Medical Microbiology Commons^™

The Role Of Histone Methylation Of H3k4 In Polarization Of Macrophages Stimulated By Immune Complex And Lipopolysaccharide And Its Therapeutic Potential In Sepsis, Vichaya Ruenjaiman

Chulalongkorn University Theses and Dissertations (Chula ETD)

Macrophage plasticity is a process that allows macrophages to switch between two opposing phenotypes based on differential stimuli. Functional plasticity of macrophages contributes to disease pathogenesis such as cancer, metabolic diseases, autoimmune diseases and systemic infections. Epigenetics plays an important role in regulating this process. Macrophages stimulated with lipopolysaccharide (LPS) (M(LPS)) produce high level of pro-inflammatory cytokines such as IL-12, TNFα and IL-6 and low level of anti-inflammatory cytokine IL-10, while macrophages stimulated with LPS in the presence of immune complex (IC) (M(IC)) produce high level of IL-10 and low level of IL-12. In this study, we investigated the plasticity …

Mechanisms Of Ceftriaxone Resistance In Neisseria Gonorrhoeae Isolated From Thai Patients, Naris Kueakulpattana

Chulalongkorn University Theses and Dissertations (Chula ETD)

N. gonorrhoeae is the causative agent of gonorrhea, which is one of the most important sexually transmitted disease. The multidrug resistance in N. gonorrhoeae has been increasingly reported worldwide. The objectives of this study were to investigate the prevalence and the mechanisms of ceftriaxone resistance in N. gonorrhoeae Thai isolates, and to investigate the synergistic activities of antibiotic combinations against N. gonorrhoeae isolates with reduced susceptibility or resistance to ceftriaxone. A total of 134 N. gonorrhoeae isolates were included in this study. The resistance rates of ciprofloxacin, tetracycline, penicillin G, gentamicin, azithromycin, ertapenem, fosfomycin, cefixime, and ceftriaxone were 90.30%, 82.09%, …

Hsv-1 Induces Filopodia Formation In Activated T Lymphocytes, Thanayod Sasivimolrattana

Chulalongkorn University Theses and Dissertations (Chula ETD)

Herpes simplex virus type 1 (HSV-1) is a widespread pathogen, which has diverse clinical manifestations from mild localized infection to severe systemic infection. The tissue tropism of HSV-1 is mainly epithelial and mucosal cells. However, it can also multiply in T lymphocytes suggesting a cause of viremia. In this study, CD3+CD4-CD8- Jurkat T lymphocytes were used. Under activation, up-regulation of CD69 molecules on cell surface was observed. Increase yield of HSV-1 production in activated T lymphocytes was demonstrated. In addition, most of HSV-1 virion progenies from infected T lymphocytes were released extracellularly, suggesting the cause of dissemination. The mechanism which …

Characterization Of Leptospiral Extracellular Vesicles In Stress Conditions, Eakalak Phanchamnan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Pathogenic Leptospira spp. is a causative agent of leptospirosis, a worldwide zoonosis with public health concern especially in the urban slum of metropolis and rural areas in tropical and subtropical countries. The pathogenesis of leptospirosis remains elusive. Extracellular vesicles (ECVs), which pinch off from the bacterial membranes, simultaneously harbor multiple active molecules that may serve as a secretion system, communication tool, and vaccine candidates. Recently, chemically induced leptospiral ECVs were studied and used as vaccine candidates. However, the naturally produced leptospiral ECVs has not been characterized. This study aimed to identify proteins in leptospiral ECVs produced under stress conditions including …

Comprehensive Proteomics Identification Of Ifn-Λ3-Regulated Antiviral Proteins In Hbv-Transfected Cells, Jiradej Makjaroen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Interferon (IFN)-λ is a relatively unexplored, yet promising anti-viral agent. IFN-λ has recently been tested in clinical trials of chronic hepatitis B, with the advantage that side effects may be limited compared with IFN-α, as IFN-λ receptors are found only in epithelial cells. To date, IFN-λ downstream signaling pathway remains largely unelucidated, particularly via proteomics methods. Here, we report that IFN-λ3 inhibits HBV replication in HepG2.2.15 cells, reducing levels of both HBV transcripts and intracellular HBV DNA. Quantitative proteomic analysis of HBV-transfected cells was performed following 24-hour IFN-λ3 treatment, with parallel IFN-α2a and PBS treatments for comparison using a dimethyl …

The Severity Of Cryptococcus Neoformans Infection In Fc Gamma Receptor Iib Deficient Mice, Saowapha Surawut

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cryptococcus neoformans, an encapsulated yeast commonly infecting the central nervous system, refers to as cryptococcal meningitis or cryptococcosis is commonly found in Thailand. C. neoformans is able to replicate, survive inside host macrophages, evade from the cells and use macrophages as a vehicle to disseminate to the target organs, a mechanism known as Trojan horse. Therefore, the containment of C. neoformans in phagocytic cell is important for host protective immunity. Cryptococcosis is common in immunocompromised host such as in patients with low CD4+ T helper cells in HIV-infection and patients taking immunosuppressive drugs. However, the incidence of cryptococcosis in healthy …

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 …

Snf1 Dependent Destruction Of Med13 Is Required For Programmed Cell Death Following Oxidative Stress In Yeast, Stephen D Willis, David C Stieg, R. Shah, Randy Strich, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

All eukaryotic cells, when faced with unfavorable environmental conditions, have to decide whether to mount a survival or cell death response. The conserved cyclin C and its kinase partner Cdk8 play a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core mediator complex of RNA polymerase II. In S. cerevisiae, oxidative stress triggers Med13 destruction¹, which thereafter releases cyclin Ci nto the cytoplasm. Cytoplasmic cyclin C associates with mitochondria where it induces hyper-fragmentation and programmed cell death². This suggests a model in …

Synergy Of Two Low-Affinity Nlss Determines The High Avidity Of Influenza A Virus Nucleoprotein Np For Human Importin Α Isoforms., Wei Wu, Rajeshwer S. Sankhala, Tyler J Florio, Lixin Zhou, Nhan L.T. Nguyen, Ravi K. Lokareddy, Gino Cingolani, Nelly Panté

Department of Biochemistry and Molecular Biology Faculty Papers

The influenza A virus nucleoprotein (NP) is an essential multifunctional protein that encapsidates the viral genome and functions as an adapter between the virus and the host cell machinery. NPs from all strains of influenza A viruses contain two nuclear localization signals (NLSs): a well-studied monopartite NLS1 and a less-characterized NLS2, thought to be bipartite. Through site-directed mutagenesis and functional analysis, we found that NLS2 is also monopartite and is indispensable for viral infection. Atomic structures of importin α bound to two variants of NLS2 revealed NLS2 primarily binds the major-NLS binding site of importin α, unlike NLS1 that associates …

Taking Control: Reorganization Of The Host Cytoskeleton By Chlamydia., Jordan Wesolowski, Fabienne Paumet

Department of Microbiology and Immunology Faculty Papers

Both actin and microtubules are major cytoskeletal elements in eukaryotic cells that participate in many cellular processes, including cell division and motility, vesicle and organelle movement, and the maintenance of cell shape. Inside its host cell, the human pathogen Chlamydia trachomatis manipulates the cytoskeleton to promote its survival and enhance its pathogenicity. In particular, Chlamydia induces the drastic rearrangement of both actin and microtubules, which is vital for its entry, inclusion structure and development, and host cell exit. As significant progress in Chlamydia genetics has greatly enhanced our understanding of how this pathogen co-opts the host cytoskeleton, we will discuss …

Ablation Of An Ovarian Tumor Family Deubiquitinase Exposes The Underlying Regulation Governing The Plasticity Of Cell Cycle Progression In Toxoplasma Gondii, Animesh Dhara, Rodrigo De Paula Baptista, Jessica C. Kissinger, Ernest Charles Snow, Anthony P. Sinai

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Toxoplasma genome encodes the capacity for distinct architectures underlying cell cycle progression in a life cycle stage-dependent manner. Replication in intermediate hosts occurs by endodyogeny, whereas a hybrid of schizogony and endopolygeny occurs in the gut of the definitive feline host. Here, we characterize the consequence of the loss of a cell cycle-regulated ovarian tumor (OTU family) deubiquitinase, OTUD3A of Toxoplasma gondii (TgOTUD3A; TGGT1_258780), in T. gondii tachyzoites. Rather than the mutation being detrimental, mutant parasites exhibited a fitness advantage, outcompeting the wild type. This phenotype was due to roughly one-third of TgOTUD3A-knockout (TgOTUD3A-KO) tachyzoites exhibiting deviations from endodyogeny …

Suppression Of Mrnas Encoding Cd63 Family Tetraspanins From The Carcinogenic Liver Fluke Opisthorchis Viverrini Results In Distinct Tegument Phenotypes., Sujittra Chaiyadet, Watchara Krueajampa, Wiphawi Hipkaeo, Yada Plosan, Supawadee Piratae, Javier Sotillo, Michael Smout, Banchob Sripa, Paul J Brindley, Alex Loukas, Thewarach Laha

Microbiology, Immunology, and Tropical Medicine Faculty Publications

The liver fluke Opisthorchis viverrini infects 10 million people in Southeast Asia and causes cholangiocarcinoma (CCA). Fluke secreted and tegumental proteins contribute to the generation of a tumorigenic environment and are targets for drug and vaccine-based control measures. Herein, we identified two tetraspanins belonging to the CD63 family (Ov-TSP-2 and Ov-TSP-3) that are abundantly expressed in the tegument proteome of O. viverrini. Ov-tsp-2 and tsp-3 transcripts were detected in all developmental stages of O. viverrini. Protein fragments corresponding to the large extracellular loop (LEL) of each TSP were produced in recombinant form and antibodies were raised in rabbits. Ov-TSP-2 and …

A Coal Miner With Weakness, Fatigue, Nausea, Fever, Chills, Night Sweats And Dyspnea, Larry Nichols

Marshall Journal of Medicine

Delayed or missed diagnoses are a constant hazard in primary care. This is the case report of a 51-year-old coal miner, who presented as an ambulatory outpatient on a Friday with weakness, fatigue, nausea, fever, chills, night sweats and dyspnea. Chest x-ray on Saturday showed pneumonia and pleural effusion, while blood testing showed renal failure, but these results were not known by his physician until Monday, when he was hospitalized with severe sepsis due to fatal Austrian syndrome of pneumococcal pneumonia, endocarditis and meningitis. Analysis of the delay of diagnosis in this case suggests the possibility that a weekend effect …

Differentiation And Protective Capacity Of Virus-Specific Cd8, Vesselin T. Tomov, Olesya Palko, Chi Wai Lau, Ajinkya Pattekar, Yuhang Sun, Ralitza Tacheva, Bertram Bengsch, Sasikanth Manne, Gabriela L. Cosma, Laurence C. Eisenlohr, Timothy J. Nice, Herbert W. Virgin, E. John Wherry

Department of Microbiology and Immunology Faculty Papers

Noroviruses can establish chronic infections with active viral shedding in healthy humans but whether persistence is associated with adaptive immune dysfunction is unknown. We used genetically engineered strains of mouse norovirus (MNV) to investigate CD8⁺ T cell differentiation during chronic infection. We found that chronic infection drove MNV-specific tissue-resident memory (Trm) CD8⁺ T cells to a differentiation state resembling inflationary effector responses against latent cytomegalovirus with only limited evidence of exhaustion. These MNV-specific Trm cells remained highly functional yet appeared ignorant of ongoing viral replication. Pre-existing MNV-specific Trm cells provided partial protection against chronic infection but largely ceased …

Human Herpesvirus 8 Infects And Replicates In Langerhans Cells And Interstitial Dermal Dendritic Cells And Impairs Their Function., Giovanna Rappocciolo, Mariel Jais, Paolo A Piazza, Diana C Delucia, Frank J Jenkins, Charles R Rinaldo

Microbiology, Immunology, and Tropical Medicine Faculty Publications

The predominant types of dendritic cells (DC) in the skin and mucosa are Langerhans cells (LC) and interstitial dermal DC (iDDC). LC and iDDC process cutaneous antigens and migrate out of the skin and mucosa to the draining lymph nodes to present antigens to T and B cells. Because of the strategic location of LC and iDDC and the ability of these cells to capture and process pathogens, we hypothesized that they could be infected with human herpesvirus 8 (HHV-8) (Kaposi's sarcoma [KS]-associated herpesvirus) and have an important role in the development of KS. We have previously shown that HHV-8 …

The Trophic Life Cycle Stage Of The Opportunistic Fungal Pathogen Pneumocystis Murina Hinders The Ability Of Dendritic Cells To Stimulate Cd4+ T Cell Responses, Heather M. Evans, Andrew Simpson, Shu Shen, Arnold J. Stromberg, Carol L. Pickett, Beth A. Garvy

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The life cycle of the opportunistic fungal pathogen Pneumocystis murina consists of a trophic stage and an ascus-like cystic stage. Infection with the cyst stage induces proinflammatory immune responses, while trophic forms suppress the cytokine response to multiple pathogen-associated molecular patterns (PAMPs), including β-glucan. A targeted gene expression assay was used to evaluate the dendritic cell response following stimulation with trophic forms alone, with a normal mixture of trophic forms and cysts, or with β-glucan. We demonstrate that stimulation with trophic forms downregulated the expression of multiple genes normally associated with the response to infection, including genes encoding …

T-Cell Responses Targeting Hiv Nef Uniquely Correlate With Infected Cell Frequencies After Long-Term Antiretroviral Therapy., Allison S Thomas, Kimberley L Jones, Rajesh T Gandhi, Deborah K Mcmahon, Joshua C Cyktor, Dora Chan, Szu-Han Huang, Ronald Truong, Alberto Bosque, Amanda B Macedo, Colin Kovacs, Erika Benko, Joseph J Eron, Ronald J Bosch, Christina M Lalama, Samuel Simmens, Bruce D Walker, John W Mellors, R Brad Jones

Microbiology, Immunology, and Tropical Medicine Faculty Publications

HIV-specific CD8+ T-cell responses limit viral replication in untreated infection. After the initiation of antiretroviral therapy (ART), these responses decay and the infected cell population that remains is commonly considered to be invisible to T-cells. We hypothesized that HIV antigen recognition may persist in ART-treated individuals due to low-level or episodic protein expression. We posited that if persistent recognition were occurring it would be preferentially directed against the early HIV gene products Nef, Tat, and Rev as compared to late gene products, such as Gag, Pol, and Env, which have higher barriers to expression. Using a primary cell model of …

Evaluating A Preoperative Protocol That Includes Magnetic Resonance Imaging For Lymph Node Metastasis In The Cholangiocarcinoma Screening And Care Program (Cascap) In Thailand., Metha Songthamwat, Nittaya Chamadol, Narong Khuntikeo, Jadsada Thinkhamrop, Supinda Koonmee, Nathaphop Chaichaya, Jeffrey Bethony, Bandit Thinkhamrop

Microbiology, Immunology, and Tropical Medicine Faculty Publications

BACKGROUND: Treatment planning especially liver resection in cholangiocarcinoma (CCA) depends on the extension of tumor and lymph node metastasis which is included as a key criterion for operability. Magnetic resonance imaging (MRI) offers a rapid and powerful tool for the detection of lymph node metastasis (LNM) and in the current manuscript is assessed as a critical tool in the preoperative protocol for liver resection for treatment of CCA. However, the accuracy of MRI to detect LNM from CCA had yet to be comprehensively evaluated.

METHODS: The accuracy of MRI to detect LNM was assessed in a cohort of individuals with …

Characterization Of Different Molecular Markers For Identification Of Salmonella Enterica Serovar Typhi In Pakistani Population, Faizan Muttiullah, Fida Muhammad Khan, Fakhar-I- Abbas, Sabiha Shamim

Journal of Bioresource Management

Typhoid is caused by Salmonella enterica serovar Typhi that is usually diagnosed by using serologic and immuno-chromatographic techniques in developing counties including Pakistan, which is thought to be an unreliable diagnostic method. For accurate diagnosis we used molecular techniques to amplify 204 bp StyR-36 and 498 bp flagellin gene for the identification of Salmonella enterica serovar Typhi. This study was done on 58 individuals diagnosed positive of typhoid via serologic tests and 50 healthy individuals as a control group. Success rate of amplification for flagellin gene was 77.58% while that for StyR-36 gene was 68.97% showing that flagellin gene primer …

Silver Oxide Coatings With High Silver-Ion Elution Rates And Characterization Of Bactericidal Activity., Sarah S Goderecci, Eric Kaiser, Michael Yanakas, Zachary Norris, Jeffrey Scaturro, Robert Oszust, Clarence D Medina, Fallon Waechter, Min Heon, Robert R Krchnavek, Lei Yu, Samuel E Lofland, Renee M Demarest, Gregory A Caputo, Jeffrey D Hettinger

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

This paper reports the synthesis and characterization of silver oxide films for use as bactericidal coatings. Synthesis parameters, dissolution/elution rate, and bactericidal efficacy are reported. Synthesis conditions were developed to create AgO, Ag₂O, or mixtures of AgO and Ag₂O on surfaces by reactive magnetron sputtering. The coatings demonstrate strong adhesion to many substrate materials and impede the growth of all bacterial strains tested. The coatings are effective in killing Escherichia coli and Staphylococcus aureus, demonstrating a clear zone-of-inhibition against bacteria growing on solid media and the ability to rapidly inhibit bacterial growth in planktonic culture. Additionally, the coatings exhibit very …