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Pathogenic Microbiology Commons

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Full-Text Articles in Pathogenic Microbiology

Defensin Transcript Distribution In Tissues And Life Stages Of The Ixodid Ticks Amblyomma Americanum And Ixodes Scapularis, Stephanie M. Todd Jul 2006

Defensin Transcript Distribution In Tissues And Life Stages Of The Ixodid Ticks Amblyomma Americanum And Ixodes Scapularis, Stephanie M. Todd

Biological Sciences Theses & Dissertations

A number of bacterial, viral, and protozoan diseases are transmitted to humans via arthropods. Arthropods possess an innate immune system to destroy invading microorganisms. However, arthropods unable to rid their systems of pathogens function as disease vectors. The American dog tick, Dermacentor variabilis, destroys invading Borrelia burgdorferi spirochetes, preventing transmission. In contrast, the black-legged tick, Ixodes scapularis, which is unable to destroy acquired B. burgdorferi, successfully vectors the pathogen. The Lone Star tick, Amblyomma americanum, vectors a similar pathogen called Borrelia lonestari. The distribution of defensin, an antimicrobial peptide of the innate immune system, was examined in A. americanum and/. …


Farnesol Restores Wild-Type Colony Morphology To 96% Of Candida Albicans Colony Morphology Variants Recovered Following Treatment With Mutagens, Ellen C. Jensen, Jacob M. Hornby, Nicole E. Pagliaccetti, Chuleeon M. Wolter, Kenneth Nickerson, Audrey L. Atkin Apr 2006

Farnesol Restores Wild-Type Colony Morphology To 96% Of Candida Albicans Colony Morphology Variants Recovered Following Treatment With Mutagens, Ellen C. Jensen, Jacob M. Hornby, Nicole E. Pagliaccetti, Chuleeon M. Wolter, Kenneth Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

Candida albicans is a diploid fungus that undergoes a morphological transition between budding yeast, hyphal, and pseudohyphal forms. The morphological transition is strongly correlated with virulence and is regulated in part by quorum sensing. Candida albicans produces and secretes farnesol that regulates the yeast to mycelia morphological transition. Mutants that fail to synthesize or respond to farnesol could be locked in the filamentous mode. To test this hypothesis, a collection of C. albicans mutants were isolated that have altered colony morphologies indicative of the presence of hyphal cells under environmental conditions where C. albicans normally grows only as yeasts. All …


Bacteriophage Migration Via Nematode Vectors: Host-Parasite-Consumer Interactions In Laboratory Microcosms, John J. Dennehy, Nicholas A. Friedenberg, Yul W. Yang, Paul E. Turner Mar 2006

Bacteriophage Migration Via Nematode Vectors: Host-Parasite-Consumer Interactions In Laboratory Microcosms, John J. Dennehy, Nicholas A. Friedenberg, Yul W. Yang, Paul E. Turner

Dartmouth Scholarship

Pathogens vectored by nematodes pose serious agricultural, economic, and health threats; however, little is known of the ecological and evolutionary aspects of pathogen transmission by nematodes. Here we describe a novel model system with two trophic levels, bacteriophages and nematodes, each of which competes for bacteria. We demonstrate for the first time that nematodes are capable of transmitting phages between spatially distinct patches of bacteria. This model system has considerable advantages, including the ease of maintenance and manipulation at the laboratory bench, the ability to observe many generations in short periods, and the capacity to freeze evolved strains for later …


Molecular Epidemiology Of Antibiotic Resistant Salmonella Enterica Strains From Different Animal And Human Sources In Ireland, David George Lee Jan 2006

Molecular Epidemiology Of Antibiotic Resistant Salmonella Enterica Strains From Different Animal And Human Sources In Ireland, David George Lee

Theses

In this study, 176 isolates of Salmonella were collected from different laboratories in Ireland. All isolates were confirmed to be of the genus Salmonella by performing bacteriological and biochemical tests. Briefly, all isolates were cultured onto XLD agar after which pure cultures were verified and stocked at this institute. Definitive identification was carried out using the API 20-E system and a separate urease test was also performed on all isolates. After confirmation of the genus, all isolates were prepared for antibiotic susceptibility testing and r-types were determined using sixteen antibiotics. Depending on the antibiotic resistance profiles, isolates were selected for …


Myxozoan Genera: Definition And Notes On Taxonomy, Life-Cycle Terminology And Pathogenic Species, Jiří Lom, Iva Dyková Jan 2006

Myxozoan Genera: Definition And Notes On Taxonomy, Life-Cycle Terminology And Pathogenic Species, Jiří Lom, Iva Dyková

Harold W. Manter Laboratory of Parasitology: Library Materials

A list of myxozoan genera is presented in the current taxonomical scheme. These genera are defined; their type species and most important pathogens along with their hosts are listed. Simultaneously, definitions of actinospore stages representing sexual stages of the myxosporean life cycle are given; altogether, 17 actinospore collective groups with 180 types have been described. Life cycles of the two classes of the phylum Myxozoa, Malacosporea and Myxosporea, are briefly outlined with specification of the appropriate terms. Up to now, 4 malacosporean and 2,180 myxosporean species assigned to a total of 62 genera, have been established. The surviving classification of …


Determination Of Mrna Half-Lives In Candida Albicans Using Thiolutin As A Transcription Inhibitor, Bessie W. Kebaara, Lindsey E. Nielsen, Kenneth Nickerson, Audrey L. Atkin Jan 2006

Determination Of Mrna Half-Lives In Candida Albicans Using Thiolutin As A Transcription Inhibitor, Bessie W. Kebaara, Lindsey E. Nielsen, Kenneth Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

A method for determining mRNA half-lives in the polymorphic fungus Candida albicans is described. It employs growth in a defined medium, the inhibition of transcription with thiolutin (10–20 μg/mL), and quantitative Northern blotting. The method is effective for the A72, SC5314, and CAI-4 strains of C. albicans, and for mRNAs that have a wide variety of decay rates and steady-state abundances. The range of half-lives detected (from 4–168 min) shows that this method is effective for mRNAs with widely varying half-lives. The mRNA decay rates obtained are compared with those for orthologous mRNAs from Saccharomyces cerevisiae. This procedure …