11 results on '"Guzman-Verri, Caterina"'
Search Results
2. Brucella neotomae infection in humans, Costa Rica
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Suarez-Esquivel, Marcela, Ruiz-Villalobos, Nazareth, Jimenez-Rojas, Cesar, Barquero-Calvo, Elfas, Chacon-Dfaz, Carlos, Vfquez-Ruiz, Eunice, Rojas-Campos, Norman, Baker, Kate S., Oviedo-Sanchez, Gerardo, Amuy, Ernesto, Chaves-Olarte, Esteban, Thomson, Nicholas R., Moreno, Edgardo, and Guzman-Verri, Caterina
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Brucella -- Research ,Health - Abstract
Members of the genus Brucella are the infectious agents of brucellosis, a neglected disease responsible for economic losses resulting from abortion and low performance in production animals (1). The 4 [...]
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- 2017
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3. New Bruce-ladder multiplex PCR assay for the biovar typing of Brucella suis and the discrimination of Brucella suis and Brucella canis
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López-Goñi, Ignacio, García-Yoldi, David, Marín, Clara M., de Miguel, María J., Barquero-Calvo, Elías, Guzmán-Verri, Caterina, Albert, David, and Garin-Bastuji, Bruno
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- 2011
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4. The two-component system BvrR/BvrS regulates the expression of the type IV secretion system VirB in Brucella abortus
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Martinez-Nunez, Carola, Altamirano-Silva, Pamela, Alvarado-Guillen, Francisco, Moreno, Edgardo, Guzman-Verri, Caterina, and Chaves-Olarte, Esteban
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Gene expression -- Physiological aspects ,Bacteria, Pathogenic -- Genetic aspects ,Bacteria, Pathogenic -- Physiological aspects ,Bacterial proteins -- Properties ,Biological sciences - Abstract
The pathogenesis of Brucella is related to the ability to multiply intracellularly, an event controlled by the two-component system BvrR/BvrS (TCS BvrRS) and the type IV secretion machinery VirB (T4SS VirB). We have hypothesized that the TCS BvrRS transcriptionally regulates the T4SS VirB. To test this hypothesis, we have compared the levels of VirB proteins in the wild-type strain Brucella abortus 2308 and mutant strains devoid of the sensor and regulator genes (bvrS and bvrR mutants, respectively). While the bvrR and bvrS mutants showed low levels of the VirB1, VirB5, VirB8, and VirB9 proteins, the same proteins were overexpressed in the bvrR mutant complemented with a plasmid carrying a functional bvrR gene. Quantitation of virB5 mRNA confirmed these data and indicated that the influence of the TCS BvrRS on the T4SS VirB occurs at the transcriptional level. The expression of the transcriptional activator VjbR also depended on the TCS BvrRS. In addition, we demonstrate a direct interaction between the promoter region of the VirB operon and the response regulator BvrR. Altogether these data demonstrate that the TCS BvrRS controls the expression of the T4SS VirB through direct and indirect mechanisms. doi: 10.1128/JB.00567-10
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- 2010
5. Neurobrucellosis in stranded dolphins, Costa Rica
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Hernandez-Mora, Gabriela, Gonzalez-Barrientos, Rocio, Morales, Juan-Alberto, Chaves-Olarte, Esteban, Guzman-Verri, Caterina, Baquero-Calvo, Elias, De-Miguel, Maria-Jesus, Marin, Clara-Maria, Blasco, Jose-Maria, and Moreno, Edgardo
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Delphinidae -- Health aspects ,Dolphins -- Health aspects ,Brucellosis -- Risk factors ,Brucellosis -- Diagnosis ,Brucellosis -- Research ,Disease transmission -- Health aspects ,Disease transmission -- Research - Abstract
Ten striped dolphins, Stenella coeruleoalba, stranded along the Costa Rican Pacific coast, had meningoencephalitis and antibodies against Brucella spp. Brucella ceti was isolated from cerebrospinal fluid of 6 dolphins and [...]
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- 2008
6. Incomplete activation of Escherichia coli hemolysin (HlyA) due to mutations in the 3' reguion of hlyC
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Guzman-Verri, Caterina, Garcia, Fernando, and Arvidson, Staffan
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Escherichia coli -- Research ,Hemolysis and hemolysins -- Research ,Gene mutations -- Research ,Biological sciences - Abstract
A mutational analysis of the carboxy-terminal region of Escherichia coli hemolysin (HlyA) was conducted. Results of the research indicated that the incomplete activation of E. coli HlyA is due to the mutations in the 3' region of hlyC. Furthermore, the production of simultaneous secretion on non-acylated, monoacylated and fully acelated HlyA forms is the result of a decreased affinity of HlyC for individual HlyA acylation sites.
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- 1997
7. Brucella sequence Type 27 isolated from Dwarf Sperm Whale (Kogia sima) stranded in the Costa Rican Pacific Coast
- Author
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Suárez-Esquivel, Marcela, primary, Ruiz-Villalobos, Nazareth, additional, Hernández-Mora, Gabriela, additional, González-Barrientos, Rocío, additional, David Palacios-Alfaro, Jose, additional, Barquero-Calvo, Elías, additional, Chaves-Olarte, Esteban, additional, Thomson, Nicholas, additional, Moreno, Edgardo, additional, and Guzman-Verri, Caterina, additional
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- 2019
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8. Brucellosis caused by the wood rat pathogen Brucella neotomae: two case reports
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Villalobos-Vindas, Juan M., primary, Amuy, Ernesto, additional, Barquero-Calvo, Elías, additional, Rojas, Norman, additional, Chacón-Díaz, Carlos, additional, Chaves-Olarte, Esteban, additional, Guzman-Verri, Caterina, additional, and Moreno, Edgardo, additional
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- 2017
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9. Brucella abortus Strain 2308 Wisconsin Genome: Importance of the Definition of Reference Strains
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Suarez-Esquivel, Marcela, Ruiz-Villalobos, Nazareth, Castillo-Zeledon, Amanda, Jimenez-Rojas, Cesar, Roop, R. Martin II, Comerci, Diego J., Barquero-Calvo, Elias, Chacon-Diaz, Carlos, Caswell, Clayton C., Baker, Kate S., Chaves-Olarte, Esteban, Thomson, Nicholas R., Moreno, Edgardo, Letesson, Jean J., De Bolle, Xavier, Guzman-Verri, Caterina, Suarez-Esquivel, Marcela, Ruiz-Villalobos, Nazareth, Castillo-Zeledon, Amanda, Jimenez-Rojas, Cesar, Roop, R. Martin II, Comerci, Diego J., Barquero-Calvo, Elias, Chacon-Diaz, Carlos, Caswell, Clayton C., Baker, Kate S., Chaves-Olarte, Esteban, Thomson, Nicholas R., Moreno, Edgardo, Letesson, Jean J., De Bolle, Xavier, and Guzman-Verri, Caterina
- Abstract
Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference strains as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing analysis of the reference strain B. abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version through a link at https://en.wikipedia.org/wiki/Brucella#Genomics. Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same strain. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of strain definition needs to be revised.
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- 2016
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10. Standardization of a molecular characterization protocol to identify land bacteria strains of the brucella kind
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MUNOZ VARGAS, LOHENDY, BARQUERO-CALVO, ELIAS, Moreno, Edgardo, and Guzman-Verri, Caterina
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BRUCELOSIS ,DIAGNOSIS (VETERINARY MEDICINE) ,DIAGNOSTICO (MEDICINA VETERINARIA) ,DIAGNOSTICO DE LABORATORIO (MEDICINA VETERINARIA) ,BRUCELLA ,NORMALIZACION ,BACTERIAS ,PROTOCOLO - Abstract
La brucelosis es la enfermedad zoonótica más extendida en el mundo que afecta diversos animales, incluyendo especies domésticas y de vida silvestre. Es causada por una bacteria perteneciente al género Brucella, el cual incluye nueve especies distintas e infectantes de mamíferos terrestres y marinos. Cada especie de Brucella presenta variaciones en la secuencia de ADN que afectan a los nucleótidos en una posición específica del genoma. A estas variaciones se les llama polimorfismo. El polimorfismo de las especies de Brucella localizado en los genes que codifican para las proteínas glk, omp25ytrpE, se utilizó para desarrollar un ensayo múltiple basado en la extensión de cebadores, el cual permite identificar un aislamiento como miembro de una de las nueve especies reconocidas. Los métodos tradicionales para la identificación de Brucella a nivel de especie consumen mucho tiempo y ponen en riesgo al personal laboratorial. Es por ello que la finalidad de este trabajo es evitar la ambigüedad, agilizar el procedimiento, disminuir el tiempo de respuesta y generar una herramienta laboratorial más efectiva para mejorar la vigilancia epidemiológica, el diagnóstico y el abordaje de la brucelosis en Costa Rica. El siguiente trabajo presenta la estandarización del protocolo para la extracción de ADN de Brucella, así como de una serie de amplificaciones de fragmentos de genes de interés por medio de la reacción en cadena de la polimerasa (PCR) y la estandarización de la reacción de extensión de cebadores. Brucellosis is the most widespread zoonotic disease worldwide that affects various animals, including domestic species and wildlife. It is caused by bacteria belonging to the genus Brucella, which includes nine different species and infective terrestrial and marine mammals. Each species of Brucella has variations in DNA sequence involving nucleotides in a specific position in the genome. These variations are called polymorphisms The polymorphism of Brucella species located in the genes coding for proteins glk, omp25, and trpE was used to develop a multiplex assay based on primer extension, with which it can identify an isolate as a member of nine recognized species. Traditional methods for identification of Brucella at the species level, time consuming and endanger laboratory staff. That is why the aim of this work is to avoid ambiguity, to streamline the procedure, reduce the response time and generate a more effective laboratory tool for improving epidemiological surveillance, diagnosis and approach of brucellosis in Costa Rica. This paper presents the standardization of the protocol for DNA extraction of Brucella, the standardization of a series of amplifications of fragments of genes of interest through the chain reaction (PCR) and standardization of the extension reaction primers. Brucelose é a doença zoonótica mais distribuída por todo o mundo e que afeta várias espécies animais incluindo espécies domésticas e selvagens. É causada por uma bactéria pertencente ao género Brucella que inclui nove espécies diferentes e é infectante para mamíferos terrestres e marinhos. Cada espécie de Brucella tem variações na sequência de DNA envolvendo os nucleótidos de uma posição especifica do genoma. Estas variações são chamadas polimorfismos. O polimorfismo das espécies de Brucella localizado no código genético para proteínas glk, omp25 e trpE foi utilizado para desenvolver um ensaio múltiplo baseado na primeira extensão, com a qual se pode identificar e isolar como membro de uma das 9 espécies. Os métodos tradicionais para identificação de Brucella ao nível da espécie, consomem muito tempo e põe em risco o pessoal de laboratório. É por isso que o objectivo deste trabalho é evitar a ambiguidade, agilizar o procedimento, reduzir o tempo de resposta e gerar uma ferramenta laboratorial mais efectiva para melhorar a vigilância epidemiológica, diagnostico e aproximação à brucelose na Costa Rica. Este artigo, apresenta a estandardização do protocolo para extracção de DNA de Brucella, estandardização de uma série de amplificações de fragementos genéticos de interesse através da reacção de polimerase em cadeia (PCR) e estandardização da reacção dos primers de extensão. Universidad Nacional, Costa Rica Escuela de Medicina Veterinaria
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- 2011
11. Virulence mechanisms of two gram negative bacteria : studies on Escherichia coli hemolysin HlyA and on the interaction of Brucella abortus with non-phagocytic cells
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Guzman-Verri, Caterina and Guzman-Verri, Caterina
- Abstract
Virulence factors may be classified in two general groups: those that cause damage to the host and those that promote bacterial colonization and invasion. In this study, the tissue damaging Escherichia coli hemolysin HlyA and the mechanism of internalization of the intracellular parasite Brucella abortus were investigated. HIyA is a pore-forming toxin belonging to the family of Gram negative exo-proteins known as RTX (from Repeat in Toxins). HIyA is activated by fatty acylation of two internal lysine residues, by a mechanism requiring acyl carrier protein and HlyC. Site directed mutagenesis studies of hlyC identified amino acid residues essential for HlyC acyl transferase activity as well as other residues that generated simultaneous secretion of bi-, mono- and non-acylated HIyA molecules. HlyC was not detected by Western blot in an E. coli strain encoding hlyC and hIyA, while four different isoforms were found in a strain encoding hlyC alone. As similar hlyC mRNA levels were found in both strains, it was concluded that HlyC was probably degraded by a HlyA dependent mechanism. Degradation of HlyC was performed by multiple protease systems such as Clp, FtsH and Lon. Internalization of B. abortus was studied by fluorescence and transmission electron microscopy. Brucella did not induce major cytoskeletal rearrangements in HeLa cells despite the fact that both, the actin and microtubule networks were needed for its uptake. Treatment of HeLa cells with different bacterial toxins specific for small GTPases together with mutant studies demonstrated that Rho, Rac and Cdc42 were involved in Brucella internalization. Moreover, immunoprecipitation of active Rho, Rac and Cdc42 demonstrated that Brucella is capable of activating Cdc42 during entry to HeLa cells. Analysis by two-dimensional gel electrophoresis of wild type and non virulent B. abortus BvrR-BvrS two component system mutants revealed differences in various protein groups in outer membrane fragments. Two protein grou
- Published
- 2002
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