Microbiology Commons^™

Vertical Transmission Of Zika Virus In Monodelphis Domestica, Mohini Moulick

Theses and Dissertations

Zika Viral infection in pregnant women may lead to infants born with microcephaly and other neurological complications, making Zika viral research imperative. Prior research demonstrated Monodelphis domestica to be a unique animal model for Zika virus studies, and viral proteins were detected in brain tissue of juveniles after intracerebral inoculation of infants. We wanted to determine if we can detect a viral protein, non-structural protein 1 (NS1), in brain tissue after intraperitoneal inoculation and we found it to be possible through immunohistochemistry (IHC) analysis. We also investigated if inoculated dams (mothers) would give rise to Zika positive pups (natural inoculation), …

Use Of Transposon Screening For Salicylic Acid-Assisted Desiccation Killing In Salmonella, Shannon D. Elliott

Electronic Theses and Dissertations

Salmonella enterica serovar Typhimurium is one of the most prevalent food-borne pathogens, affecting millions around the world every year, making it a threat to global health. Salmonella possesses the ability to survive the normally lethal condition of desiccation, however, discovery of the genes and mechanisms behind this phenomenon are still ongoing. Using a transposon mutagenesis approach to construct a broad transposon library, this study aimed to uncover genes that may be contributing to changes in Salmonella’s survivability under desiccation, particularly when exposed to the antimicrobial molecule salicylic acid. Building on previous findings showing salicylic acid can alter cell viability …

Securing Rice Safety Through Innovative Radiative Heat Treatment And Proper Storage, Faith Achieng Ouma

Graduate Theses and Dissertations

Securing the microbial safety of rice is a rising priority within the food industry, especially when used as an ingredient to manufacture ready-to-eat, minimally-processed products. Mold contamination is typically the most problematic for rice because certain species of Aspergillus produce toxic secondary metabolites known as aflatoxins, rendering the grain unfit for human and animal consumption. The objectives of this study are to: (1) investigate the effectiveness of using high-power (915 MHz frequency), short-duration microwaves (MWs) to inactivate microbes on rough rice; (2) use a three-level screening design to determine which storage factors, such as temperature, relative humidity (RH), storage duration, …

Radiofrequency And Gaseous Technologies For Enhancing The Microbiological Safety Of Low Moisture Food Ingredients, Surabhi Wason

Graduate Theses and Dissertations

High heat resistance and long survival of Salmonella in low moisture food ingredients (LMFIs) such as spices and seeds are concerning as they are typically consumed without cooking. Therefore, it is challenging to effectively inactivate pathogenic bacteria without negatively impacting the quality of the treated product. This dissertation aimed to develop and evaluate novel intervention technologies: in-package radiofrequency steaming and non-thermal gaseous technologies to improve the microbial safety of LMFIs. The dissertation can be divided into three parts. The first part of this dissertation on the thermal inactivation kinetics of Salmonella and a surrogate, Enterococcus faecium NRRL B-2354on black pepper …

Isolation And Structural Determination Of Bioactive Metabolites From The Soil Bacterium, Arthrobacter Sp. Tajx1902, Amonah Arije

Electronic Theses and Dissertations

As antimicrobial resistance persistently disrupts the treatment of microbial infection, natural product chemistry has played a significant role in identifying novel drugs with novel modes of action critical to getting ahead of resistance. The primary goal of this project is to extract and identify potential novel antimicrobial natural products produced by Arthrobacter sp. Although underexplored, Arthrobacter sps. have been known to produce bioactive compounds with versatility; one such is a depsipeptide with quorum-sensing inhibitory activity.¹ In this research, an Arthrobacter sp. TAJX1902, isolated from a soil sample, showed inhibitory activity against a filamentous indicator bacterium and a violacein-producing Janthinobacterium …

Microsporidian Spores And The Integrin Binding Loop Of The Madam Protein Are Important For Integrin Signaling And Attachment To Host Cells, Cindy L. Barrett

Electronic Theses and Dissertations

Microsporidia are a distant fungal pathogen that have severe clinical consequences for the immunocompromised. Previous work identified a microsporidian pathogen protein termed Microsporidian ADAM or MADAM. This protein has close sequence homology to other ADAM proteins (A Disintegrin and Metalloproteinase) in two microsporidian species, Encephalitozoon intestinalis and E. cuniculi. ADAM proteins have a wide range of functions, including binding to integrins and host signaling. It is known that many pathogens manipulate integrins to invade host cells, and it is predicted that microsporidia are also exploiting this host target. Previous work with the MADAM protein demonstrated that this protein has a …

Hunger Extends Lifespan By Modulating Histone Proteins, Hailan Liu, Hongjie Li, Yong Xu

Faculty, Staff and Students Publications

No abstract provided.

Heterogeneity Of The Group B Streptococcal Type Vii Secretion System And Influence On Colonization Of The Female Genital Tract, Brady L Spencer, Alyx M Job, Clare M Robertson, Zainab A Hameed, Camille Serchejian, Caitlin S Wiafe-Kwakye, Jéssica C Mendonça, Morgan A Apolonio, Prescilla E Nagao, Melody N Neely, Natalia Korotkova, Konstantin V Korotkov, Kathryn A Patras, Kelly S Doran

Faculty, Staff and Students Publications

Type VIIb secretion systems (T7SSb) in Gram-positive bacteria facilitate physiology, interbacterial competition, and/or virulence via EssC ATPase-driven secretion of small ɑ-helical proteins and toxins. Recently, we characterized T7SSb in group B Streptococcus (GBS), a leading cause of infection in newborns and immunocompromised adults. GBS T7SS comprises four subtypes based on variation in the C-terminus of EssC and the repertoire of downstream effectors; however, the intraspecies diversity of GBS T7SS and impact on GBS-host interactions remains unknown. Bioinformatic analysis indicates that GBS T7SS loci encode subtype-specific putative effectors, which have low interspecies and inter-subtype homology but contain similar domains/motifs and therefore …

Molecular Mechanisms Behind Sars-Cov-2 Induced Host Genome Restructuring, Erin Simpson

Dissertations and Theses (Open Access)

Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2) has caused unprecedented morbidity and mortality worldwide. There are two pathophysiological hallmarks associated with severe patient outcomes after SARS-CoV-2 acute infection, namely delayed/weakened interferon production and overactive inflammatory responses. Our previous work has shown that these altered immune responses are due, at least in part, to significant alterations in 3D genome organization and epigenetic landscape following SARS-CoV-2 infection that are distinct from and more severe than changes caused by other viral infections or immune stimulants. While these changes at the chromatin level are important for understanding the immune dysregulation seen in some cases …

Elucidating Acetate Metabolism: Identification Of Transporters And Enzymes Required For Acetate Utilization In The Fungal Pathogen Cryptococcus Neoformans, Perry L. Kezh

All Dissertations

Cryptococcus neoformans is the leading cause of fungal meningitis world-wide. While exposure to this environmental sporophyte is common during childhood, those who are immune compromised are at risk of infection. Following inhalation, this basidiomycetous fungus subsequently colonizes other organs though hematogenous dissemination, eventually crossing the blood brain barrier and colonizing the brain where it causes as cryptococcal meningitis. Changes in the availability of carbon sources stemming from the movement from soil to the lungs induce changes in fungal metabolism. Specifically, alveolar macrophages, which present a first line of defense against infection, provide a glucose-/amino acid-poor environment. As such, the use …

Effect Of Authentic Kefir And Nigella Sativa On Broilers Challenged By Coccidia And Clostridium Perfringens, Julian E. Nixon

All Dissertations

Black seed oil concentrations of 0%, 0.1%, 1% and 5% were added to milk inoculated with kefir grains and incubated at 25°C for 22 h. The pH and microbial count indicated 1% black seed oil caused low inhibition (P > 0.05) of fermentation, but 5% black seed oil caused significant inhibition of the kefir microorganisms (P < 0.05).

Cobb 500 male chicks (n = 256) were distributed in a randomized block design and received one of four treatments: CTRL1 (Non-medicated, no kefir, no Clostridium perfringens), CTRL2 (Non-medicated, no kefir, C. perfringens inoculated), CTRL3 (BMD medicated, no kefir, C. perfringens inoculated), KTRT (Non-medicated, …

Microbial Commensals Of Tricolored Bats In Georgia And Their Probiotic Potential, Jordyn Upton

Master of Science in Integrative Biology Theses

Pseudogymnoascus destructans (Pd) is a fungal pathogen that has been spreading in North American bats since its initial discovery in 2006. P. destructans is the causative agent of white-nose syndrome (WNS), a disease leading to as much as a 90% decrease in some eastern United States bat populations, with select hibernacula experiencing complete extirpation of the hibernating population. To date, there is no effective scaled probiotic for WNS, but probiotics inoculums have shown success in the management of other recently emerged fungal pathogens of wildlife, such as chytridiomycosis in amphibians. Host microbiomes have come under investigation in other disease systems …

The Role Of Adenovirus Serotype 5 E4 11k In The Relocalization Of The Cellular P Body Proteins, Kasey A. Karen, La`Quita Randolph, Kevin Neubrecht, Heather Vincent

Georgia Journal of Science

Human adenoviruses are a useful tool to understand basic cellular biology in addition to viral infections. Historically, cellular splicing was first discovered in adenovirus, but other cellular processes, such as double-strand break repair and aggresome formation, have been further elucidated through adenoviral infection. The adenovirus protein E4 11k has been shown to disrupt cytoplasmic processing bodies (p bodies), which are not well-understood but are involved in mRNA metabolism. Several p body proteins were found to be reorganized in the cytoplasm with adenovirus serotype 5 (Ad5) able to cause the colocalization of these p body proteins with aggresomes. The p body …

N-Acetyltransferase 9 Ameliorates Aβ42-Mediated Neurodegeneration In The Drosophila Eye, Prajakta Deshpande, Anuradha Venkatakrishnan Chimata, Emily E. Snider, Aditi Singh, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer’s disease (AD), a progressive neurodegenerative disorder, manifests as accumulation of amyloid-beta-42 (Aβ42) plaques and intracellular accumulation of neurofibrillary tangles (NFTs) that results in microtubule destabilization. Targeted expression of human Aβ42 (GMR > Aβ42) in developing Drosophila eye retinal neurons results in Aβ42 plaque(s) and mimics AD-like extensive neurodegeneration. However, there remains a gap in our understanding of the underlying mechanism(s) for Aβ42-mediated neurodegeneration. To address this gap in information, we conducted a forward genetic screen, and identified N-acetyltransferase 9 (Mnat9) as a genetic modifier of GMR > Aβ42 neurodegenerative phenotype. Mnat9 is known to stabilize microtubules by inhibiting c-Jun-N- …

Investigating The Physiological Mechanisms Between Resistance Training And Pain Relief In The Cancer Population: A Literature Review, Yvonne Jiang, Peter C. Angeletti, Amy J. Hoffman

Nebraska Center for Virology: Faculty Publications

This literature review examines the mechanisms of how exercise, specifically in the form of resistance training, may lead to pain relief in the cancer population. Primary data from three different cancer populations: breast, prostate, and lung, will be examined. A number of experimental studies have been conducted to confirm the effectiveness of resistance training on pain relief as well as the biochemical pathways that relate to this process. In this review, we will examine 5 randomized controlled trials. For the purposes of this review, pain is defined as physical suffering or discomfort associated with illness. Pain is the body’s natural …

Sars‑Cov‑2 Entry Into And Evolution Within A Skilled Nursing Facility, Nicole R. Sexton, Parker Parker Cline, Emily N. Gallichotte, Emily Fitzmeyer, Michael C. Young, Ashley J. Janich, Kristy L. Pabilonia, Nicole Ehrhart, Gregory D. Ebel

Nebraska Center for Virology: Faculty Publications

SARS-CoV-2 belongs to the family Coronaviridae which includes multiple human pathogens that have an outsized impact on aging populations. As a novel human pathogen, SARS-CoV-2 is undergoing continuous adaptation to this new host species and there is evidence of this throughout the scientific and public literature. However, most investigations of SARS-CoV-2 evolution have focused on largescale collections of data across diverse populations and/or living environments. Here we investigate SARS-CoV-2 evolution in epidemiologically linked individuals within a single outbreak at a skilled nursing facility beginning with initial introduction of the pathogen. The data demonstrate that SARSCoV- 2 was introduced to the …

Evaluation Of Bio-Friendly Formulations From Siderophore-Producing Fluorescent Pseudomonas As Biocontrol Agents For The Management Of Soil-Borne Fungi, Fusarium Oxysporum And Rhizoctonia Solani, Gaber Attia Abo-Zaid, Ahmed Salah Abdullah, Nadia Abdel-Mohsen Soliman, Ebaa Ebrahim El-Sharouny, Abdulaziz A. Al-Askar, Yiming Su, Ahmed Abdelkhalek, Soraya Abdel-Fattah Sabry

Civil and Environmental Engineering Faculty Publications

Secretion of siderophores by Pseudomonas aeruginosa F2 and P. fluorescens JY3 was evaluated on chrome azurol S (CAS) agar plates and their inhibitory effect was inspected against Fusarium oxysporum and Rhizoctonia solani. Production of siderophores as biocontrol agents from F2 and JY3 was accomplished in two optimized media. Afterward, cell-free supernatants of the bacterial cultures containing siderophores were used for the preparation of two bio-friendly formulations for the management of F. oxysporum and R. solani under greenhouse conditions. The investigated bacterial isolates, F2 and JY3, showed antagonistic activity in vitro against F. oxysporum and R. solani and produced siderophores …

Evaluating Vaccine Management Strategies For Edwardsiella Ictaluri Infections In Zebrafish (Danio Rerio), Brandy Malbrough

LSU Master's Theses

Aquaculture is a globally important industry that faces significant challenges due to infectious diseases, which can result in substantial financial losses. In 2011, a new strain of Edwardsiella ictaluri emerged as a major pathogen affecting zebrafish in the ornamental fish industry, leading to high mortality rates and posing a severe threat to the sector. Vaccines provide potential benefits for disease prevention in aquaculture, particularly live-attenuated vaccines (LAVs), which induce strong host immune responses. Bacterial attenuation for vaccine development has evolved from serial passage to more targeted genetic modification techniques. However, regulatory constraints limit the availability of licensed LAVs for aquaculture. …

Microbe Hunters, Paul De Kruif

Zea E-Books Collection

Microbe Hunters by Paul de Kruif was first published in 1926 by Harcourt, Brace and Company, New York. It dramatically recounts the breakthrough discoveries of the fundamental elements of bacteriology. It features exciting profiles of Antony Leeuwenhoek, Lazzaro Spallanzani, Louis Pasteur, Robert Koch, Émile Roux, Emil Behring, Élie Metchnikoff, Theobald Smith, David Bruce, Ronald Ross, Battista Grassi, Walter Reed, and Paul Ehrlich. Their development of germ theory and its scientific proofs led to the first effective treatments for human diseases like anthrax, rabies, diptheria, malaria, sleeping sickness, syphilis, and yellow fever. They also made discoveries that saved the dairy, wine, …

Diving Into Aquatic Microbial Ecology And Evolution With Anne Thompson, Anne Thompson

PDXPLORES Podcast

On this episode of PDXPLORES, Assistant Professor of Biology, Anne Thompson, discusses her award-winning research work studying the diverse ecology of microorganisms found in Earth’s oceans. Thompson’s research examines microbial mortality impacts on the structure of oceanic food webs, carbon flow, and cell interactions that create dynamic patterns of nutrient and energy abundance within diverse aquatic ecosystems.

Click on the "Download" button to access the audio transcript.

Roving Methyltransferases Generate A Mosaic Epigenetic Landscape And Influence Evolution In Bacteroides Fragilis Group, Michael J Tisza, Derek D N Smith, Andrew E Clark, Jung-Ho Youn, Pavel P Khil, John P Dekker

Faculty, Staff and Students Publications

Three types of DNA methyl modifications have been detected in bacterial genomes, and mechanistic studies have demonstrated roles for DNA methylation in physiological functions ranging from phage defense to transcriptional control of virulence and host-pathogen interactions. Despite the ubiquity of methyltransferases and the immense variety of possible methylation patterns, epigenomic diversity remains unexplored for most bacterial species. Members of the Bacteroides fragilis group (BFG) reside in the human gastrointestinal tract as key players in symbiotic communities but also can establish anaerobic infections that are increasingly multi-drug resistant. In this work, we utilize long-read sequencing technologies to perform pangenomic (n = …

Yes-Associated Protein-1 Overexpression In Ocular Surface Squamous Neoplasia; A Potential Diagnostic Marker And Therapeutic Target, Peter Julius, Stepfanie N. Siyumbwa, Fred Maate, Phyllis Moonga, Guobin Kang, Trevor Kaile, John T. T., Charles Wood

Nebraska Center for Virology: Faculty Publications

Yes-associated protein-1 (YAP-1) is a Hippo system transcription factor, which serves as an oncogene in squamous cell carcinoma, and several solid tumors when the Hippo pathway is dysregulated. Yet, the activity of YAP-1 in ocular surface squamous neoplasia (OSSN) has not been determined. Here, we investigate the relationship between YAP-1 overexpression and OSSN. Using a cross-sectional study design, we recruited 227 OSSN patients from the University Teaching Hospitals in Lusaka, Zambia. Immunohistochemistry was used to assess YAP-1 protein overexpression in tumor tissue relative to surrounding benign squamous epithelium. OSSN patient samples (preinvasive, n = 62, 27% and invasive, n = …

Horizontal Transfer Of Probable Chicken-Pathogenicity Chromosomal Islands Between Staphylococcus Aureus And Staphylococcus Agnetis, Douglas D. Rhoads, Jeff Pummil, Nnamdi S. Ekesi, Adnan A.K. Alrubaye

Cell and Molecular Biology Faculty Publications and Presentations

Staphylococcus agnetis is an emerging pathogen in chickens but has been most commonly isolated from sub-clinical mastitis in bovines. Previous whole-genome analyses for known virulence genes failed to identify determinants for the switch from mild ductal infections in cattle to severe infections in poultry. We now report identification of a family of 15 kbp, 17–19 gene mobile genetic elements (MGEs) specific to chicken osteomyelitis and dermatitis isolates of S. agnetis. These MGEs can be present in multiple copies per genome. The MGE has been vectored on a Staphylococcus phage that separately lysogenized two S. agnetis osteomyelitis strains. …

Silver Ions Inhibit Bacterial Movement And Stall Flagellar Motor, Benjamin Russell, Ariel Rogers, Ryan Yoder, Matthew Kurilich, Venkata Rao Krishnamurthi, Jingy Chen, Yong Wang

Physics Faculty Publications and Presentations

Silver (Ag) in different forms has been gaining broad attention due to its antimicrobial activities and the increasing resistance of bacteria to commonly prescribed antibiotics. However, various aspects of the antimicrobial mechanism of Ag have not been understood, including how Ag affects bacterial motility, a factor intimately related to bacterial virulence. Here, we report our study on how Ag⁺ ions affect the motility of E. coli bacteria using swimming, tethering, and rotation assays. We observed that the bacteria slowed down dramatically by >70% when subjected to Ag⁺ ions, providing direct evidence that Ag⁺ ions inhibit the motility …

Characterization Of Antimicrobial Properties Of Excrement And Functional Microbiome Of Black Vultures (Coragyps Atratus), Bridgette Gray

Theses

Black vultures, Coragyps atratus, are obligate scavenging birds that consume and dispose of decaying carcasses and carrion. They fulfill a key ecological niche in the environments in which they live. It has been observed that these vultures sometimes excrete bodily waste onto their legs. This adaptive behavior could help aid them in controlling bacteria and other microbes they encounter while stepping into a carcass to eat. This study directly examined the antimicrobial properties of the excrement of black vultures across various bacterial species utilizing a zone of inhibition test and a nematode species utilizing a survival assay. The black vulture …

Sympatric Soil Microbe Interactions Between Streptomyces And Fusarium Isolates, Lehren A. Olk-Szost

All NMU Master's Theses

Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive …

Nac1 Confines Virus‐Specific Memory Formation Of Cd4+ T Cells Through The Rock1‐Mediated Pathway, Liqing Wang, Hao-Yun Peng, Jugal Kishore Das, Anil Kumar, Yijie Ren, Darby J. Ballard, Xiaofang Xiong, Wen Yang, Xingcong Ren, Paul De Figueiredo, Jin-Ming Yang, Jianxun Song

Markey Cancer Center Faculty Publications

Nucleus accumbens‐associated protein 1 (NAC1), a transcriptional cofactor, has been found to play important roles in regulating regulatory T cells, CD8 + T cells, and antitumor immunity, but little is known about its effects on T‐cell memory. In this study, we found that NAC1 expression restricts memory formation of CD4 + T cells during viral infection. Analysis of CD4 + T cells from wild‐type (WT) and NAC1‐ deficient (−/−) mice showed that NAC1 is essential for T‐cell metabolism, including glycolysis and oxidative phosphorylation, and supports CD4 + T‐cell survival in vitro. We further demonstrated that a deficiency of NAC1 downregulates …

Longitudinal Analysis Of The Evolution Of Cellular Immunity To Sars-Cov-2 Induced By Infection And Vaccination, Spyridoula Vasileiou, Manik Kuvalekar, Yovana Velazquez, Ayumi Watanabe, Mansi Narula, Aster G Workineh, Matthew French-Kim, Alejandro Torres Chavez, Sarah Gilmore, Cliona M Rooney, Ann M Leen

Faculty, Staff and Students Publications

No abstract provided.

Vincristine/Irinotecan/Temsirolimus Upfront Window Treatment Of High-Risk Hepatoblastoma: A Report From The Children’S Oncology Group Ahep0731 Study Committee, Patrick A Thompson, Marcio H Malogolowkin, Wayne L Furman, Jin Piao, Mark D Krailo, Nadia Chung, Lindsay Brock, Alexander J Towbin, Elizabeth B Mccarville, Milton J Finegold, Sarangarajan Ranganathan, Stephen P Dunn, Max R Langham, Eugene D Mcgahren, Gregory M Tiao, Christopher B Weldon, Allison F O'Neill, Carlos Rodriguez-Galindo, Rebecka L Meyers, Howard M Katzenstein

Faculty, Staff and Students Publications

Background: Survival for children with metastatic hepatoblastoma (HB) remains suboptimal. We report the response rate and outcome of two courses of vincristine/irinotecan/temsirolimus (VIT) in children with high-risk (HR)/metastatic HB.

Procedures: Patients with newly diagnosed HB received HR window chemotherapy if they had metastatic disease or a serum alpha-fetoprotein (AFP) level less than 100 ng/mL. Patients received vincristine (days 1 and 8), irinotecan (days 1-5), and temsirolimus (days 1 and 8). Cycles were repeated every 21 days. Responders had either a 30% decrease using RECIST (Response Evaluation Criteria in Solid Tumors) criteria OR a 90% (>1 log10 decline) AFP decline …

Exploring The Interactions Between Sars-Cov-2 And Host Proteins, Sojan Shrestha

School of Biological Sciences: Dissertations, Theses, and Student Research

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current pandemic, Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 is considered to be of zoonotic origin; it originated in non-human animals and was transmitted to humans. Since the early stage of the pandemic, however, the evidence of transmissions from humans to animals (reverse zoonoses) has been found in multiple animal species including mink, white-tailed deer, and pet and zoo animals. Furthermore, secondary zoonotic events of SARS-CoV-2, transmissions from animals to humans, have been also reported. It is suggested that non-human hosts can act as SARS-CoV-2 reservoirs where accumulated …