Medical Microbiology Commons^™

Database-Guided Discovery Of Potent Peptides To Combat Hiv-1 Or Superbugs., Guangshun Wang

Journal Articles: Pathology and Microbiology

Antimicrobial peptides (AMPs), small host defense proteins, are indispensable for the protection of multicellular organisms such as plants and animals from infection. The number of AMPs discovered per year increased steadily since the 1980s. Over 2,000 natural AMPs from bacteria, protozoa, fungi, plants, and animals have been registered into the antimicrobial peptide database (APD). The majority of these AMPs (>86%) possess 11-50 amino acids with a net charge from 0 to +7 and hydrophobic percentages between 31-70%. This article summarizes peptide discovery on the basis of the APD. The major methods are the linguistic model, database screening, de novo …

Microproteinuria During Opisthorchis Viverrini Infection: A Biomarker For Advanced Renal And Hepatobiliary Pathologies From Chronic Opisthorchiasis, Prasert Saichua, Paiboon Sithithaworn, Amar R. Jariwala, David J. Diemert, Jiraporn Sithithaworn, Banchob Sripa, Thewarach Laha, Eimorn Mairiang, Chawalit Pairojkul, Maria V. Periago, Narong Khuntikeo, Jason Mulvenna, Jeffrey M. Bethony

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Approximately 680 million people are at risk of infection with Opisthorchis viverrini (OV) andClonorchis sinensis, with an estimated 10 million infected with OV in Southeast Asia alone. While opisthorchiasis is associated with hepatobiliary pathologies, such as advanced periductal fibrosis (APF) and cholangiocarcinoma (CCA), animal models of OV infection show that immune-complex glomerulonephritis is an important renal pathology that develops simultaneously with hepatobiliary pathologies. A cardinal sign of immune-complex glomerulonephritis is the urinary excretion of immunoglobulin G (IgG) (microproteinuria). In community-based studies in OV endemic areas along the Chi River in northeastern Thailand, we observed that over half of …

Anr And Its Activation By Plch Activity In Pseudomonas Aeruginosa Host Colonization And Virulence, Angelyca A. Jackson, Maegan J. Gross, Emily F. Daniels, Thomas H. Hampton, John H. Hammond, Isabelle Vallet-Gely, Simon L. Dove, Bruce A. Stanton, Deborah A. Hogan

Dartmouth Scholarship

Pseudomonas aeruginosa hemolytic phospholipase C (PlcH) degrades phosphatidylcholine (PC), an abundant lipid in cell membranes and lung surfactant. A ΔplcHR mutant, known to be defective in virulence in animal models, was less able to colonize epithelial cell monolayers and was defective in biofilm formation on plastic when grown in lung surfactant. Microarray analyses found that strains defective in PlcH production had lower levels of Anr-regulated transcripts than the wild type. PC degradation stimulated the Anr regulon in an Anr-dependent manner under conditions where Anr activity was submaximal because of the presence of oxygen. Two PC catabolites, choline and glycine …

Competition For Antigen Selects T Cell Responses That Undergo Memory Inflation And Maintains Clonal Dominance During Mcmv Infection, Holly Turula, Lila A. Farrington, Corinne Smith, Ann B. Hill, Christopher M Snyder

Department of Microbiology and Immunology Faculty Papers

Cytomegalovirus (CMV) establishes a life-long, persistent/latent infection. Continuous immune surveillance by CMV-specific CD8+ T cells results in their accumulation over time, a process called “memory inflation”. These “inflationary” T cells migrate systemically and comprise the largest T cell populations in humans, making CMV-based vaccines attractive. Why T cells specific for only some CMV-derived epitopes undergo inflation is unclear. We found previously that recombinant murine (M)CMV expressing the SIINFEKL peptide only induced inflation of SIINFEKL-specific T cells, in contrast to wild-type MCMV infection. We show here that:

• Co-infecting mice with viruses expressing and lacking SIINFEKL enabled T cells with multiple specificities …

Oral Transmission Of Listeria Monocytogenes In Mice Via Ingestion Of Contaminated Food, Elsa N. Bou Ghanem, Tanya Myers-Morales, Grant S. Jones, Sarah E. F. D'Orazio

Microbiology, Immunology, and Molecular Genetics Faculty Publications

L. monocytogenes are facultative intracellular bacterial pathogens that cause food borne infections in humans. Very little is known about the gastrointestinal phase of listeriosis due to the lack of a small animal model that closely mimics human disease. This paper describes a novel mouse model for oral transmission of L. monocytogenes. Using this model, mice fed L. monocytogenes-contaminated bread have a discrete phase of gastrointestinal infection, followed by varying degrees of systemic spread in susceptible (BALB/c/By/J) or resistant (C57BL/6) mouse strains. During the later stages of the infection, dissemination to the gall bladder and brain is observed. The …

Holobiont Nutrition: Considering The Role Of The Gastrointestinal Microbiota In The Health Benefits Of Whole Grains, Jens Walter, Ines Martinez, Devin J. Rose

Food for Health: Publications

Intake of whole grains and other food products high in dietary fiber have long been linked to the prevention of chronic diseases associated with inflammation. A contribution of the gastrointestinal microbiota to these effects has been suggested, but little is known on how whole grains interact with gut bacteria. We have recently published the first human trial that made use of next-generation sequencing to determine the effect of whole grains (whole grain barley, brown rice or a mixture of the two) on fecal microbiota structure and tested for associations between the gut microbiota and blood markers of inflammation, glucose and …

Secretion Of Tcpf By The Vibrio Cholerae Toxin-Coregulated Pilus Biogenesis Apparatus Requires An N-Terminal Determinant, Christina J. Megli, Ronald K. Taylor

Dartmouth Scholarship

Type IV pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. We and others have shown that type IV pili are important for protein secretion across the outer membrane, similar to type II secretion systems. This study explored the relationship between protein secretion and pilus formation in Vibrio cholerae. The toxin-coregulated pilus (TCP), a type IV pilus required for V. cholerae pathogenesis, is necessary for the secretion of the colonization factor TcpF (T. J. Kirn, N. Bose, and R. K. Taylor, Mol. Microbiol. 49:81–92, 2003). This phenomenon is not unique to V. cholerae; secreted …

Competition For Antigen At The Level Of The Apc Is A Major Determinant Of Immunodominance During Memory Inflation In Murine Cytomegalovirus Infection., Lila A Farrington, Tameka A Smith, Finn Grey, Ann B Hill, Christopher M. Snyder

Department of Microbiology and Immunology Faculty Papers

The unique ability of CMV to drive the expansion of virus-specific T cell populations during the course of a lifelong, persistent infection has generated interest in the virus as a potential vaccine strategy. When designing CMV-based vaccine vectors to direct immune responses against HIV or tumor Ags, it becomes important to understand how and why certain CMV-specific populations are chosen to inflate over time. To investigate this, we designed recombinant murine CMVs (MCMVs) encoding a SIINFEKL-enhanced GFP fusion protein under the control of endogenous immediate early promoters. When mice were infected with these viruses, T cells specific for the SIINFEKL …

Break Out: Urogenital Schistosomiasis And Schistosoma Haematobium Infection In The Post-Genomic Era, Paul J. Brindley, Peter J. Hotez

Microbiology, Immunology, and Tropical Medicine Faculty Publications

No abstract provided.

Regulation Of Igfbp-5 And Osteoblast Functions By Nuclear Factor I, Laura A. Perez-Casellas

Loma Linda University Electronic Theses, Dissertations & Projects

The Insulin-like Growth Factor (IGF) system is a major target of GC inhibition in bone. We found that GCs inhibit expression of IGF binding protein-5 (IGFBP5) which binds IGFs and stimulates osteoblast activity by IGF dependent and independent mechanisms. GC-induced inhibition of IGFPB5 promoter activity was mediated by a composite response element that has binding sites for transcription factor activator protein 2 (AP-2) and nuclear factor I (NFI). The work in this dissertation identifies the NFI gene family as an important regulator of IGFBP-5 transcription primarily in human, as well as murine osteoblasts. The mechanism of IGFBP5 gene regulation involves …

A Genetic Resource For Rapid And Comprehensive Phenotype Screening Of Nonessential Staphylococcus Aureus Genes., Paul D. Fey, Jennifer L. Endres, Vijaya Kumar Yajjala, Todd J. Widhelm, Robert J. Boissy, Jeffrey L. Bose, Kenneth W. Bayles

Journal Articles: Pathology and Microbiology

UNLABELLED: To enhance the research capabilities of investigators interested in Staphylococcus aureus, the Nebraska Center for Staphylococcal Research (CSR) has generated a sequence-defined transposon mutant library consisting of 1,952 strains, each containing a single mutation within a nonessential gene of the epidemic community-associated methicillin-resistant S. aureus (CA-MRSA) isolate USA300. To demonstrate the utility of this library for large-scale screening of phenotypic alterations, we spotted the library on indicator plates to assess hemolytic potential, protease production, pigmentation, and mannitol utilization. As expected, we identified many genes known to function in these processes, thus validating the utility of this approach. Importantly, we …

Effects Of Treatment On Ige Responses Against Parasite Allergen-Like Proteins And Immunit To Reinfection In Childhood Schistosome And Hookworm Coinfections, Angela Pinot De Moira, Frances M. Jones, Shona Wilson, Edridah Tukahebwa, Colin M. Fitzsimmons, Joseph K. Mwatha, Jeffrey M. Bethony, Narcis B. Kabatereine, David W. Dunne

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Naturally occurring human immunity to both schistosomiasis and hookworm infection has been associated with IgE responses against parasite allergen-like proteins. Since the two helminths frequently coinfect the same individuals, there is growing advocacy for their concurrent treatment. However, both helminths are known to exert strong immunomodulatory effects; therefore, coinfected individuals could have immune responses different from those characteristically seen in monoinfected individuals. In this study, we measured changes in IgE, IgG1, and IgG4 responses to schistosome and hookworm antigens, including the allergen-like proteins Schistosoma mansoni tegumental-allergen-like 1 protein (SmTAL1), SmTAL2, and Necator americanus Ancylostoma-secreted protein-2 (Na-ASP-2), following concurrent …

Htlv Tax: A Fascinating Multifunctional Co-Regulator Of Viral And Cellular Pathways, Robert Currer, Rachel Van Duyne, Elizabeth Jaworski, Irene Guendel, Gavin Sampey, Ravi Das, Aarthi Narayanan, Fatah Kashanchi

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Human T-cell lymphotropic virus type 1 (HTLV-1) has been identified as the causative agent of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The virus infects between 15 and 20 million people worldwide of which approximately 2–5% develop ATL. The past 35 years of research have yielded significant insight into the pathogenesis of HTLV-1, including the molecular characterization of Tax, the viral transactivator, and oncoprotein. In spite of these efforts, the mechanisms of oncogenesis of this pleiotropic protein remain to be fully elucidated. In this review, we illustrate the multiple oncogenic roles of Tax by summarizing a recent …

Transcriptional Responses Of In Vivo Praziquantel Exposure In Schistosomes Identifies A Functional Role For Calcium Signalling Pathway Member Camkii, Hong You, Donald P. Mcmanus, Wei Hu, Michael J. Smout, Paul J. Brindley, Geoffrey N. Gobert

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Treatment for clinical schistosomiasis has relied centrally on the broad spectrum anthelmintic praziquantel; however, there is limited information on its mode of action or the molecular response of the parasite. This paper presents a transcriptional and functional approach to defining the molecular responses of schistosomes to praziquantel. Differential gene expression in Schistosoma japonicum was investigated by transcriptome-wide microarray analysis of adult worms perfused from infected mice after 0.5 to 24 hours after oral administration of sub-lethal doses of praziquantel. Genes up-regulated initially in male parasites were associated with “Tegument/Muscle Repair” and “Lipid/Ion Regulation” functions and were followed by “Drug Resistance” …

Thrombospondin-1 Signaling Through Cd47 Inhibits Self-Renewal By Regulating C-Myc And Other Stem Cell Transcription Factors, Sukhbir Kaur, David R. Soto-Pantoja, Erica V. Stein, Chengyu Liu, Abdel G. Elkahloun, Michael L. Pendrak, Alina Nicolae, Satya P. Singh, Zuqin Nie, David Levens, Jeffrey S. Isenberg, David D. Roberts

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Signaling through the thrombospondin-1 receptor CD47 broadly limits cell and tissue survival of stress, but the molecular mechanisms are incompletely understood. We now show that loss of CD47 permits sustained proliferation of primary murine endothelial cells, increases asymmetric division, and enables these cells to spontaneously reprogram to form multipotent embryoid body-like clusters. c-Myc, Klf4, Oct4, and Sox2 expression is elevated in CD47-null endothelial cells, in several tissues of CD47- and thrombospondin-1-null mice, and in a human T cell line lacking CD47. CD47 knockdown acutely increases mRNA levels of c-Myc and other stem cell transcription factors in cells and in vivo, …

Cd56negcd16+ Nk Cells Are Activated Mature Nk Cells With Impaired Effector Function During Hiv-1 Infection, Jeffrey M. Milush, Sandra López-Vergès, Vanessa A. York, Steven G. Deeks, Jeffrey N. Martin, Frederick M. Hecht, Lewis L. Lanier, Douglas F. Nixon

Microbiology, Immunology, and Tropical Medicine Faculty Publications

BACKGROUND: A subset of CD3(neg)CD56(neg)CD16⁺ Natural Killer (NK) cells is highly expanded during chronic HIV-1 infection. The role of this subset in HIV-1 pathogenesis remains unclear. The lack of NK cell lineage-specific markers has complicated the study of minor NK cell subpopulations.

RESULTS: Using CD7 as an additional NK cell marker, we found that CD3(neg)CD56(neg)CD16⁺ cells are a heterogeneous population comprised of CD7⁺ NK cells and CD7(neg) non-classical myeloid cells. CD7⁺CD56(neg)CD16⁺ NK cells are significantly expanded in HIV-1 infection. CD7⁺CD56(neg)CD16⁺ NK cells are mature and express KIRs, the C-type lectin-like receptors NKG2A and NKG2C, and natural cytotoxicity receptors similar to …

Two Coiled-Coil Domains Of Chlamydia Trachomatis Inca Affect Membrane Fusion Events During Infection., Erik Ronzone, Fabienne Paumet

Department of Microbiology and Immunology Faculty Papers

Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A) appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using …

Toward A Network Model Of Mhc Class Ii-Restricted Antigen Processing., Michael A Miller, Asha Purnima V Ganesan, Laurence C. Eisenlohr

Department of Microbiology and Immunology Faculty Papers

The standard model of Major Histocompatibility Complex class II (MHCII)-restricted antigen processing depicts a straightforward, linear pathway: internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4(+) T cells (TCD4+). Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while …

Amalgamation Of Nucleosides And Amino Acids In Antibiotic Biosynthesis, Sandra H. Barnard

Theses and Dissertations--Pharmacy

The rapid increase in antibiotic resistance demands the identification of novel antibiotics with novel targets. One potential antibacterial target is the biosynthesis of peptidoglycan cell wall, which is both ubiquitous and necessary for bacterial survival. Both the caprazamycin-related compounds A-90289 and muraminomicin, as well as the capuramycin-related compounds A-503083 and A-102395 are potent inhibitors of the translocase I enzyme, one of the key enzymes required for cell wall biosynthesis. The caprazamycin-related compounds contain a core nonproteinogen b-hydroxy-a-amino acid referred to as 5’-C-glycyluridine (GlyU). Residing within the biosynthetic gene clusters of the aforementioned compounds is a shared open reading …

Molecular Mechanisms Related To Endotoxemia In Primary Human Cardiomyocytes In Culture, Atijah J. Collins

PCOM Biomedical Studies Student Scholarship

Cardiovascular disease (CVD) is the leading cause of death in the United States and has been for the past 80 years. Development of novel therapeutic agents to address the large number of CVD deaths requires an in depth understanding of the structural and functional properties of human cardiomyocytes. Over the last few years we have been developing an in vitro paradigm to assess molecular cardiodynamics in Primary Human Cardiomyocyte in culture (PHCC). We tested the hypothesis whether endotoxemia would exhibit a marked decrease in contractile proteins and cause apoptosis in PHCC. In the current series of experiments, we induced endotoxemia …

Characterization Of Brer Interaction With The Bile Response Promoters Breab And Brer In Vibrio Cholerae, Francisca A. Cerda-Maira, Gabriela Kovacikova, Brooke A. Jude, Karen Skorupski, Ronald Taylor

Dartmouth Scholarship

The Vibrio cholerae BreR protein is a transcriptional repressor of the breAB efflux system operon, which encodes proteins involved in bile resistance. In a previous study (F. A. Cerda-Maira, C. S. Ringelberg, and R. K. Taylor, J. Bacteriol. 190:7441-7452, 2008), we used gel mobility shift assays to determine that BreR binds at two independent binding sites at the breAB promoter and a single site at its own promoter. Here it is shown, by DNase I footprinting and site-directed mutagenesis, that BreR is able to bind at a distal and a proximal site in the breAB promoter. However, only one of …

Inhibition Of The Host Translation Shutoff Response By Herpes Simplex Virus 1 Triggers Nuclear Envelope-Derived Autophagy, Kerstin Radtke, Luc English, Christiane Rondeau, David Leib

Dartmouth Scholarship

Macroautophagy is a cellular pathway that degrades intracellular pathogens and contributes to antigen presentation. Herpes simplex virus 1 (HSV-1) infection triggers both macroautophagy and an additional form of autophagy that uses the nuclear envelope as a source of membrane. The present study constitutes the first in-depth analysis of nuclear envelope-derived autophagy (NEDA). We established LC3a as a marker that allowed us to distinguish between NEDA and macroautophagy in both immunofluorescence and flow cytometry. NEDA was observed in many different cell types, indicating that it is a general response to HSV-1 infection. This autophagic pathway is known to depend on the …

Investigating The Role For Il-21 In Rabies Virus Vaccine-Induced Immunity., Corin L Dorfmeier, Evgeni P Tzvetkov, Anthony Gatt, James P Mcgettigan

Department of Microbiology and Immunology Faculty Papers

Over two-thirds of the world's population lives in regions where rabies is endemic, resulting in over 15 million people receiving multi-dose post-exposure prophylaxis (PEP) and over 55,000 deaths per year globally. A major goal in rabies virus (RABV) research is to develop a single-dose PEP that would simplify vaccination protocols, reduce costs associated with RABV prevention, and save lives. Protection against RABV infections requires virus neutralizing antibodies; however, factors influencing the development of protective RABV-specific B cell responses remain to be elucidated. Here we used a mouse model of IL-21 receptor-deficiency (IL-21R-/-) to characterize the role for IL-21 in RABV …

Comparison Of Heterologous Prime-Boost Strategies Against Human Immunodeficiency Virus Type 1 Gag Using Negative Stranded Rna Viruses., Tessa M Lawrence, Celestine N Wanjalla, Emily A Gomme, Christoph Wirblich, Anthony Gatt, Elena Carnero, Adolfo García-Sastre, Douglas S Lyles, James P Mcgettigan, Matthias J Schnell

Department of Microbiology and Immunology Faculty Papers

This study analyzed a heterologous prime-boost vaccine approach against HIV-1 using three different antigenically unrelated negative-stranded viruses (NSV) expressing HIV-1 Gag as vaccine vectors: rabies virus (RABV), vesicular stomatitis virus (VSV) and Newcastle disease virus (NDV). We hypothesized that this approach would result in more robust cellular immune responses than those achieved with the use of any of the vaccines alone in a homologous prime-boost regimen. To this end, we primed BALB/c mice with each of the NSV-based vectors. Primed mice were rested for thirty-five days after which we administered a second immunization with the same or heterologous NSV-Gag viruses. …

Isolated Laryngeal Leishmaniasis In Immunocompetent Patients: An Underdiagnosed Disease., Salvatore Cocuzza, Alessio Strazzulla, Marilia Rita Pinzone, Stefano Cosentino, Agostino Serra, Rosario Caltabiano, Salvatore Lanzafame, Bruno Cacopardo, Giuseppe Nunnari

Department of Microbiology and Immunology Faculty Papers

We describe a case of isolated primary laryngeal leishmaniasis in an immunocompetent Italian patient with a previous medical history negative for visceral or cutaneous leishmaniasis, presenting with hoarseness. We also summarize the epidemiological, clinical, and diagnostic features and the therapeutic management of other cases of laryngeal leishmaniasis in immunocompetent subjects, described in the literature. Considering the insidious and nonspecific clinical presentation, the increasing number of different forms of mild or underestimated immunosuppressive conditions, and the number of people travelling in endemic zones, along with the ability of Leishmania amastigotes to survive for a long period in the body, we believe …

Neisseria Oralis Sp. Nov., Isolated From Healthy Gingival Plaque And Clinical Samples, William J. Wolfgang, Teresa V. Passaretti, Reashma Jose, Jocelyn Cole, An Coorevits, Andrea N. Carpenter, Sherly Jose, Anita Van Landschoot, Jacques Izard, Donna J. Kohlerschmidt, Peter Vandamme, Floyd E. Dewhirst, Mark A. Fisher, Kimberlee A. Musser

Department of Food Science and Technology: Faculty Publications

A polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida, and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbor, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the …

Molecular Characterization Of A Tetraspanin From The Human Liver Fluke, Opisthorchis Viverrini, Supawadee Piratae, Smarn Tesana, Malcolm K. Jones, Paul J. Brindley, Alex Loukas, Erica Lovas, Veerachai Eursitthichai, Banchob Sripa, Sirikanda Thanasuwan, Thewarach Laha

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Background

The human liver fluke, Opisthorchis viverrini, is designated as a group 1 carcinogen, and is the major risk factor for cholangiocarcinoma in endemic countries throughout Southeast Asia. Proteins in the excretory-secretory products and tegumental surface membranes of the fluke have been proposed to play pivotal roles in parasite survival in the host, and subsequent pathogenesis. These macromolecules are therefore valid targets for the development of vaccines and new drugs to control the infection. Tetraspanins (TSP) are prominent components of the tegument of blood flukes where they are essential for tegument formation, are directly exposed to the immune system, …

Myeloid-Derived Suppressor Cells In Murine Retrovirus-Induced Aids Inhibit T- And B-Cell Responses In Vitro That Are Used To Define The Immunodeficiency, Kathy A. Green, W. James Cook, William R. Green

Dartmouth Scholarship

Myeloid-derived suppressor cells (MDSCs) have been characterized in several disease settings, especially in many tumor systems. Compared to their involvement in tumor microenvironments, however, MDSCs have been less well studied in their responses to infectious disease processes, in particular to retroviruses that induce immunodeficiency. Here, we demonstrate for the first time the development of a highly immunosuppressive MDSC population that is dependent on infection by the LP-BM5 retrovirus, which causes murine acquired immunodeficiency. These MDSCs express a cell surface marker signature (CD11b Gr-1 Ly6C ) characteristic of monocyte-type MDSCs. Such MDSCs profoundly inhibit immune responsiveness by a cell dose- and …

Ccpa Regulates Arginine Biosynthesis In Staphylococcus Aureus Through Repression Of Proline Catabolism., Austin S. Nuxoll, Steven M. Halouska, Marat Sadykov, Mark L. Hanke, Kenneth W. Bayles, Tammy Kielian, Robert Powers, Paul D. Fey

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of community-associated and nosocomial infections. Imperative to the success of S. aureus is the ability to adapt and utilize nutrients that are readily available. Genomic sequencing suggests that S. aureus has the genes required for synthesis of all twenty amino acids. However, in vitro experimentation demonstrates that staphylococci have multiple amino acid auxotrophies, including arginine. Although S. aureus possesses the highly conserved anabolic pathway that synthesizes arginine via glutamate, we demonstrate here that inactivation of ccpA facilitates the synthesis of arginine via the urea cycle utilizing proline as a substrate. Mutations within putA, rocD, …

Systematic Review Of Tst Responses In People Living With Hiv In Under-Resourced Settings: Implications For Isoniazid Preventive Therapy., Andrew D. Kerkhoff, Katharina Kranzer, Taraz Samandari, Jessica Nakiyingi-Miiro, Christopher C. Whalen, Anthony D. Harries, Stephen D. Lawn

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Background

People living with HIV (PLWH) who have positive tuberculin skin tests (TST) benefit from isoniazid preventive therapy (IPT) whereas those testing TST-negative do not. Revised World Health Organization guidelines explicitly state that assessment of TST is not a requirement for initiation of IPT. However, it is not known what proportions of patients will benefit from IPT if implemented without targeting according to TST status. We therefore determined the proportions of PLWH who test TST-positive.

Methodology/Principal Findings

We systematically reviewed the literature published between January 1990 and February 2012 to determine the proportions of patients without active tuberculosis attending HIV …