Browsing Microbiology and Immunology by Issue Date
Now showing items 41-60 of 268
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The Pseudomonas Quinolone Signal Regulates rhl Quorum Sensing in Pseudomonas aeruginosa
(East Carolina University, 2000-05)The opportunistic pathogen Pseudomonas aeruginosa uses intercellular signals to control the density-dependent expression of many virulence factors. The las and rhl quorum-sensing systems function, respectively, through the ... -
The Pseudomonas aeruginosa devB/SOL Homolog, pgl, Is a Member of the hex Regulon and Encodes 6-Phosphogluconolactonase
(East Carolina University, 2000-07)A cyclic version of the Entner-Doudoroff pathway is used by Pseudomonas aeruginosa to metabolize carbohydrates. Genes encoding the enzymes that catabolize intracellular glucose to pyruvate and glyceraldehyde 3- phosphate ... -
The Redox-Sensitive Transcriptional Activator OxyR Regulates the Peroxide Response Regulon in the Obligate Anaerobe Bacteroides fragilis
(East Carolina University, 2000-09)The peroxide response-inducible genes ahpCF, dps, and katB in the obligate anaerobe Bacteroides fragilis are controlled by the redox-sensitive transcriptional activator OxyR. This is the first functional oxidative ... -
Transcriptional Activation of Bordetella Alcaligin Siderophore Genes Requires the AlcR Regulator with Alcaligin as Inducer
(East Carolina University, 2001-01)Genetic and biochemical studies have established that Fur and iron mediate repression of Bordetella alcaligin siderophore system (alc) genes under iron-replete nutritional growth conditions. In this study, transcriptional ... -
Inhibition of Quorum Sensing by a Pseudomonas aeruginosa dksA Homologue
(East Carolina University, 2001-03)The Pseudomonas aeruginosa las (lasR-lasI) and rhl (rhlR-rhlI) quorum-sensing systems regulate the expression of several virulence factors, including elastase and rhamnolipid. P. aeruginosa strain PR1-E4 is a lasR deletion ... -
Using death to one's advantage: HIV modulation of apoptosis
(East Carolina University, 2001-03)Infection by human immunodeficiency virus (HIV) is associated with an early immune dysfunction and progressive destruction of CD4+ T lymphocytes. This progressive disappearance of T cells leads to a lack of immune control ... -
Enhanced Avidity Maturation of Antibody to Human Immunodeficiency Virus Envelope: DNA Vaccination with gp120-C3d Fusion Proteins
(East Carolina University, 2001-06-10)DNA vaccination can elicit both humoral and cellular immune responses and can confer protection against several pathogens. However, DNA vaccines expressing the envelope (Env) protein of human immunodeficiency virus (HIV) ... -
Interference with Pseudomonas quinolone signal synthesis inhibits virulence factor expression by Pseudomonas aeruginosa
(East Carolina University, 2001-09-25)Pseudomonas aeruginosa is an opportunistic pathogen that controls numerous virulence factors through intercellular signals. This bacterium has two quorum-sensing systems (las and rhl), which act through the intercellular ... -
What Constitutes an Extended-Spectrum beta-lactamase?
(East Carolina University, 2002-02) -
Aerobic-Type Ribonucleotide Reductase in the Anaerobe Bacteroides fragilis
(East Carolina University, 2002-02)Bacteroides fragilis, a component of the normal intestinal flora, is an obligate anaerobe capable of long-term survival in the presence of air. Survival is attributed to an elaborate oxidative stress response that controls ... -
Deficiency of a Sinorhizobium meliloti bacA Mutant in Alfalfa Symbiosis Correlates with Alteration of the Cell Envelope
(East Carolina University, 2002-10)The BacA protein is essential for the long-term survival of Sinorhizobium meliloti and Brucella abortus within acidic compartments in plant and animal cells, respectively. Since both the S. meliloti and B. abortus bacA ... -
Functions Required for Extracellular Quinolone Signaling by Pseudomonas aeruginosa
(East Carolina University, 2002-12)A set of 30 mutants exhibiting reduced production of the phenazine poison pyocyanin were isolated following transposon mutagenesis of Pseudomonas aeruginosa PAO1. The mutants could be subdivided into those with defects in ... -
Autolysis and Autoaggregation in Pseudomonas aeruginosa Colony Morphology Mutants
(East Carolina University, 2002-12)Two distinctive colony morphologies were noted in a collection of Pseudomonas aeruginosa transposon insertion mutants. One set of mutants formed wrinkled colonies of autoaggregating cells. Suppressor analysis of a subset ... -
Enhancement of Antibodies to the Human Immunodeficiency Virus Type 1 Envelope by Using the Molecular Adjuvant C3d
(East Carolina University, 2003-02)DNA vaccines expressing the envelope (Env) protein of the human immunodeficiency virus have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies in a variety of animal models. In this ... -
Genetic Organization and Iron-Responsive Regulation of the Brucella abortus 2,3-Dihydroxybenzoic Acid Biosynthesis Operon, a Cluster of Genes Required for Wild-Type Virulence in Pregnant Cattle
(East Carolina University, 2003-04)Brucella abortus reportedly produces the monocatechol siderophore 2,3-dihydroxybenzoic acid (2,3-DHBA) in response to iron limitation. Nucleotide sequence analysis of the cloned DHBA biosynthesis locus from virulent B. ... -
Production of the Siderophore 2,3-Dihydroxybenzoic Acid Is Required for Wild-Type Growth of Brucella abortus in the Presence of Erythritol under Low-Iron Conditions In Vitro
(East Carolina University, 2003-05)Production of the siderophore 2,3-dihyroxybenzoic acid (2,3-DHBA) is required for the wild-type virulence of Brucella abortus in cattle. A possible explanation for this requirement was uncovered when it was determined that ... -
Generation and characterization of the humoral immune response to DNA immunization with a chimeric beta-amyloid-interleukin-4 minigene
(East Carolina University, 2003-12)Active immunization with fibrillar beta-amyloid peptide (AB42) as well as passive transfer of anti-AB antibodies significantly reduces AB plaque deposition, neuritic dystrophy, and astrogliosis in the brain of mutant amyloid ... -
A Multicomponent System Is Required for Tetracycline-Induced Excision of Tn4555
(East Carolina University, 2004-01)Bacteroides spp. are the predominant organisms in the intestinal tract, and they also are important opportunistic pathogens. Antibiotic therapy of Bacteroides infections often is complicated by the prevalence of drug-resistant ... -
Similarity to peroxisomal-membrane protein family reveals that Sinorhizobium and Brucella BacA affect lipid-A fatty acids
(East Carolina University, 2004-04-06)Sinorhizobium meliloti, a legume symbiont, and Brucella abortus, a phylogenetically related mammalian pathogen, both require the bacterial-encoded BacA protein to establish chronic intracellular infections in their respective ...