Microbiology Commons^™

Cytotoxicity, Antimicrobial And Antioxidant Activities Of Boletus Bicolor, A Basidiomycetes Mushroom Indigenous To Tanzania, Donatha Tibuhwa

Tanzania Journal of Science

Boletus bicolor commonly known as coloured bolete is a basidiomyctes mushroom species widely used as a delicacy and its extract has been used traditionally to treat several human ailments in Tanzania. This study evaluates its extracts in order to provide a scientific foundation on the possible application in folk medicine system based on the biochemical evaluation. Standard microbes Bacillus subtilis and Candida albicans were used to test, the antifungal and antibacterial activity.  Cytotoxicity test was also done on the extracts using brine shrimp test. Besides, the extracts were also used to investigate for antioxidant activity using DPPH  (1, 1-diphenyl-2-picrylhydrazyl radical). …

Comparison Between Listeria Sensu Stricto And Listeria Sensu Lato Strains Identifies Novel Determinants Involved In Infection, Jakob Schardt, Grant Jones, Stefanie Müller-Herbst, Kristina Schauer, Sarah E. F. D'Orazio, Thilo M. Fuchs

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The human pathogen L. monocytogenes and the animal pathogen L. ivanovii, together with four other species isolated from symptom-free animals, form the "Listeria sensu stricto" clade. The members of the second clade, "Listeria sensu lato", are believed to be solely environmental bacteria without the ability to colonize mammalian hosts. To identify novel determinants that contribute to infection by L. monocytogenes, the causative agent of the foodborne disease listeriosis, we performed a genome comparison of the two clades and found 151 candidate genes that are conserved in the Listeria sensu stricto species. Two factors were …

Modification Of The Ribosome As Part Of The Adaptive Response To Oxidative Stress In Yeast, Jessica A Zinskie, Daniel Shedlovskiy, Ethan Gardner, Dimitri G Pestov, Natalia Shcherbik

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Living organisms are constantly exposed to a variety of environmental and internal stressors tha tare detrimental to their cellular physiology and viability. One such condition, oxidativestress, is caused by abnormal amounts of Reactive Oxygen Species (ROS) that can lead to damage to proteins, nucleic acids, and lipids. Although the mechanisms to neutralize ROS have been widely studied, the understanding of ROS‐mediated signaling for these mechanisms is rather incomplete and sparse. We have uncovered a previously undescribed phenomenon of yeast ribosomes to respond to elevated levels of ROS through a specific endonucleolytic cleavage of the 25S rRNA in the c‐loop of …

The Role Of Mapk And Scf In The Destruction Of Med13 In Cyclin C Mediated Cell Death, David C Stieg, Stephen D Willis, Joseph Scuorzo, Mia Song, Vidyaramanan Ganesan, Randy Strich, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

In response to stress, the yeast¹ and mammalian² cyclin C translocate from the nucleus to the cytoplasm, where it associates with the GTPase Drp1/Dnm1 to drive mitochondrial fragmentation and apoptosis. Therefore, the decision to release cyclin C represents a key life or death decision. In unstressed cells, the cyclin C‐Cdk8 kinase regulates transcription by associating with the Mediator of RNA polymerase II. We previously reported that the Mediator component Med13 anchors cyclin C in the nucleus³. Loss of Med13 function leads to constitutive cytoplasmic localization of cyclin C, resulting in fragmented mitochondria, hypersensitivity to stress and …

Translocation Of Cyclin C During Oxidative Stress Is Regulated By Interactions With Multiple Trafficking Proteins, Daniel G J Smethurst, Katrina F Cooper, Randy Strich

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Eukaryotic cells take cues from their environment and interpret them to enact a response. External stresses can produce a decision between adjusting to behaviors which promote surviving the stress, or enacting a cell death program. The decision to undergo programmed cell death (PCD) is controlled by a complex interaction between nuclear and mitochondrial signals. The mitochondria are highly dynamic organelles that constantly undergo fission and fusion. However, a dramatic shift in mitochondrial morphology toward fission occurs early in the PCD process. We have identified the transcription factor cyclin C as the biochemical trigger for stress‐induced mitochondrial hyper‐fragmentation in yeast (Cooper …

Optimizing Transposon Mutagenesis In Vibrio Strains To Identify Genes Involved In Antibiotic Production, Mahnur Khan

Honors Projects

Based on previous studies that have shown the competitive nature of non-pathogenic environmental strains of Vibrio, we hypothesize that environmentally derived bacteria can inhibit Vibrio pathogens, and possibly be a source of novel antibiotics. A previous experiment performed in the lab tested environmental Vibrio strains from various habitats against the pathogenic strains, Vibrio cholerae and Vibrio parahaemolyticus. Of the 3,456 strains collected, members of the Wildschutte lab identified 102 environmental strains of Vibrio that inhibited the growth of both pathogens. The data suggests that environmental Vibrio strains directly inhibit the growth of related pathogens. Our project involves the …

Comparison Of Bacterial And Archaeal Communities In The Subsurface Versus Surface: Implications For Nitrogen Cycling, Jason Cody Kimble 5059801155

Biology ETDs

Arid-land caves are thought to be extremely nitrogen-limited, but almost nothing is known about how microbes in subsurface arid-land environments obtain this essential element to meet cellular demand. The depth of caves beneath the surface may represent a critical factor affecting microbial nitrogen cycling in these environments. Percolation of water and nutrients from a precipitation pulse event would affect deep arid-land carbonate caves at a much slower rate. To obtain nitrogen in deep, carbonate caves, microorganisms could use fixed N in the host rock for assimilatory biochemical pathways or for a respiratory electron acceptor. However, the latter process leads to …

Mutational Analysis Of The Molluscum Contagiosum Virus Mc160 Protein, Henri Estanbouli

Seton Hall University Dissertations and Theses (ETDs)

The Molluscum Contagiosum Virus (MCV), belongs to a family of large DNA viruses called Poxviridae. MCV causes a common skin infection resulting in benign neoplasms. 122 million cases of MC were reported in 2010. The virus is not primarily lethal, though fatalities have occurred due to secondary bacterial infections. Even with the high volume of reported cases, MCV is very much understudied, and its pathogenicity is not well understood. Thus, with that in mind, a more in-depth understanding of the MCV-host interactions is a priority. Presumably during infection, MCV utilizes immune evasion molecules to inhibit activation of the host pro-inflammatory …

Effects Of Adenovirus Infection On The Localization Of Cellular Protein Pat1b, Emilee Friedman, Kasey A. Karen

Georgia Journal of Science

Adenoviruses are a diverse family of nonenveloped, double-stranded DNA viruses with a variety of vertebrate hosts including humans. Over 50 serotypes of human adenovirus have been identified, and cause a number of illnesses, including conjunctivitis, gastroenteritis, and respiratory infections. The life cycle of adenovirus is divided into immediate early, early, and late phases, with immediate early proteins controlling transcription and the cell cycle, early proteins being largely regulatory, and late proteins being structural. Early proteins such as E4 11k have been demonstrated to relocalize key cellular proteins, including proteins found within mRNA processing bodies (p-bodies). It is hypothesized that E4 …

Changing Antimalarial Drug Sensitivities In Uganda, Stephanie Alexis Rasmussen

Dissertations, Masters Theses, Capstones, and Culminating Projects

Dihydroartemisinin-piperaquine (DP) has demonstrated excellent efficacy for the treatment and prevention of malaria in Uganda. However, resistance to both components of this regimen has emerged in Southeast Asia. The efficacy of artemether-lumefantrine, the first-line regimen to treat malaria in Uganda, has also been excellent, but continued pressure may select for parasites with decreased sensitivity to lumefantrine. To gain insight into current drug sensitivity patterns, ex vivo sensitivities were assessed and genotypes previously associated with altered drug sensitivity were characterized for 58 isolates collected in Tororo, Uganda from subjects presenting in 2016 with malaria from the community or as part of …

Human Metapneumovirus Induces Formation Of Inclusion Bodies For Efficient Genome Replication And Transcription, Nicolás P. Cifuentes-Muñoz, Jean Branttie, Kerri Beth Slaughter, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Human metapneumovirus (HMPV) causes significant upper and lower respiratory disease in all age groups worldwide. The virus possesses a negative-sense single-stranded RNA genome of approximately 13.3 kb encapsidated by multiple copies of the nucleoprotein (N), giving rise to helical nucleocapsids. In addition, copies of the phosphoprotein (P) and the large RNA polymerase (L) decorate the viral nucleocapsids. After viral attachment, endocytosis, and fusion mediated by the viral glycoproteins, HMPV nucleocapsids are released into the cell cytoplasm. To visualize the subsequent steps of genome transcription and replication, a fluorescence in situ hybridization (FISH) protocol was established to detect different viral RNA …

Vibrio Vulnificus Monitoring Along The Coastal Bend And The Rio Grande Valley, Texas, Louay Bachnak

Honors Theses

Vibrio vulnificus is a common opportunistic pathogen found in marine, coastal, and estuarine waters. This one micrometer microorganism is the leading cause of deaths in the United States due to food poisoning after consumption of raw or undercooked seafood. The optimal temperature for survival is between 15.6°C and 35.0°C with moderate salinities – conditions frequently found in the Gulf of Mexico (Lin, Payne, & Schwarz, 2003).

In the United States, V. vulnificus infections are more common in states bordering the Gulf of Mexico, including Texas. However, infections can still occur in individuals consuming infected food more inland or sustain wounds …

Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres

Senior Theses

The rapid emergence of antibiotic-resistant bacteria is a global public health concern that threatens the efficacy of antibiotic drugs. We found that natural remedies, specifically coconut oil, honey and cinnamon essential oil, have the potential to be used as a clinical alternative to treat antibiotic-resistant infections. In this experiment, we performed a disk diffusion test and measured the area of inhibition of each treatment to compare the effectiveness of natural and prescription antibiotics. Cinnamon essential oil showed significantly greater antibiotic activity compared to a prescription treatment, amoxicillin. With bacterial resistance continuously expanding, more work needs to be done to determine …

Fungi Of Forests: Examining The Diversity Of Root-Associated Fungi And Their Responses To Acid Deposition, Donald Jay Nelsen

Graduate Theses and Dissertations

Global importance of forests is difficult to overestimate, given their role in oxygen production, ecological roles in nutrient cycling and supporting numerous living species, and economic value for industry and as recreational zones. Fitness of the forest-forming trees strongly depends on microbial communities associated with tree roots. In particular, fungi impact tree fitness: mycorrhizal species provide water and nutrients for the trees in exchange for C, endophytic fungi play key roles in host defense against pathogenic organisms, and saprotrophic fungi decompose dead organic matter and facilitate nutrient cycling. In addition, pathogenic fungal species strongly affect forest fitness. Despite their importance, …

Fluorescence-Reported Allelic Exchange Mutagenesis Reveals A Role For Chlamydia Trachomatis Tmea In Invasion That Is Independent Of Host Ahnak, M. J. Mckuen, Konrad E. Mueller, Y. S. Bae, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Development of approaches to genetically manipulate Chlamydia is fostering important advances in understanding pathogenesis. Fluorescence-reported allelic exchange mutagenesis (FRAEM) now enables the complete deletion of specific genes in C. trachomatis L2. We have leveraged this technology to delete the coding sequences for a known type III effector. The evidence provided here indicates that CT694/CTL0063 is a virulence protein involved in chlamydial invasion. Based on our findings, we designate the gene product corresponding to ct694-ctl0063 translocated membrane-associated effector A (TmeA). Deletion of tmeA did not impact development of intracellular chlamydiae. However, the absence of TmeA manifested as a decrease in infectivity …

Role Of Incompatibility Group 1 (Inci1) Plasmid-Encoded Factors On Salmonella Enterica Antimicrobial Resistance And Virulence, Pravin Raghunath Kaldhone

Graduate Theses and Dissertations

Foodborne illnesses are a leading cause of infectious diseases in the world. Among enteric organisms Salmonella is a key pathogen. It’s high prevalence in poultry and other food-animal sources make it imperative to study. Salmonella has the ability to modify its genetic content with help of mobile genetic elements such as plasmids. Incompatibiltiy group 1 (IncI1) plasmids are commonly reported in Salmonella. This study evaluates role on IncI1 plasmids in antimicrobial resistance and virulence in Salmonella. Genetic determinants of resistance and virulence are noted among our IncI1-containing Salmonella isolates. These genetic elements are also transferable and reported to carry respective …

Mechanism Of Candida Albicans Biofilm And Virulence Inhibition By A Bacterial Secreted Factor, Carrie Graham

Dissertations and Theses (Open Access)

The human microbiome is a diverse polymicrobial population comprised of both fungi and bacteria. Perturbations of the normal microbiome can have a profound impact on health, including the development of infections. Exploitation of these polymicrobial interactions has the potential to provide novel treatment and prevention strategies for infectious diseases. Enterococcus faecalis, a Gram-positive bacterium, and Candida albicans, a polymorphic fungus, occupy overlapping niches as ubiquitous constituents of the gastrointestinal and oral microbiome. Both species are also amongst the most important and problematic, opportunistic nosocomial pathogens and are often co-isolated during infection. Surprisingly, these two species antagonize each other’s …

Type Ix Secretion System: Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru

Electronic Theses and Dissertations

Porphyromonas gingivalis and Tannerella forsythia are two of the primary pathogens that are associated in the etiology and progression of chronic periodontitis. In T. forsythia, KLIKK proteases are the recently identified group of proteolytic enzymes that are secreted through Type IX secretion system (T9SS). Among, these KLIKK proteases a synergistic relationship was observed between karilysin and mirolysin in invading the host complement system for the survival of the bacteria. Since, karilysin has been already characterized, in this study we propose to study about mirolysin through structural, biochemical and biological characterization. The obtained results from the experiments has shown the …

Phosphate Signaling Through Alternate Conformations Of The Pstscab Phosphate Transporter, Ramesh Krishna Vuppada

Theses and Dissertations

Phosphate is an essential compound for life. Escherichia coli employs a signal transduction pathway that controls the expression of genes that are required for the high-affinity acquisition of phosphate and the utilization of alternate sources of phosphorous. These genes are only expressed when environmental phosphate is limiting. The seven genes for this signaling pathway encode the two-component regulatory proteins PhoB and PhoR, as well as the high-affinity phosphate transporter PstSCAB and an auxiliary protein called PhoU. As the sensor kinase PhoR has no periplasmic sensory domain, the mechanism by which these cells sense environmental phosphate is not known. This paper …

Experimental Approaches To Understand And Control Salmonella Infection In Poultry, Yichao Yang

Graduate Theses and Dissertations

Salmonella is a major foodborne pathogen around the world and chickens are the major reservoir to transmit Salmonella into the human food chain. For decreasing the infection of Salmonella, we developed six attenuated live vaccines based on Salmonella Enteritidis (SE) and Typhimurium (ST) for testing the cross-serovar and cross-serogroup protection from the challenge of Salmonella Heidelberg and Campylobacter jejuni. One of the constructed vaccine strain showed ability to protect against challenge from Salmonella Heidelberg. Even though some preventive approaches are able to decrease Salmonella colonization in the gastrointestinal tract of chickens or other farm animals, Salmonella transmission mechanisms remain unclear. …

Influence Of Epstein-Barr Virus On Systemic Lupus Erythematosus Disease Development And The Role Of Depression On Disease Progression, Caleb Cornaby

Theses and Dissertations

Systemic Lupus Erythematosus (SLE) is an autoimmune disease affecting 20 to 250 individuals per 100,000 worldwide. Symptomology includes dermatological manifestations such as discoid lesions, acute cutaneous rashes, and oral and nasal ulcers, along with musculoskeletal, pulmonary, and renal complications. Abnormal T and B lymphocyte function and apoptosis, immune complex clearance, complement function, and nucleosome processing are typical of disease pathophysiology. SLE is the result of both environmental and genetic factors, which together create the conditions leading to disease onset and progression. Of these environmental factors, Epstein-Barr virus (EBV) infection is known to cause the genesis of cross-reactive antibodies in SLE …

Acetobacter Fabarum Genes Influencing Drosophila Melanogaster Phenotypes, Kylie Makay White

Theses and Dissertations

Research in our lab has predicted hundreds of bacterial genes that influence nine different traits in the fruit fly, Drosophila melanogaster. As a practical alternative to creating site-directed mutants for each of the predicted genes, we created an arrayed transposon insertion library using a strain of Acetobacter fabarum DsW_054 isolated from fruit flies. Creation of the Acetobacter fabarum DsW_054 gene knock-out library was done through random transposon insertion, combinatorial mapping and Illumina sequencing. Successful mapping of transposon insertion was achieved for 6418 mutants with hits within 63% of annotated genes within Acetobacter fabarum DsW_054. Insertion sites were verified in …

Single Nucleotide Polymorphisms In Efflux Pumps Genes In Extensively Drug Resistant Mycobacterium Tuberculosis Isolates From Pakistan, Akbar Kanji, Rumina Hasan, Asho Ali, Ambreen Zaver, Ying Zhang, Kehkashan Imtiaz, Wanliang Shi, Taane G. Clark, Ruth Mcnerney, Jody Phelan

Department of Pathology and Laboratory Medicine

It is challenging to understand mechanisms of drug resistance in Mycobacterium tuberculosis (MTB) due to the large variability in resistance associated genes. Efflux pump genes contribute to drug resistance and thus add to this complexity. Efflux pump gene protein superfamilies have been characterized by genome analysis of drug resistant strains and through invitro transcriptional studies. However, there is limited information regarding efflux pump genes in extensively drug resistant (XDR) tuberculosis (TB) isolates. Whole genome sequencing (WGS) based analysis of 37 extensively drug resistant (XDR) and five drug sensitive (DS) MTB clinical isolates was performed. Single nucleotide polymorphisms (SNPs) in efflux …

Development Of A Cholera Toxin Cta2/B Based Staphylococcus Aureus Vaccine To Prevent Bovine Mastitis, Neha Misra

Boise State University Theses and Dissertations

Staphylococcus aureus is an important pathogen causing chronic and invasive disease worldwide. This bacterium is a leading cause of community and hospital acquired infections in humans, and is also known to infect wild and domestic animals. Bovine mastitis, or inflammation of the udder, is one of the most economically relevant diseases of the dairy industry, with a high incidence worldwide. S. aureus is a major etiological agent causing this disease. S. aureus mastitis is highly contagious and difficult or impossible to treat. Management practices at dairy farms, that include good sanitation and antibiotic use, have been partially successful in reducing …

Complete Sequencing And Comparative Analysis Of The Genomes Of The First Magnetotactic Gammaproteobacteria Isolated In Pure Culture: Strains Bw-2 And Ss-5, Corey Geurink

UNLV Theses, Dissertations, Professional Papers, and Capstones

The genomes of the first two discovered magnetotactic bacteria (MTB) belonging to the ammaproteobacteria, strains BW-2 and SS-51, were sequenced, sealed, annotated and compared to MTB of other phylogenetic groups. Cells of both strains are rod-shaped and biomineralize cuboctahedral and elongated octahedral crystals of magnetite, respectively, that are enveloped in a protein-embedded, lipid-bilayer membrane referred to as the magnetosome membrane or vesicle. The crystals and their associated membranes are known as magnetosomes. Magnetosome crystals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and, because of their specific mineral compositions, crystal morphologies and sizes, the biomineralization processes involved in magnetosome formation …

A Potential Solution To A Poopy Problem: Bile Salt Analogs As Prophylactics Against Clostridium Difficile Infection, Jacqueline Renee Phan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridium difficile infection (CDI) is a major cause of antibiotic-associated diarrhea. In 2011, over 500,000 patients were diagnosed with CDI in the United States and over 29,000 people died of CDI-related complications. With an average of $35,000 to treat a single case of inpatient CDI, cost burden to the healthcare system can reach up to $3.2 billion annually. As both hospital- and community-acquired CDI incidences rise due to the emergence of hypervirulent strains and CDI reoccurrences of up to 25%, standard treatments are rendered less effective and new methods of prevention are critical.

CDI is caused by bacteria called Clostridium …

Embracing Bacterial Cellulose As A Catalyst For Sustainable Fashion, Luis Quijano

Senior Honors Theses

Bacterial cellulose is a leather-like material produced during the production of Kombucha as a pellicle of bacterial cellulose (SCOBY) using Kombucha SCOBY, water, sugar, and green tea. Through an examination of the bacteria that produces the cellulose pellicle of the interface of the media and the air, currently named Komagataeibacter xylinus, an investigation of the growing process of bacterial cellulose and its uses, an analysis of bacterial cellulose’s properties, and a discussion of its prospects, one can fully grasp bacterial cellulose’s potential in becoming a catalyst for sustainable fashion. By laying the groundwork for further research to be conducted …

The Algz/R Two-Component System Is Responsible For Attenuation Of Virulence In Pseudomonas Aeruginosa, Danielle A. Williams

Electronic Theses and Dissertations

Pseudomonas aeruginosa is an important opportunistic pathogen. Many P. aeruginosa virulence factors are regulated by the AlgZ/R two component system. AlgZ is the sensor histidine kinase which phosphorylates AlgR, the response regulator. AlgR activates transcription of different gene targets based upon its phosphorylation state. The genes that encode AlgZ and AlgR are transcribed in an operon. While regulation of algR expression has been well studied, regulation of algZ expression has not. Using a pilW mutant in concert with algZTF-lacZ transcriptional fusion, we conducted a transposon mutagenesis to identify algZ regulators. We identified an unknown autoregulatory loop. The type …

Complete Genome Sequence Of A New Isolate Of Solenopsis Invictavirus 3 From Solenopsis Invicta × Richteri Hybrid Ants, Steven M. Valles, Jason B. Oliver, Karla M. Addesso

Agricultural and Environmental Sciences Faculty Research

Solenopsis invicta virus 3 (SINV-3) is a positive-sense, single-stranded RNA virus that infects the red imported fire ant, Solenopsis invicta Buren. We report here the full genome (10,383 nucleotides) of an isolate infecting Solenopsis invicta× richteri hybrid ants, which we have identified as SINV-3 hybrid.

Development Of A Broadly Protective Modified-Live Virus Vaccine Candidate Against Porcine Reproductive And Respiratory Syndrome Virus, Haiyan Sun, Aspen Workman, Fernando A. Osorio, David J. Steffen, Hiep L.X. Vu

Nebraska Center for Virology: Faculty Publications

Modified-live virus (MLV) vaccines are widely used to protect pigs against porcine reproductive and respiratory syndrome virus (PRRSV). However, current MLV vaccines do not confer adequate levels of heterologous protection, presumably due to the substantial genetic diversity of PRRSV isolates circulating in the field. To overcome this genetic variation challenge, we recently generated a synthetic PRRSV strain containing a consensus genomic sequence of PRRSV-2. We demonstrated that our synthetic PRRSV strain confers unprecedented levels of heterologous protection. However, the synthetic PRRSV strain at passage 1 (hereafter designated CON-P1) is highly virulent and therefore, is not suitable to be used as …