Infectious Disease Commons^™

Coordinated Regulation By Agra, Sara, And Sarr To Control Agr Expression In Staphylococcus Aureus, Dindo Reyes, Diego O. Andrey, Antoinette Monod, William L. Kelley, Gongyi Zhang, Ambrose L. Cheung

Dartmouth Scholarship

The agr locus of Staphylococcus aureus is composed of two divergent transcripts (RNAII and RNAIII) driven by the P2 and P3 promoters. The P2-P3 intergenic region comprises the SarA/SarR binding sites and the four AgrA boxes to which AgrA binds. We reported here the role of AgrA, SarA, and SarR on agr P2 and P3 transcription. Using real-time reverse transcription (RT)-PCR and promoter fusion studies with selected single, double, triple, and complemented mutants, we showed that AgrA is indispensable to agr P2 and P3 transcription, whereas SarA activates and SarR represses P2 transcription. In vitro runoff transcription assays revealed that …

Tropical Medicine: A Clinical Text, 8th Edition, Revised And Expanded, Kevin M. Cahill, M.D.

Institute of International Humanitarian Affairs

The history of tropical medicine is as dramatic as the story of humankind. It has its own myths and legends, including tales of epidemics that destroyed whole civilizations. Today, with silent stealth, tropical diseases still claim more lives than all the current wars combined. Having had the privilege of working throughout Africa, Asia, and Latin America, as well as in the great medical centers of Europe and the United States, the author presents the details essential for understanding pathogenesis, clinical manifestations, therapy, and prevention of the major tropical diseases. The text, now in its eighth edition, has been used for …

Hiv And Concurrent Sexual Partnerships: Modelling The Role Of Coital Dilution, Larry Sawers, Alan G. Isaac, Eileen Stillwaggon

Economics Faculty Publications

Background: The concurrency hypothesis asserts that high prevalence of overlapping sexual partnerships explains extraordinarily high HIV levels in sub-Saharan Africa. Earlier simulation models show that the network effect of concurrency can increase HIV incidence, but those models do not account for the coital dilution effect (nonprimary partnerships have lower coital frequency than primary partnerships).

Methods: We modify the model of Eaton et al (AIDS and Behavior, September 2010) to incorporate coital dilution by assigning lower coital frequencies to non-primary partnerships. We parameterize coital dilution based on the empirical work of Morris et al (PLoS ONE, December …

Characterization Of Vibrio Cholerae O1 El Tor Biotype Variant Clinical Isolates From Bangladesh And Haiti, Including A Molecular Genetic Analysis Of Virulence Genes, Mike S. Son, Christina J. Megli, Gabriela Kovacikova, Firdausi Qadri, Ronald K. Taylor

Dartmouth Scholarship

Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and …

Health-Related Quality Of Life In The Gender, Race, And Clinical Experience Trial., Judith Feinberg, Michael Saag, Kathleen Squires, Judith Currier, Robert Ryan, Bruce Coate, Joseph Mrus

Division of Infectious Diseases and Environmental Medicine Faculty Papers

Background. We report health-related QoL (HRQoL) from GRACE (Gender, Race, And Clinical Experience) study by sex and race over 48 weeks. Methods. 429 treatment-experienced adults (HIV-1 RNA ≥ 1000 copies/mL) received darunavir/ritonavir 600/100 mg twice daily plus an appropriate background regimen. QoL was measured by the Functional Assessment of HIV Infection (FAHI) questionnaire. Results. 67% women and 77% men, including 67.4% black, 76.0% Hispanic, and 73.8% white patients, completed the trial. Baseline total FAHI scores were similar between sexes and races. Total FAHI of the entire population improved by Week 4 (P < .05); near-maximum changes obtained by Week 12 were maintained through Week 48. Women and black patients demonstrated larger improvements in total FAHI versus men, and Hispanic and white patients, respectively. Conclusion. HRQoL improved in all sex and racial/ethnic groups. Sex-based and race-based differences in improvements in FAHI subscales may provide insight into subtle differences of HIV-1 and treatment on HRQoL in different populations.

Protection And Attachment Of Vibrio Cholerae Mediated By The Toxin-Coregulated Pilus In The Infant Mouse Model, Shelly J. Krebs, Ronald K. Taylor

Dartmouth Scholarship

Colonization of the human small intestine by Vibrio cholerae is an essential step in pathogenesis that requires the type IV toxin-coregulated pilus (TCP). To date, three functions of TCP have been characterized: it serves as the CTXΦ receptor, secretes the colonization factor TcpF, and functions in microcolony formation by mediating bacterium-bacterium interactions. Although type IV pili in other pathogenic bacteria have been characterized as playing a major role in attachment to epithelial cells, there are very few studies to suggest that TCP acts as an attachment factor. Taking this into consideration, we investigated the function of TCP in attachment to …

Comparison Of Adenoviruses As Oncolytics And Cancer Vaccines In An Immunocompetent B Cell Lymphoma Model, Eric A. Weaver, Christopher Y. Chen, Shannon M. May, Mary E. Barry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

We have screened human adenoviruses (Ads) for oncolytic activity against a variety of mouse and hamster cell lines and have found a number that are susceptible to a variety of Ad serotypes. A20 lymphoma is derived from BALB/c mice and is susceptible to infection and killing by a variety of human Ads. A20 is also a suitable cancer vaccine model, because these cells express a unique immunoglobulin variable region that can be targeted by vaccination. To compare Ads as cancer vaccines versus Ads as oncolytics, A20 tumors were initiated in immunocompetent BALB/c mice. Mice immunized with first-generation Ad5 expressing the …

Recruitment And Retention Of Diverse Populations In Antiretroviral Clinical Trials: Practical Applications From The Gender, Race And Clinical Experience Study., Ron Falcon, Dawn Averitt Bridge, Judith Currier, Kathleen Squires, Debbie Hagins, Deborah Schaible, Robert Ryan, Joseph Mrus

Division of Infectious Diseases and Environmental Medicine Faculty Papers

BACKGROUND: Women, particularly women of color, remain underrepresented in antiretroviral (ARV) clinical trials. To evaluate sex-based differences in darunavir/ritonavir-based therapy, the Gender, Race And Clinical Experience (GRACE) study was designed to enroll and retain a high proportion of women representative of the racial/ethnic demographics of women with HIV/AIDS in the United States. The recruitment and retention strategies used in GRACE are described in this article.

METHODS: Recruitment and retention strategies targeting women included selecting study sites that focused on women, involving community consultants, site-specific enrollment plans, access to other ARV drugs, study branding, site and patient toolkits, targeted public relations, …

Generation Of A Kupffer Cell-Evading Adenovirus For Systemic And Liver-Directed Gene Transfer, Reeti Khare, Shannon M. May, Francesco Vetrini, Eric A. Weaver, Donna Palmer, Amanda Rosewell, Nathan Grove, Philip Ng, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

As much as 90% of an intravenously (i.v.) injected dose of adenovirus serotype 5 (Ad5) is absorbed and destroyed by liver Kupffer cells. Viruses that escape these cells can then transduce hepatocytes after binding factor X (FX). Given that interactions with FX and Kupffer cells are thought to occur on the Ad5 hexon protein, we replaced its exposed hypervariable regions (HVR) with those from Ad6. When tested in vivo in BALB/c mice and in hamsters, the Ad5/6 chimera mediated >10 times higher transduction in the liver. This effect was not due to changes in FX binding. Rather, Ad5/6 appeared to …

Cerebral Nocardiosis, Rohana Naqi, Humera Ahsan, Muhammad Azeemuddin

Department of Radiology

Localized and multisystem nocardiosis is an opportunistic disease that occurs commonly in immunocompromised patients. Rarely, it is also seen in immunocompetent individuals. The most common disease sites include lung, skin and central nervous system. We report a case of 73 years old man who is a known case of rheumatoid arthritis for more than 15 years and was on Methotrexate and Prednisolone. Now presented with generalized tonic clonic seizures. His Magnetic Resonace Imaging (MRI) scan showed a ring enhancing lesion with mild surrounding oedema in right posterior parietal cortex. Based on the finding, the most probable diagnosis of cerebral abscess …

Real-World Comparison Of Two Molecular Methods For Detection Of Respiratory Viruses, Syed Asad Ali, James E. Gern, Tina V. Hartert, Kathryn M. Edwards, Marie R. Griffin, E Kathryn Mille, Tebeb Gebretsadik, Tressa Pappas, Wai Ming Lee, John V. Williams

Department of Paediatrics and Child Health

Background: Molecular polymerase chain reaction (PCR) based assays are increasingly used to diagnose viral respiratory infections and conduct epidemiology studies. Molecular assays have generally been evaluated by comparing them to conventional direct fluorescent antibody (DFA) or viral culture techniques, with few published direct comparisons between molecular methods or between institutions. We sought to perform a real-world comparison of two molecular respiratory viral diagnostic methods between two experienced respiratory virus research laboratories.
Methods: We tested nasal and throat swab specimens obtained from 225 infants with respiratory illness for 11 common respiratory viruses using both a multiplex assay (Respiratory MultiCode-PLx Assay [RMA]) …

Multilaboratory Evaluation Of Real-Time Pcr Tests For Hepatitis B Virus Dna Quantification, Angela M. Caliendo, Alexander Valsamakis, James W. Bremer, Andrea Ferreira-Gonzalez, Suzanne Granger, Linda Sabatini, Gregory J. Tsongalis

Dartmouth Scholarship

The performance characteristics of four different assays for hepatitis B virus (HBV) quantification were assessed: the Abbott RealTime HBV IUO, the Roche Cobas AmpliPrep/Cobas TaqMan HBV test, the Roche Cobas TaqMan HBV test with HighPure system, and the Qiagen artus HBV TM ASR. Limit of detection (LOD), linear range, reproducibility, and agreement were determined using a serially diluted plasma sample from a single chronically infected subject. Each assay was tested by at least three laboratories. The LOD of the RealTime and two TaqMan assays was approximately 1.0 log₁₀ IU/ml; for artus HBV (which used the lowest volume of extracted …

Health Needs Of Hiv-Infected Women In The United States: Insights From The Women Living Positive Survey., Kathleen E Squires, Sally L Hodder, Judith Feinberg, Dawn Averitt Bridge, Staats Abrams, Stephen P Storfer, Judith A Aberg

Department of Medicine Faculty Papers

The objective of this study was to describe attitudes, opinions, and perceived health needs of HIV-infected women in the United States. In this cross-sectional study, women were invited to participate in the Women Living Positive survey, a structured interview instrument with 45 questions. Collected data were deidentified and the margin of error was calculated as four percentage points. Incoming toll-free phone interviews were conducted from December 21, 2006, through March 14, 2007 among subjects recruited from a U.S. national network of AIDS counseling centers. Seven hundred HIV-infected women (43% African American, 28.5% Hispanic, 28.5% Caucasian; median age, 42.5 years) receiving …

Direct, Physically-Motivated Derivation Of The Contagion Condition For Spreading Processes On Generalized Random Networks, Peter Sheridan Dodds, Kameron Decker Harris, Joshua L. Payne

Dartmouth Scholarship

For a broad range of single-seed contagion processes acting on generalized random networks, we derive a unifying analytic expression for the possibility of global spreading events in a straightforward, physically intuitive fashion. Our reasoning lays bare a direct mechanical understanding of an archetypal spreading phenomena that is not evident in circuitous extant mathematical approaches.

Evaluation Of A Novel Non-Penetrating Electrode For Use In Dna Vaccination, Amy Donate, Domenico Coppola, Yolmari Cruz, Richard Heller

Bioelectrics Publications

Current progress in the development of vaccines has decreased the incidence of fatal and non-fatal infections and increased longevity. However, new technologies need to be developed to combat an emerging generation of infectious diseases. DNA vaccination has been demonstrated to have great potential for use with a wide variety of diseases. Alone, this technology does not generate a significant immune response for vaccination, but combined with delivery by electroporation (EP), can enhance plasmid expression and immunity. Most EP systems, while effective, can be invasive and painful making them less desirable for use in vaccination. Our lab recently developed a non-invasive …

A Novel Approach For A New Era: Successful Integration Of Multidisciplinary, Hepatitis C Care Within An Established Hiv Primary Care Practice, Joseph L. Yozviak Do, Facp, Orlando J. Penaloza Md, Facp, Timothy J. Friel Md

Department of Medicine

No abstract provided.

Advances And Future Challenges In Adenoviral Vector Pharmacology And Targeting, Reeti Khare, Christopher Y. Chen, Eric A. Weaver, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Adenovirus is a robust vector for therapeutic applications, but its use is limited by our understanding of its complex in vivo pharmacology. In this review we describe the necessity of identifying its natural, widespread, and multifaceted interactions with the host since this information will be crucial for efficiently redirecting virus into target cells. In the rational design of vectors, the notion of overcoming a sequence of viral “sinks” must be combined with re-targeting to target populations with capsid as well as shielding the vectors from pre-existing or toxic immune responses. It must also be noted that most known adenoviral pharmacology …

Whole-Genome Sequencing Of Staphylococcus Aureus Strain Rn4220, A Key Laboratory Strain Used In Virulence Research, Identifies Mutations That Affect Not Only Virulence Factors But Also The Fitness Of The Strain, Dhanalakshmi Nair, Guido Memmi, David Hernandez, Jonathan Bard, Marie Beaume, Steven Gill, Patrice Francois, Ambrose L. Cheung

Dartmouth Scholarship

Staphylococcus aureus RN4220, a cloning intermediate, is sometimes used in virulence, resistance, and metabolic studies. Using whole-genome sequencing, we showed that RN4220 differs from NCTC8325 and contains a number of genetic polymorphisms that affect both virulence and general fitness, implying a need for caution in using this strain for such studies.

Enhanced Neutralization Potency Of Botulinum Neurotoxin Antibodies Using A Red Blood Cell-Targeting Fusion Protein., Sharad P Adekar, Andrew T Segan, Cindy Chen, Rodney Bermudez, M D Elias, Bernard H Selling, B P Kapadnis, Lance L Simpson, Paul M Simon, Scott K Dessain

Division of Infectious Diseases and Environmental Medicine Faculty Papers

Botulinum neurotoxin (BoNT) potently inhibits cholinergic signaling at the neuromuscular junction. The ideal countermeasures for BoNT exposure are monoclonal antibodies or BoNT antisera, which form BoNT-containing immune complexes that are rapidly cleared from the general circulation. Clearance of opsonized toxins may involve complement receptor-mediated immunoadherence to red blood cells (RBC) in primates or to platelets in rodents. Methods of enhancing immunoadherence of BoNT-specific antibodies may increase their potency in vivo. We designed a novel fusion protein (FP) to link biotinylated molecules to glycophorin A (GPA) on the RBC surface. The FP consists of an scFv specific for murine GPA fused …

Improving Outcomes For Hispanic Patients Undergoing Peginterferon/Ribavirin Therapy For Chronic Hepatitis C In An Internist-Led, Multidisciplinary, Multi-Cultural Practice: A Unique Application Of The Medical, Joseph L. Yozviak Do, Facp, Orlando J. Penaloza Md, Facp, Judith A. Knoop

Department of Medicine

No abstract provided.