vorkommen und die Verbreitung von Enterobacter sakazakii untersucht und molekularbiologisch typisiert. Aus den gewonnenen Daten konnten Maßnahmen für die Betriebshygiene und Prozesssicherheit abgeleitet und ergriffen werden.