Browsing Microbiology and Immunology by Author "Smith, C. Jeffrey"
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Aerobic-Type Ribonucleotide Reductase in the Anaerobe Bacteroides fragilis
Smalley, Darren; Rocha, Edson R.; Smith, C. Jeffrey (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 ... -
Analysis of rRNA restriction fragment length polymorphisms from Bacteroides spp. and Bacteroides fragilis isolates associated with diarrhea in humans and animals.
Smith, C. Jeffrey; Callihan, Donald R. (East Carolina University, 1992-04)The Escherichia coli rRNA operon rrnB was used as a 32P-labeled hybridization probe in Southern blots of genomic DNAs from representative strains of the saccharolytic, gram-negative, obligate anaerobes of the genus Bacteroides. ... -
Analysis of the Zinc Finger Domain of TnpA, a DNA Targeting Protein Encoded by Mobilizable Transposon Tn4555
Bacic, Melissa K.; Jain, Jinesh C.; Parker, Anita C.; Smith, C. Jeffrey (East Carolina University, 2007-07)The mobilizable transposon Tn4555, found in Bacteroides spp., is an important antibiotic resistance element encoding a broad spectrum beta-lactamase. Tn4555 is mobilized by conjugative transposons such as CTn341 which can ... -
The Bacteroides mobilizable transposon Tn4555 integrates by a site-specific recombination mechanism similar to that of the gram-positive bacterial element Tn916
Tribble, Gena D.; Parker, Anita C.; Smith, C. Jeffrey (East Carolina University, 1997-04)The Bacteroides mobilizable transposon Tn4555 is a 12.2-kb molecule that encodes resistance to cefoxitin. Conjugal transposition is hypothesized to occur via a circular intermediate and is stimulated by coresident tetracycline ... -
Biochemical and genetic analyses of a catalase from the anaerobic bacterium Bacteroides fragilis.
Rocha, Edson R.; Smith, C. Jeffrey (East Carolina University, 1995-06)A single catalase enzyme was produced by the anaerobic bacterium Bacteroides fragilis when cultures at late log phase were shifted to aerobic conditions. In anaerobic conditions, catalase activity was detected ... -
Characterization of a Peroxide-Resistant Mutant of the Anaerobic Bacterium Bacteroides fragilis
Rocha, Edson R.; Smith, C. Jeffrey (East Carolina University, 1998-11)A Bacteroides fragilis mutant resistant to hydrogen peroxide and alkyl peroxide was isolated by enrichment in increasing concentrations of hydrogen peroxide. The mutant strain was constitutively resistant to 100 mM H2O2 ... -
Characterization of Bacteroides fragilis Hemolysins and Regulation and Synergistic Interactions of HlyA and HlyB
Robertson, Kirstin P.; Smith, C. Jeffrey; Gough, Andrea M.; Rocha, Edson R. (East Carolina University, 2006-04)This study describes the presence of 10 hemolysin orthologs in the genome of the opportunistic human anaerobic pathogen Bacteroides fragilis, which is currently classified as a nonhemolytic bacterium. The hemolysins were ... -
Characterization of the Primary Starch Utilization Operon in the Obligate Anaerobe Bacteroides fragilis: Regulation by Carbon Source and Oxygen
Spence, Cheryl; Wells, W. Greg; Smith, C. Jeffrey (East Carolina University, 2006-07)The opportunistic pathogen Bacteroides fragilis is a commensal organism in the large intestine, where it utilizes both dietary and host-derived polysaccharides as a source of carbon and energy. In this study, a four-gene ... -
Cloning and characterization of the endogenous cephalosporinase gene, cepA, from Bacteroides fragilis reveals a new subgroup of Ambler class A beta-lactamases.
Rogers, Marc B.; Parker, Anita C.; Smith, C. Jeffrey (East Carolina University, 1993-11)Bacteroides frgiglis CS30 is a clinical isolate resistant to high concentrations of benzylpenicillin and cephaloridine but not to cephamycin or penem antibiotics. beta-Lactam resistance is mediated by a chromosomally encoded ... -
Function and regulation of the polysaccharide utilization locus, don, in the gut symbiont bacteroides fragilis
Cao, Yanlu (East Carolina University, 2014)Bacteroides fragilis is the most common anaerobe isolated from clinical infections and in this report we demonstrate a novel feature of the species that is critical to their success as an opportunistic pathogen. Among the ... -
Genetic and biochemical analysis of a novel Ambler class A β-Lactamase responsible for cefoxitin resistance in Bacteroides species.
Parker, Anita C.; Smith, C. Jeffrey (East Carolina University, 1993-05)A clinical isolate of Bacteroides vulgatus was resistant to tetracycline, clindamycin, ampicillin, cephaloridine, cefoxitin, and other 13-lactam antibiotics except imipenem. 13-Lactam resistance was mediated by a ... -
Identification of a circular intermediate in the transfer and transposition of Tn4555, a mobilizable transposon from Bacteroides spp.
Smith, C. Jeffrey; Parker, Anita C. (East Carolina University, 1993-05)Transmissible cefoxitin (FX) resistance in Bacteroides vulgatus CLA341 was associated with the 12.5-kb, mobilizable transposon, Tn4555, which encoded the 13-lactamase gene cfxA. Transfer occurred by a conjugation-like ... -
Insertional activation of cepA leads to high-level beta-lactamase expression in Bacteroides fragilis clinical isolates.
Rogers, Marc B.; Bennett, Tamara K.; Payne, Catherine M.; Smith, C. Jeffrey (East Carolina University, 1994-07)Bacteroides fragilis is an important opportunistic pathogen of humans and is resistant to many drugs commonly used to treat anaerobic infections, including P-lactams. A strain set comprised of B. fragilis isolates producing ... -
Molecular and genetic analysis of the Bacteroides uniformis cephalosporinase gene, cblA, encoding the species-specific beta-lactamase.
Smith, C. Jeffrey; Bennett, Tamara K.; Parker, Anita C. (East Carolina University, 1994-08)The gene, cbl, encoding the species-specific, clavulanate-susceptible, endogenous cephalosporinase was cloned from Bacteroides uniforinis WAL-7088. The nucleotide sequence was determined, and the cbl structural gene was ... -
A Multicomponent System Is Required for Tetracycline-Induced Excision of Tn4555
Parker, Anita C.; Smith, C. Jeffrey (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 ... -
Oxidative stress response in an anaerobe, Bacteroides fragilis: a role for catalase in protection against hydrogen peroxide.
Rocha, Edson R.; Selby, Tina; Coleman, James P.; Smith, C. Jeffrey (East Carolina University, 1996-12)Survival of Bacteroides fragilis in the presence of oxygen was dependent on the ability of bacteria to synthesize new proteins, as determined by the inhibition of protein synthesis after oxygen exposure. The B. fragilis ... -
The Redox-Sensitive Transcriptional Activator OxyR Regulates the Peroxide Response Regulon in the Obligate Anaerobe Bacteroides fragilis
Rocha, Edson R.; Owens, Gary Jr; Smith, C. Jeffrey (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 ... -
Regulation of Bacteriodes fragilis katB mRNA by oxidative stress and carbon limitation.
Rocha, Edson R.; Smith, C. Jeffrey (East Carolina University, 1997-11)Regulation of the katB catalase gene in the anaerobic bacterium Bacteroides fragilis was studied. Northern blot hybridization analyses revealed that katB was transcribed as an approximately 1.6-kb monocistronic mRNA. The ... -
Role of the Iron Storage Ferritins Dps and DpsL during the Prolonged Oxidative Stress Response of Bacteroides fragilis
Betteken, Michael I. (East Carolina University, 2015-12-02)Bacteroides fragilis is a Gram negative anaerobe and member of the human intestinal tract microbiome. B. fragilis serves many beneficial roles within the intestinal tract; however, its translocation to the peritoneal cavity ... -
Thioredoxin Reductase Is Essential for Thiol/Disulfide Redox Control and Oxidative Stress Survival of the Anaerobe Bacteroides fragilis
Rocha, Edson R.; Tzianabos, Arthur O.; Smith, C. Jeffrey (East Carolina University, 2007-11)Results of this study showed that the anaerobic, opportunistic pathogen Bacteroides fragilis lacks the glutathione/glutaredoxin redox system and possesses an extensive number of putative thioredoxin (Trx) orthologs. ...