Microbiology Commons^™

Frequency And Etiology Of Community-Acquired Bloodstream Infection In Hospitalized Febrile Children, Tufail Soomro, Shiyam Sunder Tikmani, Sumera Aziz Ali

Community Health Sciences

Background: Blood stream infection is a serious problem that needs immediate attention and treatment. We aim to identify the frequency of common organisms in blood culture of febrile pediatric patients so that empirical antibiotic therapy can be started timely.
Methods: This cross-sectional study was conducted in pediatric ward Civil Hospital Sukkur from 1st May 2013 to 31st October 2014. Children of both genders who are between the age of one month to 15 years admitted to the pediatric ward with a fever of > 38.0 c and with a history of fever ˃ two days and whose blood culture has been …

Clinical Coagulase-Negative Staphylococci; Identification, Characterisation And Treatment, Emma Gabriel

Theses

The work presented in this thesis focuses on clinically significant staphylococci (with an emphasis on coagulase-negative staphylococci) in terms of their isolation, identification, characterisation, and biocontrol.

CoNS are increasingly being recognised as true nosocomial pathogens yet remain under-characterised, particularly from an Irish clinical perspective. We examined a large cohort of clinically-derived CoNS, isolated from blood (n=l35), identifying them to species level. Extensive antibiotic resistance against nine clinically-relevant antibiotics was recorded. Additionally, widespread biofilm forming capabilities associated with increased virulence was detected both phenotypically and genotypically. We identified multiple species of CoNS in circulation in an Irish healthcare setting, and determined …

An Investigation Of The Use Of Natural Agents To Control Mycobacteria, Olga Lesniak

Theses

Economic losses that are caused by Mycobacterium avium paratuberculosis (MAP) infections represent a major obstacle for farmers and also for the dairy industry. In order to control the population of MAP, alternative control agents must be investigated. One of the studies described in this thesis focused on using a bacteriophage therapy based approach to assess its efficacy on simulated industrial environments and food models. Another study described in this thesis investigated the antimicrobial effects of parsley and garlic on a range of mycobacteria species. Both studies used conventional microbiological methods such as plaque assays, AlamarBlue assay (MABA) and growth curves, …

The Expression Of Major Histocompatibility Class I And Major Histocompatibility Class Ii On Macrophages In The Presence Of Aryl Hydrocarbon Antagonist (Ch-223191), Caitlin Wilson

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Macrophages are crucial for ridding the body of debris and foreign cells. The aryl hydrocarbon receptor (AhR) also plays a critical role in immunity. This study examined the effect of the AhR on the expression of major histocompatiability complex class I (MHCI) and MHC class II (MHCII) in two murine macrophage cell lines. This study used Raw264.7 and J774A.1 murine macrophage cell lines. The Raw264.7 cells are from male BALB/c mice while the J774A.1 cells are from female BALB/cN mice. The addition of the AhR anatagonist CH-223191 (AhRa) showed that the AhR does not significantly impact MHCI expression. However, MHCII …

Anaplasma Marginale Actively Modulates Vacuolar Maturation During Intracellular Infection Of Its Tick Vector, Dermacentor Andersoni, Foregivemore Magunda, Chelsea Wright Thompson, David A. Schneider, Susan M. Noh

Biological Sciences Faculty Publications

ABSTRACT Tick-borne transmission of bacterial pathogens in the order Rickettsiales is responsible for diverse infectious diseases, many of them severe, in humans and animals. Transmission dynamics differ among these pathogens and are reflected in the pathogen-vector interaction. Anaplasma marginale has been shown to establish and maintain infectivity within Dermacentor spp. for weeks to months while escaping the complex network of vacuolar peptidases that are responsible for digestion ofthe tick blood meal. How this prolonged maintenance of infectivity in a potentially hostile environment is achieved has been unknown. Using the natural vector Dermacentor andersoni, we demonstrated that A. marginale …

Characterizing The Role Of The Fact Complex In Hiv-1 Infection, Angelica Patricia Lopez

Open Access Theses & Dissertations

The lens epithelium-derived growth factor p75 (LEDGF/p75) is a chromatin-bound protein essential for efficient lentiviral integration. Knockdown of this protein severely affects HIV-1 integration levels and thus itâ??s replication. Genome-wide studies have located LEDGF/p75 inside actively transcribed genes where it mediates lentiviral integration. Although this is clearly established, the molecular mechanisms of LEDGF/p75 in HIV-1 infection remain in part elusive.

Using protein-protein interaction assays, we demonstrated that LEDGF/p75 complexes with a chromatin remodeling complex, Facilitates Chromatin Transcription (FACT), a heterodimer of the structure specific recognition protein 1 (SSRP1) and the human homolog of suppressor of Ty 16 (hSpt16). The FACT …

Defining And Characterizing The Step In The Hiv-1 Viral Life Cycle Affected By Fullerene Derivatives, Zachary Sean Martinez

Open Access Theses & Dissertations

Fullerene derivatives, both C60 and C70, were synthesized and characterized to test their activity against HIV-1 infection. The derivatives tested have previously been reported to inhibit HIV-1 replication and/or in vitro activity of reverse transcriptase. It was found that viruses produced in the presence of low micromolar concentrations of most of these fullerene derivatives exhibit a reduction in viral infectivity greater than 99%. Quantification of virion-associated viral RNA and p24 indicates that RNA packaging and viral production were unremarkable in these viruses. These compounds did not affect infectivity of mature virions, indicating no effect on the early steps of the …

Determining The Role Of Poly [Adp-Ribose] Polymerase 1 (Parp-1) In Retroviral Infection, Luis Valdes Rodriguez

Open Access Theses & Dissertations

Possible links between PARP-1 and HIV-1 have been previously reported but the role of this protein during viral infection has remained elusive. Based on the high evolutionary conservation of PARP-1, from Drosophila to humans, we have been able to counteract the difficulties related with the functional redundancy manifested in the PARP family by studying the influence of PARP-1 on the expression of an endogenous retrovirus using the chicken B lymphoblastoid cell line DT40, this cell line exhibits low PARP-1 functional redundancy and is viable after PARP-1 knockout. We have determined that the transcription level of the endogenous retrovirus RAV-1 is …

Effects Of Epichloë Coenophiala−Tall Fescue Symbiosis On Plant-Microbe-Soil Interactions In A Temperate Pasture, Lindsey C. Slaughter

Theses and Dissertations--Plant and Soil Sciences

Plants interact in myriad ways with microorganisms to influence ecosystem processes such as nutrient cycling, which can regulate ecosystem response to global change. One important plant-microbe symbiosis occurs between cool-season grasses and asexual fungal Epichloë endophytes, such as tall fescue (Schedonorus arundinaceus) and Epichloë coenophiala. Because the common toxic strain of the endophyte (CTE) harms grazing livestock, non-livestock toxic endophyte (NTE) strains have been developed and are increasingly deployed in pastures. Little is known about how these symbioses impact other plant-microbe interactions and microbe-mediated soil processes in grassland ecosystems. I conducted three studies to determine how E. …

Cell Viability, Cytoskeleton Organization And Cytokines Secretion Of Raw 264.7 Macrophages Exposed To Gram-Negative Bacterial Components, Ali Awadh Alshehri

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Macrophages play an important role in innate immunity by controlling cellular responses. In this study, the effects of gram-negative bacterial components (Flagellin, lipoprotein, lipopolysaccharides (LPS), outer membrane proteins-A (OMP-A) and peptidoglycan) were determined on cell viability, morphology, cytoskeletal filament and cytokines secretion of murine RAW 264.7 macrophages at 24 hours. The effect of LPS, flagellin and peptidoglycan from gram negative bacteria on viability murine RAW 264.7 macrophages were evaluated using different concentrations (1, 5 and 10 µg/ml). Cells stimulated with LPS displayed ~ 2-fold decrease (P=0.001) in cell viability compared to control cells at 24 hours whereas cells stimulated with …

The Expression Of Dopamine-Related Genes And Behavioral Performance In Mice, Victoria Lynne Dershem

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While the neurotransmitter dopamine has been well-studied for its role in mood regulation and activation of the intrinsic reward pathway, several psychiatric disorders linked to dopamine are also known to cause memory impairment, a phenomenon which has attracted much less attention. In the current study, whole-transcriptome RNA sequencing was performed, and transcript levels of several dopamine-related genes were compared to results of behavioral assays designed to test spatial and emotional memory, as well as anxiety. The results suggest a positive relationship between expression level of Nurr1, a nuclear receptor known to initiate transcription of genes necessary for dopaminergic signaling, …

Development And Validation Of Virus And Ebola Misconceptions Assessment (Viremia): Ebola Virus Misconceptions In College Students, Michele Miller

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In this study an assessment (VirEMiA) on college students' knowledge and misconceptions of the Ebola virus was created and validated. VirEMiA was then used to determine what misconceptions college students have about Ebola, if there is a difference in misconceptions between students with and without a strong science background, and if Just-in-Time Teaching (JiTT) increases students' knowledge of Ebola and decreases their misconceptions. VirEMiA was shown to be a valid and reliable assessment whether confidence was integrated (seprel=0.97) or not (seprel=0.98), and for measuring misconceptions (seprel=0.97). If psychology and nursing majors were considered to have a strong background in science, …

Relationships Between Fecal Indicator Bacteria And Environmental Factors At Edgewater Beach, Anna M. King

Williams Honors College, Honors Research Projects

To provide more timely estimates of indicator bacteria concentrations in recreational waters, environmental agencies are using predictive models to supplement conventional bacteria enumeration methods. As a tool to develop predictive models, correlational relationships between variables can be examined, to determine the statistical significance of explanatory variables. Prior research at Lake Erie beaches suggests that environmental conditions such as average wave height, rainfall, turbidity, and water temperature may demonstrate a strong relationship to concentrations of fecal indicator bacteria Escherichia coli and Enterococcus faecalis (enterococci). These relationships were examined at Edgewater Beach in Cleveland, Ohio, using statistical correlation tests on data collected …

Metabolism Of Herpes Simplex Virus 1 Infected Raw 264.7 Macrophages, Mary K. Jenkins

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Macrophages are immune cells that phagocytize pathogens and act as antigen presenting cells. Macrophages are critical in regulating the adaptive immune response and play a key role in neutralizing infection. Macrophages exhibit a variety of phenotypes which have different energy requirements. In the case of HSV-1 infection the virus has been shown to alter metabolic processes of its host. Utilizing a XF24 Extracellular Flux Analyzer the metabolic activity of M0, M1, and M2 (IL-4, IL-13, and IL-10) RAW 264.7 macrophages was quantified for both uninfected cells and in response to HSV-1 infection. The analysis showed uninfected M0 and M2 (IL-4, …

The Anti-Apoptotic Effect Of Hsv-1 On Murine Macrophages: Raw 246.7 Murine Macrophage Cell Line, Mofeda Abdussalam Alhanghari

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Herpes simplex virus type 1 (HSV-1) is a worldwide pathogen that affects humans and has the ability to establish a latent state of infection in the sensory nerve ganglia after primary infection of epithelial cells (Boutell and Everett, 2003). HSV-1 is a very contagious virus, which can be transmitted from person to person and cause cold sores in the infected person. Rarely, infection can lead to more serious complications, such as encephalitis. Most HSV-1 infections usually occur in childhood with lifelong potential for symptomatic or asymptomatic viral shedding episodes (Looker et al., 2015). HSV- 1 infects 60%-80% of people throughout …

Late Events Of Human Metapneumovirus Infection: Insights Into Viral Spread Within The Respiratory Epithelium, Farah El Najjar

Theses and Dissertations--Molecular and Cellular Biochemistry

Human metapneumovirus (HMPV) is a leading cause of respiratory tract infections worldwide across all age groups, and is particularly devastating in the pediatric, elderly and immunocompromised populations. Despite its high prevalence and burden on human health, there are currently no treatments or vaccines against HMPV infections. HMPV is an enveloped virus that belongs to the paramyxovirus family. Paramyxoviruses in general form by assembly of virus components at the plasma membrane followed by budding and release of virus particles into the extracellular matrix to spread infection. The process of forming new virus particles requires complex interactions between viral and cellular components …

Role Of The Exopolysaccharide Alginate In Adherence To And Inflammation Of Pulmonary Epithelial Cells, Brian E. Crossley

Theses and Dissertations

Pseudomonas aeruginosa (PA) infections in Cystic Fibrosis (CF) patients are not easily cleared due to the conversion from a nonmucoid to a mucoid phenotype. Alginate is an acetylated exopolysaccharide produced by mucoid PA that is responsible for increased resistance to antibiotics, host phagocytic killing, and propagating biofilm formation. Understanding the interaction between PA and host cells is critical to understanding chronic infection and inflammation in CF. In order to investigate this, we used A549 pulmonary epithelial cells and murine alveolar macrophages (MH-S) to examine host response to nonmucoid versus mucoid PA infection. Adhesion assays in A549 pulmonary epithelial cells revealed …

Delineating ΔNp63α'S Function In Epithelial Cells, Suraj Sakaram

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ΔNp63α, the most physiologically relevant isoform of p63, a p53 family member protein, maintains the proliferative capacity of the basal layer of epithelial tissues and is highly expressed in non-melanoma skin cancer. It has been implicated in a variety of different cancers, including breast, lung, and prostate cancers, however the complex role it plays in disease remains poorly understood. Elucidating ΔNp63α’s regulatory network may provide insight into its role in epithelial tissues and in cancer progression. The objective of this thesis is to investigate ΔNp63α’s upstream regulation in the context of non-melanoma skin cancer as well as expand on ΔNp63α’s …

Species Differences In The Effects Of Tcdd On A Transcriptional Regulatory Region Within The Ig Heavy Chain Gene, Zahra J. Alfaheeda

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The immunoglobulin heavy chain gene (Igh) is regulated by numerous regulatory elements including the 3'Igh regulatory region (3'IghRR). Several transcription factors are involved in modulating the 3'IghRR including NF-B, AP-1, and the aryl hydrocarbon receptor (AhR). The AhR is a ligand-activated transcription factor that mediates the transcription of genes involved in the metabolism of environmental toxicants such as TCDD. TCDD binds AhR and regulates immunoglobulin (Ig) expression in B cells of animal models. This modulation appears to be directly mediated by binding of the AhR to dioxin response elements (DRE) within the 3'IghRR. Structural differences have been found between the …

Comparing Antibody-Coated Immune Beads With Flow Cytometry To Measure Ss-2-Microglubulin+ Murine Spleen Cells, Amal Fahad Alajman

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In diseases like AIDS, Multiple Myeloma, Multiple Sclerosis (MS), Type 1 Diabetes, and Systemic Lupus Erythromatosus the detection of major histocompatibility complex type 1 molecules (MHC 1) can be a helpful component of disease diagnosis and prognosis. Most somatic mammalian cells display to varying degrees major histocompatibility complex (MHC) class 1 antigen on the cell surface. MHC1 molecules consist of a polymorphic alpha a chain and a monomorphic beta chain, beta 2 microglubulin (ß2m). The ß2M composition is fairly constant within a species whereas the alpha chain is not. The polymorphic alpha chain is encoded by an MHC complex gene …

The Impact Of Hsv-1 Infection, Socs1 Peptide, And Socs3 Peptide Mimetic On Cell Viability, Morphology, And Cytoskeleton Proteins Of Unpolarized And Cytokine-Polarized M1 Raw 264.7 Murine Macrophages, Mubarak Almutairi

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Mubarak Huraysan Almutairi. M.S. Department of Microbiology and Immunology, Wright State University, 2016. The Impact of HSV-1 Infection, SOCS1 peptide, and SOCS3 peptide mimetic on Cell Viability, Morphology, and Cytoskeleton Proteins of Unpolarized and Cytokine-Polarized M1 RAW 264.7 Murine Macrophages. The immune response against HSV-1 involves macrophages in both innate and adaptive immunity by limiting HSV-1 replication. In this study, the effects of HSV-1 challenge on cell viability, morphology, and cytoskeletal filament in unpolarized and cytokine-polarized murine RAW 264.7 macrophages at 24 and 48 hours were monitored. Because the distribution of cytoskeleton throughout the cell is critical in cell viability …

Correlating Innate Functional Recovery From Stroke Either With Stem Cell Proliferation And/Or Limb Rehabilitation, Devipriyanka Nagarajan

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In the present study 10-12 month female rats were examined for functional recovery from stroke and this recovery was compared with the stem cell/progenitor cell proliferation in the brain (which was measured by Ki67). The cell proliferation indicated by Ki67 showed a 6 fold increase in control animals compared to the rehabilitation animals. The contralateral functional recovery in control animals were 46.6% and in the rehabilitation animals were 24.5%. The physical rehabilitation was carried out to determine if limb rehabilitation can promote greater functional recovery. The results showed that when the animals were made to over use their impaired limb …

Sequence-Based Methods For Detecting And Evaluating The Human Gut Mycobiome, Mallory J. Suhr, Nabaraj Banjara, Heather E. Hallen-Adams

Department of Food Science and Technology: Faculty Publications

We surveyed the fungal microbiota in 16 fecal samples from healthy humans with a vegetarian diet. Fungi were identified using molecular cloning, 454 pyrosequencing and a Luminex analyte specific reagent (ASR) assay, all targeting the ITS region of the rRNA genes. Fungi were detected in each fecal sample and at least 46 distinct fungal operational taxonomic units (OTUs) were detected, from two phyla — Ascomycota and Basidiomycota. Fusarium was the most abundant genus, followed by Malassezia, Penicillium, Aspergillus, and Candida. Commonly detected fungi such as Aspergillus and Penicillium, as well as known dietary fungi Agaricus bisporus and …

Complete Genome Sequence Of Highly Virulent Porcine Reproductive And Respiratory Syndrome Virus Variants That Recently Emerged In The United States, Aspen M. Workman, Timothy P.L. Smith, Fernando A. Osorio, Hiep L.X. Vu

Nebraska Center for Virology: Faculty Publications

A recent outbreak of particularly virulent disease caused by porcine reproductive and respiratory syndrome virus has occurred in swine herds across the United States. We report here the complete genome sequence of eight viral isolates from four Nebraska herds experiencing an outbreak of severe disease in 2016.

Domain I Of The 5′ Non-Translated Genomic Region In Coxsackievirus B3 Rna Is Not Required For Productive Replication, L. Jaramillo, S. Smithee, S. Tracy, N. M. Chapman

Nebraska Center for Virology: Faculty Publications

Domain I is a cloverleaf-like secondary structure at the 5′ termini of all enterovirus genomes, comprising part of a cis-acting replication element essential for efficient enteroviral replication. 5′ genomic terminal deletions up to as much as 55% of domain I can occur without lethality following coxsackie B virus infections. We report here that the entire CVB structural domain I can be deleted without lethality.

Reversion To Wildtype Of A Mutated And Nonfunctional Coxsackievirus B3cre(2c), Shane Smithee, Steven Tracy, Nora M. Chapman

Nebraska Center for Virology: Faculty Publications

The cis-acting replication element (CRE) in the 2C protein coding region [CRE(2C)] of enteroviruses (EV) facilitates the addition of two uridine residues (uridylylation) onto the virus-encoded protein VPg inorder for it to serve as the RNA replication primer. We demonstrated that coxsackievirus B3 (CVB3) is replication competent in the absence of a native (uridylylating) CRE(2C) and also demonstrated that lackof a functional CRE(2C) led to generation of 5’ terminal genomic deletions in the CVB3 CRE-knock-out (CVB3-CKO) population. We asked whether reversion of the mutated CRE(2C) occurred, thus permitting sustained replication, and when were 5’ terminal deletions generated during replication. Virions …

Replicating Single-Cycle Adenovirus Vectors Generate Amplified Influenza Vaccine Responses, Catherine M. Crosby, William E. Matchett, Stephanie S. Anguiano-Zarate, Christopher A. Parks, Eric A. Weaver, Larry R. Pease, Richard J. Webby, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Head-to-head comparisons of conventional influenza vaccines with ade- novirus (Ad) gene-based vaccines demonstrated that these viral vectors can mediate more potent protection against influenza virus infection in animal models. In most cases, Ad vaccines are engineered to be replication-defective (RD-Ad) vectors. In contrast, replication-competent Ad (RC-Ad) vaccines are markedly more potent but risk causing adenovirus diseases in vaccine recipients and health care workers. To harness antigen gene replication but avoid production of infectious virions, we de- veloped “single-cycle” adenovirus (SC-Ad) vectors. Previous work demonstrated that SC-Ads amplify transgene expression 100-fold and produce markedly stronger and more persistent immune responses than …

Noninvasive Measurement Of Electrical Events Associated With A Single Chlorovirus Infection Of A Microalgal Cell, Seung-Woo Lee, Eun-Hee Lee, Gerhard Thiel, James L. Van Etten, Ravi Saraf

Department of Chemical and Biomolecular Engineering: Faculty Publications

Chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) contains a viral-encoded K⁺ channel imbedded in its internal membrane, which triggers host plasma membrane depolarization during virus infection. This early stage of infection was monitored at high resolution by recording the cell membrane depolarization of a single Chlorella cell during infection by a single PBCV-1 particle. The measurement was achieved by depositing the cells onto a network of one-dimensional necklaces of Au nanoparticles, which spanned two electrodes 70 μm apart. The nanoparticle necklace array has been shown to behave as a single-electron device at room temperature. The resulting electrochemical field-effect transistor …

Killer Toxin From Several Food-Derived Debaryomyces Hansenii Strains Effective Against Pathogenic Candida Yeasts, Nabaraj Banjara, Kenneth Nickerson, Mallory J. Suhr, Heather E. Hallen-Adams

Kenneth Nickerson Papers

Candida yeasts are the dominant fungi in the healthy human microbiome, but are well-known for causing disease following a variety of perturbations. Evaluation of fungal populations from the healthy human gut revealed a significant negative correlation between the foodborne yeast, Debaryomyces hansenii, and Candida species. D. hansenii is reported to produce killer toxins (mycocins) effective against other yeast species. In order to better understand this phenomenon, a collection of 42 D. hansenii isolates was obtained from 22 cheeses and evaluated for killer activity against Candida albicans and Candida tropicalis over a range of temperatures and pH values. Twenty three …

The Impact Of Urbanization On Mosquito-Borne Viruses, Nikhita Puthuveetil

Undergraduate Research Posters

Mosquito-borne diseases such as yellow fever, dengue, and West Nile are rapidly emerging across the globe. Their emergence is often aided by the growth of their vector population, or the organisms that transmit the virus to the host. Urbanization and land use often destroys the habitat of the virus and its vector. However, the virus and its vector often survive despite the changes to its environment. The goal of this paper is to find out exactly how urbanization and changes in land use affect mosquito-borne viruses and how these viruses survive despite the destruction of their habitats. To understand how …