- Restrictions on Access:
- Open Access.
- Vancomycin Resistant Enterococcus (VRE) is a nosocomial pathogen that spreads durably and with potency throughout the United States hospital systems. To combat this issue multiple studies have been employed to determine the best ways to diminish the buildup of antibiotic resistance within VRE patients. This thesis describes and analyzes two experiments performed on mice in order to better understand VRE, its colonization within the mouse gut and its transmission pathways. The first experiment attempted to determine the longevity of VRE colonization and daptomycin-resistant VRE colonization within the mouse gut microbiome based upon different antibiotic treatment groups and inoculum sizes. The second experiment replicated part of the first experiment, but an additional untreated mouse was added to the cages of the VRE-colonized mice to determine if exposure to another animal with an undisturbed microbiome affected the duration of VRE carriage within the mice. The results from the first experiment showed that the inoculum of sensitive and daptomycin-resistant (S+R) VRE greatly reduced the levels of daptomycin-resistant VRE within the mouse gut compared to the experimental group that contained only the daptomycin-resistant inoculum. The results from the second experiment showed that VRE-colonized mice that were co-housed with untreated mice, it swiftly reduced the VRE colonization relative to isolated mice almost equally for both the control groups and daptomycin-treated groups. The addition of sensitive bacteria and the presence of a normal mouse in these two experiments had a greater impact on colonization than the antibiotic treatment of daptomycin. More studies need to be done to fully understand the infectious dynamics of VRE, but these two mouse model experiments have illuminated some distinct variations between the sensitive and resistant bacteria, such as the resistance prevalence and longevity changes when both daptomycin-sensitive and resistant strains are present. The second study has shown the effectiveness of the addition of another mouse at diminishing VRE carriage, even though we are still working towards understanding the mechanism. This experiment has been an effective start to understanding VRE and determining better ways to combat this deadly bacterium.
- Dissertation Note:
- B.S. Pennsylvania State University 2020.
- Technical Details:
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
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