Microbiology Commons^™

Maporal Hantavirus Β-Integrin Utilization And Sensitivity To Favipiravir, Kristin K. Buys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hantaviruses are members of the Bunyaviridae family of viruses. Pathogenic hantaviruses are the etiologic agents of hemorrhagic fever with renal syndrome (HFRS), a disease principally endemic in the Old World, and hantavirus pulmonary syndrome (HPS), a disease primarily restricted to the Americas. Maporal virus (MPRLV), a recently isolated hantavirus, has been found to cause disease in hamsters that resembles HPS in humans. However, the virus has not been linked to human cases of HPS. Considerable evidence suggests that β-integrin usage mediating infection may serve to distinguish hantaviruses pathogenic to humans from nonpathogenic, but this receptor usage pattern information is not …

Kinetic, Mechanistic, And Structural Investigation Of Features Controlling Stereoselectivity Of (R)- And (S)-Hydroxypropyl Com Dehydrogenases From Xanthobacter Autrophicus Strain Py2, Dariusz Adam Sliwa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enantiopure alcohols are valuable intermediates in fine organic synthesis, in particular for preparation of biologically active compounds. The necessity of preparing single enantiomer drugs in an optically pure form has triggered much research, especially in the pharmaceutical industry. The biocatalytical production of chiral alcohols by alcohol dehydrogenase enzymes is characterized by the asymmetric reduction of the corresponding ketones, usually with high degree of stereoselectivity. The commercial value of the enzymes as stereoselective biocatalysts has been a significant driving force in understanding features that control their mechanism of catalysis and stereoselectivity. This work focuses on two enantiocomplementary dehydrogenase enzymes ((R …

Host Signaling Response To Adhesion Of Bifidobacterium Infantis, Reed N. Gann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations of the molecular binding partners of the probiotic bacterium Bifidobacterium longum subspecies infantis (B. infantis) and the pathogen Salmonella enterica subspecies enterica serovar Typhimurium LT2 (Salmonella ser. Typhimurium) found that these two very different bacteria bind gangliosides. However, these organisms lead to completely different host health outcomes when present in the gut. B. infantis is the founding microbial population in the intestinal tract of breast-fed infants. S. typhimurium is the most important food-borne pathogen that results in humans. This study used an in vitro gut epithelial cell model to examine the host cellular response to adhesion …

The Hypericum Perforatum Herb As An Antimycobacterial Agent And Its Implications As An Additional Tuberculosis Medication, Trent W. Mortensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An immediate demand exists for new tuberculosis (TB) antibiotics due to the ever-increasing spread of drug-resistant strains. The drug-development process goes through four phases, the first (Phase 0) of which is to demonstrate and investigate drug effectiveness and toxicity. This research investigated the effectiveness of the Hypericum perforatum herb (commonly St. John's wort (SJW)) in its growth inhibition of mycobacteria and its viability effect on human lung cells.

Organic-solvent SJW extracts were effective at inhibiting every nonpathogenic genetically sequenced Mycobacterium isolate currently available (six isolates) in preliminary studies. Quantitative studies of five Mycobacterium isolates showed an order of concentration sensitivity …

Survival Of Mycoplasma Species In Recycled Bedding Sand And Possible Implications For Disease Transmission To Ruminants, Anne E. Justice-Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mycoplasmas are a group of bacteria which are small in size, lack a cell wall, and have small genomes in comparison to other bacteria. The members of the group that are pathogenic utilize several mechanisms to evade the host's immune system. These processes affect surveillance and control mechanisms such as serologic testing and vaccination. Many of these organisms cause diseases of livestock, which heavily impact production parameters such as weight gain, milk yield, and egg production. Mycoplasmas also cause disease in people.

Mycoplasma spp. can cause mastitis, metritis, pneumonia, and arthritis. The currently documented routes of transmission of Mycoplasma spp. …

Development Of A Laboratory Based System For Selecting Insect Pathogenic Fungi With Greatest Potential For Success In The Field, Chad Alton Keyser

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many insects are important agricultural pests, and active control is necessary to keep them at abeyance. The naturally occurring entomopathogenic fungus Metarhizium is a promising tool to control pest insects, and its use avoids the well-known harmful side effects of chemical pesticides. Thousands of unique isolates of Metarhizium exist throughout the world. These isolates vary widely in their ability to cause infection and to tolerate stressful habitats. The research reported here tests the THESIS: A laboratory-based system can be devised that identifies, from among many Metarhizium isolates, those isolates with the greatest potential for successful biological control of pest insects …

Effect Of Dipterinyl Calcium Pentahydrate On Hepatitis B Virus Replication In Transgenic Mice, P Moheno, John D. Morrey, D Fuchs

John D. Morrey

Dipterinyl calcium pentahydrate (DCP) has previously been shown to inhibit MDA-MB-231 human breast cancer xenographs in nude mice in a manner correlated with increases in plasma IL-12 and IL-4 concentrations, and decreases in plasma IL-6 levels. DCP also inhibits indoleamine 2,3-dioxygenase (IDO), an immuno-inhibitory enzyme, in human PBMCs (Peripheral Blood Mononuclear Cells).

Assessing Changes In Vascular Permeability In A Hamster Model Of Viral Hemorrhagic Fever, B B. Gowen, J G. Julander, N R. London, M H. Wong, D Larson, John D. Morrey, D Y. Li, M Bray

John D. Morrey

A number of RNA viruses cause viral hemorrhagic fever (VHF), in which proinflammatory mediators released from infected cells induce increased permeability of the endothelial lining of blood vessels, leading to loss of plasma volume, hypotension, multi-organ failure, shock and death. The optimal treatment of VHF should therefore include both the use of antiviral drugs to inhibit viral replication and measures to prevent or correct changes in vascular function. Although rodent models have been used to evaluate treatments for increased vascular permeability (VP) in bacterial sepsis, such studies have not been performed for VHF.

Development Of A New Tacaribe Arenavirus Infection Model And Its Use To Explore Antiviral Activity Of A Novel Aristeromycin Analog, B B. Gowen, M H. Wong, D Larson, W Ye, K H. Jung, E J. Sefing, R Skirpstunas, D F. Smee, John D. Morrey, S W. Schneller

John D. Morrey

A growing number of arenaviruses can cause a devastating viral hemorrhagic fever (VHF) syndrome. They pose a public health threat as emerging viruses and because of their potential use as bioterror agents. All of the highly pathogenic New World arenaviruses (NWA) phylogenetically segregate into clade B and require maximum biosafety containment facilities for their study. Tacaribe virus (TCRV) is a nonpathogenic member of clade B that is closely related to the VHF arenaviruses at the amino acid level. Despite this relatedness, TCRV lacks the ability to antagonize the host interferon (IFN) response, which likely contributes to its inability to cause …

Effects Of The Combination Of Favipiravir (T-705) And Oseltamivir On Influenza A Virus Infections In Mice, D F. Smee, B L. Hurst, M H. Wong, K W. Bailey, E B. Tarbet, John D. Morrey, Y Furuta

John D. Morrey

Favipiravir (T-705 [6-fluoro-3-hydroxy-2-pyrazinecarboxamide]) and oseltamivir were combined to treat influenza virus A/NWS/33 (H1N1), A/Victoria/3/75 (H3N2), and A/Duck/MN/1525/81 (H5N1) infections. T-705 alone inhibited viruses in cell culture at 1.4 to 4.3 µM. Oseltamivir inhibited these three viruses in cells at 3.7, 0.02, and 0.16 µM and in neuraminidase assays at 0.94, 0.46, and 2.31 nM, respectively. Oral treatments were given twice daily to mice for 5 to 7 days starting, generally, 24 h after infection. Survival resulting from 5 days of oseltamivir treatment (0.1 and 0.3 mg/kg/day) was significantly better in combination with 20 mg/kg of body weight/day of T-705 against …