Bacteriology Commons^™

Sulfolobus Spindle-Shaped Virus 1 Growth Kinetics, Setarah Mohammad Nader

PSU McNair Scholars Online Journal

Geothermal and hypersaline environments are rich in viral particles, among which spindle-shaped morphologies predominate. Currently, viruses with spindle- or lemon-shaped virions are unique to Archaea and belong to two distinct viral families. The larger of the two families, the Fuselloviridae, encompasses spindle-shaped viruses with very short tails, which infect Sulfolobus solfataricus and close relatives. Sulfolobus spindle-shaped virus 1 (SSV1) is the best-known member of the family and was one of the first hyperthermophilic archaeal viruses to be isolated. However, our knowledge of fuselloviral life cycles and the relationships between these viruses and their hosts is still limited. As a …

Colonization Density Of The Upper Respiratory Tract As A Predictor Of Pneumonia-Haemophilus Influenzae, Moraxella Catarrhalis, Staphylococcus Aureus, And Pneumocystis Jirovecii., Daniel E Park, Henry C Baggett, Stephen R C Howie, Qiyuan Shi, Nora L Watson, W Abdullah Brooks, Perch Study Group

Epidemiology Faculty Publications

Background.

There is limited information on the association between colonization density of upper respiratory tract colonizers and pathogen-specific pneumonia. We assessed this association for Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Pneumocystis jirovecii. Methods.

In 7 low- and middle-income countries, nasopharyngeal/oropharyngeal swabs from children with severe pneumonia and age-frequency matched community controls were tested using quantitative polymerase chain reaction (PCR). Differences in median colonization density were evaluated using the Wilcoxon rank-sum test. Density cutoffs were determined using receiver operating characteristic curves. Cases with a pathogen identified from lung aspirate culture or PCR, pleural fluid culture or …

Pas Signaling Mechanisms In Aer And Aer2, Darysbel Garcia

Loma Linda University Electronic Theses, Dissertations & Projects

PAS domains are widespread signal sensors that share a conserved three-dimensional αβ fold that consists of a central β-sheet flanked by several α- helices. The aerotaxis receptor Aer from Escherichia coli and the Aer2 chemoreceptor from Pseudomonas aeruginosa both contain PAS domains. Aer senses oxygen (O2) indirectly via an FAD cofactor bound to its PAS domain, while Aer2 directly binds O2 to its PAS b-type heme cofactor. The Aer and Aer2 PAS domains both interact with a signal transduction domain known as a HAMP domain. The PAS-HAMP arrangement differs between Aer and Aer2, with Aer- PAS residing adjacent to its …

Characterization Of Genes Involved In Phycobiliprotein Biosynthesis In Fremyella Diplosiphon And Thermosynechococcus Elongatus, Christina M. Kronfel

LSU New Orleans Theses and Dissertations

Cyanobacteria are photosynthetic organisms that efficiently capture light by utilizing the light-harvesting complexes called phycobilisomes. In many cyanobacteria, phycobilisomes are composed of an allophycocyanin core with phycocyanin and phycoerythrin (PE) rods radiating from the core. These phycobiliproteins have multiple bilin chromophores, such as phycoerythrobilin (PEB), covalently attached to specific cysteine (Cys) residues for efficient photosynthetic light capture. Chromophore ligation on phycobiliprotein subunits occurs through bilin lyase catalyzed reactions.

This study mainly focuses on characterizing the roles of enzymes that are involved in the biosynthetic pathway of the phycobiliproteins within two cyanobacteria Thermosynechococcus elongatus and Fremyella diplosiphon. A combination of molecular …

Effect Of Spatial Influence On Endophyte Diversity Within Alnus Rubra, Sebastian L. Singleton

Student Research Symposium

Red alders (Alnus rubra) of the Pacific Northwest are characterized as actinorhizal dicotyledons; plants that possess that ability to form symbiotic relationships with endophytic organisms, which result in nitrogen-fixing nodules. In Alders of the order Fagales, such a symbiotic relationship with Frankia bacteria allows these plants to play crucial environmental roles as pioneer species able to colonize and enrich nutrient-deficient soils. This ability has a major impact on ecological succession by enabling other species to establish. Although inoculation with frankia bacteria is known to increase symbiotic nitrogen fixation capabilities of actinorhizal plants, whether they could confer the same benefit to …

Ancient Bacteria–Amoeba Relationships And Pathogenic Animal Bacteria, Joan E. Strassmann, Longfei Shu

Biology Faculty Research

Long before bacteria infected humans, they infected amoebas, which remain a potentially important reservoir for human disease. Diverse soil amoebas including Dictyostelium and Acanthamoeba can host intracellular bacteria. Though the internal environment of free-living amoebas is similar in many ways to that of mammalian macrophages, they differ in a number of important ways, including temperature. A new study in PLOS Biology by Taylor-Mulneix et al. demonstrates that Bordetella bronchiseptica has two different gene suites that are activated depending on whether the bacterium finds itself in a hot mammalian or cool amoeba host environment. This study specifically shows that B. …

Preliminary Analyses Of The Diversity Of Soil Microbes On The Campus Of The University Of The Incarnate Word, Viridiana Wheeler

Theses & Dissertations

Soil samples were examined outside Bonilla Science Hall on the campus of the University of the Incarnate Word in San Antonio, Texas, at three time points between the calendar years 2016 and 2017. These time points correspond to Fall, Winter, and Spring. Samples were taken at two topsoil depths, 1 cm and 4 cm, to determine if there is a difference in bacterial load or distribution across the time frame examined.

Soil samples were diluted and plated on nutrient agar plates in order to identify unique colony morphologies. A total of 132 distinct morphological isolates were identified and sequenced. Of …

Lymphoid Hematopoiesis And The Role Of B-Cells In Transgenic Mouse Model Of Sickle Cell Disease, Christina Cotte

University Scholar Projects

Sickle cell disease (SCD) has been shown to be associated with decreased baseline immunity and thus increased susceptibility to infection. I sought to discern possible causes of this by looking into the correlations between SCD and hematopoiesis, the immune system and the neuroendocrine system, and ultimately by conducting experiments surrounding the impaired immune system of SCD. These experiments focused on the potential causes and effects of the diminution of B-1a cells in the SCD spleen. Adoptive transfers, infections with Streptococcus pneumoniae, and histologic imaging were conducted to establish if the diminution of the B-1a cells in the SCD spleen …

Borrelia Burgdorferi-Specific Iga In Lyme Disease, Christina D'Arco, Raymond Dattwyler, Paul Arnaboldi

NYMC Faculty Publications

The laboratory diagnosis of Lyme disease is currently dependent on the detection of IgM and IgG antibodies against Borrelia burgdorferi, the causative agent of the disease. The significance of serum IgA against B. burgdorferi remains unclear. The production of intrathecal IgA has been noted in patients with the late Lyme disease manifestation, neuroborreliosis, but production of antigen-specific IgA during early disease has not been evaluated. In the current study, we assessed serum IgA binding to the B. burgdorferi peptide antigens, C6, the target of the FDA-cleared C6 EIA, and FlaB(211-223)-modVlsE(275-291), a peptide containing a Borrelia flagellin epitope linked to a …

Cloning And Expression Of C-Terminal Fragment Of Tonb From Rhizobium Leguminosarum Atcc 14479, Brooke E. Baxter

Undergraduate Honors Theses

The TonB-ExbB-ExbD complex is essential for the siderophore mediated acquisition of iron by Gram negative bacteria. The system provides energy from the proton motive force to the outer membrane in order for the iron siderophore complex to enter into the cell. The main protein involved in energy transduction, TonB, has been extensively studied in the species Escherichia Coli. It has been determined that the protein consists of 239 amino acids. In comparison, however, the TonB of Rhizobium leguminosarum consists of 457 amino acids with the same conserved regions. What is in question, therefore, is how the additional amino acids …

Determination Of The Effects That A Previously Uncharacterized Secreted Product From Klebsiella Pneumoniae Has On Citrobacter Freundii And Enterobacter Cloacae Biofilms, Cody M. Hastings

Undergraduate Honors Theses

More so than ever, Multiple Drug Resistant (MDR) bacteria are on the rise due to overuse of antibiotics along with natural selection for adaptations that enhance drug-resistant properties. One particular bacterial family, Enterobacteriaceae, has been problematic, exhibiting several bacterial members that have developed a precipitous resistance to modern antibiotics and are also primary causative agents of nosocomial, or hospital acquired, infections. Citrobacter freundii (CF) and Enterobacter cloacae (ECL) are two species of the Enterobacteriaceae family causing significant medical concern due to their role in producing numerous opportunistic infections such as bacteremia, lower respiratory tract infections, urinary tract infections, and endocarditis. …

Molecular Subtyping Of Staphylococcus Aureus Isolates From The U.P. Community For The Presence Of Toxin-Encoding Genes, Carol I. Kessel

All NMU Master's Theses

Staphylococcus aureus is the most common cause of human bacterial infections; however, humans can also be asymptomatically colonized with S. aureus. Asymptomatic carriers can potentially spread S. aureus infection to others. These infections can range from mild to severe. The pathology of a S. aureus infection is often dependent on which toxins are expressed and the virulence factors with which they are associated. One goal of this study was to isolate S. aureus from healthy, consenting adult volunteers who submitted nasal swabs for culture and qRT-PCR analysis to determine which strains are present in the community. This knowledge could …

Evaluating The Impact Of Post-Translational Modifications By The Secreted Zinc Metalloprotease, Gele, On The Major Autolysin Of E. Faecalis, Atla, And A Stress-Induced Protein, Salb, Emily K. Stinemetz

Dissertations and Theses (Open Access)

AtlA is the major peptidoglycan hydrolase of E. faecalis involved in cell separation of dividing cells. SalB is a secreted stress-induced protein regulated by the CroRS system. In addition, these two proteins also appear to be affected by the virulence factor, gelatinase (GelE). GelE is a secreted zinc metalloprotease known to impact various cellular functions by post- translational modification of protein substrates. The overall objective of this work was to understand how GelE cleavage of secreted proteins, specifically AtlA and SalB, changes their function. Herein, I discovered that GelE modifies both AtlA and SalB. As visualized by Western blot analysis …

Characterization Of The Role Of The Pkm101-Encoded T4ss Outer Membrane Core Complex In Substrate Transfer, Pilus Biogenesis, And Recipient Cell Contact, Jay E. Gordon

Dissertations and Theses (Open Access)

The bacterial type IV secretion systems (T4SS) encoded on the Escherichia coli pKM101 and R388 conjugative plasmids and the Agrobacterium tumefaciens virB operon are composed of 12 subunits arranged in an architecturally similar fashion. Structural studies of the T4SS from R388 (Trw_R388) highlighted the presence of a distinct outer membrane core complex (OMCC) and inner membrane complex (IMC) joined together by a central stalk. This thesis is focused on the development of the pKM101 model system and the role of an OMCC cap region formed by alpha helical antenna projections (AP) found in VirB10 and TraF_pKM101. …

The Making Of A Pathogen: Implications Of Phage Domestication In Acinetobacter Baumannii, Allison Welp

Undergraduate Theses

Mutations and horizontal gene transfer have allowed for rapid evolution of many species of bacteria, allowing them to become more virulent and resistant to antibiotics. As a result of these changes, Acinetobacter baumannii has become one of the most prominent drug-resistant bacteria in hospitals. This nosocomial pathogen is capable of causing a range of infections—from pneumonia to sepsis—and is extremely difficult to eradicate from hospital settings. Despite its current status, this species has not always been apparent in healthcare. The emergence of this organism has been extremely rapid; once an innocuous environmental organism, A. baumannii is now resistant to all …

The Incidence Of Mrsa Infections In The United States: Is A More Comprehensive Tracking System Needed?, Kevin T. Kavanagh, Said Abusalem, Lindsay E. Calderon

EKU Faculty and Staff Scholarship

A review of epidemiological studies on the incidence of MRSA infections overtime was performed along with an analysis of data available for download from Hospital Compare (https://data.medicare.gov/data/hospital-compare). We found the estimations of the incidence of MRSA infections varied widely depending upon the type of population studied, the types of infections captured and in the definitions and terminology used to describe the results. We could not find definitive evidence that the incidence of MRSA infections in U.S. community or facilities is decreasing significantly. Of concern are recent data reported to the National Healthcare Safety Network (NHSN) on MRSA bloodstream infections which …

Enhanced Control Of Mycobacterium Tuberculosis Extrapulmonary Dissemination In Mice By An Arabinomannan-Protein Conjugate Vaccine, R Prados-Rosales, L Carreno, T Cheng, C Blanc, B Weinrick, Aharona Glatman-Freedman, A Casadevall, S Hung, A Tripathi, J Xu, Aharona Glatman-Freedman, W Jacobs Jr., J Chan, S Porcelli, J Achkar, A Casadevall

NYMC Faculty Publications

Currently there are a dozen or so of new vaccine candidates in clinical trials for prevention of tuberculosis (TB) and each formulation attempts to elicit protection by enhancement of cell-mediated immunity (CMI). In contrast, most approved vaccines against other bacterial pathogens are believed to mediate protection by eliciting antibody responses. However, it has been difficult to apply this formula to TB because of the difficulty in reliably eliciting protective antibodies. Here, we developed capsular polysaccharide conjugates by linking mycobacterial capsular arabinomannan (AM) to either Mtb Ag85b or B. anthracis protective antigen (PA). Further, we studied their immunogenicity by ELISA and …

Draft Genome Sequences Of Three Closely Related Isolates Of The Purple Nonsulfur Bacterium Rhodovulum Sulfidophilum, Michael S. Guzman, Beau Mcginley, Natalia Santiago-Merced, Dinesh Gupta, Arpita Bose

Biology Faculty Research

We report here the draft genome sequences of three isolates of Rhodovulum sulfidophilum from a single population that will serve as a model system for understanding genomic traits that underlie metabolic variation within closely related marine purple nonsulfur bacteria in natural microbial communities.

Environmental Changes Turn On The Sinorhizobium Melitloti Exor-Exos/Chvi (Rsi) Host Invasion Switch, Shari N. Walcott

Dissertations, Theses, and Capstone Projects

The free-living Gram-negative soil bacterium, Sinorhizobium meliloti, must switch into its host-invading form in order to infect the root hairs of the host plant, alfalfa (Medicago sativa), and establish a nitrogen-fixing symbiosis. The activation of the switch is believed to occur inside the infection chamber that is formed by curling of the root hairs. It is not fully understood what signals in the environment of the root hairs trigger and infection chamber S. meliloti to switch into a host-invading form since these signals were not extensively examined until now. This switch can be observed directly, due to …

Development Of A Novel Method To Express And Purify Vaccinia Virus Early Transcription Factors A7 And D6 Using Bacteria, Omkar M. Gandbhir

Seton Hall University Dissertations and Theses (ETDs)

The eradication of Smallpox is one of the greatest human achievements. However other poxviruses still exist infecting humans (Molluscum Contagiosum, monkeypox, and Vaccinia) or livestock (cowpox, sheeppox). Though vaccines and anti-virals exist, the side effects are serious, and viral resistance has been detected. The genome amongst poxviruses is highly conserved, early gene promoters maintain a specific critical consensus region that can be targeted for development of novel broad spectrum therapeutics. Using Vaccinia early transcription factors (VETFs) a novel method of expressing and purifying VETF A7 and D6 was developed. A7 and D6 are required for transcription of early genes recruiting …