Bacteriology Commons^™

Equine Serum Antibody Responses To Streptococcus Equi And Streptococcus Zooepidemicus, Rafaela De Negri

Theses and Dissertations--Veterinary Science

Streptococcus zooepidemicus (Sz) and Streptococcus equi (Se) share 98% DNA sequence homology, but display different pathogenic properties. Infection by one organism does not cross-protect against the other. To better understand pathogenic differences between these organisms and gain information about which proteins are expressed in horses infected experimentally with Se, intrauterine Sz or naturally with respiratory Sz we compared antibody specificities of convalescent sera using ELISA. These comparisons were based on sets of 8 and 14 immunoreactive recombinant proteins of Se strain CF32 and Sz strain NC78, respectively. Sera from donkeys that were previously naturally affected with strangles and later developed …

Neisseria Oralis Sp. Nov., Isolated From Healthy Gingival Plaque And Clinical Samples, William J. Wolfgang, Teresa V. Passaretti, Reashma Jose, Jocelyn Cole, An Coorevits, Andrea N. Carpenter, Sherly Jose, Anita Van Landschoot, Jacques Izard, Donna J. Kohlerschmidt, Peter Vandamme, Floyd E. Dewhirst, Mark A. Fisher, Kimberlee A. Musser

Department of Food Science and Technology: Faculty Publications

A polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida, and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbor, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the …

Characterization Of Brer Interaction With The Bile Response Promoters Breab And Brer In Vibrio Cholerae, Francisca A. Cerda-Maira, Gabriela Kovacikova, Brooke A. Jude, Karen Skorupski, Ronald Taylor

Dartmouth Scholarship

The Vibrio cholerae BreR protein is a transcriptional repressor of the breAB efflux system operon, which encodes proteins involved in bile resistance. In a previous study (F. A. Cerda-Maira, C. S. Ringelberg, and R. K. Taylor, J. Bacteriol. 190:7441-7452, 2008), we used gel mobility shift assays to determine that BreR binds at two independent binding sites at the breAB promoter and a single site at its own promoter. Here it is shown, by DNase I footprinting and site-directed mutagenesis, that BreR is able to bind at a distal and a proximal site in the breAB promoter. However, only one of …

Seroprevalence Of Brucellosis In Livestock Within Three Endemic Regions Of The Country Of Georgia, Eliso Mamisashvili, Ian T. Kracalik, Tinatin Onashvili, Lela Kerdzevadze, Ketevan Goginashvili, Tamar Tigilauri, Marina Donduashvili, Marina Nikolaishvili, Irma Beradze, Marina Zakareishvili, Maka Kokhreidze, Makvala Gelashvili, Nino Vepkhvadze, S. Elizabeth Rácz, Philip H. Elzer, Mikeljon P. Nikolich, Jason K. Blackburn

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Brucellosis is the one of most common livestock zoonoses in Georgia, resulting in significant economic losses. Livestock were sampled in three regions of Georgia (Kakheti, Kvemo Kartli, Imereti). Districts that historically reported high numbers of brucellosis related morbidity were selected for serological, bacteriological and molecular surveys. Surveying efforts yielded samples from 10,819 large and small ruminants. In total, 735 serological tests were positive on Rose Bengal and 33 bacterial isolates were recovered and identified as Brucella melitensis or Brucella abortus by microbiology and AMOS-PCR. A Bayesian framework was implemented to estimate the true prevalence of the disease given an imperfect …

Cure From The Cave: Volcanic Cave Actinomycetes And Their Potential In Drug Discovery, Naowarat (Ann) Cheeptham Dr., Tara Sadoway, Devon Rule, Kent Watson, Paul Moote, Laiel C. Soliman, Nicholas Azad, Kingsley Donkor, Derrick Horne

International Journal of Speleology

Volcanic caves have been little studied for their potential as sources of novel microbial species and bioactive compounds with new scaffolds. We present the first study of volcanic cave microbiology from Canada and suggest that this habitat has great potential for the isolation of novel bioactive substances. Sample locations were plot ted on a contour map that was compiled in ArcView 3.2. Over 400 bacterial isolates were obtained from the Helmcken Falls cave in Wells Gray Provincial Park, British Columbia. From our preliminary screen, of 400 isolates tested, 1% showed activity against extended spectrum ß-lactamase E. coli, 1.75% against Escherichia …

Bacteriophage Ecology In A Commercial Cucumber Fermentation, Jean Lu, Ilenys M. Perez-Diaz, Janet S. Hayes, Fred Bredit Jr.

Faculty Articles

To reduce high-salt waste from cucumber fermentations, low-salt fermentations are under development. These fermentations may require the use of starter cultures to ensure normal fermentations. Because potential phage infection can cause starter culture failure, it is important to understand phage ecology in the fermentations. This study investigated the phage ecology in a commercial cucumber fermentation. Brine samples taken from a fermentation tank over a 90-day period were plated onto deMan-Rogosa-Sharpe agar plates. A total of 576 lactic acid bacterial isolates were randomly selected to serve as potential hosts for phage isolation. Filtered brine served as a phage source. Fifty-seven independent …

Anti-Germinants As A New Strategy To Prevent Clostridium Difficile Infections, Amber Janece Howerton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridium difficileinfections (CDI) have emerged as a leading cause of hospital-associated complications. CDI is the major cause of antibiotic-related cases of diarrhea and nearly all cases of pseudomembranous colitis. The infective form of C. difficileis the spore, a dormant and hardy structure that forms under stress. Germination of C. difficile spores into toxin producing bacteria in the GI tract of susceptible patients is the first step in CDI establishment. Patient susceptibility occurs with a disruption of the natural gut microbiota by broad-spectrum antibiotics. Antibiotic treatments usually resolve CDI but refractory cases are on the rise. Of great concern is the …

Natural And Lignocellulose-Enriched Microbial Communities In Great Boiling Spring, Nv, Jessica Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

The natural microbial communities present in Great Boiling Spring were investigated and contrasted against those present after in situ enrichment with lignocellulose. High-throughput cultivation-independent DNA sequencing of the V8 region of the small subunit (SSU) rRNA gene generated a total of 274,119 quality-filtered pyrosequencing fragments. Twelve natural spring samples were analyzed, including four high-temperature water samples and eight sediment samples ranging from 87 - 62 °C. Eight lignocellulosic enrichments incubated in the spring sediment and water at two high-temperature sites were analyzed. The natural water communities were found to be extremely uneven but relatively constant throughout time. The natural sediment …

The Evolution Of Host Specificity In The Vertebrate Gut Symbiont Lactobacillus Reuteri, Steven Frese

Department of Food Science and Technology: Dissertations, Theses, and Student Research

The vertebrate gut is home to one of the densest populations of life on Earth. This microbial community has a profound effect on host health, nutrition, development, behavior, and evolution. However, very little is known about how these microbes have evolved with their vertebrate hosts, how and whether they select hosts or how they remain associated with their hosts. Recent work identified Lactobacillus reuteri as an organism that is composed of host-specific sub-populations, each population associated with a different host animal. Representatives from each host-associated population were tested for their ability to colonize gnotobiotic mice, which only rodent strains could …

Fecal Indicator Bacteria In Knitting Mill Creek With A Comparison Of Methods Used To Enumerate E. Coli, Manju Nagarajan

OES Theses and Dissertations

This research seeks to evaluate the impact of an urban, multi-use neighborhood on the bacteriological quality of water in Knitting Mill Creek, a blind arm of the Lafayette River, a sub-estuary of the lower Chesapeake Bay. A principal objective was to determine the effects of rainfall, a surrogate for run-off, on water-column concentrations of fecal-indicator bacteria (FIB). I collected water samples weekly (September 2009-December 2010) and biweekly (January 2010-December 2011) at a storm-sewer outfall and a nearby marina and quantified their E. coli and enterococci concentrations using Colilert-18 and Enterolert, most-probable-number assays. In addition, I took monthly samples for these …

Borrelia Burgdorferi Cp32 Bpab Modulates Expression Of The Prophage Nucp Nuclease And Ssbp Single-Stranded Dna-Binding Protein, Alicia M. Chenail, Brandon L. Jutras, Claire A. Adams, Logan H. Burns, Amy Bowman, Ashutosh Verma, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Borrelia burgdorferi BpaB proteins of the spirochete's ubiquitous cp32 prophages are DNA-binding proteins, required both for maintenance of the bacteriophage episomes and for transcriptional regulation of the cp32 erp operons. Through use of DNase I footprinting, we demonstrate that BpaB binds the erp operator initially at the sequence 5′-TTATA-3′. Electrophoretic mobility shift assays indicated that BpaB also binds with high affinity to sites located in the 5′ noncoding regions of two additional cp32 genes. Characterization of the proteins encoded by those genes indicated that they are a single-stranded DNA-binding protein and a nuclease, which we named SsbP and NucP, …

Genomic Characteristics Of An Environmental Microbial Community Harboring A Novel Human Uncultured Tm7 Bacterium Associated With Oral Diseases, Michael Abrams, David Barton, Eamon Vandaei, Diana Romero, Adam Caldwell, Cleber C. Ouverney

Faculty Publications, Biological Sciences

The diversity of prokaryotes associated with humans has been dominated by uncultured species (not isolated in pure culture). For instance, nearly 80% of the human gut and 68% of the human oral microbes are thought to be uncultured; some of which have been associated with human oral, digestive, vaginal, and cardiovascular diseases. The revalence of uncultured pathogens is expected to continue to increase within the near future. In fact, public databases such as GenBank have nearly quadrupled the number of candidate phyla (those made entirely of uncultured organisms) since the 1980s and currently lists many new lineages of unclassified Bacteria …

The Crispr/Cas Adaptive Immune System Of Pseudomonas Aeruginosa Mediates Resistance To Naturally Occurring And Engineered Phages, Kyle C. Cady, Joe Bondy-Denomy, Gary E. Heussler, Alan R. Davidson, George A. O'Toole

Dartmouth Scholarship

Here we report the isolation of 6 temperate bacteriophages (phages) that are prevented from replicating within the laboratory strain Pseudomonas aeruginosa PA14 by the endogenous CRISPR/Cas system of this microbe. These phages are only the second identified group of naturally occurring phages demonstrated to be blocked for replication by a nonengineered CRISPR/Cas system, and our results provide the first evidence that the P. aeruginosa type I-F CRISPR/Cas system can function in phage resistance. Previous studies have highlighted the importance of the protospacer adjacent motif (PAM) and a proximal 8-nucleotide seed sequence in mediating CRISPR/Cas-based immunity. Through engineering of a protospacer …

Minor Pilins Of The Type Iv Pilus System Participate In The Negative Regulation Of Swarming Motility, S L. Kuchma, E. F. Griffin, G. A. O'Toole

Dartmouth Scholarship

Pseudomonas aeruginosa exhibits distinct surface-associated behaviors, including biofilm formation, flagellum-mediated swarming motility, and type IV pilus-driven twitching. Here, we report a role for the minor pilins, PilW and PilX, components of the type IV pilus assembly machinery, in the repression of swarming motility. Mutating either the pilW or pilX gene alleviates the inhibition of swarming motility observed for strains with elevated levels of the intracellular signaling molecule cyclic di-GMP (c-di-GMP) due to loss of BifA, a c-di-GMP-degrading phosphodiesterase. Blocking PilD peptidase-mediated processing of PilW and PilX renders the unprocessed proteins defective for pilus assembly but still functional in c-di-GMP-mediated swarming …

Production And Degradation Of 4-Ethylphenol In Lactobacillus Sp. Pep8 Cultures And In Blended Swine Lagoon Enrichments, Clinton W. Copp

Masters Theses & Specialist Projects

4-Ethylphenol (4-EP) is a malodorant of swine waste and is derived from a component of lignin called p-coumaric acid (p-CA). The production of 4-EP from lignin in swine waste is untested. Additionally, the effect of Fe (III) on 4-EP levels is unknown. Four experiments were performed to determine if Lactobacillus sp. pep8 cultures, as well as enriched swine lagoon slurries, could liberate p-CA from lignin and convert p-CA to 4-EP. Furthermore, it was tested if the addition of Fe (III) influences the conversion of p- CA to 4-EP.

Experiment 1 tested Lactobacillus sp. pep8 cultures to determine if the addition …

Regulation Of To Xin Synthesis By Clostridium Difficile, Charles Darkoh

Dissertations and Theses (Open Access)

Clostridium difficile is the leading definable cause of nosocomial diarrhea worldwide due to its virulence, multi-drug resistance, spore-forming ability, and environmental persistence. The incidence of C. difficile infection (CDI) has been increasing exponentially in the last decade. Virulent strains of C. difficile produce either toxin A and/or toxin B, which are essential for the pathogenesis of this bacterium. Current methods for diagnosing CDI are mostly qualitative tests that detect the bacterium, the toxins, or the toxin genes. These methods do not differentiate virulent C. difficile strains that produce active toxins from non-virulent strains that do not produce toxins or produce …

Epoxide-Mediated Cifr Repression Of Cif Gene Expression Utilizes Two Binding Sites In Pseudomonas Aeruginosa, Alicia E. Ballok, Christopher D. Bahl, Emily L. Dolben, Allia K. Lindsay, Jessica D. St. Laurent, Deborah Hogan, Dean Madden, George A. O'Toole

Dartmouth Scholarship

Pseudomonas aeruginosa secretes an epoxide hydrolase virulence factor that reduces the apical membrane expression of ABC transporters such as the cystic fibrosis transmembrane conductance regulator (CFTR). This virulence factor, named CFTR inhibitory factor (Cif), is regulated by a TetR-family, epoxide-responsive repressor known as CifR via direct binding and repression. We identified two sites of CifR binding in the intergenic space between cifR and morB, the first gene in the operon containing the cif gene. We have mapped these binding sites and found they are 27 bp in length, and they overlap the -10 and +1 sites of both the cifR …

Serratia Marcescens: The Miracle Bacillus, Alan L. Gillen, Rebekah Gibbs

Faculty Publications and Presentations

The objectives of this article are to explain the mysterious appearance of crimson-colored bacteria on food and communion bread/wafers, over the centuries, as well as to describe the biological basis

Efficacy Comparison Of Various Pcr Master Mixes And Thermal Cycling Parameters For Detection Of Brucella Abortus In Multiplex Assays, Kevin J. Testo, Jason A. Olivas, Alda C. Carrillo, Pejman Naraghi-Arani

STAR Program Research Presentations

Diagnostic testing for bioterrorism agents in food is essential for the safety and welfare of the general populace. Multiplex assays provide the means to test for multiple pathogen signatures with a single polymerase chain reaction (PCR) test. PCR, Luminex xMAP ® infrared fluorophore bead technology, and flow cytometry, multiplex diagnostic assays are incredibly specific and sensitive to highly conserved regions at various loci in a microbe’s genome. In order to increase the effectiveness of the PCR and the resulting fluorescent response of the beads, different PCR master mix commercial kits were compared to the standard AgPath RT-PCR mix. This study …

Identification Of Persistent Long Range Interactions In GA95 And GB95 Through Thermal Unfolding Simulations, Milen Redai Tesfamariam

Chemistry & Biochemistry Theses & Dissertations

For over five decades, different experiments have been performed to research how proteins attain their native three dimensional structures. However, the folding problem continues to be a puzzle in modern science. The design of two proteins that have maximal sequence identity but different folds and functions is one method that is being used to study the relationship between protein structure and amino acid sequence. In particular, mutant proteins of Streptococcus protein G, G_A and G_B, have 95% sequence identity and a 3a helix fold and β4/a fold, respectively. Molecular dynamics simulations of G_A95 …