Bacteriology Commons^™

Probing The Porphyromonas Gingivalis Nitrosative Stress Response Network, Alexandra Galina

Theses and Dissertations

Objective: To persist in the oral cavity, the perio-pathogen Porphyromonas gingivalis must have an efficient nitrosative stress response mechanism. To better understand how P. gingivalis responds to nitrite (NO₂^-) we must determine what genes are involved in the nitrosative stress response network.

Methods: Through genomic screening, a list of genes was generated that were hypothesized to be part of the nitrosative stress response network and believed to be involved in nitrate/nitrite metabolism or redox state of the cells. Protein coding regions were replaced with the ermF sequence by allelic exchange mutagenesis. 15 mutants were created …

Distribution Patterns Of Allorhizobium Vitis In Missouri Vineyards And Non-Vineyard Soils, Jacquelyn M. Wray

Graduate Theses/Dissertations

Crown gall disease causes significant economic loss to the grape and wine industry. Preventive strategies are most effective for mitigating the loss of grapevines in vineyards, as there is no known cure for this disease. The bacterium Allorhizobium vitis carrying a tumor-inducing (Ti) plasmid is the causative agent. A. vitis bacteria live systemically in the grapevine before causing visible symptoms and can survive in residual plant tissues and soil for more than two years. Diagnostic methods have been developed to detect A. vitis bacteria in grapevines and soil. However, more reliable, specific, and high-throughput diagnostics are still needed for screening …

Comparing The Microbiomes Of Dental Plaques In 19th Century Ancestral Remains, Ananya Udyaver

Undergraduate Research Posters

During the construction of VCU’s Hermes A. Kontos Medical Sciences Building in April 1994, nineteenth century ancestral remains were found in an abandoned well on the Medical College of Virginia (MCV) campus. This well, now known as the East Marshall Street Well (EMSW), is thought to have been used as a disposal location for cadaver dissection for surgical and other medical waste in the past. VCU is now seeking to use DNA sequencing technology to match and assemble bones from each individual for a proper burial, uncover the cultural and historical context in which these people lived, and bring a …

Indigenous Toxin Affects Cell Viability, While An Artificial Proteolytic Queueing Causes The Upregulation Of Specific Genes, Mohammed Salahuddin

Electronic Theses and Dissertations

Studying bacterial physiology is crucial to understand the fundamental mechanisms that govern bacterial growth, survival, and adaptation. This thesis combines two chapters investigating bacterial physiology by studying important cellular processes like bacterial toxin-antitoxin systems and proteolytic pathways. The first chapter involves studying bacterial toxin-antitoxin systems to understand the regulation and function of hypothetical toxin-antitoxin (TA) systems of bacteria and the effects of these TA systems on bacterial growth and survival. The emergence of these genetic modules in bacterial research and the unrevealing of some of their important roles in cell physiology in recent years has drawn much attention in scientific …

Effects Of Altering Physiologically Relevant Cholesterol Levels And Media Types On Porin Gene Expression In Klebsiella Pneumoniae And The Resulting Impact On Antibiotic Resistance, Megan R. Camden

UNF Graduate Theses and Dissertations

Klebsiella pneumoniae is a Gram-negative, non-motile bacterium belonging to the Enterobacteriaceae family. K. pneumoniae is a rising threat in the clinical setting, as there has been a large increase in the presence of antibiotic resistant isolates. While much research is conducted on laboratory and clinical strains of bacteria, not much is known regarding the impact that human physiology can have on bacterial gene expression, and in response, to antibiotic susceptibility. The goal of this study is to determine if physiologically relevant cholesterol levels and media types impact porin gene expression and antibiotic resistance in K. pneumoniae. To accomplish this, …

The Type Iv Pilus Secretin Bfpb: Structural Analysis And Binding Interactions, Janay I. Little

Theses and Dissertations

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhea in young children. The type IV pilus (T4P) of EPEC, known as the bundle-forming pilus (BFP), plays an important role in EPEC pathogenesis. T4Ps are a family of surface appendages that are important for adhesion, colonization, biofilm formation, virulence, twitching motility and many other functions. One essential component of the BFP system is the secretin, BfpB. Secretins are a large family of integral outer membrane proteins found in T4Ps as well as type II and type III secretion systems, and filamentous phages. Details of the secretin structure have been limited to the overall …

Treponema Denticola Synthesizes C-Di-Amp And Encodes The Cdaa-Type Diadenylate Cyclase Cdaa, Claire R. O'Brien

Theses and Dissertations

Periodontitis is a form of oral disease characterized by dysbiosis of the oral microbiome, leading to inflammation, bone resorption, and in severe cases, entire tooth loss, affecting 42% of adults in the US. One of the bacteria most associated with periodontal disease progression is Treponema denticola (Td), an oral spirochete which inhabits the mouth in small quantities during health but which can dominate the biofilms that form during periodontal disease. The ability of Td to survive in a disease environment and contribute to the progression of disease requires the use of robust signaling networks. Analysis of Td cultures …

Functional Residues Of Cjpata, Robert Lamont

Theses and Dissertations (Comprehensive)

Antibiotic resistance in pathogenic bacteria continues to challenge clinicians and threaten the lives of infected individuals. For this reason, new classes of antibiotics or new targets for antibiotic therapy are needed to circumvent this global health crisis. In Gram-negative bacteria, the enzymes peptidoglycan O-acetyltransferase A and B (PatA and PatB), are responsible for adding acetyl groups to the C-6 hydroxyl group of N-acetyl muramic acid (MurNAc) in peptidoglycan (PG). These acetyl groups are responsible for inhibiting the activity of lysozyme from host organisms that hydrolyze the β1-4 glycosidic linkage between MurNAc and N-acetylglucosamine (GlcNAc). The acetyl groups …

Prevalence And Plasmid Profiles Of Enterobacteriaceae Isolates Obtained From Individuals With Asymptomatic Bacteriuria In Okada, Edo State, Nigeria, Osarumwense Precious Otote, Maureen Uchechukwu Okwu, Osazee Ekundayo Izevbuwa, Happy Ovuerhi Oferiofe

Makara Journal of Science

Asymptomatic bacteriuria (ASB) is the presence of bacteria in apparently healthy individuals. Although, the prevalence varies widely with age, gender, and the presence or absence of genitourinary abnormalities, the detection of pathogenic bacteria in urine constitutes firm evidence of infection. The objectives of this study were to isolate members of the family Enterobacteriaceae from urine samples of research participants, and to determine the antibacterial susceptibility and plasmid profiles of the isolates. A total of 122 mid-stream urine samples consisting of 72 male and 50 female participants from selected primary and secondary schools were collected. The age of the participants used …

Rapid Bacterial And Fungal Successional Dynamics In First Year After Chaparral Wildfire, M. Fabiola Pulido-Chavez, James W. J. Randolph, Cassandra A. Zalman, Loralee Larios, Peter M. Homyak, Sydney I. Glassman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The rise in wildfire frequency and severity across the globe has increased interest in secondary succession. However, despite the role of soil microbial communities in controlling biogeochemical cycling and their role in the regeneration of post-fire vegetation, the lack of measurements immediately post-fire and at high temporal resolution has limited understanding of microbial secondary succession. To fill this knowledge gap, we sampled soils at 17, 25, 34, 67, 95, 131, 187, 286, and 376 days after a southern California wildfire in fire-adapted chaparral shrublands. We assessed bacterial and fungal biomass with qPCR of 16S and 18S and richness and composition …

Evaluation Of Antibacterial Potential Of Artemisinin Extracts Of Artemisia Annua In Vivo And In Vitro, Arsalan Khan, Akhtar Ali, Imtiaz Ali Shah, Umm-E- Aimen, Waseem Ullah, Imtiaz Khan

Journal of Bioresource Management

To ensure universal health care, the World Health Organization recognized the significance of complementary and alternative medicines (CAM) and recommended the use of natural herbs and plants bearing therapeutic potential and fewer adverse effects. Therefore, Artemisia annua herb was evaluated for its antibacterial potential and therapeutic efficacy against Staphylococcus aureus, Streptococcus and Escherichia coli both in vitro and in vivo. Artemisinin was extracted from Artemisia annua by chemical treatment. Subsequently, the culture sensitivity tests were performed on MHA by disk diffusion method to determine the antibacterial potential of the Artemisinin extracts against the test bacteria (in vitro phase). …

Functional Analysis Of Legionella Pneumophila Effector Protein, Shreya Neupane

Masters Theses & Specialist Projects

Legionella pneumophila is a gram-negative bacterium that causes Legionnaire’s disease (a severe form of pneumonia) in humans. L. pneumophila can cause infection by utilizing its Type IV secretion system, a protein secretion system that transports proteins from the bacterial cytosol into the infected macrophage. Effectors released from the Type Iv secretion system allow L. pneumophila to create a safe environment to survive, replicate and cause infection. One such effector, RavQ, inhibits cell proliferation of mammalian HEK 293T cells and localizes to the cell’s nucleus, leading us to hypothesize that RavQ interferes with cellular activity in the nucleus. To detect its …

Single-Cell Approach Reveals Intercellular Heterogeneity In Phage-Producing Capacities, Sherin Kannoly, Gabriella Oken, Jonathan Shadan, David Musheyev, Kevin Singh, Abhyudai Singh, John J. Dennehy

Publications and Research

Bacteriophage burst size is the average number of phage virions released from infected bacterial cells, and its magnitude depends on the duration of an intracellular progeny accumulation phase. Burst size is often measured at the population level, not the single-cell level, and consequently, statistical moments are not commonly available. In this study, we estimated the bacteriophage lambda (ƛ) single-cell burst size mean and variance following different intracellular accumulation period durations by employing Escherichia coli lysogens bearing lysis-deficient ƛ prophages. Single lysogens can be isolated and chemically lysed at desired times following prophage induction to quantify progeny intracellular accumulation within individual …

Potential Use Of Proteolytic Bacteria Paenibacillus Dendritiformis (Bt7) Isolated From Batu Tannery Effluents For The Detergent Industry, Chandran Masi, Degafneh Tadesse, Abate Ayele

Karbala International Journal of Modern Science

This research was aimed at identifying a bacterium that can produce alkaline proteases. As a result, bacteria that produce proteases were isolated from Batu tannery effluents, tested for protease synthesis on skim milk agar plates, and validated with a protease assay. Microscopic and molecular phylogenetic analyses identified Paenibacillus dendritiformis (BT7) as the bacterial isolate with the highest alkaline protease production. The isolate's maximum enzyme production was obtained by 2% inoculum size, 40°C temperature, 9.0 pH, and a 48-hour incubation time with production media components such as glucose, casein, MgCl2, and 2% NaCl. The maximal enzyme activity was 270 U/mL under …

Occurrence Of Kanamycin-Resistant Bacteria Relative To Anthropogenic Pollution Along Richland Creek In Nashville, Tn​, Jolene Ho Mach, Annie Le, Brandon Torres Ramirez

Science University Research Symposium (SURS)

The overuse of antibiotics has caused an increase in antibiotic-resistant (AR) bacteria, which is a serious public health concern. Previous studies showed a significant correlation between anthropogenic pollution and AR bacteria. This project aims to identify AR bacteria in Richland Creek relative to local anthropogenic pollution. Water samples were collected at four locations along Richland Creek in Nashville, Tennessee. Bacteria resistant to the antibiotic kanamycin were isolated from the water samples, identified to genera using DNA barcoding, and compared among the sites. We expect to see a greater abundance and diversity of kanamycin-resistant bacteria closer to the end than near …

A Membrane Transporter Required For Quorum Sensing And Virulence Of The Rice Pathogen Burkholderia Glumae, Asif Iqbal

LSU Doctoral Dissertations

Burkholderia glumae is a Gram-negative bacterium causing bacterial panicle blight (BPB) in rice. BPB can cause severe damage to rice and reduce rice yield up to 75%, while no effective treatment has been developed to control the disease. B. glumae produces and secretes an essential virulence factor, toxoflavin, which is mainly responsible for the symptoms of BPB. Synthesis and transport of toxoflavin are regulated in a quorum-sensing dependent manner. Members of the DedA superfamily are putative membrane transporters and found in nearly all species. Mutation of dedA in Burkholderia species results in sensitivity to colistin, an antibiotic belonging to the …

Laguncularia Racemosa Top-Layer Sediment Microorganism Makeup In Relation To Differing Levels Of Perceived Anthropogenic Impact In Bocas Del Drago, Bocas Del Toro, Panama, Gabrielle Glendening

Independent Study Project (ISP) Collection

As mangrove forests are destroyed by human factors across the earth, many crucial ecological processes that take place in these systems of trees are obstructed. One of the most important roles played by mangroves is their ability to sequester carbon in the sediment, as this storage of carbon helps diminish atmospheric warming. Many sediment microorganisms help in this process of carbon sequestration and play various other vital roles in mangrove ecosystems. Microorganisms in marine sediments can be used to assess the health of the surrounding environment. Past research has found significant differences in sediment microorganism composition, abundance, and diversity in …

Forty Years Without Family: Three Novel Bacteriophages With High Similarity To Spp1 Reveal Decades Of Evolutionary Stasis Since The Isolation Of Their Famous Relative, Veronique A. Delesalle, Brianne E. Tomko, Albert C. Vill, Katherine B. Lichty, Gregory P. Krukonis

Biology Faculty Publications

SPP1, an extensively studied bacteriophage of the Gram-positive Bacillus subtilis, is a model system for the study of phage–host interactions. Despite progress in the isolation and characterization of Bacillus phages, no previously fully sequenced phages have shared more than passing genetic similarity to SPP1. Here, we describe three virulent phages very similar to SPP1; SPP1 has greater than 80% nucleotide sequence identity and shares more that 85% of its protein coding genes with these phages. This is remarkable, given more than 40 years between the isolation of SPP1 and these phages. All three phages have somewhat larger genomes and more …

Ridinilazole: A Novel, Narrow-Spectrum Antimicrobial Agent Targeting Clostridium (Clostridioides) Difficile, Deirdre A. Collins, Thomas V. Riley

Research outputs 2022 to 2026

Clostridium (Clostridioides) difficile infection (CDI) remains an urgent threat to patients in health systems worldwide. Recurrent CDI occurs in up to 30% of cases due to sustained dysbiosis of the gut microbiota which normally protects against CDI. Associated costs of initial and recurrent episodes of CDI impose heavy financial burdens on health systems. Vancomycin and metronidazole have been the mainstay of therapy for CDI for many years; however, these agents continue to cause significant disruption to the gut microbiota and thus carry a high risk of recurrence for CDI patients. Treatment regimens are now turning towards novel narrow spectrum antimicrobial …

Elucidation Of Gene Essentiality And Genetic Determinants Of Intrinsic P-Aminosalicylic Acid Resistance In Mycobacterium Kansasii, Keith J. Levendosky

Dissertations, Theses, and Capstone Projects

Mycobacterium kansasii (Mk) is an opportunistic pathogen capable of causing tuberculosis-like pulmonary disease in immunocompromised individuals and those with other risk factors including chronic obstructive pulmonary disease or malignancy. Mk is frequently isolated from man-made water sources where it forms resilient biofilms, posing a health risk to these susceptible individuals. Despite its medical relevance as an environmental pathogen, and a close phylogenetic relationship with the obligate pathogen Mycobacterium tuberculosis (Mtb), few studies to date have probed the molecular biology and genetics of Mk. Here, we sought to apply a transposon (Tn) mutagenesis tool to dissect …