Organisms Commons^™

A Novel Application Of Galleria Mellonella Larvae To Study Pathogenesis Of Rickettsia Rickettsii Infection, Jacob M. Jones

Honors College Theses

Rickettsia are obligate intracellular tick-borne bacteria that cause acute undifferentiated febrile illness accompanied by headache, malaise, myalgias, and disseminated endothelial infection. Immune responses to Rickettsia and pathogenesis of rickettsioses are not fully understood. Current work with Rickettsia is limited to vertebrate models that are strictly regulated and have low throughput. Since the innate immune system of vertebrates retains striking similarities with the immune response in insects, invertebrates are being used to study host responses to various pathogens. The purpose of this study was to evaluate if larvae of the greater wax moth Galleria mellonella (GML) can be used as an …

289— Phenotypic Characterization Of Neurospora Crassa Fsd-1 Overexpression Strains, Hannah Smith

GREAT Day Posters

Neurospora crassa is a model filamentous fungal organism that can reproduce both asexually and sexually. Little is known about the molecular mechanisms that regulate the N. crassa female sexual development cycle. The transcription factor fsd-1 is necessary for sexual development, and fsd-1 deletion strains show delayed development of female reproductive structures and are sterile. Through previous experiments, we have been able to determine that there are three different transcripts of the fsd-1 gene, which differ by the length and intron/exon structure of their 5’ untranslated region. This project focuses on phenotypically characterizing the reproductive ability of strains overexpressing fsd-1, for …

Assessing Arthropod Responses To Volatile Organic Compounds From The Algal Microbiome Of A Sloth Using Drosophila Melanogaster, Lilli Gordon

Honors Theses

Sloths contain an unexplored ecosystem of microbial diversity in their fur, including algae, fungi, bacteria, and arthropods. These symbionts are able to communicate through the chemicals they release, including volatile organic compounds (VOCs), which can lead to unique ecological interactions. The VOCs released from the algal polycultures of sloth hairs merit further investigation in their ability to cause a response from other organisms in this microbial community and within a broader ecological context. This research team aimed to assess the response of Drosophila melanogaster as test subjects when exposed to VOCs of the algal microbiome of a sloth. Exploratory research …

Effects Of Strong Oxidants Present In Acer Spp. On Hemolysis Methemoglobin Production In Equine Erythrocytes, Gabrielle Mcgeorge, Jeffrey Lehman

Undergraduate Honors Thesis Projects

Maple toxicosis is a deadly condition affecting equines after they have ingested wilted leaves of the genus Acer (i.e., maple species). It is characterized by hemolytic anemia and methemoglobinemia. Although the toxins responsible for causing toxicosis have not been identified, they are thought to be strong oxidants. The objective of this study is to determine the effect of eight compounds (galloyl derivatives) found in Acer spp. on hemolysis and methemoglobin production in bioassays with equine erythrocytes. Seven of the compounds are known constituents of Acer spp. that are commercially available. One of the compounds--acertannin--was isolated and characterized from leaf extracts …

Restoration Agriculture In Louisiana: On The Prospects And Ethics Of Creating A Permanent, Dynamic Agricultural System Suited For Louisiana's Environment, Noah Willsea

Honors Capstones

No abstract provided.

Purification And Functional Characterization Of The Iron-Responsive Transcription Factor Aft1 From C. Glabrata, Jade Ikahihifo-Bender

Senior Theses

Due to its unique ability to serve as both an electron donor and acceptor, iron is utilized as a co-factor for many biological processes, including electron transfer, oxygen binding, and vitamin synthesis. Iron is also a key factor during fungal infections as the human host and invading pathogens battle over limited iron pools. The primary iron-responsive transcription factor Aft1 in the opportunistic pathogenic yeast Candida glabrata responds to iron deficiency by activating expression of iron acquisition genes. However, the mechanisms for sensing intracellular iron levels and regulating Aft1 activity in response to iron are unknown. The C. glabrata iron regulation …

Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe

International Journal of Speleology

The emergence of antibiotic resistance is a global health crisis, thus the search for novel antimicrobial compounds has become a continuous necessity. Underexplored and extreme environments, such as cave ecosystems, have been identified as a promising potential source for the discovery of novel microorganisms with novel antimicrobial compounds (AMC). This study presents the first cave microbiological investigation in Sri Lanka, with a special preference for bioprospecting of novel AMC. The cave sediment characterization demonstrated the presence of close to strong acidic conditions (pH 3.1 – 3.3) and thus indicates the possibility of isolating acidophilic microorganisms. Eight cave wall/ceiling fungal strains …

Glucagon Blockade Restores Functional Β-Cell Mass In Type 1 Diabetic Mice And Enhances Function Of Human Islets, May-Yun Wang, E Danielle Dean, Ezekiel Quittner-Strom, Yi Zhu, Kamrul H Chowdhury, Zhuzhen Zhang, Shangang Zhao, Na Li, Reshing Ye, Young Lee, Yiyi Zhang, Shiuhwei Chen, Xinxin Yu, Derek C Leonard, Greg Poffenberger, Alison Von Deylen, S Kay Mccorkle, Amnon Schlegel, Kyle W Sloop, Alexander M Efanov, Ruth E Gimeno, Philipp E Scherer, Alvin C Powers, Roger H Unger, William L Holland

Faculty, Staff and Students Publications

We evaluated the potential for a monoclonal antibody antagonist of the glucagon receptor (Ab-4) to maintain glucose homeostasis in type 1 diabetic rodents. We noted durable and sustained improvements in glycemia which persist long after treatment withdrawal. Ab-4 promoted β-cell survival and enhanced the recovery of insulin+ islet mass with concomitant increases in circulating insulin and C peptide. In PANIC-ATTAC mice, an inducible model of β-cell apoptosis which allows for robust assessment of β-cell regeneration following caspase-8–induced diabetes, Ab-4 drove a 6.7-fold increase in β-cell mass. Lineage tracing suggests that this restoration of functional insulin-producing cells was at least partially …

3d Printing Of Human Microbiome Constituents To Understand Spatial Relationships And Shape Parameters In Bacteriology, Jacques Izard, Teklu Kuru Gerbaba, Shara R. P. Yumul

Department of Food Science and Technology: Faculty Publications

Effective laboratory and classroom demonstration of microbiome size and shape, diversity, and ecological relationships is hampered by a lack of high-resolution, easy-to-use, readily accessible physical or digital models for use in teaching. Three-dimensional (3D) representations are, overall, more effective in communicating visuospatial information, allowing for a better understanding of concepts not directly observable with the unaided eye. Published morphology descriptions and microscopy images were used as the basis for designing 3D digital models, scaled at 20,000×, using computer-aided design software (CAD) and generating printed models of bacteria on mass-market 3D printers. Sixteen models are presented, including rod-shaped, spiral, flask-like, vibroid, …

Pegylated Arginine Deiminase Depletes Plasma Arginine But Maintains Tissue Arginine Availability In Young Pigs, Mahmoud A Mohammad, Inka C Didelija, Barbara Stoll, Trung C Nguyen, Juan C Marini

Faculty, Staff and Students Publications

Pegylated arginine deiminase (ADI-PEG20) results in the depletion of arginine with the production of isomolar amounts of citrulline. This citrulline has the potential to be utilized by the citrulline recycling pathway regenerating arginine and sustaining tissue arginine availability. The goal of this research was to test the hypothesis that ADI-PEG20 depletes circulating arginine in pigs but maintains tissue arginine concentration and function, and to characterize the kinetics of citrulline and arginine. Two multitracer approaches (bolus dose and primed-continuous infusion) were used to investigate the metabolism of arginine and citrulline in Control (

When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki

Publications and Research

Vibrio cholerae, the causative agent of the diarrheal disease cholera, is a microbe capable of inhabiting two different ecosystems: chitinous surfaces in brackish, estuarine waters and the epithelial lining of the human gastrointestinal tract. V. cholerae defends against competitive microorganisms with a contact-dependent, contractile killing machine called the type VI secretion system (T6SS) in each of these niches. The T6SS resembles an inverted T4 bacteriophage tail and is used to deliver toxic effector proteins into neighboring cells. Pandemic strains of V. cholerae encode a unique set of T6SS effector proteins, which may play a role in pathogenesis or pandemic …

Cryo-Electron Tomography Of Candida Glabrata Plasma Membrane Proteins, Cristina Jiménez-Ortigosa, Jennifer Jiang, Muyuan Chen, Xuyuan Kuang, Kelley R Healey, Paul Castellano, Nikpreet Boparai, Steven J Ludtke, David S Perlin, Wei Dai

Faculty, Staff and Students Publications

Fungal plasma membrane proteins have long been recognized as targets for the development of antifungal agents. Despite recent progress in experimental approaches and computational structural predictions, our knowledge of the structural dynamics and spatial distribution of these membrane proteins in the context of their native lipid environment remains limited. By applying cryo-electron tomography (cryoET) and subtomogram analysis, we aim to characterize the structural characteristics and spatial distribution of membrane proteins present in Candida glabrata plasma membranes. This study has resulted in the identification of the membrane-embedded structure of the fungal H+-ATPase, Pma1. Tomograms of the plasma membrane revealed that Pma1 …

Eosinophils Attenuate Hepatic Ischemia-Reperfusion Injury In Mice Through St2-Dependent Il-13 Production, Yaochun Wang, Yang Yang, Meng Wang, Shuhong Wang, Jong-Min Jeong, Long Xu, Yankai Wen, Christoph Emontzpohl, Constance Lynn Atkins, Kevin Duong, Nicolas F Moreno, Xiaoyi Yuan, David R Hall, Wasim Dar, Dechun Feng, Bin Gao, Yong Xu, Zoltan Czigany, Sean P Colgan, J Steve Bynon, Shizuo Akira, Jared M Brown, Holger K Eltzschig, Elizabeth A Jacobsen, Cynthia Ju

Faculty, Staff and Students Publications

Eosinophils are a myeloid cell subpopulation that mediates type 2 T helper cell immune responses. Unexpectedly, we identified a rapid accumulation of eosinophils in 22 human liver grafts after hepatic transplantation. In contrast, no eosinophils were detectable in healthy liver tissues before transplantation. Studies with two genetic mouse models of eosinophil deficiency and a mouse model of antibody-mediated eosinophil depletion revealed exacerbated liver injury after hepatic ischemia and reperfusion. Adoptive transfer of bone marrow-derived eosinophils normalized liver injury of eosinophil-deficient mice and reduced hepatic ischemia and reperfusion injury in wild-type mice. Mechanistic studies combining genetic and adoptive transfer approaches identified …

Epidemiology And Outcomes Of Hospitalized Adults With Sars-Cov-2 Community-Acquired Pneumonia In Louisville, Kentucky, Julio A. Ramirez, T'Shura Ali, Thomas Chandler, Stephen P. Furmanek, Daniya Sheikh, Vidyulata Salunkhe, Steven Gootee, Mohammad Tahboub, William A. Mattingly, Demetra Antimisiaris, Jiapeng Huang, Jose Bordon, Rodrigo Cavallazzi, Paul Schulz, William P. Mckinney, Dawn Balcom, Mark Burns, Ruth Carrico, Forest W. Arnold, Cerid Covid-19 Study Group

The University of Louisville Journal of Respiratory Infections

Background: During the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV-2 community-acquired pneumonia (CAP) has been the primary cause of hospitalization. The objective of this study was to evaluate the clinical characteristics and outcomes of 1,013 patients hospitalized with SARS-CoV-2 CAP from September 2020 through March 2021 in Louisville, Kentucky.

Methods: This was a retrospective observational study of 1,013 patients hospitalized with SARS-CoV-2 CAP at eight of the adult hospitals in the city of Louisville from September 2020 through March 2021. Patients with 1) a positive reverse transcriptase-polymerase chain reaction (RT-PCR) for SARS-CoV-2, 2) fever, cough, or …

Sociodemographic, Clinical Characteristics, And Outcomes Of Influenza Pneumonia Patients Admitted In A Tertiary Care Hospital In Karachi, Pakistan: Findings From A Cross-Sectional Study, Fazal Ur Rehman, Muhammad Arslan Ahmed, Kashif Aziz, Mahmooda Jabeen Ashraf, Tazein Amber, Sumera Aziz Ali

Section of Internal Medicine

Objective: To determine the sociodemographic, clinical characteristics, and outcomes of influenza pneumonia patients in tertiary care hospital, Karachi Pakistan.
Study design: A cross-sectional study.
Place and duration of study: The Aga Khan University Hospital Karachi Pakistan from January 2013 to December 2018. Methodology: All adult patients who were older than 18 years and suspected to have viral pneumonia were included in the study. Data were abstracted on 105 patients and were entered on preformed proforma after reviewing the files of patients.
Results: Ninety-four (89.5%) patients were influenza positive and 15.2% (n=16) had been vaccinated. Around 92.4% (n=97), 81.9% (n=86) and …

Streptococcus Cristatus – An Oral Bacterium Causing A Case Of Mild Bacteremia And “Possible Endocarditis”, Camilo Guzman, Adi Zaclli, John Molinari

Medical Student Research Symposium

Streptococcus cristatus is a member of the Mitis streptococcus group. Like other members of this group, it resides in mucosal surfaces of the oral cavity but rarely causes disease. We present a case of S. cristatus bacteremia and “possible endocarditis” (per the modified Duke criteria) in a 59-year-old male suffering from end- stage cryptogenic cirrhosis. To date, it is the fifth reported case of disease caused by the microbe, and the first adult case in which S. cristatus was the sole microbe identified. Our patient had a history of dental caries and poor dentition, which were likely the source of …

Functional Influence Of 14-3-3 (Ywha) Proteins In Mammals, Elizabeth Barley, Santanu De

Mako: NSU Undergraduate Student Journal

The 14-3-3 (YWHA) proteins are homologous, ubiquitous, and conserved in most organisms ranging from plants to animals and play important roles in regulating key cellular events such as cell signaling, development, apoptosis, etc. These proteins consist of seven isoforms in mammals, termed under Greek alphabetization: beta (β), gamma (γ), epsilon (ε), eta (η), tau/theta (τ), sigma (σ), and zeta (ζ). Each of these isoforms can interact with a plethora of binding partners and has been shown to serve a distinct role in molecular crosstalk, biological processes, and disease susceptibility. Protein 14-3-3 isoforms are scaffolding proteins capable of forming homodimers and …

Lyme Disease Essentials For Healthcare Workers, Donita Blanken-Little

DNP Research Projects

No abstract provided.

Covid-19 Presenting With Spontaneous Pneumothorax, Intisar Ahmed, Hunaina Shahab, Muhammad Arslan Ahmed, Muhammad Sohaib

Section of Cardiology

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease mainly affects respiratory system. Its common clinical findings include fever, cough and shortness of breath. Characteristic radiological features of the disease include peripherally distributed, bilateral ground-glass opacities, predominantly involving the lower lung zones. In this report, we present a case of COVID-19 disease presenting with spontaneous pneumothorax. A 26-year male patient was admitted to the Emergency Department with fever, dry cough, shortness of breath and right-sided chest pain. Radiographic imaging of the patient revealed pneumothorax on the right and peripherally distributed non-homogenous opacification. …

Characterizing The Physiology And Genetics Of Contact Dependent Growth Inhibiton Systems In Burkholderia Species, Alice Elizabeth Oates

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Contact-dependent growth inhibition (CDI) systems mediate interbacterial competition. The genes encoding these systems are widespread among Gram-negative bacteria, including Burkholderia pathogens. CDI systems of Burkholderia species are composed of two-partner secretion pathway proteins and function to deliver the toxic C-terminus of a polymorphic surface-exposed exoprotein BcpA (Burkholderia CDI protein A) to the cytoplasm of neighboring recipient bacteria upon cell-cell contact. Specific outer and inner membrane proteins facilitate BcpA translocation both out of the donor bacterium and into the recipient cell cytoplasm. Most Burkholderia species-specific CDI translocation factors in recipient cells are unknown. BcpA intoxication functions as a mechanism by …