Microbiology Commons^™

Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta

Dissertations, Master's Theses and Master's Reports - Open

Antibiotics are emerging contaminants worldwide. Due to insufficient policy regulations, public awareness, and the constant exposure of the environment to antibiotic sources has created a major environmental concern. Wastewater treatment plants (WWTP) are not equipped to filter-out these compounds before the discharge of the disinfected effluent into water sources (e.g., lakes and streams) and current available technologies are not equipped to remediate these compounds from environmental sources. Hence, the challenge remains to establish a biological system to remove these antibiotics from wastewater. An invitro hydroponic remediation system was developed using vetiver grass (Chrysopogon zizanioides L. Nash) to remediate tetracycline …

The Burden Of Avian Influenza Viruses In Community Ponds In California, Zin Htway

Walden Dissertations and Doctoral Studies

Emerging influenza viruses continue to challenge public health. The problem is public health science professionals have been battling emerging human influenza diseases with tactile and reactionary methods because there is a lack of knowledge and data at the human-animal interface. This research was a baseline study of the proportion of influenza A virus (IAV) in urban and rural communities in California. The population was artificial recirculating water ponds in the geographic locations of rural and urban Californian communities. Surface water samples [N = 182] were collected from artificial recirculating ponds in California. Positivity for IAV was verified by real time …

Effects Of Elevated Salinity And Oxidative Stress On The Physiology Of The Toxigenic Cyanobacterium Microcystis Aeruginosa, Billy Christopher Warhurst

UNF Graduate Theses and Dissertations

Harmful algal blooms (HABs) are found worldwide, particularly in places where warm, well-lit, and stagnant waters are common. HABs can have negative effects on aquatic plants and wildlife due to the reduction in light availability associated with turbidity, decrease in O₂ availability, and the production of secondary metabolites that can harm or even prove lethal. Aquatic ecosystems are regularly being affected by elevated salinity because of recent water management strategies, episodes of drought, and salt water intrusion. This research focused on how salinity levels ranging from 0-10ppt affected physiological attributes such as cellular growth and abundance, cell mortality, toxin …

Identification Of Clinical Markers That Predict The Outcomes Of Methicillin-Resistant Staphylococcus Aureus Infections And Identification Of Synergistic Antibiotic Combinations For The Treatment Of These Infections, Virginia Long

Master's Theses

Methicillin-resistant Staphylococcus aureus(MRSA) is a prominent nosocomial infection. Vancomycin is the mainstay of treatment, but it has a high rate of failure. Combination therapies can be used, but synergy is often not tested in clinical laboratories. Physicians are at a disadvantage because they cannot predict MRSA outcomes. The first aim of the study was to identify clinical and demographic markers that could predict infection recurrence or prolonged bacteremia. This was accomplished using retrospective chart review and statistical analysis. The second aim of the study was to identify which combinations, of those commonly used for MRSA treatment at Loyola, demonstrate the …

Host Proteins Interact With The Hiv-1 Core To Facilitate And Restrict, Zana Lukic

Dissertations

Host cell proteins, termed restriction factors, which inhibit viral replication at various stages of the viral life cycle, determine the species-specific tropism of numerous retroviruses. Many members of the TRIM family of proteins act as viral restriction factors. One well-characterized example is the ability of TRIM5á from rhesus macaques (rhTRIM5á) to inhibit human immunodeficiency virus type-1 (HIV-1) soon after viral entry but prior to reverse transcription (RT). It is well established that the restriction requires an interaction between the viral capsid lattice and the B30.2/SPRY domain of TRIM5á. Following the binding of the viral core, TRIM5á mediates an event or …

Adenovirus Vectors As Potent Adjuvants In Vaccine Development, Kathleen Ann Mcguire

Dissertations

Due to their ability to activate the immune system, replication-defective Adenoviruses (Ad) are potential vaccine vectors for several pathogens. The proinflammatory response to Ad contributes to the response to vaccine antigens. We found that reactive oxygen species (ROS) are an important signal in the proinflammatory response to Ad. We identified that serotype 5 adenovirus (Ad5) elicits ROS by inducing mitochondrial membrane damage, a process that is dependent on endosomal membrane rupture and Cathepsin release. This mitochondrial dysfunction contributes to NLRP3 inflammasome- and NFκB-dependent innate immune activation. The ROS-dependent inflammatory response likely contributes to the adaptive immune response by supporting DC …

Dielectric Barrier Discharge Atmospheric Cold Plasma For Inactivation Of Pseudomonas Aeruginosa Biofilms, Dana Ziuzina, Sonal Patil, Patrick J. Cullen, Daniela Boehm, Paula Bourke

Articles

In recent years, atmospheric cold plasma (ACP) has been widely investigated for potential application as an alternative decontamination technology in biomedical and healthcare sectors. In this study, the antimicrobial efficacy of ACP against Pseudomonas aeruginosa biofilms was investigated. The 48-h biofilms were treated inside sealed polypropylene containers with a high-voltage dielectric barrier discharge (DBD) ACP (80 kVRMS) and subsequently stored for 24 h at room temperature. Treatment for 60 s by either the direct or indirect mode of ACP exposure (inside or outside plasma discharge, respectively) reduced bacterial populations by an average of 5.4 log cycles from an initial 6.6 …

Reconsidering The Model Of Trim5Α Assembly: The Role Of The Linker2 (L2) Region In Trim5Α Assembly, Laura Johnsen

Master's Theses

The TRIM5α protein from rhesus macaques (TRIM5αrh) exhibits a remarkable ability to potently inhibit infection by Human Immunodeficiency Virus Type-1 (HIV-1). Extensive studies have shown that TRIM5α is capable of self-associating at many levels, eventually leading to the formation of a hexameric assembly that can superimpose on the hexameric lattice of the HIV-1 capsid. The mechanism underlying the self-association of TRIM5α and the molecular determinants of self-association remain to be completely understood. In this study, we show that the Linker 2 (L2) region of TRIM5rh is important for dimerization and higher order self-association, both of which are independent processes. Additionally, …

Characterization Of The Female Urinary Microbiota And Their Association With The Female Bladder Uroepithelium, Evann Elizabeth Hilt

Master's Theses

The current clinical dogma assumes that urine is sterile in the absence of clinically relevant infection. However, recent evidence has demonstrated the existence of a female urinary microbiota in women with and without lower urinary tract symptoms. With the knowledge that the lower urinary tract possesses its own unique microbiota, I hypothesize that certain bacterial species of the female microbiota may be the cause or play a role in lower urinary tract syndromes such as overactive bladder syndrome (OAB). About 40-50% of OAB patients do not respond to conventional anti-muscarinic and beta-3 adrenergic agonist drug treatment. One possible explanation for …

An Investigation Of The Role Of Vibrio Vulnificus Rbda And Vibrio Parahaemolyticus Sypa In Biofilm Formation, Cecilia Thompson

Master's Theses

Vibrio vulnificus and Vibrio parahaemolyticus are both bacteria that cause human infection. V. vulnificus has a polysaccharide locus, rbd, responsible for bacterial aggregation, a form of biofilm. This locus is conserved in V. parahaemolyticus and in the non-pathogen V. fischeri.

In V. fischeri, the polysaccharide locus, syp, has been extensively characterized and shown to be important for biofilm formation. In V. fischeri, the first gene, sypA, is critical for biofilm formation. V. fischeri biofilm-proficient strains form wrinkled colonies. In contrast, sypA mutants form smooth colonies, indicating a lack of biofilm formation.

To understand the function of RbdA and SypAVP, proteins …

Host Entry Factors For Human Coronaviruses, Taylor Heald-Sargent

Dissertations

Coronaviruses infect a diverse range of animals from birds to pigs and cats to humans. Coronaviruses employ RNA-based replicative processes and as such are genetically adaptable to acquire novel host ranges. A coronavirus from one species can jump to another by shifting its entry requirements. As we learned from the Severe Acute Respiratory Syndrome (SARS) pandemic, this shift in species can have detrimental consequences. Thus, it is imperative that we understand the virus-host interaction during the entry process.

This dissertation focuses on host entry factors that influence human coronavirus entry. Recently, a new class of proteases, the type II transmembrane …

Identifying Novel Factors Involved In Biofilm Formation By Vibrio Fischeri, Valerie Ray

Dissertations

Biofilm formation by bacteria provides them with a means to survive harsh environmental conditions and promote colonization of a particular surface (biotic or abiotic). Due to the resistance properties of biofilms, biofilm-forming bacteria are difficult to treat in the context of host infections. Thus, investigating the processes that control biofilm formation will promote the development of novel therapeutics. To study biofilm formation in the context of a host, I utilized as a model system the marine bacterium Vibrio fischeri, which must be competent to form a biofilm to colonize its squid host Euprymna scolopes. Biofilm formation by V. fischeri requires …

Multifunctional Coronavirus Papain-Like Proteases As Targets For Antiviral Therapeutics And Vaccines, Anna Maria Mielech

Dissertations

Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and Middle Ease Respiratory Syndrome coronavirus (MERS-CoV) pose a severe threat to humans because of high mortality. Despite the risk of coronavirus (CoV) emerging in the human population there are no antiviral drugs or vaccines to combat coronavirus infection. The focus of my dissertation was to study the multifunctionality of papain-like proteases (PLPs) encoded within coronavirus genomes to facilitate the development of antiviral drugs and vaccines. The viral PLPs are critical for processing the amino-terminal end of the replicase during virus replication and are attractive targets for antiviral therapies.

In my research, I analyzed …

Ticks And Spotted Fever Group Rickettsiae Of Southeastern Virginia, Robyn M. Nadolny, Chelsea L. Wright, Daniel E. Sonenshine, Wayne L. Hynes, Holly D. Gaff

Biological Sciences Faculty Publications

The incidence of tick-borne rickettsial disease in the southeastern United States has been rising steadily through the past decade, and the range expansions of tick species and tick-borne infectious agents, new and old, has resulted in an unprecedented mix of vectors and pathogens. The results of an ongoing 4-year surveillance project describe the relative abundance of questing tick populations in southeastern Virginia. Since 2009, more than 66,000 questing ticks of 7 species have been collected from vegetation in a variety of habitats, with Amblyomma americanum constituting over 95% of ticks collected. Other species represented included Ixodes scapularis, Dermacentor variabilis …

Tick-Bourne Pathogens Of Potential Zoonotic Importance In The Southern African Region, Simbarashe Chitanga, Holly Gaff, Samson Mukaratirwa

Biological Sciences Faculty Publications

The aim of this communication is to provide preliminary information on the tick-borne pathogens of potential zoonotic importance present in southern Africa, mainly focusing on their geographical distribution and host range, and to identify research gaps. The following tick-borne zoonoses have been reported to occur in southern Africa based mainly on case reports: Crimean–Congo haemorrhagic fever caused by Crimean–Congo haemorrhagic fever virus; ehrlichiosis caused by Ehrlichia ruminantium, Ehrlichia canis and Anaplasma phagocytophilum; babesiosis caused by Babesia microti; relapsing fever caused by Borrelia duttonii and rickettsioses caused by Rickettsia africae, Rickettsia aeschlimannii and Rickettsia conorii. The …

Single-Tube Real-Time Pcr Assay For Differentiation Of Ixodes Affinis And Ixodes Scapularis, Chelsea L. Wright, Wayne L. Hynes, Breanna T. White, Mindy N. Marshall, Holly D. Gaff, David T. Gauthier

Biological Sciences Faculty Publications

Ixodes affinis Neumann (1899) and Ixodes scapularis Say (1821) are tick vectors of the etiologic agent of Lyme disease, Borrelia burgdorferi sensu stricto. Ixodes affinis and I. scapularis are morphologically very similar, and as they are sympatric in the mid- and south-Atlantic U.S. coastal states, their accurate identification is crucial to studies of disease and vector ecology in this area. This work describes a rapid, single-tube SYBR® Green-based real-time PCR assay for differentiation of I. affinis and I. scapularis at all life stages. The assay employs 2 pairs of species specific primers directed against the internal transcribed spacer 2 (ITS2) …

Prevalence Of Ehrlichia Chaffeensis And Ehrlichia Ewingii In Amblyomma Americanum And Dermacentor Variabilis Collected From Southeastern Virginia, 2010-2011, Chelsea L. Wright, Holly D. Gaff, Wayne L. Hynes

Biological Sciences Faculty Publications

Amblyomma americanum is the most commonly-encountered tick species in southeastern Virginia, representing approximately 95% of the human-biting tick population in this area. Here we investigated the prevalence of Ehrlichia chaffeensis and Ehrlichia ewingii in questing Amblyomma americanum and Dermacentor variabilis ticks collected from multiple sites in southeastern Virginia from 2010–2011. Although both Ehrlichia species were detected in Amblyomma americanum, no evidence of either pathogen was found in Dermacentor variabilis. Prevalence of E. chaffeensis varied by location, ranging from 0 – 5.08% among Amblyomma americanum populations. Ehrlichia ewingii prevalence was slightly higher, ranging from 0 – 8.20% among A. …

The Composition And Stability Of The Vaginal Microbiota Of Normal Pregnant Women Is Different From That Of Non-Pregnant Women, Roberto Romero, Sonia S. Hassan, Pawel Gajer, Adi L. Tarca, Douglas W. Fadrosh, Lorraine Nikita, Marisa Galuppi, Ronald F. Lamont, Piya Chaemsaithong, Jezid Miranda, Tinnakorn Chaiworapongsa, Jacques Ravel

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

This study was undertaken to characterize the vaginal microbiota throughout normal human pregnancy using sequence-based techniques. We compared the vaginal microbial composition of non-pregnant patients with a group of pregnant women who delivered at term.

Results

A retrospective case–control longitudinal study was designed and included non-pregnant women (n = 32) and pregnant women who delivered at term (38 to 42 weeks) without complications (n = 22). Serial samples of vaginal fluid were collected from both non-pregnant and pregnant patients. A 16S rRNA gene sequence-based survey was conducted using pyrosequencing to characterize the structure and stability of the vaginal …

Characterization Of The Effects Of Iron On Neisseria Gonorrhoeae Surface Protein Modulation And Host Cell Interactions, Aminat Oki

Theses and Dissertations

Iron is an essential nutrient that is sequestered by iron-binding proteins in the human host resulting in a hostile environment for microbes. Neisseria gonorrhoeae, however, can utilize numerous iron-binding proteins such as transferrin and lactoferrin to acquire this nutrient. During initial infection, gonococci have access to transferrin and lactoferrin present in semen and vaginal fluids, as well as to hemoglobin present in blood during menses or disseminated infections. Consequently, the gonococcus likely encounters conditions of high iron at some stages in the course of natural infection. Potential contributions of iron to gonococcal invasion have however been largely over looked in …

Anaplasma Phagocytophilum Nutritional Virulence Mechanisms Target The Host Cell Secretory Pathway, Hilary Kay Truchan

Theses and Dissertations

Obligate intracellular pathogens must acquire host cell-derived nutrients to facilitate their survival. One such bacterial pathogen, Anaplasma phagocytophilum, replicates within neutrophils and non-phagocytic cells in a bacterial-modified, host cell-derived vacuole. The bacterium exploits host cell vesicular trafficking pathways to route nutrients to its vacuole and utilizes Rab GTPases, guanine nucleotide-dependent, vesicular trafficking regulators, to do so. We previously discovered that the A. phagocytophilum vacuolar membrane is decorated with a specific subset of Rab GTPases - Rab1, Rab4A, Rab10, Rab11, Rab14, Rab22A and Rab35. Rab1 is exclusively found on the endoplasmic reticulum (ER) and thus its localization suggests that the …