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Articles 181 - 186 of 186

Full-Text Articles in Medical Microbiology

Biological Diversity Of Prokaryotic Type Iv Secretion Systems, Cristina E Alvarez-Martinez, Peter J Christie Dec 2009

Biological Diversity Of Prokaryotic Type Iv Secretion Systems, Cristina E Alvarez-Martinez, Peter J Christie

Faculty, Staff and Student Publications

Type IV secretion systems (T4SS) translocate DNA and protein substrates across prokaryotic cell envelopes generally by a mechanism requiring direct contact with a target cell. Three types of T4SS have been described: (i) conjugation systems, operationally defined as machines that translocate DNA substrates intercellularly by a contact-dependent process; (ii) effector translocator systems, functioning to deliver proteins or other macromolecules to eukaryotic target cells; and (iii) DNA release/uptake systems, which translocate DNA to or from the extracellular milieu. Studies of a few paradigmatic systems, notably the conjugation systems of plasmids F, R388, RP4, and pKM101 and the Agrobacterium tumefaciens VirB/VirD4 system, …


Pcr-Based Assay Using Occult Blood Detection Cards For Detection Of Diarrheagenic Escherichia Coli In Specimens From Us Travelers To Mexico With Acute Diarrhea, Kevin A Grimes, Jamal A Mohamed, Herbert L Dupont, Ranjit S Padda, Zhi-Dong Jiang, Jose Flores, Jaime Belkind-Gerson, Francisco G Martinez-Sandoval, Pablo C Okhuysen Jul 2008

Pcr-Based Assay Using Occult Blood Detection Cards For Detection Of Diarrheagenic Escherichia Coli In Specimens From Us Travelers To Mexico With Acute Diarrhea, Kevin A Grimes, Jamal A Mohamed, Herbert L Dupont, Ranjit S Padda, Zhi-Dong Jiang, Jose Flores, Jaime Belkind-Gerson, Francisco G Martinez-Sandoval, Pablo C Okhuysen

Faculty, Staff and Student Publications

Large field studies of travelers' diarrhea for multiple destinations are limited by the need to perform stool cultures on site in a timely manner. A method for the collection, transport, and storage of fecal specimens that does not require immediate processing and refrigeration and that is stable for months would be advantageous. This study was designed to determine if enterotoxigenic Escherichia coli (ETEC) and enteroaggregative E. coli (EAEC) DNA could be identified from cards that were processed for the evaluation of fecal occult blood. U.S. students traveling to Mexico during 2005 to 2007 were monitored for the occurrence of diarrheal …


Clinical And Microbiological Aspects Of Linezolid Resistance Mediated By The Cfr Gene Encoding A 23s Rrna Methyltransferase, Cesar A Arias, Martha Vallejo, Jinnethe Reyes, Diana Panesso, Jaime Moreno, Elizabeth Castañeda, Maria V Villegas, Barbara E Murray, John P Quinn Mar 2008

Clinical And Microbiological Aspects Of Linezolid Resistance Mediated By The Cfr Gene Encoding A 23s Rrna Methyltransferase, Cesar A Arias, Martha Vallejo, Jinnethe Reyes, Diana Panesso, Jaime Moreno, Elizabeth Castañeda, Maria V Villegas, Barbara E Murray, John P Quinn

Faculty, Staff and Student Publications

The cfr (chloramphenicol-florfenicol resistance) gene encodes a 23S rRNA methyltransferase that confers resistance to linezolid. Detection of linezolid resistance was evaluated in the first cfr-carrying human hospital isolate of linezolid and methicillin-resistant Staphylococcus aureus (designated MRSA CM-05) by dilution and diffusion methods (including Etest). The presence of cfr was investigated in isolates of staphylococci colonizing the patient's household contacts and clinical isolates recovered from patients in the same unit where MRSA CM-05 was isolated. Additionally, 68 chloramphenicol-resistant Colombian MRSA isolates recovered from hospitals between 2001 and 2004 were screened for the presence of the cfr gene. In addition to erm(B), …


Functional Taxonomy Of Bacterial Hyperstructures, Vic Norris, Tanneke Den Blaauwen, Armelle Cabin-Flaman, Roy H Doi, Rasika Harshey, Laurent Janniere, Alfonso Jimenez-Sanchez, Ding Jun Jin, Petra Anne Levin, Eugenia Mileykovskaya, Abraham Minsky, Milton Saier, Kirsten Skarstad Mar 2007

Functional Taxonomy Of Bacterial Hyperstructures, Vic Norris, Tanneke Den Blaauwen, Armelle Cabin-Flaman, Roy H Doi, Rasika Harshey, Laurent Janniere, Alfonso Jimenez-Sanchez, Ding Jun Jin, Petra Anne Levin, Eugenia Mileykovskaya, Abraham Minsky, Milton Saier, Kirsten Skarstad

Faculty, Staff and Student Publications

The levels of organization that exist in bacteria extend from macromolecules to populations. Evidence that there is also a level of organization intermediate between the macromolecule and the bacterial cell is accumulating. This is the level of hyperstructures. Here, we review a variety of spatially extended structures, complexes, and assemblies that might be termed hyperstructures. These include ribosomal or "nucleolar" hyperstructures; transertion hyperstructures; putative phosphotransferase system and glycolytic hyperstructures; chemosignaling and flagellar hyperstructures; DNA repair hyperstructures; cytoskeletal hyperstructures based on EF-Tu, FtsZ, and MreB; and cell cycle hyperstructures responsible for DNA replication, sequestration of newly replicated origins, segregation, compaction, and …


Vancomycin-Resistant Enterococcus Faecalis Endocarditis: Linezolid Failure And Strain Characterization Of Virulence Factors, Constantine Tsigrelis, Kavindra V Singh, Thais D Coutinho, Barbara E Murray, Larry M Baddour Feb 2007

Vancomycin-Resistant Enterococcus Faecalis Endocarditis: Linezolid Failure And Strain Characterization Of Virulence Factors, Constantine Tsigrelis, Kavindra V Singh, Thais D Coutinho, Barbara E Murray, Larry M Baddour

Faculty, Staff and Student Publications

Infective endocarditis due to vancomycin-resistant (VR) Enterococcus faecalis has only rarely been reported. We report a case of VR E. faecalis endocarditis that failed to respond to linezolid therapy, outline the virulence traits of the isolate, and review previously published cases of VR E. faecalis endocarditis.


Association Of Putative Enteroaggregative Escherichia Coli Virulence Genes And Biofilm Production In Isolates From Travelers To Developing Countries, Jamal A Mohamed, David B Huang, Zhi-Dong Jiang, Herbert L Dupont, James P Nataro, Jaime Belkind-Gerson, Pablo C Okhuysen Jan 2007

Association Of Putative Enteroaggregative Escherichia Coli Virulence Genes And Biofilm Production In Isolates From Travelers To Developing Countries, Jamal A Mohamed, David B Huang, Zhi-Dong Jiang, Herbert L Dupont, James P Nataro, Jaime Belkind-Gerson, Pablo C Okhuysen

Faculty, Staff and Student Publications

Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen that causes acute and chronic diarrhea among children, human immunodeficiency virus-infected patients, and travelers to developing regions of the world. The pathogenesis of EAEC strains involves the production of biofilm. In this study, we determined the association between presence of putative EAEC virulence genes and biofilm formation in 57 EAEC isolates (as defined by HEp-2 adherence) from travelers with diarrhea and in 18 EAEC isolates from travelers without diarrhea. Twelve nondiarrheagenic E. coli isolates from healthy travelers were used as controls. Biofilm formation was measured by using a microtiter plate assay …