Microbiology Commons^™

Seroprevalence And Genetic Characterization Of Toxoplasma Gondii In Three Species Of Pet Birds In China, Wei Cong, Meng Qing-Feng, Hui-Qun Song, Dong-Hui Zhou, Si-Yang Huang, Ai-Dong Qian, Chunlei Su, Xing-Quan Zhu

Microbiology Publications and Other Works

Background

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common zoonosis worldwide, affecting a wide range of warm-blooded mammals and birds worldwide. However, no information on T. gondii infection in pet birds in China is available. Therefore, this study was performed to determine the prevalence of T. gondii infection in pet birds in Gansu province, China.

Methods

A total of 687 blood samples were collected from pet birds (Carduelis spinus, Alauda gulgula, Cocothraustes migratorlus) in three representative administrative regions in Gansu province, northwest China between August 2011 and September 2012 T. gondii antibodies …

Biochar And Vermicompost Amendments In Vegetable Cropping Systems: Impacts On Soil Quality, Soil-Borne Pathogens And Crop Productivity, Nathan Lee Shoaf

Open Access Theses

Amending soils with biochar and vermicompost has the potential to provide multiple benefits for specialty crops including pathogen suppression and increased crop productivity. Oomycete pathogens such as Phytophthora capsici can devastate crop fields and they are difficult to control presenting significant management challenges for Midwestern growers. Soils amended with a microbially-inoculated softwood biochar increased carrot root growth relative to the control and corn stover biochar in 2011, while the corn stover biochar also increased carrot root growth relative to the control, but only in two varieties. Neither biochar treatment influenced carrot growth in 2012. In greenhouse trials, vermicompost amendments provided …

Environmental Influences On Bacterio-Phytoplanktonic Coupling And Bacterial Growth Efficiency In A Sub-Tropical Estuary, Rachel Kotkowski

FIU Electronic Theses and Dissertations

Bacterio-phytoplanktonic coupling and bacterial growth efficiency (BGE) measurements were used to analyze microbial trophic dynamics and the influence of environmental factors in Florida Bay, Florida. Phytoplankton gross primary productivity (GPP) was measured using 24-hour in situ oxygen incubations; bacterial productivity (BP) was measured using ³H- thymidine incorporation. Weak bacterio-phytoplanktonic coupling was observed over the sampling period. BP was more influenced by local total nitrogen concentrations while GPP was more evenly distributed. BGE rates were low but consistent with marine and estuarine ecosystems worldwide. Results suggest that bacterioplankton growth in Florida Bay is relatively uncoupled from phytoplankton production, which may …

Effect Of Carvacrol-Loaded Nanoemulsions On A Bioluminescent Strain Of Escherichia Coli O157:H7, Clara Maria Vasquez Mejia

Open Access Theses

Nanoemulsions have been shown to be effective delivery vehicles for poorly water soluble natural antimicrobials. In this study the antimicrobial activity of carvacrol (5-isopropyl-2-methylphenol) nanoemulsions against a bioluminescent Escherichia coli O157:H7 was investigated using light emission as an indicator of cell viability. Different emulsifiers (Ultralec Lecithin and Tween 20), oils (Palm stearin and Coconut oil) and various carvacrol concentrations (0, 1, 2 and 2.5%) were evaluated. Bioluminescence was monitored in situ using a Hamamatsu (photo multiplier tube) sensor module integrated with a Programmable Logic Controller interfaced with a PC for data acquisition. Bioluminescence decreased rapidly with the addition of emulsions …

Selected Durability Studies Of Geopolymer Concrete With Respect To Carbonation, Elevated Temperature, And Microbial Induced Corrosion, Mohammad Sufian Badar

Doctoral Dissertations

This thesis reports a comprehensive study related to the experimental evaluation of carbonation in reinforced geopolymer concrete, the evaluation of geopolymer concretes at elevated temperature, and the resistance of geopolymer concrete to microbial induced corrosion (MIC).

Carbonation: Reinforced concretes, made of geopolymer, prepared from two class F fly ashes and one class C fly ash, were subjected to accelerated carbonation treatment for a period of 450 days. Electrochemical, microstructure and pore structure examinations were performed to evaluate the effect of corrosion caused due to carbonation. GPC specimens prepared from class F fly ash exhibited lower corrosion rates by a factor …

Comparison Of Two Separation Methods For Biological Particles: Field-Flow Fractionation (Fff) And Sucrose Density Gradients, Cody E. Garrison

OES Theses and Dissertations

Sucrose gradient centrifugation and Field-flow fractionation (FFF) are two different particle separation methods that overcome the problems of similar size microorganisms clumping together during standard filtration methods. FFF separates particles based on size and density via the parabolic velocity profile of laminar flow in a ribbon-like channel. The sucrose method separates particles via centrifugation in a density gradient. Both techniques worked well in separating eukaryotic from prokaryotic microbes, with the preferred method depending on the type and relative abundance of organisms to be separated. Minicells were separated from mother cells in transformed Escherichia coli cultures, heterotrophic flagellates (e.g., Diplonema papillatum …

Reciprocity In Microbiome And Immune System Interactions And Its Implications In Disease And Health., Enayat Nikoopour, Bhagirath Singh

Microbiology & Immunology Publications

Adaptation of the whole microbial normal flora residing in a host to its natural habitat over an evolutionary period has resulted in peaceful coexistence with mutual benefits for both microbiota and host in steady state. This symbiotic relationship between host and microbiota has a significant impact on shaping the immune response in the host to achieve an immune tolerance to microbiota but retaining the ability to respond to invading pathogens. Perturbation of this balance by manipulation of microbial communities in the host can lead to immune dysregulation and susceptibility to diseases. By studying the host in the absence of microbiota …

Characterization Of Rhizobial Diversity And Relationship Of Rhizobial Partner And Legume Performance In Four South Florida Pine Rockland Soils, Vanessa Sánchez

FIU Electronic Theses and Dissertations

Pine rocklands are endangered ecosystems unique to south Florida, the Bahamas and Cuba. As a result of their karstic calcium carbonate­rich soil, these systems are limited in phosphorus and nitrogen, making symbiotic associations critical to plant growth. Four leguminous species (Cajanus cajan, Chamaecrista fasciculata, Tephrosia angustissima, and Abrus precatorious) were used to determine the relationship between rhizobial partners and plant performance, and the symbiosis related gene nifH was amplified to characterize the diversity of rhizobial symbionts. Plants were grown in soils from four different south Florida pine rocklands, and a salinity treatment was added to determine …

The Roles Of Microcystin And Sulfide In Physiology And Tactic Responses Of Pathogenic And Non-Pathogenic Mat-Forming Cyanobacteria, Abigael C. Brownell

FIU Electronic Theses and Dissertations

Planktothricoides raciborskii and Roseofilum reptotaenium are physiologically similar, yet ecologically distinct organisms found in a hot spring outflow and coral black band disease (BBD), respectively. The aim of this study was to elucidate the relationship between R. reptotaenium and sulfide in BBD, to compare microcystin (MC) production in response to environmental factors, and to determine chemotactic responses to MC and sulfide by the two organisms. Results showed that the pathogenicity of R. reptotaenium in BBD is dependent on sulfate-reducing bacteria as secondary pathogens. Roseofilum reptotaenium produced significantly more MC than P. raciborskii, as measured using ELISA. Roseofilum reptotaenium …

Deletion Mutant Library For Investigation Of Functional Outputs Of Cyclic Diguanylate Metabolism In Pseudomonas Aeruginosa Pa14, Dae-Gon Ha, Megan E. Richman, George A. O'Toole

Dartmouth Scholarship

We constructed a library of in-frame deletion mutants targeting each gene in Pseudomonas aeruginosa PA14 predicted to participate in cyclic di-GMP (c-di-GMP) metabolism (biosynthesis or degradation) to provide a toolkit to assist investigators studying c-di-GMP-mediated regulation by this microbe. We present phenotypic assessments of each mutant, including biofilm formation, exopolysaccharide (EPS) production, swimming motility, swarming motility, and twitch motility, as a means to initially characterize these mutants and to demonstrate the potential utility of this library.

Cd46-Mediated Transduction Of A Species D Adenovirus Vaccine Improves Mucosal Vaccine Efficacy, Zenaido T. Camacho, Michael A. Barry, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

The high levels of preexisting immunity against Adenovirus type 5 (Ad5) have deemed Ad5 unusable for translation as a human vaccine vector. Low seroprevalent alternative viral vectors may be less impacted by preexisting immunity, but they may also have significantly different phenotypes from that of Ad5. In this study we compare species D Ads (26, 28, and 48) to the species C Ad5. In vitro transduction studies show striking differences between the species C and D viruses. Most notably, Ad26 transduced human dendritic cells much more effectively than Ad5. In vivo imaging studies showed strikingly different transgene expression profiles. The …

The Wnt/Planar Cell Polarity Pathway Component Vangl2 Induces Synapse Formation Through Direct Control Of N-Cadherin, Tadahiro Nagaoka, Riuko Ohashi, Ayumu Inutsuka, Seiko Sakai, Nobuyoshi Fujisawa, Minesuke Yokoyama, Yina H. Huang, Michihiro Igarashi, Masashi Kishi

Dartmouth Scholarship

Although regulators of the Wnt/planar cell polarity (PCP) pathway are widely expressed in vertebrate nervous systems, their roles at synapses are unknown. Here, we show that Vangl2 is a postsynaptic factor crucial for synaptogenesis and that it coprecipitates with N-cadherin and PSD-95 from synapse-rich brain extracts. Vangl2 directly binds N-cadherin and enhances its internalization in a Rab5-dependent manner. This physical and functional interaction is suppressed by β-catenin, which binds the same intracellular region of N-cadherin as Vangl2. In hippocampal neurons expressing reduced Vangl2 levels, dendritic spine formation as well as synaptic marker clustering is significantly impaired. Furthermore, Prickle2, another postsynaptic …

Structure And Function Of Zooplankton-Associated Bacterial Communities In A Temperate Estuary Change More With Time Than With Zooplankton Species, Samatha L. Bickel, Kam W. Tang, Hans-Peter Grossart

VIMS Articles

Zooplankton support distinct bacterial communities in high concentrations relative to the surrounding water, but little is known about how the compositions and functionalities of these bacterial communities change through time in relation to environmental conditions. We conducted a year-long field study of bacterial communities associated with common zooplankton groups as well as free-living bacterial communities in the York River, a tributary of Chesapeake Bay. Bacterial community genetic fingerprints and their carbon substrate usage were examined by denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA and by Biolog EcoPlates, respectively. Zooplankton-associated communities were genetically distinct from free-living bacterial communities but …

Characterization Of Fusobacterium Isolates From The Respiratory Tract Of White-Tailed Deer (Odocoileus Virginianus ), Amit Kumar, Dvm, Ms, Phd

Amit Kumar, DVM, MS, PhD

A total of 23 clinical isolates of Fusobacterium spp. were recovered at necropsy over a 2-year period from the respiratory tract of white-tailed deer (Odocoileus virginianus). Isolates were identified as Fusobacterium varium (18/23),Fusobacterium necrophorum subsp. funduliforme (3/23), and Fusobacterium necrophorum subsp. necrophorum (2/23). Usingpolymerase chain reaction–based detection of virulence genes, all F. necrophorum isolates were positive for the promoter region of the leukotoxin operon and the hemagglutinin-related protein gene, while all F. varium isolates were negative. The presence of the leukotoxin gene in F. necrophorum isolates and the absence of this gene in F. varium isolates were confirmed by Southern …

Cluster M Mycobacteriophages Bongo, Pegleg, And Rey With Unusually Large Repertoires Of Trna Isotypes, Welkin H. Pope, Kirk R. Anders, Madison Baird, Charles A. Bowman, Michelle M. Boyle, Gregory W. Broussard, Tiffany Chow, Kari L. Clase, Shannon Cooper, Kathleen A. Cornely, Randall J. Dejong, Veronique A. Delesalle, Lisa Deng, David Dunbar, Nicholas P. Edgington, Christina M. Ferreira, Kathleen Weston Hafer, Grant A. Hartzog, J. Robert Hatherill, Lee E. Hughes, Khristina Ipapo, Greg P. Krukonis, Christopher G. Meier, Denise L. Monti, Matthew R. Olm, Shallee T. Page, Craig L. Peebles, Claire A. Rinehart, Michael R. Rubin, Daniel A. Russell, Erin R. Sanders, Morgan Schoer, Christopher D. Shaffer, James Wherley, Edwin Vazquez, Han Yuan, Daiyuan Zhang, Steven G. Cresawn, Deborah Jacobs-Sera, Roger W. Hendrix, Graham F. Hatfull

Chemistry & Biochemistry Faculty Publications

Genomic analysis of a large set of phages infecting the common host Mycobacterium smegmatis mc2155 shows that they span considerable genetic diversity. There are more than 20 distinct types that lack nucleotide similarity with each other, and there is considerable diversity within most of the groups. Three newly isolated temperate mycobacteriophages, Bongo, PegLeg, and Rey, constitute a new group (cluster M), with the closely related phages Bongo and PegLeg forming subcluster M1 and the more distantly related Rey forming subcluster M2. The cluster M mycobacteriophages have siphoviral morphologies with unusually long tails, are homoimmune, and have larger than average genomes …

Comparafac: A Library And Tools For Rapid And Quantitative Comparison Of Dissolved Organic Matter Components Resolved By Parallel Factor Analysis., Thomas B. Parr, Tsutomu Ohno, Kevin Simon

Publications

Parallel Factor Analysis (PARAFAC) is a well-established method for characterizing dissolved organic matter (DOM). While methods for sample processing and PARAFAC analysis are well defined and robust, subsequent classification of DOM fluorescence components and comparisons of components among studies remain highly qualitative. Because these comparisons often guide the interpretation of subsequent data, it is important that quantitatively accurate comparisons be made. We developed a statistical tool, comPARAFAC, using a modified Tucker’s Congruence Coefficient (mTCC), an established method of factor comparison, to provide a quantitative basis for comparing models. To develop and test this tool we used mTCC to compare factors …

A Genomewide Overexpression Screen Identifies Genes Involved In The Phosphatidylinositol 3-Kinase Pathway In The Human Protozoan Parasite Entamoeba Histolytica, Amrita B. Koushik, Brenda H. Welter, Michelle L. Rock, Lesly A. Temesvari

Publications

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. E. histolytica relies on motility, phagocytosis, host cell adhesion, and proteolysis of extracellular matrix for virulence. In eukaryotic cells, these processes are mediated in part by phosphatidylinositol 3-kinase (PI3K) signaling. Thus, PI3K may be critical for virulence. We utilized a functional genomics approach to identify genes whose products may operate in the PI3K pathway in E. histolytica. We treated a population of trophozoites that were overexpressing genes from a cDNA library with a near-lethal dose of the PI3K inhibitor wortmannin. This screen was based on the rationale …

Chip-Seq And Rna-Seq Reveal An Amrz-Mediated Mechanism For Cyclic Di-Gmp Synthesis And Biofilm Development By Pseudomonas Aeruginosa, Christopher J. Jones, David Newsom, Benjamin Kelly, Yasuhiko Irie, Laura K. Jennings, Binjie Xu, Dominique H. Limoli, Joe J. Harrison, Matthew R. Parsek, Peter White, Daniel J. Wozniak

Biology Faculty Publications

The transcription factor AmrZ regulates genes important for P. aeruginosa virulence, including type IV pili, extracellular polysaccharides, and the flagellum; however, the global effect of AmrZ on gene expression remains unknown, and therefore, AmrZ may directly regulate many additional genes that are crucial for infection. Compared to the wild type strain, a ΔamrZ mutant exhibits a rugose colony phenotype, which is commonly observed in variants that accumulate the intracellular second messenger cyclic diguanylate (c-di-GMP). Cyclic di-GMP is produced by diguanylate cyclases (DGC) and degraded by phosphodiesterases (PDE). We hypothesized that AmrZ limits the intracellular accumulation of c-di-GMP through transcriptional repression …

Vaccines Within Vaccines: The Use Of Adenovirus Types 4 And 7 As Influenza Vaccine Vectors, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Adenovirus Types 4 and 7 (Ad4 and Ad7) are associated with acute respiratory distress (ARD). In order to prevent widespread Ad-associated ARD (Ad-ARD) the United States military immunizes new recruits using a safe and effective lyophilized wildtype Ad4 and Ad7 delivered orally in an enteric-coated capsule. We cloned Ad4 and Ad7 and modified them to express either a GFP-Luciferase (GFPLuc) fusion gene or a centralized influenza H1 hemagglutinin (HA1-con). BALB/c mice were injected with GFPLuc expressing viruses intramuscularly (i.m.) and intranasally (i.n.). Ad4 induced significantly higher luciferase expression levels as compared with Ad7 by both routes. Ad7 transduction was restored …

Deep Rna Sequencing Reveals Hidden Features And Dynamics Of Early Gene Transcription In Paramecium Bursaria Chlorella Virus 1, Guillaume Blanc, Michael Mozar, Irina V. Agarkova, James R. Gurnon, Giane Yanai-Balser, Janet M. Rowe, Yuannan Xia, Jean-Jack Riethoven, David D. Dunigan, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

Paramecium bursaria chlorella virus 1 (PBCV-1) is the prototype of the genus Chlorovirus (family Phycodnaviridae) that infects the unicellular, eukaryotic green alga Chlorella variabilis NC64A. The 331-kb PBCV-1 genome contains 416 major open reading frames. A mRNA-seq approach was used to analyze PBCV-1 transcriptomes at 6 progressive times during the first hour of infection. The alignment of 17 million reads to the PBCV-1 genome allowed the construction of single-base transcriptome maps. Significant transcription was detected for a subset of 50 viral genes as soon as 7 min after infection. By 20 min post infection (p.i.), transcripts were detected for …