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1.
Mem Inst Oswaldo Cruz ; 105(5): 657-60, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20835612

RESUMEN

Helicobacter pylori infection is associated with peptic ulcer and gastric carcinoma. The oral cavity may be a reservoir for H. pylori; however, the results of studies on this subject are controversial. We employed single-step and nested polymerase chain reactions (PCR) to detect the presence of the vacA, ureA and 16S rDNA genes of H. pylori in the stomach, saliva and dental plaque of 30 subjects. The results were confirmed by sequencing. Nested 16S rDNA and ureA amplification was achieved in 80% of gastric, 30% of saliva and 20% of dental plaque specimens. Sequencing of 10, seven and four 16S rDNA products from stomach, saliva and dental plaque, respectively, showed > 99% identity with H. pylori. Sequencing of the other four oral cavity PCR products showed similarity with Campylobacter and Wolinella species. Additionally, the vacA genotype identified in the samples of different sites was the same within a given subject.H. pylori may be found in the oral cavity of patients with gastric infection, thus it could be a source of transmission. However, results obtained with detection methods based only on PCR should be interpreted with caution because other microorganisms that are phylogenetically very close to H. pylori are also present in the mouth.


Asunto(s)
Placa Dental/microbiología , Dispepsia/microbiología , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Saliva/microbiología , Estómago/microbiología , Proteínas Bacterianas/análisis , Proteínas Bacterianas/genética , Biopsia , ADN Bacteriano/genética , ADN Ribosómico/genética , Femenino , Infecciones por Helicobacter/transmisión , Helicobacter pylori/genética , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
2.
Mem. Inst. Oswaldo Cruz ; 105(5): 657-660, Aug. 2010. tab
Artículo en Inglés | LILACS | ID: lil-557225

RESUMEN

Helicobacter pylori infection is associated with peptic ulcer and gastric carcinoma. The oral cavity may be a reservoir for H. pylori; however, the results of studies on this subject are controversial. We employed single-step and nested polymerase chain reactions (PCR) to detect the presence of the vacA, ureA and 16S rDNA genes of H. pylori in the stomach, saliva and dental plaque of 30 subjects. The results were confirmed by sequencing. Nested 16S rDNA and ureA amplification was achieved in 80 percent of gastric, 30 percent of saliva and 20 percent of dental plaque specimens. Sequencing of 10, seven and four 16S rDNA products from stomach, saliva and dental plaque, respectively, showed > 99 percent identity with H. pylori. Sequencing of the other four oral cavity PCR products showed similarity with Campylobacter and Wolinella species. Additionally, the vacA genotype identified in the samples of different sites was the same within a given subject.H. pylori may be found in the oral cavity of patients with gastric infection, thus it could be a source of transmission. However, results obtained with detection methods based only on PCR should be interpreted with caution because other microorganisms that are phylogenetically very close to H. pylori are also present in the mouth.


Asunto(s)
Femenino , Humanos , Masculino , Persona de Mediana Edad , Placa Dental , Dispepsia , Infecciones por Helicobacter , Helicobacter pylori , Saliva , Estómago , Biopsia , Proteínas Bacterianas , Proteínas Bacterianas , ADN Bacteriano , ADN Ribosómico , Infecciones por Helicobacter/transmisión , Helicobacter pylori , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADN
3.
Curr Microbiol ; 53(5): 370-3, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17019646

RESUMEN

Since we have limited knowledge about the occurrence of Helicobacter in wild animals, we searched for Helicobacter species in the gastrointestinal tract of 75 rodents captured in forest remnants of Minas Gerais, Brazil. Fragments from the antrum and corpus of the stomach and from the colon were taken for PCR assays for Helicobacter detection. Although gastric mucosa was Helicobacter-positive in only one animal, the bacterium was detected in the colonic mucosa of 23 rodents (30.7%). Helicobacter detection was more frequent in the colon of terraced rice rat (56%) and house rat (30%) in contrast to punare and Spix's yellow-toothed cavy, in which the presence of the bacterium was not detected. Helicobacter rodentium, H. marmotae, H. cinaedi, and other species closely related to the murine helicobacters were presumptively identified by DNA sequencing. Wild rodents may serve as a reservoir of these Helicobacter species in nature.


Asunto(s)
Tracto Gastrointestinal/microbiología , Helicobacter/aislamiento & purificación , Roedores/microbiología , Animales , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
4.
Braz. j. microbiol ; Braz. j. microbiol;33(3): 202-208, July-Sept. 2002. tab
Artículo en Inglés | LILACS | ID: lil-349768

RESUMEN

Trehalose accumulation, invertase activity and physiological characteristics of 86 yeast isolates from short fermentative cycles during the production of cachaça in three artisanal distilleries of the State of Minas Gerais were studied. Among these isolates, 70 percent were able to grow at temperatures between 40 and 42ºC. Only Saccharomyces cerevisiae isolates were able to grow over 40ºC. Lower temperatures (<40ºC) favoured the growth of yeasts such as Candida parapsilosis-like, C. maltosa-like, Kloeckera japonica, S. exiguus and C. bombicola-like. The isolates from all three distilleries were ethanol tolerant, produced invertase, and accumulate trehalose in the presence of glucose. The strains isolated from distillery A presented more resistance to ethanol (around 84.2 percent of the strains were able to grow in the presence of 12 percent ethanol) when compared to the ones from distilleries C and B (9.5 percent and no strain, respectively). The strains of S. cerevisiae isolated from the three distilleries presented a higher capacity to produce invertase and accumulate trehalose in the presence of glucose. Based on the results of thermal and ethanol stress experiments, it was possible to identify strong relationship between intracellular trehalose accumulation and cell viability. The increase in cell viability was even more pronounced when the strains were subjected to a pre-treatment at sublethal temperatures


Asunto(s)
Bebidas Alcohólicas , Etanol , Técnicas In Vitro , Saccharomyces cerevisiae , Trehalosa , Levaduras , Fermentación , Métodos
5.
Can J Microbiol ; 48(5): 399-406, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12109879

RESUMEN

Twenty-seven Schizosaccharomyces pombe isolates from seven cachaça distilleries were tested for maximum temperature of growth and fermentation, osmotolerance, ethanol resistance, invertase production, and trehalose accumulation. Two isolates were selected for studies of trehalose accumulation under heat shock and ethanol stress. The S. pombe isolates were also characterized by RAPD-PCR. The isolates were able to grow and ferment at 41 degrees C, resisted concentrations of 10% ethanol, and grew on 50% glucose medium. Four isolates yielded invertase activity of more than 100 micromol of reducing sugar x mg(-1) x min(-1). The S. pombe isolates were able to accumulate trehalose during stationary phase. Two isolates, strains UFMG-A533 and UFMG-A1000, submitted to a 15 min heat shock, were able to accumulate high trehalose levels. Strain UFMG-A533 had a marked reduction in viability during heat shock, but strain UFMG-A1000 preserved a viability rate of almost 20% after 15 min at 48 degrees C. No clear correlation was observed between trehalose accumulation and cell survival during ethanol stress. Strain UFMG-A1000 had higher trehalose accumulation levels than strain UFMG-A533 under conditions of combined heat treatment and ethanol stress. Molecular analysis showed that some strains are maintained during the whole cachaça production period; using the RAPD-PCR profiles, it was possible to group the isolates according to their isolation sites.


Asunto(s)
Bebidas Alcohólicas/microbiología , Saccharum/metabolismo , Saccharum/microbiología , Schizosaccharomyces/clasificación , Schizosaccharomyces/fisiología , Trehalosa/metabolismo , Brasil , ADN de Hongos/análisis , Fermentación , Glicósido Hidrolasas/metabolismo , Reacción en Cadena de la Polimerasa , Técnica del ADN Polimorfo Amplificado Aleatorio , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , beta-Fructofuranosidasa
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