Microbiology Commons^™

Biochemical Characterization Of Binding Partners Of Two Hsp70 Co-Chaperones In Saccharomyces Cerevisiae, Jacob Verghese

Dissertations and Theses (Open Access)

Cells are exposed to a variety of environmental and physiological changes including temperature, pH and nutrient availability. These changes cause stress to cells, which results in protein misfolding and altered cellular protein homeostasis. How proteins fold into their three-dimensional functional structure is a fundamental biological process with important relevance to human health. Misfolded and aggregated proteins are linked to multiple neurodegenerative diseases, cardiovascular disease and cystic fibrosis. To combat proteotoxic stress, cells deploy an array of molecular chaperones that assist in the repair or removal of misfolded proteins.

Hsp70, an evolutionarily conserved molecular chaperone, promotes protein folding and helps maintain …

Interactions Of Zooplankton And Phytoplankton With Cyanobacteria, Rebecca Alexander

School of Natural Resources: Dissertations, Theses, and Student Research

Cyanobacteria are a major concern in Nebraska reservoirs and are capable of producing toxins that can cause skin irritations and gastrointestinal problems, as well as affect the nervous system. It is important to determine the mechanisms that can cause cyanobacteria blooms due to the effect they can have on human health. The interaction of zooplankton and other phytoplankton groups with cyanobacteria is important because there is a biological component in surface waters that should be taken into consideration along with the physical and chemical parameters that have been noted to promote cyanobacteria. For example, zooplankton have the ability to alter …

The Role Of Hsc-70 In Very Low Density Lipoprotein Tranport Vesicle Golgi Fusion Complex Formation, Erika Nafi Valencia

HIM 1990-2015

Excess production and secretion of very low-density lipoprotein (VLDL) by the liver into the circulatory system is directly related to atherosclerosis, a chronic cardiovascular disease that threatens the lives of many worldwide and continues to be a leading cause of death in the United States. The rate-limiting step in VLDL secretion is its transport from the site of biogenesis, the hepatic endoplasmic reticulum to the cis-Golgi. This step is mediated by a specialized ER- derived vesicle, the VLDL transport vesicle (VTV). Upon exit of the ER the VTV targets, fuses and delivers VLDL into the lumen of the Golgi. 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 …

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 …

Peroxiredoxin Ii Regulates Effector And Secondary Memory Cd8+ T Cell Responses, Ryan D. Michalek, Katie E. Crump, Ashley E. Weant, Elizabeth M. Hiltbold, Daniel G. Juneau, Eun-Yi Moon, Dae-Yeul Yu, Leslie B. Poole, Jason M. Grayson

Biology Faculty Articles

Reactive oxygen intermediates (ROI) generated in response to receptor stimulation play an important role in cellular responses. However, the effect of increased H₂O₂on an antigen-specific CD8⁺ T cell response was unknown. Following T cell receptor (TCR) stimulation, the expression and oxidation of peroxiredoxin II (PrdxII), a critical antioxidant enzyme, increased in CD8⁺ T cells. Deletion of PrdxII increased ROI, S phase entry, division, and death during in vitro division. During primary acute viral and bacterial infection, the number of effector CD8⁺ T cells in PrdxII-deficient mice was increased, while the number of memory …

Structure-Function Analysis Of A Protein Encoded By The Bhv-1 Latency Related Gene, Devis Sinani

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Bovine herpes virus 1 (BHV-1) is a significant viral pathogen in cattle that induces a myriad of clinical symptoms. These symptoms include: conjunctivitis, upper respiratory tract infections, genital disorders, and abortions. BHV-1 infection can also lead to transient immune-suppression, which predisposes cattle to secondary bacterial infection leading to life-threatening pneumonia referred to as bovine respiratory disease (BRD). Following acute infection, BHV-1 establishes latency in sensory neurons within trigeminal ganglia. Reactivation of the virus can occur periodically, resulting in virus transmission. The latency-related (LR) RNA is the only abundantly expressed transcript in latently infected sensory neurons and it encodes several proteins, …

Regulation Of Alternative Carbon Metabolism In Candida Albicans, Arely Y. Gonzalez

Dissertations and Theses (Open Access)

Candida albicans is the most important fungal pathogen of humans. Transcript profiling studies show that upon phagocytosis by macrophages, C. albicans undergoes a massive metabolic reorganization activating genes involved in alternative carbon metabolism, including the glyoxylate cycle, β-oxidation and gluconeogenesis. Mutations in key enzymes such as ICL1 (glyoxylate cycle) and FOX2 (fatty acid β-oxidation) revealed that alternative carbon metabolic pathways are required for full virulence in C. albicans. These studies indicate C. albicans uses non-preferred carbon sources allowing its adaptation to microenvironments were nutrients are scarce. It has become apparent that the regulatory networks required for regulation of alternative …

The Role Of The Arched Helicases In Exosome-Mediated Function, A. Alejandra Klauer

Dissertations and Theses (Open Access)

RNA processing and degradation are two important functions that control gene expression and promote RNA fidelity in the cell. A major ribonuclease complex, called the exosome, is involved in both of these processes. The exosome is composed of ten essential proteins with only one catalytically active subunit, called Rrp44. While the same ten essential subunits make up both the nuclear and cytoplasmic exosome, there are nuclear and cytoplasmic exosome cofactors that promote specific exosome functions in each of the cell compartments. To date, it is unclear how the exosome distinguishes between RNA substrates. We hypothesize that compartment specific cofactors may …

Regulation Of The Heat Shock Response By Thiol-Reactive Compounds In The Yeast Saccharomyces Cerevisiae, Yanyu Wang

Dissertations and Theses (Open Access)

Cells govern their activities and modulate their interactions with the environment to achieve homeostasis. The heat shock response (HSR) is one of the most well studied fundamental cellular responses to environmental and physiological challenges, resulting in rapid synthesis of heat shock proteins (HSPs), which serve to protect cellular constituents from the deleterious effects of stress. In addition to its role in cytoprotection, the HSR also influences lifespan and is associated with a variety of human diseases including cancer, aging and neurodegenerative disorders. In most eukaryotes, the HSR is primarily mediated by the highly conserved transcription factor HSF1, which recognizes target …

Transcriptional Analysis Of Cervical Epithelial Cell Responses To Hiv-1, Andrew A. Block

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

Human Immunodeficiency Virus type 1 (HIV-1) infection causes a growing pandemic throughout the world, of which women comprise 51% of people who live with HIV-1, more than 60% in sub-Saharan Africa. HIV-1 infections of women are mainly acquired through female reproductive tract where cervical and vaginal epithelial cells are the first line of defense. Although HIV-1 does not directly infect epithelial cells, HIV-1 obligatorily interacts with and crosses over epithelial layer to infect susceptible target cells, mainly CD4+ T cells, in the lamina propria to initiate an infection. However, the mechanism and ramification of the interaction of HIV-1 and epithelial …

Histologic Findings In Biopsies/Resection Specimens From The Small Intestine With Special Emphasis On Celiac Disease: Experience From A Developing Country In South Asia, Huma Arshad, Zubair Ahmad

Department of Pathology and Laboratory Medicine

Biopsies from the small intestine especially the duodenum are now being performed much more frequently than in the past. The most frequent reason for performing duodenal biopsies is to evaluate for malabsorption. In the last few years, increased awareness has resulted in more biopsies sent for evaluation of malabsorption, especially celiac disease (CD). In the duodenum, features of malabsorption (increased intraepithelial lymphocytes, villous shortening, and atrophy) were the most common histologic finding seen in 63.4% of cases. Serum tTG levels were available for correlation in 52.8% of cases. In patients with confirmed CD, 53.4% were MARSH IIIb, and 29.5% were …

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 …

Nitrite Oxidation In Geothermal Springs: Evidence Of An Upper Temperature Limit For Thermophilic Nitrite-Oxidizing Bacteria Of 60 - 65 °C, Tara Edwards

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite growing evidence of the importance of nitrification in terrestrial geothermal environments, little is known about nitrite oxidation in these environments. In order to further our knowledge, this study combined cultivation-dependent and -independent approaches with measurements of nitrogen speciation along the outflow channels of two Great Basin geothermal springs. Enrichment cultures were inoculated with sediment slurries from sites ranging in temperature from 42 - 87 °C at the sources and along the outflows of >15 hot springs. While attempts to enrich nitrite-oxidizing bacteria (NOB) from sites greater than or equal to 61 °C were unsuccessful, NOB were enriched from five …

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 …

Allogeneic Stem Cell Transplantation In Acute Myeloid Leukemia, Natasha Bahadur Ali, Salman Adil, Mohammad Usman Shaikh, Nehal Masood

Department of Pathology and Laboratory Medicine

We report a case series of 12 patients with acute myeloid leukemia who underwent allogeneic stem cell transplant with a matched related donor. Male to female ratio was 1:1. The main complication post-transplant was graft-versus-host disease (n=7 patients). Transplant-related mortality involved one patient; cause of death was multi-organ failure. After a median follow up of 36.0±11.3 months, overall survival was 16%.

Inactivation Of Bacterial Opportunistic Skin Pathogens By Nonthermal Dc-Operated Afterglow Atmospheric Plasma, L. C. Heller, C. M. Edelblute, A. M. Mattson, X. Hao, J. F. Kolb

Bioelectrics Publications

AIMS: Multidrug-resistant opportunistic pathogens are clinically significant and require the development of new antimicrobial methods. In this study, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus cells were exposed to atmospheric plasma on agar plates and in vitro on porcine skin for the purpose of testing bacterial inactivation.

METHODS AND RESULTS: Microbial inactivation at varying exposure durations was tested using a nonthermal plasma jet generated with a DC voltage from ambient air. The observed reduction in colony forming units was quantified as log₁₀ reductions.

CONCLUSIONS: Direct plasma exposure significantly inactivated seeded bacterial cells by approx. 6 log_{10 …}

Diagnostic Utility Of Anti-Citrullinated Protein Antibody And Its Comparison With Rheumatoid Factor In Rheumatoid Arthritis, Aysha Habib, Lena Jafri, M. Ahraz Hussain, Saliha Ishaq

Department of Pathology and Laboratory Medicine

Objective: To assess the diagnostic utility of anti-citrullinated protein antibody (anti-CCP) in rheumatoid arthritis (RA) and compare it with rheumatoid factor (RF). Study Design: Analytical study. Place and Duration of Study: Section of Chemical Pathology, Department of Pathology and Microbiology and Medicine, the Aga Khan University, Karachi, from January to May 2010. Methodology: A review of medical records of patients presenting to the clinics with complaints of muscular or joint pains and who were tested for their serum anti-CCP was done. Inclusion criteria were presence of clinical synovitis in at least one joint and an absence of alternative diagnosis. Patients …

Scribble Acts In The Drosophila Fat-Hippo Pathway To Regulate Warts Activity, Shilpi Verghese, Indrayani Waghmare, Hailey Kwon, Katelin Hanes, Madhuri Kango-Singh

Biology Faculty Publications

Epithelial cells are the major cell-type for all organs in multicellular organisms. In order to achieve correct organ size, epithelial tissues need mechanisms that limit their proliferation, and protect tissues from damage caused by defective epithelial cells. Recently, the Hippo signaling pathway has emerged as a major mechanism that orchestrates epithelial development. Hippo signaling is required for cells to stop proliferation as in the absence of Hippo signaling tissues continue to proliferate and produce overgrown organs or tumors. Studies in Drosophila have led the way in providing a framework for how Hippo alters the pattern of gene transcription in target …

Multifocal Venous Thrombosis In Behcet’S Disease, Lena Jafri, Nosheen Nasir, Aysha Almas

Department of Pathology and Laboratory Medicine

Behcet's disease is a multisystem inflammatory vascular disorder with a chronic course characterized by recurrent oral and genital ulcers, eye lesion, arthritis and skin lesions. It has a typically waxing and waning course. The cause and pathogenesis of the disease are unclear and specific treatment is not available. A 39 years old man presented with rash, ocular manifestation and left leg swelling. He was found to have deep venous thrombosis of left leg along with recurrent cerebral venous thrombosis. He was a known case of Behcet's disease since 3 years and had been on anticoagulants since then.

Macrolide And Fluoroquinolone Resistance In Helicobacter Pylori Isolates: An Experience At A Tertiary Care Centre In Pakistan, Sana Rajper, Erum Khan, Zubair Ahmad, Syed Muhammad Zaheer Alam, Adil Akbar, Rumina Hasan

Department of Pathology and Laboratory Medicine

Objective:
To assess fluoroquinolone and clarithromycin susceptibility pattern along with the types of genomic mutations involved in the resistance of Helicobacter pylori isolates.
Methods:
The cross-sectional study was conducted at the Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, from June 2009 to July 2010, and comprised 162 gastric biopsy samples which were tested with GenoTypeHelicoDR (Hain Lifescience GmbH, Germany), a reverse hybridisation multiplex polymerase chain reaction (PCR) line probe assay (LiPA). Also, 23S rRNA (ribosomal ribonucleic acid) gene was analysed with three-point mutations at A2146G, A2146C and A2147G for clarithromycin, and gyrA gene was analyzed at two …

Form And Function Of Clostridium Thermocellum Biofilms, Alexandru Dumitrache, Gideon Wolfaardt, Grant Allen, Steven N. Liss, Lee R. Lynd

Dartmouth Scholarship

The importance of bacterial adherence has been acknowledged in microbial lignocellulose conversion studies; however, few reports have described the function and structure of biofilms supported by cellulosic substrates. We investigated the organization, dynamic formation, and carbon flow associated with biofilms of the obligately anaerobic cellulolytic bacterium Clostridium thermocellum 27405. Using noninvasive, in situ fluorescence imaging, we showed biofilms capable of near complete substrate conversion with a characteristic monolayered cell structure without an extracellular polymeric matrix typically seen in biofilms. Cell division at the interface and terminal endospores appeared throughout all stages of biofilm growth. Using continuous-flow reactors with a rate …

Amelioration Of Root Disease Of Subterranean Clover (Trifolium Subterraneum) By Mineral Nutrients, Tim Scanlon, Tiernan A. O’Rourke, Megan H. Ryan, Martin J. Barbetti, Krishnapillai Sivasithamparam

Journal articles

Subterranean clover (Trifolium subterraneum) is a key pasture legume across southern Australia and elsewhere. Decline in subterranean clover pastures was first recognised in Australia during the 1960s and manifests as an increase in weeds and a decrease in desirable legume species. While both root disease and poor nutrition contribute to subterranean clover pasture decline, the relationships between root disease and nutrition have not been determined. The objective of this study was to define these relationships. Field experiments were undertaken to determine the nutritional and pathogen status of soils and subterranean clover from three Western Australian field sites. Subsequently, …

Cyanolyase: A Database Of Phycobilin Lyase Sequences, Motifs And Functions, Wendy M. Schluchter, Anthony Bretaudeau, Francois Coste, Florian Humily, Laurence Garczarek, Gildas Le Corguille, Christophe Six, Morgane Ratin, Olivier Collin, Frederic Partensky

Biological Sciences Faculty Publications

CyanoLyase (http://cyanolyase.genouest.org/) is a manually curated sequence and motif database of phycobilin lyases and related proteins. These enzymes catalyze the covalent ligation of chromophores (phycobilins) to specific binding sites of phycobiliproteins (PBPs). The latter constitute the building bricks of phycobilisomes, the major light-harvesting systems of cyanobacteria and red algae. Phycobilin lyases sequences are poorly annotated in public databases. Sequences included in CyanoLyase were retrieved from all available genomes of these organisms and a few others by similarity searches using biochemically characterized enzyme sequences and then classified into 3 clans and 32 families. Amino acid motifs were computed for each family …

Of Gardens, Microorganisms, And Long Island Sound, Judy Preston

Wrack Lines

How healthy soil can make an environmental difference.

"I happened to turn over a large rounded stone in my garden to find a mesmerizing world of organisms that had, just moments earlier, been going about their business before being exposed to the sunlit world, and me."

One Can’T Stand On Its Own: Are Non-Luminescence Traits Necessary For V. Fischeri Colonization Of E. Scolopes?, Feier Liu

Honors Theses and Capstones

Vibrio fischeri and Euprymna scolopes squid establish mutualistic symbiosis and select for each other in the natural environment. V. fischeri provides bioluminescent camouflage for E. scolopes while E. scolopes provides nutrients for V. fischeri. The most intriguing aspect of this relationship is that E. scolopes is highly selective and only allows sustained colonization by luminous, but not dark V. fischeri. Luminescence is the key symbiosis trait; however, other bacterial factors may also allow squid recognition. We hypothesized that there are luminescence linked traits that contribute to colonization. V. fischeri with luminescence variation was isolated and tested for oxidative resistance, …

Ecology Of Vibrio Parahaemolyticus And Vibrio Vulnificus In The Coastal And Estuarine Waters Of Louisiana, Maryland, Mississippi, And Washington (United States), Crystal N. Johnson, John C. Bowers, Kimberly J. Griffitt, Vanessa Molina, Rachel W. Clostio, Shaofeng Pei, Edward Laws, Rohinee N. Paranjpye, Mark S. Strom, Arlene Chen, Nur A. Hasan, Anwar Huq, Nicholas F. Noriea Iii, D. Jay Grimes, Rita R. Colwell

Faculty Publications

Vibrio parahaemolyticus and Vibrio vulnificus, which are native to estuaries globally, are agents of seafood-borne or wound infections, both potentially fatal. Like all vibrios autochthonous to coastal regions, their abundance varies with changes in environmental parameters. Sea surface temperature (SST), sea surface height (SSH), and chlorophyll have been shown to be predictors of zooplankton and thus factors linked to vibrio populations. The contribution of salinity, conductivity, turbidity, and dissolved organic carbon to the incidence and distribution of Vibrio spp. has also been reported. Here, a multicoastal, 21-month study was conducted to determine relationships between environmental parameters and V. parahaemolyticus …

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 …

Spatial And Temporal Immune Response In House Flies In Response To Ingestion Of Bacillus Cereus And Eschericha Coli 0157-H7, Adam Fleming

College of Graduate Studies: Theses & Dissertations

House flies (Musca domestica L.) feed and breed on septic substrates, putting them in direct contact with a multitude of disease causing agents and can act as a bridge for those agents to humans. The house fly has previously been shown to carry many different species of bacteria that are pathogenic. Escherichia coli O157:H7 is a pathogenic enterohemorrhagic serotype of E. coli that can be vectored by the house fly. Bacillus cereus is a foodborne pathogen that has also been isolated from the house fly in previous studies. To examine vector potential for these pathogens, house flies were fed green …

Quantitative Analysis Of Methangenic Community In Anaerobic Digesters And Its Response To Freeze Drying And Exposure To Oxygen, Keerthi Cherukuri

Master's Theses (2009 -)

Methanogens are integral to carbon cycling, catalyzing the production of methane and carbon dioxide, both potent greenhouse gases. Methane is produced in a wide variety of highly reduced anaerobic environments, as well as by degradation of organic compounds in industrial and municipal wastewater. This process is carried out by the concerted activity of an interdependent microbial community, composed of Bacteria and Archaea, the later including methanogens which complete the final step and produce methane and carbon dioxide. Methanogenesis is often the rate limiting step and is sensitive to processing imbalances. Therefore, an understanding of the microbial community structure and dynamics …