Microbiology Commons^™

Antimicrobial-Resistant Listeria Species From Retail Meat In Metro Detroit, Liziane Da Rocha

Wayne State University Theses

A total of 138 Listeria isolates, including 58 Listeria welshimeri, 44 Listeria monocytogenes, and 36 Listeria innocua, from retail meat were characterized by antimicrobial susceptibility tests against nine antimicrobials. In addition, the 44 L. monocytogenes were analyzed by serotype identification using PCR and genotyping using pulsed-filed gel electrophoresis (PFGE). Resistance to one or two antimicrobials was observed in 32 Listeria (23.2%). No multidrug resistance was identified. Tetracycline resistance was the most common resistance phenotype and identified in 22 Listeria isolates. Low prevalence of resistance to ciprofloxacin, erythromycin, gentamicin, and vancomycin was also detected. L. innocua demonstrated the highest overall prevalence …

Role Of Crebh In Endotoxin Mediated Modulation Of Hepatic Metabolism, Aditya Prakash Dandekar

Wayne State University Dissertations

Bacterial endotoxins can induce a variety of physiological changes in the host. This effect is not only restricted to inflammatory changes but also comprises metabolic changes in the host body. Lipopolysaccharide (LPS), one of the key components of the bacterial cell walls, is capable of triggering host metabolic changes. Hyperlipidemia usually accompanies with high endotoxin levels as well as inflammation. Lipid metabolism disorders are one of the common hallmarks of a patient with sepsis or high levels of endotoxin through diet. Previously, we have identified an endoplasmic reticulum (ER) anchored liver-specific transcription factor CREBH (cAMP-responsive element-binding protein, hepatocyte-specific), which is …

Characterization Of Oral Microbiota In Xerostomic Versus Non-Xerostomic Volunteers And In Daily Samples Following Standard Oral Hygiene Practices, Chelsea Myers

Wayne State University Theses

A thesis presented on the characterization of oral microbiota in xerostomic versus non-xerostomic volunteers and in daily samples following standard oral hygiene practices. Xerostomia is a difficult and burdensome disease that can be very difficult to diagnose. Understanding the oral microbiota between these diseased and healthy (non-xerostomic) can give us great insight on new treatments and/or prevention. Goals of the study included determining whether there substantial differences in oral microbial populations between the two groups, and whether varying nightly oral hygiene practices had an impact on next-morning oral microbiota titers or composition. Microbial loads were determined by qPCR using broad-spectrum …

The Antimicrobial, Mechanical, Physical And Structural Properties Of Chitosan-Gallic Acid Films, Xiuxiu Sun, Zhe Wang, Hoda Kadouh, Kequan Zhou

Nutrition and Food Science Faculty Research Publications

Chitosan films incorporated with various concentrations of gallic acid were prepared and investigated for antimicrobial, mechanical, physical and structural properties. Four bacterial strains that commonly contaminate food products were chosen as target bacteria to evaluate the antimicrobial activity of the prepared gallic acid-chitosan films. The incorporation of gallic acid significantly increased the antimicrobial activities of the films against Escherichia coli, Salmonella typhimurium, Listeria innocua and Bacillus subtilis. Chitosan films incorporated with 1.5 g/100 g gallic acid showed the strongest antimicrobial activity. It was also found that tensile strength (TS) of chitosan film was significantly increased when incorporating …

Deletion Of The Human Cytomegalovirus Us17 Gene Increases The Ratio Of Genomes Per Infectious Unit And Alters Regulation Of Immune And Endoplasmic Reticulum Stress Response Genes At Early And Late Times After Infection, Stephen James Gurczynski, Subhendu Das, Philip E. Pellett

Immunology and Microbiology Faculty Research Publications

Human cytomegalovirus (HCMV) employs numerous strategies to combat, subvert, or co-opt host immunity. One evolutionary strategy for this involves capture of a host gene and then its successive duplication and divergence, forming a family of genes, many of which have immunomodulatory activities. The HCMV US12 family consists of 10 tandemly arranged sequence-related genes in the unique short (US) region of the HCMV genome (US12 to US21). Each gene encodes a protein possessing seven predicted transmembrane domains, patches of sequence similarity with cellular G-protein-coupled receptors, and the Bax inhibitor 1 family of antiapoptotic proteins. We show that one member, US17, plays …

Targeting Cxcr4 With Ctce-9908 Inhibits Prostate Tumor Metastasis, Donald Wong, Pridvi Kandagatla, Walter Korz, Sreenivasa R. Chinni

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

CXCL12/CXCR4 transactivation of epidermal growth factor family receptors in lipid raft membrane microdomains on cell surface is thought to mediate tumor growth and subsequent development of metastatic disease. CTCE-9908 is a known inhibitor of CXCR4. Herein, we tested the efficacy of CTCE-9908 in inhibiting prostate cancer cell growth, invasion, and metastasis.

Methods

We used a panel ofin vitroassays utilizing human prostate cancer cell lines and anin vivoorthotopic prostate cancer model to assess the anti-tumoral activity of CTCE-9908.

Results

We demonstrated that (a) CTCE-9908 treatment resulted in no significant change in the growth of PC-3 and C4-2B cells; (b) …

Mechanisms For Bicarbonate-Mediated Virulence In Vibrio Cholerae, Joshua James Thomson

Wayne State University Dissertations

Vibrio cholerae is the etiologic agent of the severe diarrheal disease cholera. The aquatic bacterium is ingested by humans through contaminated water or food. Disease initiation depends on the production of the major virulence factors: cholera toxin (CT) and the toxin co-regulated pilus (TCP). The bacterium responds to signals in the human host that activate a virulence regulatory cascade termed the "ToxR Regulon". The ToxR regulon consists of various transcription regulators whose activity culminates in the production of the major virulence regulator, ToxT. ToxT directly activates transcription of CT and TCP, as well as many other gene products involved in …

Recombinant Interleukin-21 Plus Sorafenib For Metastatic Renal Cell Carcinoma: A Phase 1/2 Study, Shailender Bhatia, Brendan, Marc S. Ernstoff, Michael, Elisabeth I. Heath, Wilson H. Miller Jr, Igor Puzanov, David I. Quinn, Thomas, Peter Vanveldhuizen, Kelly, Jeremy, Rachel, Naomi, Sonia, John A. Thompson

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Despite the positive impact of targeted therapies on metastatic renal cell carcinoma (mRCC), durable responses are infrequent and an unmet need exists for novel therapies with distinct mechanisms of action. We investigated the combination of recombinant Interleukin 21 (IL-21), a cytokine with unique immunostimulatory properties, plus sorafenib, a VEGFR tyrosine kinase inhibitor.

Methods

In this phase 1/2 study, 52 mRCC patients received outpatient treatment with oral sorafenib 400 mg twice daily plus intravenous IL-21 (10–50 mcg/kg) on days 1–5 and 15–19 of each 7-week treatment course. The safety, antitumor activity, pharmacokinetic and pharmacodynamic effects of the combination were …

Characterization Of Bacteriophages From Environmental Water Samples And The Potential Of Bacteriophages Tailspike Proteins (Tsp) In Bacteria Detection, Gayathri Upeksha Gunathilaka

Wayne State University Theses

ABSTRACT

CHARACTERIZATION OF BACTERIOPHAGES FROM ENVIRONMENTAL WATER SAMPLES AND THE POTENTIAL OF BACTERIOPHAGES TAILSPIKE PROTEINS (TSP) IN BACTERIA DETECTION

by

GAYATHRI UPEKSHA GUNATHILAKA

May 2014

Advisor: Dr. Yifan Zhang

Major: Nutrition and Food Science

Degree: Master of Science

The high abundance of phage in the environment and their specificity with the bacteria host make them an excellent tool for bacteria detection. To characterize phage specific to Salmonella and E. coli from water samples in the Southeastern Michigan and to develop a novel bacterial detection method using phage, environmental water samples were collected from rivers and waste water treatment plant (WWTP) …

The Movement Of Escherichia Coli And Enterococci Among Beach Sand, Lyngbya Wollei, And The Water Column: Implications For Human Health, Krystal Ann Bakkila

Wayne State University Theses

Occurrence of the filamentous cyanobacteria Lyngbya wollei has become an increasing concern in the Great Lakes region. Prior to the early 1900's, L. wollei had been occasionally documented in the Great Lakes region, but in the last decade it has been observed with increasing frequency. In the Great Lakes L. wollei has been proliferating, fragmenting, and accumulating ashore, where it decays forming thick detrital mats harboring potentially harmful bacteria such as Escherichia coli and enterococci. While the filamentous green algae species Cladophora glomerata has been well studied in this region, very little research has been done on the cyanobacteria L. …

Screening Of Natural Antimicrobial Agents And Antimicrobial-Resistant Bacteria Using A Soleris System, Mingyang Huang

Wayne State University Theses

ABSTRACT

SCREENING OF NATURAL ANTIMICROBIAL AGENTS AND ANTIMICROBIAL - RESISTANT BACTERIA USING A SOLERIS SYSTEM

by

MINGYANG HUANG

May 2014

Advisor: Dr. Yifan Zhang

Major: Food Science and Nutrition

Degree: Master of Science

Traditional broth micro-dilution method is a common assay of measuring Minimum Inhibitory Concentration (MIC) to determine the antimicrobial activity of an antimicrobial agent. However, this method is generally time-consuming and labor intensive. Alternatively, an automated optical method using the Soleris system was applied in this study. The system was compared to the traditional broth micro-dilution 96-well assay to test the antimicrobial activity of 11 essential oils and …

Role Of The Pkna And Pknb Kinases In Mycobacterium Tuberculosis, Tripti Anandan

Wayne State University Dissertations

To respond to environmental changes, M. tuberculosis possesses eleven "eukaryotic-type" Ser/Thr protein kinases. The aim of the study described in this dissertation was to identify role of two of these kinases; PknA and PknB that are essential in M. tuberculosis. Two approaches are described to screen for potential in vivo substrates of PknA/PknB. First approach is based on proteomic search by over-expressing PknA/PknB in M. tuberculosis. Proteomic search led to identification of proteasome to be a substrate of PknA and PknB in M. tuberculosis. Furthermore, I demonstrate that the phosphorylation of PrcA and PrcB by PknA regulates processing of Pre-PrcB. …

The Mechanism For Inhibition Of Vibrio Cholerae Virulence Gene Expression By Bile And Its Fatty Acid Components, Sarah Plecha

Wayne State University Dissertations

Vibrio cholerae is responsible for the diarrheal disease cholera by producing two major virulence factors: cholera toxin (CT) and toxin-coregulated pilus (TCP). During infection, V. cholerae downregulates its motility genes, which are actively expressed in the environment, and upregulates its virulence genes, which are inactive in the environment. Virulence gene transcription is regulated by the major transcriptional activator, ToxT. ToxT is regulated, in part, by host signals, which in turn, make ToxT active or inactive in respect to virulence gene expression. Host signals include temperature and pH as well as the chemical molecules bicarbonate and bile, which are positive and …

Cell Envelope Modifications By Lcp Family Proteins Of Group B Streptococcus And Virulence Singaling By Peptides Of The Salivaricin Locus Of Streptococcus Pyogenes, Hannah Morrison Rowe

Wayne State University Dissertations

ABSTRACT

CELL ENVELOPE MODIFICATIONS BY LCP FAMILY PROTEINS OF GROUP B STREPTOCOCCUS AND VIRULENCE SIGNALING BY PEPTIDES OF THE SALIVARICIN LOCUS OF STREPTOCOCCUS PYOGENES

by

HANNAH MORRISON ROWE

December 2014

Advisor: Dr. Melody Neely

Major: Immunology and Microbiology

Degree: Doctor of Philosophy

Streptococci are important human and animal pathogens. Group B Streptococcus (GBS) is a zoonotic pathogen that is the leading cause of human neonatal sepsis and meningitis. In order to cause systemic disease GBS must produce a polysaccharide capsule. Capsule expression is controlled in part by the protein CpsA. We demonstrate that deletion of the cpsA gene, or expression …

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 …

Human Cytomegalovirus Us17 Locus Fine-Tunes Innate And Intrinsic Immune Responses, Stephen James Gurczynski

Wayne State University Dissertations

HCMV employs numerous strategies to combat, subvert, or co-opt host immunity. One evolutionary strategy for this involves "capture" of a host gene and then its successive duplication and divergence, forming a gene family, many of which have immunomodulatory activities. The HCMV US12 family consists of ten tandemly arranged sequence-related genes in the unique short region of the HCMV genome (US12-US21). Each gene encodes a protein possessing seven predicted transmembrane domains, and patches of sequence similarity with cellular GPCRs and the bax inhibitor-1 family of anti-apoptotic proteins. We show that one member, US17, plays an important role during virion maturation. Microarray …

Functional Characterization Of The Cholera Toxin Promoter Of Vibrio Cholerae, Jennifer Dittmer

Wayne State University Dissertations

Vibrio cholerae is the bacterium responsible for the severe diarrheal disease cholera. The disease is directly caused by cholera toxin, which is secreted by the bacterium in the upper small intestinal lumen during the course of infection. Expression of cholera toxin, along with other virulence genes, is activated by the positive transcriptional regulator, ToxT. ToxT binds to DNA sequences known as toxboxes that are found within promoters of virulence genes and subsequently ToxT activates transcription. However, the toxboxes have not been previously characterized in arguably the most important virulence promoter in V. cholerae, the cholera toxin promoter (PctxAB). …

In Vivo Display: A Selection And Its Derivatives For Antimicrobial Peptide Lead Identification, Wesley David Colangelo

Wayne State University Dissertations

The rise of antibiotic resistance necessitates new approaches for the isolation of new antimicrobials with novel inhibitory mechanisms, bypassing the development of rapid resistance by modification of pre-existing resistance mechanisms. In response, we have developed a series of systems for the rapid isolation and identification of peptides that inhibit the growth of Escherichia coli and other bacteria, termed in vivo display (IVD).

IVD harnesses the cellular processes of E. coli for the expression of a library of random peptides at the terminus of a display protein. A library of 12-amino acid random peptide sequences was added to either the C- …

Characterization Of Intracellular Interactions Between Dengue Virus And Host Proteins, Dumrong Mairiang

Wayne State University Dissertations

Dengue virus is the causative agent of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of world population live in areas where dengue is prevalent, leading to high levels of morbidity and mortality in many areas. Currently there are no vaccines or effective treatments. The virus is transmitted from one person to another by the yellow fever mosquito, Aedes aegypti. The genome of dengue virus encodes only ten proteins implying that the virus needs to interact with and utilize several host proteins for replication. In this project, I used high-throughput yeast two-hybrid screening to identify mosquito and …

Examining Autoimmune Sequelae During Cancer Immunotherapy In A Combined Autoimmune Thyroiditis And Tumor Mouse Model, Suresh Kari

Wayne State University Dissertations

Some clinical trials of immunotherapeutic agents against cancers have resulted in the development of autoimmune sequelae, including autoimmune thyroiditis. It has been suggested that the immunotherapy resulted in an alteration in the immunoregulatory mechanism(s). Using experimental autoimmune thyroiditis (EAT), a mouse model of Hashimoto's thyroiditis (HT), the importance of regulatory T cells (Tregs) has been well established; inhibition of Tregs leads to enhanced thyroiditis with repeated doses of mouse thyroglobulin (mTg) without adjuvant. To simulate cancer patients, we developed a combined EAT and tumor model in our EAT-susceptible mice (CBA/J). In first establishing the tumor model, we found Treg depletion …

Membrane-Bound Immunomodulators As Adjuvants In A Cell Culture-Based Avian Influenza Vaccine, David Daniel Fischer

Wayne State University Dissertations

Inactivated viral vaccines often generate suboptimal immune responses. Adjuvants are incorporated into vaccines to increase their immunogenicity, however currently available adjuvants have shortcomings which have limited their use in human and veterinary medicine. This necessitates the development of new adjuvants and delivery systems. Cytokines have been extensively tested as adjuvants in vaccines but challenges such as diffusion from antigen, short half-lives and production costs have been encountered. To address this, we developed a technology that efficiently produces inactivated, whole-virus influenza vaccine bearing membrane-bound cytokines. Tethering the cytokine to the antigen of interest keeps the immunomodulator in close contact with the …

Identification Of The Role Of The Sal Locus In Streptococcus Pyogenes Virulence During Host-Pathogen Interactions, Phanramphoei Namprachan-Frantz

Wayne State University Dissertations

The pathogenesis of Streptococcus pyogenes is due to its ability to overcome and adapt to the harsh environment created by the host immune response. The focus of this project was the SalKR two-component regulatory system, which facilitates bacterial adaptation by responding to environmental signals during host pathogen-interactions. The first goal of this project was to determine a role in virulence for the SalKR regulatory system. The complete deletion of the salKR genes in the wild type S. pyogenes strain HSC5 produced a highly attenuated mutant in a Zebrafish infection model. The ΔsalKR mutant appeared to lose the ability to survive …

Laser-Induced Breakdown Spectroscopy (Libs): An Innovative Tool For Studying Bacteria, Qassem I. Mohaidat

Wayne State University Dissertations

Laser-induced breakdown spectroscopy (LIBS) has gained a reputation as a flexible and convenient technique for rapidly determining the elemental composition of samples with minimal or no sample preparation. In this dissertation, I will describe the benefits of using LIBS for the rapid discrimination and identification of bacteria (both pathogenic and non-pathogenic) based on the relative concentration of trace inorganic elements such as Mg, P, Ca, and Na. The speed, portability, and robustness of the technique suggest that LIBS may be applicable as a rapid point-of-care medical diagnostic technology.

LIBS spectra of multiple genera of bacteria such as Escherichia, Streptococcus, Mycobacterium, …

Analysis Of The Streptococcal Cpsa Protein In Dna-Binding And Regulation Of Capsule And Cell Wall Maintenance, Brett R. Hanson

Wayne State University Dissertations

The systemic pathogens Streptococcus agalactiae (GBS) and Streptococcus pneumoniae remain a significant threat to human health worldwide. The ability of these organisms to cause systemic disease is compounded by the production of a polysaccharide capsule that provides immune evasion function. The production of the polysaccharide capsule in systemic streptococcal pathogens is controlled in part by the membrane bound protein CpsA. These studies analyze the contribution of CpsA to regulation of capsule level in the model aquatic pathogen Streptococcus iniae and human specific pathogen GBS, and how this regulation affects virulence in in-vitro, ex-vivo, and in-vivo models of pathogenesis. We have …

Pleiotropic Regulatory Function Of The Lysr Family Transcriptional Regulator Cpsy During Streptococcus Iniae Systemic Infection, Jonathan Paul Allen

Wayne State University Dissertations

The ability of a pathogen to metabolically adapt to the local environment for optimal expression of virulence determinants is a continued area of research. Orthologs of the Streptococcus iniae LysR family regulator CpsY have been shown to regulate methionine biosynthesis and uptake pathways, but appear to influence expression of several virulence genes as well. A S. iniae mutant with an in-frame deletion of cpsY is highly attenuated in a zebrafish infection model. The cpsY deletion mutant displays a methionine-independent growth defect in serum, which differs from the methionine-dependent defect observed for orthologous mutants of S. mutans and S. agalactiae. …

Regulation Of Polar Peptidoglycan Biosynthesis By Wag31 Phosphorylation In Mycobacteria, Charul Jani, Hyungjin Eoh, Jae Lee, Khozima Hamasha, Moodakare Sahana, Jeong-Sun Han, Seeta Nyayapathy, Jung-Yeon Lee, Joo-Won Suh, Sang Lee, Steve J. Rehse, Dean C. Crick, Choong-Min Kang

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Sensing and responding to environmental changes is a central aspect of cell division regulation. Mycobacterium tuberculosis contains eleven Ser/Thr kinases, two of which, PknA and PknB, are key signaling molecules that regulate cell division/morphology. One substrate of these kinases is Wag31, and we previously showed that partial depletion of Wag31 caused morphological changes indicative of cell wall defects, and that the phosphorylation state of Wag31 affected cell growth in mycobacteria. In the present study, we further characterized the role of the Wag31 phosphorylation in polar peptidoglycan biosynthesis.

Results

We demonstrate that the differential growth among cells expressing different …

Analysing The Effects Of Loss Of Sin3 In Drosophila Melanogaster, Aishwarya Swaminathan

Wayne State University Dissertations

Sin3A has been previously shown to be an essential gene for Drosophila viability and is implicated in the regulation of cell cycle. In this study, we show that SIN3 is not only required for embryonic viability but also for post-embryonic development. Genetic analysis suggests that the different isoforms of SIN3 may regulate unique sets of genes during development. The developmental lethality occurring due to ubiquitous knock down of SIN3 is hypothesized to be to the result of defects in cell proliferation. Conditional knock down of SIN3 in the wing discs results in a curly wing phenotype in the adult fly. …

Immunomodulatory Effect Of Host And Fungal Eicosanoids During Host-Pathogen Interactions With Candida Albicans, Gitanjali Kundu

Wayne State University Dissertations

Candida albicans, an opportunistic fungal pathogen, poses a significant clinical threat to immunocompromised patients. Diseases associated with this fungus ranges from superficial mucosal infection to life-threatening systemic candidiasis. The mechanisms by which Candida persists at mucosal surfaces in the face of an adaptive response are unclear. Candida produces immunomodulatory oxylipins that cross-react functionally with host eicosanoids, which are considered to play important role in regulating innate and adaptive immune responses. Our objective was to characterize the role of prostaglandins produced by the host and this fungus during host pathogen interactions, both in vitro with dendritic cells (DCs) and macrophages, and …

Failure Of E. Coli Bacteria To Induce Preterm Delivery In The Rat, Emmet Hirsch, Yana Filipovich, Roberto Romero

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

We sought to develop a model of bacterially induced preterm delivery in rats to parallel similar models in mice.

Methods

Female Sprague-Dawley rats on day 17 of gestation (normal term = 21–22 days) were inoculated into the uterus with either 2 × 10⁹ – 7 × 10¹⁰ killed E. coli organisms, 1 – 4 × 10⁸ live E. coli or sterile solution. These inoculations were made either via trans-cervical catheter or by direct intrauterine injection at laparotomy. Animals were then observed for delivery for variable periods up to term. Necropsies were performed and fetal viability …

Development Of A Gene Silencing Dna Vector Derived From A Broad Host Range Geminivirus, Edward M. Golenberg, D Noah Sather, Leandria C. Hancock, Kenneth J. Buckley, Natalie M. Villafranco, David M. Bisaro

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Gene silencing is proving to be a powerful tool for genetic, developmental, and physiological analyses. The use of viral induced gene silencing (VIGS) offers advantages to transgenic approaches as it can be potentially applied to non-model systems for which transgenic techniques are not readily available. However, many VIGS vectors are derived from Gemini viruses that have limited host ranges. We present a new, unipartite vector that is derived from a curtovirus that has a broad host range and will be amenable to use in many non-model systems.

Results

The construction of a gene silencing vector derived from the …