Development And Characterization Of An In Vitro Four-Species Anaerobic Dental Biofilm Model,
2013
The University of Texas Graduate School of Biomedical Sciences at Houston
Development And Characterization Of An In Vitro Four-Species Anaerobic Dental Biofilm Model, Fernando Andrade
Dissertations and Theses (Open Access)
Dental caries is the most common chronic disease worldwide. It is characterized by the demineralization of tooth enamel caused by acid produced by cariogenic dental bacteria growing on tooth surfaces, termed bacterial biofilms. Cariogenesis is a complex biological process that is influence by multiple factors and is not attributed to a sole causative agent. Instead, caries is associated with multispecies microbial biofilm communities composed of some bacterial species that directly influence the development of a caries lesion and other species that are seemingly benign but must contribute to the community in an uncharacterized way. Clinical analysis of dental caries and …
Divergent Mechanisms Of Interaction Of Helicobacter Pylori And Campylobacter Jejuni With Mucus And Mucins,
2013
Technological University Dublin
Divergent Mechanisms Of Interaction Of Helicobacter Pylori And Campylobacter Jejuni With Mucus And Mucins, Julie Ann Naughton, Karina Mariño, Brendan Dolan, Colm Reid, Ronan Gough, Mary Gallagher, Michelle Kilcoyne, Jared Gerlachscience,, Lokesh Joshi, Pauline Rudd, Stephen Carrington, Billy Bourke, Marguerite Clyne
Articles
Helicobacter pylori and Campylobacter jejuni colonize the stomach and intestinal mucus, respectively. Using a combination of mucus-secreting cells, purified mucins, and a novel mucin microarray platform, we examined the interactions of these two organisms with mucus and mucins. H. pylori and C. jejuni bound to distinctly different mucins. C. jejuni displayed a striking tropism for chicken gastrointestinal mucins compared to mucins from other animals and preferentially bound mucins from specific avian intestinal sites (in order of descending preference: the large intestine, proximal small intestine, and cecum). H. pylori bound to a number of animal mucins, including porcine stomach mucin, but …
Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton,
2013
University of Rhode Island
Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo
Senior Honors Projects
Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue …
Molecular And Genomic Based Insights Into The Evolution Of Enterococcus Faecium From Commensal To Hospital-Adapted Pathogen,
2013
The University of Texas Graduate School of Biomedical Sciences at Houston
Molecular And Genomic Based Insights Into The Evolution Of Enterococcus Faecium From Commensal To Hospital-Adapted Pathogen, Jessica R. Galloway-Pena
Dissertations and Theses (Open Access)
The basis for the recent transition of Enterococcus faecium from a primarily commensal organism to one of the leading causes of hospital-acquired infections in the United States is not yet understood. To address this, the first part of my project assessed isolates from early outbreaks in the USA and South America using sequence analysis, colony hybridizations, and minimal inhibitory concentrations (MICs) which showed clinical isolates possess virulence and antibiotic resistance determinants that are less abundant or lacking in community isolates. I also revealed that the level of ampicillin resistance increased over time in clinical strains. By sequencing the pbp5 gene, …
Secretion Of Tcpf By The Vibrio Cholerae Toxin-Coregulated Pilus Biogenesis Apparatus Requires An N-Terminal Determinant,
2013
Dartmouth College
Secretion Of Tcpf By The Vibrio Cholerae Toxin-Coregulated Pilus Biogenesis Apparatus Requires An N-Terminal Determinant, Christina J. Megli, Ronald K. Taylor
Dartmouth Scholarship
Type IV pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. We and others have shown that type IV pili are important for protein secretion across the outer membrane, similar to type II secretion systems. This study explored the relationship between protein secretion and pilus formation in Vibrio cholerae. The toxin-coregulated pilus (TCP), a type IV pilus required for V. cholerae pathogenesis, is necessary for the secretion of the colonization factor TcpF (T. J. Kirn, N. Bose, and R. K. Taylor, Mol. Microbiol. 49:81–92, 2003). This phenomenon is not unique to V. cholerae; secreted …
Changes In Bacterial Growth Rate Govern Expression Of The Borrelia Burgdorferi Ospc And Erp Infection-Associated Surface Proteins,
2013
University of Kentucky
Changes In Bacterial Growth Rate Govern Expression Of The Borrelia Burgdorferi Ospc And Erp Infection-Associated Surface Proteins, Brandon L. Jutras, Alicia M. Chenail, Brian Stevenson
Microbiology, Immunology, and Molecular Genetics Faculty Publications
The Lyme disease spirochete controls production of its OspC and Erp outer surface proteins, repressing protein synthesis during colonization of vector ticks but increasing expression when those ticks feed on vertebrate hosts. Early studies found that the synthesis of OspC and Erps can be stimulated in culture by shifting the temperature from 23°C to 34°C, leading to a hypothesis that Borrelia burgdorferi senses environmental temperature to determine its location in the tick-mammal infectious cycle. However, borreliae cultured at 34°C divide several times faster than do those cultured at 23°C. We developed methods that disassociate bacterial growth rate and temperature, allowing …
Phi X 174,
2013
Lawrence University
Phi X 174, David J. Hall
Infectious Pathogens
Phi X 174 database number # 1CD3. Phi X 174 is a virus that infects bacteria and was the first DNA-based genome to be sequenced in 1977. This bacteriophage has a [+] circular single-stranded DNA genome. The assembly of the capsid has been successfully done in vitro and is the focus of many studies on self-assembly, drug delivery and nanotechnology.
Dengue Virus,
2013
Lawrence University
Dengue Virus, David J. Hall
Infectious Pathogens
Dengue virus, database # 1THD Dengue fever, is an infectious tropical disease caused by the dengue virus and transmitted by mosquito. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases the disease develops into the life-threatening dengue hemorrhagic fever. Dengue is a positive strand RNA virus that is part of the flavivirus family. Dengue is an enveloped virus meaning it has a nucleocapsid protecting the RNA and the nucleocapsid is surrounded by lipids (hence the name enveloped).
Human Papilloma Virus 16,
2013
Lawrence University
Human Papilloma Virus 16, David J. Hall
Infectious Pathogens
Human Papilloma virus 16, database# 1DZL Infection by most papillomaviruses is either asymptomatic or causes small benign tumors, known as papillomas or warts (e.g. human papillomavirus HPV6 or HPV11). Papillomas caused by some types, however, such as human papillomaviruses 16 and 18, carry a risk of becoming cancerous. Human papilloma virus is a non-enveloped, double stranded, circular DNA virus.
Hepatitis B,
2013
Lawrence University
Hepatitis B, David J. Hall
Infectious Pathogens
Hepatitis B, database # 2g33. Hepatitis B is an infectious inflammatory illness of the liver caused by the hepatitis B virus (HBV). Hepatitis B virus (HBV) is a member of the Hepadnavirus family.The virus particle, (virion) consists of an outer lipid envelope and an icosahedral nucleocapsid core composed of protein. These virions are 42 nM in diameter. The nucleocapsid encloses the viral DNA and a DNA polymerase that has reverse transcriptase activity.
Identifying Pathogenic Salmonella Serotypes Isolated From South Central Va Waterways Via Sequential Pcr Analysis,
2013
Longwood University
Identifying Pathogenic Salmonella Serotypes Isolated From South Central Va Waterways Via Sequential Pcr Analysis, Timothy M. Smith, Jr.
Theses & Honors Papers
Researchers often debate whether all serovars of Salmonella enterica are pathogenic to humans. Broiler houses containing chickens are a major source of Salmonella and serve as potential reservoirs. Therefore, farmers must take substantial measures in order to avoid contamination with their products. The primary objective of the study was to determine whether the four most clinically relevant Salmonella spp. serovars from poultry houses could be isolated from the environmental waterways in Prince Edward and Cumberland Counties of Virginia. The study adapted a serotyping method designed for typing Salmonella to gain a perspective of possible serovars that may be found in …
Genetic Analysis Of The Gene Varpa_4519 Encoding A Nonribosomal Peptide Synthetase Crucial For Surfactant Production In Variovorax Paradoxus Eps,
2013
California State University, San Bernardino
Genetic Analysis Of The Gene Varpa_4519 Encoding A Nonribosomal Peptide Synthetase Crucial For Surfactant Production In Variovorax Paradoxus Eps, Richard John Fredendall
Theses Digitization Project
This study investigated swarming by Variovoras paradoxus EPS to understand the genes involved and the mechanisms for swarming motility. Swarming motility is defined as a movement on a surface requiring surfactant and flagella. Swarming is a differentiation process in which bacteria enter into an excited state of constant movement. The mechanism for swarming is driven by nutrient factors, and is not based on specific development stages of the bacterial life cycle.
Resolving The Nutritional Requirements Of The Bile Acid-Dehydroxylating Gut Bacterium Clostridium Scindens,
2013
Eastern Illinois University
Resolving The Nutritional Requirements Of The Bile Acid-Dehydroxylating Gut Bacterium Clostridium Scindens, Oindrila Paul
Masters Theses
Compared to the other parts of the human body, the gastrointestinal tract harbors a complex microbiota. The impact of the indigenous microbiota on host physiology is most pronounced in the colon, where the primary bile acids chenodeoxycholic acid and cholic acid are converted, via 7α-dehydroxylation, to the toxic secondary bile acids lithocholic acid and deoxycholic acid, respectively, by Clostridium scindens, an obligate anaerobe. Interestingly, other than bile acid dehydroxylation, little is known about the basic physiology of C. scindens. Understanding the metabolism of C. scindens will hopefully provide much-needed information as to how this gut bacterium impacts human health and …
Equine Serum Antibody Responses To Streptococcus Equi And Streptococcus Zooepidemicus,
2013
University of Kentucky
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 …
Characterization Of Brer Interaction With The Bile Response Promoters Breab And Brer In Vibrio Cholerae,
2013
Dartmouth College
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 …
Neisseria Oralis Sp. Nov., Isolated From Healthy Gingival Plaque And Clinical Samples,
2013
New York State Department of Health
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 …
Seroprevalence Of Brucellosis In Livestock Within Three Endemic Regions Of The Country Of Georgia,
2013
Laboratory of the Ministry of Agriculture, Tbilisi, Georgia
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,
2013
Thompson Rivers University, Kamloops, Canada
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 …
Anti-Germinants As A New Strategy To Prevent Clostridium Difficile Infections,
2012
University of Nevada, Las Vegas
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,
2012
University of Nevada, Las Vegas
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 …
