Medical Microbiology Commons^™

Gold Nanoparticles In Clp Model And Mechanism In Bone Marrows Derived Macrophages Cell For Sepsis Severity Attenuation, Sujittra Taratummarat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sepsis is still a major worldwide- public health problem as a leading cause of the high mortality rate condition. Sepsis is the inflammatory condition in host due to bacterial infections. Sepsis severity depends on the individual's immune responses and the organism virulence factor. The current strategies for sepsis treatment are based, mainly on, symptomatic treatment with antibiotics. However, the adjuvant therapy in sepsis is interesting. Gold nanoparticles are anti-inflammatory drug from the ancient time which is still currently used for the treatment of rheumatoid arthritis. Thus, we hypothesized that gold nanoparticles could be effective in reducing an inflammation in sepsis …

Microbiota, Diet And Medication In Human Gut Disorders, Adam Clooney

Theses

The microbiota, a community of micro-organisms in a particular environment, have been intensely researched in the past decade and interest appears to continue to increase. The human body is richly populated with bacterial cells (3.8x10'^) and alterations in these communities are associated with disease. The work presented in this thesis explores aspects of microbiota research methodologies with regard to optimisation and concerns over a lack of reproducibility. Additionally, we investigated the effects of medication, in particular Proton Pump Inhibitors, on the human gut microbiota, along with comparisons between the microbiota of patients with active and inactive Inflammatory Bowel Disease.

Microbiota …

Actionable Patient Safety Solution (Apss) #3b: Antimicrobial Stewardship: The Role Of A Pharmacy And The Microbiology Lab In Patient Safety, Jerika Lam, Jason Yamaki, Ron Jordan, Celine Peters, Steven Barker, Michael Ramsay, Ariana Longley, Joe Kiani

Pharmacy Faculty Articles and Research

This report presents a plan of action for introducing an Antimicrobial Stewardship Plan (ASP) to combat the inappopriate use of antimicrobial drugs, which are a significant cause of patient morbidity and mortality.

The International Scientific Association For Probiotics And Prebiotics (Isapp) Consensus Statement On The Definition And Scope Of Prebiotics, Glenn R. Gibson, Robert W. Hutkins, Mary Ellen Sanders, Susan L. Prescott, Raylene A. Reimer, Seppo J. Salminen, Karen Scott, Catherine Stanton, Kelly S. Swanson, Patrice D. Cani, Kristin Verbeke, Gregor Reid

Department of Food Science and Technology: Faculty Publications

In December 2016, a panel of experts in microbiology, nutrition and clinical research was convened by the International Scientific Association for Probiotics and Prebiotics to review the definition and scope of prebiotics. Consistent with the original embodiment of prebiotics, but aware of the latest scientific and clinical developments, the panel updated the definition of a prebiotic: a substrate that is selectively utilized by host microorganisms conferring a health benefit. This definition expands the concept of prebiotics to possibly include non-carbohydrate substances, applications to body sites other than the gastrointestinal tract, and diverse categories other than food. The requirement for selective …

A Systems Biology Approach For Predicting Essential Genes And Deciphering Their Dynamics Under Stress In Streptococcus Sanguinis, Fadi El-Rami

Theses and Dissertations

Infectious diseases are the top leading cause of death worldwide. Identifying essential genes, genes indispensable for survival, has been proven indispensable in defining new therapeutic targets against pathogens, major elements of the minimal set genome to be harnessed in synthetic biology, and determinants of evolutionary relationships of phylogenetically distant species. Thus, essentiality studies promise valuable revenues that can decipher much of biological complexities.

Taking advantage of the available microbial sequences and the essentiality studies conducted in various microbial models, we proposed a framework for the prediction of essential genes based on our experimentally verified knowledge of the pathways involved in …

Involvement Of Notch Signaling In Interleukin-4-Stimulated Human Macrophages, Naunpun Sangphech

Chulalongkorn University Theses and Dissertations (Chula ETD)

Macrophages respond to various stimuli, resulting in distinct effector phenotypes that range from LPS-stimulated proinflammatory to IL-4-activated pro-healing phenotype. The regulatory mechanism of this polarization is not fully understood. Notch signaling pathway is a conserved signaling pathway involved in polarization of macrophages, especially proinflammatory macrophages. However, the role of Notch signaling in IL-4 stimulated macrophages (M(IL-4)) is not well defined. PPARgamma is a signature nuclear receptor in M(IL-4) that function mainly in regulating lipid metabolism. There are many reports that revealed the interaction of Notch signaling and PPARgamma in various cells but not in macrophages. In this study, the interaction …

Ctl-Mediated Immune Evasion In Hiv Viraemic Controllers And Non-Controllers, Prathanporn Kaewpreedee

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: To compare T cell response and to identify the mechanism of escape in HIV-infected volunteers. Methods: HIV-infected volunteers (CD4>450 cells/µL) were enrolled from the anonymous clinic. Volunteers were classified into two groups based on HIV plasma viral load; viraemic controllers (VC) (VL<2000 cp/mL) and non-controllers (NC) (VL>2000 cp/mL). EDTA-whole blood was collected and determined the response against Gag p24 by IFNγ ELISpot assay. Population sequencing within the Gag p24 region was performed to identify escape mutations. Results: Demographic data [age, gender, sexual preference and the presence of protective alleles (HLA-B27, -B57 and –B58)] between VC (n=23) and NC (n=41) were no statistical …

Development Of Gold Nanoparticle-Based Lateral Flow Immunoassay For Detection Of Pathogenic Leptospiral Antigen, Prayoon Lae-Ngee

Chulalongkorn University Theses and Dissertations (Chula ETD)

Leptospirosis, caused by pathogenic Leptospira spp., is a global re-emerging zoonosis and endemic disease in tropical and sub-tropical countries including Thailand. Point-of-care testing (POCT) for rapid diagnosis of leptospirosis is needed for prompt and appropriate treatment particularly in resource-poor settings. Lateral flow immunoassay (LFA)-based POCT devices are rapid, user friendly, cheap, have one-step analysis, and need no sophisticated equipment. LipL32 is a common target for diagnostic tests of leptospirosis because it is the major outer membrane protein (OMP) that is specific and highly conserved among pathogenic Leptospira. This study aimed to develop the gold nanoparticle (AuNP)-based LFA for detection of …

Characterization Of Antimicrobial-Resistant Nontyphoidal Salmonella Isolated From Humans And Food Animals In Thailand 172252256, Sirirat Luk-In

Chulalongkorn University Theses and Dissertations (Chula ETD)

The emergence and increase of resistance to antimicrobial agents, especially to extended-spectrum cephalosporins (ESCs) and fluoroquinolones in nontyphoidal Salmonella have recently become a serious therapeutic problem. The objectives of this study were to characterize antimicrobial resistance mechanisms, the clonality, and plasmid profiles among nontyphoidal Salmonella isolates from human and food animals in Thailand. A total of 897 nontyphoidal Salmonella isolates, 617 isolates from human and 280 isolates from food animal in Thailand during 2005 to 2007 and 2012 to 2016 were included in this study. The significantly higher resistance rates were found in S. Choleraesuis compared with other serotypes to …

Characterization Of T Cell Secreted Cytokines And Cytotoxic Mediators Profiling In Knee Osteoarthritis Patients, Thitiya Sae-Jung

Chulalongkorn University Theses and Dissertations (Chula ETD)

Osteoarthritis (OA) is a chronic disease associated with morphological joint changes that results in the breakdown of joint cartilage and underlying bone with erosive inflammation. Factors of OA are intrinsic factor and extrinsic factor. The pathogenesis of OA relates with immune responses and immune cells, T cells, B cells, and macrophages etc., T cells both CD4+ and CD8+ T cell are immune cells that have been suggested to play a role in OA. However, we found many finding in CD8+ T cells such as a high proportion of CD8+ T cell was observed in tissue of knee joint. In addition, …

Antimicrobial Effect Of High Dose Ascorbate In Mouse Model With Bacterial Infection, Chulamartd Wirapakorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ascorbate or Vitamin C is a vitamin that is important to the body. It contributes to the immunity, involves the collagen formation, acts as an antioxidant and has the ability to destroy cancer cells and bacteria. These abilities depend on the concentration of ascorbate. Bactericidal properties of ascorbate were interesting, especially in the high concentrations. Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli are a common etiologies of nosocomial infection in Thailand and worldwide. These bacteria have developed mechanisms of antibiotics resistance and cause more violence in the disease. Hence, the time-killing assay was used to explore the bactericidal …

Immune Response In Pythiosis Patients Treated With Pythium Insidiosum Antigen (Pia), Navaporn Worasilchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Immunotherapy using Pythium insidiosum antigen (PIA) is one of the combination treatment for P. insidiosum infected patients along with amputation and certain antifungal agents. The protocol of first prime (day0) after diagnosis and six booster doses (at 0.5, 1, 1.5, 3, 6, 12 months; mo.) along a year period were performed based on previous study. The switching of T-helper2 (Th2) to Th1 after immunotherapy along with the clinical improvement in equine and rabbit models were revealed whereas studies in human are very limited. To investigate the immune response in PIA treated pythiosis patients, cytokine profile (CMI response), P. insidiosum specific …

The Antiviral Activity Of Phenolic Lipids Group Against Dengue Virus, Parichat Kanyaboon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Dengue virus causes a global burden that specific chemotherapy has not been established in a clinical setting. A previous report suggested that anacardic acid saturated (C15:0), a member of phenolic lipids, inhibited hepatitis C virus infection. Here, we explored structure activity relationship of phenolic lipids homologues with anti-DENV properties in the cell-based system. Our results indicated that Cardol triene (C15:3) expressed DENV1-4 inhibition, but not to Zika virus (SV0010/15) with the EC50s of 5.35 ± 1.16 µM, 7.13 ± 0.72 µM, 8.98 ± 1.77 µM, and 8.21 ± 0.34 µM, respectively. Also, the compound showed good CC50s to Vero cells …

Induction Of Interleukin-1 Receptor Antagonist (Il-1ra) By Porcine Reproductive And Respiratory Syndrome Virus (Prrsv), Teerawut Nedumpun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Porcine respiratory and reproductive syndrome virus (PRRSV) is one of the major pathogens affecting pig production industry worldwide. Impaired innate and adaptive immune responses are evidenced through the course of PRRSV infection. Several evidences indicate that PRRSV suppresses host immune responses via several immune evasion strategies. Interleukin-1 receptor antagonist (IL-1Ra) is known as an early inhibitory cytokine that suppresses innate immune functions and T lymphocyte responses. The aims of this study were to explore the induction of IL-1Ra by PRRSV and the negative immunomodulatory effects of PRRSV-induced IL-1Ra on porcine immune responses. In this study, the previous monocytes-derived dendritic cells …

Comparative Genomic Analysis Of Two Serotype 1/2b Listeria Monocytogenes Isolates From Analogous Environmental Niches Demonstrates The Influence Of Hypervariable Hotspots In Defining Pathogenesis, Aidan Casey, Kieran Jordan, Aidan Coffey, Edward M. Fox, Olivia Mcauliffe

Department of Biological Sciences Publications

The vast majority of clinical human listeriosis cases are caused by serotype 1/2a, 1/2b, 1/2c, and 4b isolates of Listeria monocytogenes. The ability of L. monocytogenes to establish a systemic listeriosis infection within a host organism relies on a combination of genes that are involved in cell recognition, internalization, evasion of host defenses, and in vitro survival and growth. Recently, whole genome sequencing and comparative genomic analysis have proven to be powerful tools for the identification of these virulence-associated genes in L. monocytogenes. In this study, two serotype 1/2b strains of L. monocytogenes with analogous isolation sources, but …

The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin-Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn Hauke, Gabriela Kovacikova

Dartmouth Scholarship

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent …

Motility And Adhesion Through Type Iv Pili In Gram-Positive Bacteria, Kurt H. Piepenbrink, Eric J. Sundberg

Food for Health: Publications

Type IV pili are hair-like bacterial surface appendages that play a role in diverse processes such as cellular adhesion, colonization, twitching motility, biofilm formation, and horizontal gene transfer. These extracellular fibers are composed exclusively or primarily of many copies of one or more pilin proteins, tightly packed in a helix so that the highly hydrophobic amino-terminus of the pilin is buried in the pilus core. Type IV pili have been characterized extensively in Gram-negative bacteria, and recent advances in high-throughput genomic sequencing have revealed that they are also widespread in Gram-positive bacteria. Here, we review the current state of knowledge …

Reexamining Chronic Toxoplasma Gondii Infection: Surprising Activity For A "Dormant" Parasite, Anthony P. Sinai, Elizabeth A. Watts, Animesh Dhara, Robert D. Murphy, Matthew S. Gentry, Abhijit R. Patwardhan

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Purpose of Review

Despite over a third of the world’s population being chronically infected with Toxoplasma gondii, little is known about this largely asymptomatic phase of infection. This stage is mediated in vivo by bradyzoites within tissue cysts. The absence of overt symptoms has been attributed to the dormancy of bradyzoites. In this review, we reexamine the conventional view of chronic toxoplasmosis in light of emerging evidence challenging both the nature of dormancy and the consequences of infection in the CNS.

Recent Findings

New and emerging data reveal a previously unrecognized level of physiological and replicative capacity of bradyzoites …

Endosomal Trafficking As A Determinant Of Antifungal Tolerance In The Pathogenic Fungus Candida Albicans, Arturo Luis Luna

Theses and Dissertations (ETD)

Several important antifungal drugs inhibit the synthesis of ergosterol, a lipid that modulates the thickness, fluidity and permeability of fungal cell membranes. These include the azole antifungals, which block ergosterol biosynthesis by inhibiting lanosterol demethylase (Erg11p). The resulting depletion of cellular ergosterol and the accumulation of ‘toxic’ sterol intermediates are both thought to cause plasma membrane dysfunction and ultimately growth arrest. However, the effects of ergosterol depletion upon the function of intracellular membranes and organelles are not well described. The purpose of this study was to characterize the effects of azole treatment upon the integrity of the Candida albicans vacuole, …

Global Role Of Cyclic Amp Signaling In Ph-Dependent Responses In Candida Albicans, Jeffrey M. Hollomon, Nora Grahl, Sven D. Willger, Katja Koeppen, Deborah A. Hogan

Dartmouth Scholarship

Candida albicans behaviors are affected by pH, an important environmental variable. Filamentous growth is a pH-responsive behavior, where alkaline conditions favor hyphal growth and acid conditions favor growth as yeast. We employed filamentous growth as a tool to study the impact of pH on the hyphal growth regulator Cyr1, and we report that downregulation of cyclic AMP (cAMP) signaling by acidic pH contributes to the inhibition of hyphal growth in minimal medium with GlcNAc. Ras1 and Cyr1 are generally required for efficient hyphal growth, and the effects of low pH on Ras1 proteolysis and GTP binding are consistent with diminished …