Study of Pathogenicity of Various Serovars of Enterococcus faecalis

Yoshioka, Migaku; Kumamoto, Yoshiaki; Hirose, Takaoki; Maekawa, Shizue

doi:10.11150/kansenshogakuzasshi1970.69.181

Cited by 4 publications

(2 citation statements)

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“…E. faecalis has been implicated as the etiologic agent in a variety of human diseases, including endocarditis [5] and chronic obstructive bronchitis [6]. Control of enterococcal infection has become a significant clinical concern with the advent of drug resistance, particularly strains of E. faecalis resistant to vancomycin [7].…”

Section: Introductionmentioning

confidence: 99%

Enterococcus faecalis glutathione reductase: purification, characterization and expression under normal and hyperbaric O2 conditions

Patel

Marcinkeviciene

Blanchard

1998

FEMS Microbiology Letters

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Glutathione reductase is found ubiquitously in eukaryotes and Gram-negative bacteria, and plays a significant role in bacterial defense against oxidative stress. Glutathione reductase from the Gram-positive bacterium Enterococcus faecalis was purified to homogeneity using anion exchange, hydrophobic interaction, and affinity chromatography. The homogeneous 49-kDa enzyme contained 1 mol bound FAD per subunit. The determined N-terminal amino acid sequence of the E. faecalis enzyme displays significant identity with glutathione reductases from other Gram-negative and Gram-positive bacteria, as well as yeast and human erythrocyte reductases. The kinetic mechanism is ping-pong, and the determined kinetic parameters exhibited by the E. faecalis glutathione reductase are similar to those found for glutathione reductases from yeast, Escherichia coli, and human erythrocyte. A two-fold increased expression of glutathione reductase activity and a three-fold induction of glutathione peroxidase activity were observed under hyperbaric O2 growth conditions without a corresponding change in the total glutathione and soluble thiol content. The difference in the expression of the enzyme, and its cognate substrate's intracellular concentration, under these conditions suggest that the gene encoding glutathione reductase is responsive to oxygen concentration, but that the genes encoding the glutathione synthesizing enzymes are not linked to an oxygen-sensitive promoter.

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Section: Introductionmentioning

confidence: 99%

Enterococcus faecalis glutathione reductase: purification, characterization and expression under normal and hyperbaric O2 conditions

Patel

Marcinkeviciene

Blanchard

1998

FEMS Microbiology Letters

View full text Add to dashboard Cite

show abstract

“…faecalis has been implicated as the etiologic agent in a variety of human diseases, including endocarditis [5] and chronic obstructive bronchitis [6]. Control of enterococcal infection has become a signi¢cant clinical concern with the advent of drug resistance, particularly strains of E. faecalis resistant to vancomycin [7].…”

Section: Introductionmentioning

confidence: 99%

Enterococcus faecalis glutathione reductase: purification, characterization and expression under normal and hyperbaric O2 conditions

Patel¹

1998

FEMS Microbiology Letters

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Glutathione reductase is found ubiquitously in eukaryotes and Gram-negative bacteria, and plays a significant role in bacterial defense against oxidative stress. Glutathione reductase from the Gram-positive bacterium Enterococcus faecalis was purified to homogeneity using anion exchange, hydrophobic interaction, and affinity chromatography. The homogeneous 49-kDa enzyme contained 1 mol bound FAD per subunit. The determined N-terminal amino acid sequence of the E. faecalis enzyme displays significant identity with glutathione reductases from other Gram-negative and Gram-positive bacteria, as well as yeast and human erythrocyte reductases. The kinetic mechanism is ping-pong, and the determined kinetic parameters exhibited by the E. faecalis glutathione reductase are similar to those found for glutathione reductases from yeast, Escherichia coli, and human erythrocyte. A two-fold increased expression of glutathione reductase activity and a three-fold induction of glutathione peroxidase activity were observed under hyperbaric O P growth conditions without a corresponding change in the total glutathione and soluble thiol content. The difference in the expression of the enzyme, and its cognate substrate's intracellular concentration, under these conditions suggest that the gene encoding glutathione reductase is responsive to oxygen concentration, but that the genes encoding the glutathione synthesizing enzymes are not linked to an oxygen-sensitive promoter. z

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Genetic Variation and Evolution of the Pathogenicity Island of Enterococcus faecalis

et al. 2009

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Enterococcus faecalis is a leading cause of nosocomial infections and is known for its ability to acquire and transfer virulence and antibiotic resistance determinants from other organisms. A 150-kb pathogenicity island (PAI) encoding several genes that contribute to pathogenesis was identified among antibiotic-resistant clinical isolates. In the current study, we examined the structure of the PAI in a collection of isolates from diverse sources in order to gain insight into its genesis and dynamics. Using multilocus sequence typing to assess relatedness at the level of strain background and microarray analysis to identify variations in the PAI, we determined the extent to which structural variations occur within the PAI and also the extent to which these variations occur independently of the chromosome. Our findings provide evidence for a modular gain of defined gene clusters by the PAI. These results support horizontal transfer as the mechanism for accretion of genes into the PAI and highlight a likely role for mobile elements in the evolution of the E. faecalis PAI.Enterococcus faecalis is a core constituent of the intestinal flora of humans and a leading cause of nosocomial infections worldwide (35). Enterococci are associated with a variety of pathologies, including pelvic infections, intra-abdominal abscesses, postsurgical infection, bacteremia, endocarditis, and urinary tract infections (12,20,30). The ability of E. faecalis to cause serious infection is connected to the inherent hardiness of the bacterium, which enables it to tolerate desiccation, persist in the hospital environment, and then endure host defenses (20,22). In addition, enterococci are particularly adept at acquiring resistance to antibiotics and disseminating these elements within and beyond the genus (30, 48).Pathogenicity islands (PAIs) are large, horizontally transmitted elements found in many gram-positive and gram-negative pathogens (14). They are believed to contribute to the rapid evolution of nonpathogenic organisms into pathogenic forms (2, 26). The PAI of E. faecalis is approximately 150 kb and encodes multiple factors that contribute to its virulence, including the cytolysin toxin (3, 18), the enterococcal surface protein Esp (40), and Gls-24-like proteins (44), as well as traits suspected of contributing to pathogenicity or altering its relationship with the host, including a bile acid hydrolase, carbohydrate utilization pathways, and many additional genes of unknown function (38). The PAI, or parts thereof, has been identified in hundreds of E. faecalis isolates, and variation in genetic content has been noted (25,30,32,39). It is enriched among infection-derived isolates (38) and highly clonal lineages containing multiple antibiotic resistance elements (30). Variation has been found in the occurrence of genes within the PAI, even within a genetic (clonal) lineage, suggesting that segments of the island can vary independently of the whole (38). Indeed, movement of genes derived from an internal portion of the PAI has been det...

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Study of Pathogenicity of Various Serovars of Enterococcus faecalis

Cited by 4 publications

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Enterococcus faecalis glutathione reductase: purification, characterization and expression under normal and hyperbaric O2 conditions

Enterococcus faecalis glutathione reductase: purification, characterization and expression under normal and hyperbaric O2 conditions

Enterococcus faecalis glutathione reductase: purification, characterization and expression under normal and hyperbaric O2 conditions

Genetic Variation and Evolution of the Pathogenicity Island of Enterococcus faecalis

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