Microbiology Commons^™

Phylometrics: A Pipeline For Inferring Phylogenetic Trees From A Sequence Relationship Network Perspective, Samuel A. Smits, Cleber C. Ouverney

Faculty Publications, Biological Sciences

Background
Comparative sequence analysis of the 16S rRNA gene is frequently used to characterize the microbial diversity of environmental samples. However, sequence similarities do not always imply functional or evolutionary relatedness due to many factors, including unequal rates of change and convergence. Thus, relying on top BLASTN hits for phylogenetic studies may misrepresent the diversity of these constituents. Furthermore, attempts to circumvent this issue by including a large number of BLASTN hits per sequence in one tree to explore their relatedness presents other problems. For instance, the multiple sequence alignment will be poor and computationally costly if not relying on …

Interferon Regulatory Factor 3-Dependent Pathways Are Critical For Control Of Herpes Simplex Virus Type 1 Central Nervous System Infection, Vineet D. Menachery, Tracy J. Pasieka, David A. Leib

Dartmouth Scholarship

The initiation of the immune response at the cellular level relies on specific recognition molecules to rapidly signal viral infection via interferon (IFN) regulatory factor 3 (IRF-3)-dependent pathways. The absence of IRF-3 would be expected to render such pathways inoperative and thereby significantly affect viral infection. Unexpectedly, a previous study found no significant change in herpes simplex virus (HSV) pathogenesis in IRF-3^−/− mice following intravenous HSV type 1 (HSV-1) challenge (K. Honda, H. Yanai, H. Negishi, M. Asagiri, M. Sato, T. Mizutani, N. Shimada, Y. Ohba, A. Takaoka, N. Yoshida, and T. Taniguchi, Nature 434:772-777, 2005). In contrast, the …

Dorsal Eye Selector Pannier (Pnr) Suppresses The Eye Fate To Define Dorsal Margin Of The Drosophila Eye, Sarah M. Oros, Meghana Tare, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Axial patterning is crucial for organogenesis. During Drosophila eye development, dorso-ventral (DV) axis determination is the first lineage restriction event. The eye primordium begins with a default ventral fate, on which the dorsal eye fate is established by expression of the GATA-1 transcription factor pannier (pnr). Earlier, it was suggested that loss of pnr function induces enlargement in the dorsal eye due to ectopic equator formation. Interestingly, we found that in addition to regulating DV patterning, pnr suppresses the eye fate by downregulating the core retinal determination genes eyes absent (eya), sine oculis (so) and dacshund (dac) to define the …

Benign Metastasizing Leiomyoma, Saira Fatima, Zubair Ahmad, Mohammad Azam

Department of Pathology and Laboratory Medicine

Benign metastasizing leiomyoma (BML) is a rare condition, affecting predominantly reproductive-age females with uterine leiomyomata and is most often associated with multiple benign-appearing smooth muscle tumors in lungs. We report herein a case of a 38-year-old woman who presented with multiple uterine fibroids for which hysterectomy was carried out on her. Postoperatively, she developed left-sided pleural effusion. Computed chest tomography (CT) scan revealed multiple nodules in both lungs and pleurae. Histopathology of one of the pleura-based nodules revealed a neoplasm composed of interlacing fascicles of spindle cells with uniform nuclei. The tumor cells were positive for alpha-smooth muscle actin and …

The Human Oral Microbiome, Floyd E. Dewhirst, Tuste Chen, Jacques Izard, Bruce J. Paster, Anne C. R. Tanner, Wen-Han Yu, Abirami Lakshmanan, William G. Wade

Department of Food Science and Technology: Faculty Publications

The human oral cavity contains a number of different habitats, including the teeth, gingival sulcus, tongue, cheeks, hard and soft palates, and tonsils, which are colonized by bacteria. The oral microbiome comprises over 600 prevalent taxa at the species level, with distinct subsets predominating at different habitats. The oral microbiome has been extensively characterized by cultivation and culture-independent molecular methods such as 16S rRNA cloning. Unfortunately, the vast majority of unnamed oral taxa are referenced by clone numbers or 16S rRNA GenBank accession numbers, often without taxonomic anchors. The first aim of this research was to collect 16S rRNA gene …

The Armadillo Repeat Protein Pf16 Is Essential For Flagellar Structure And Function In Plasmodium Male Gametes, Ursula Straschil, Arthur M. Talman, David J. P. Ferguson, Karen A. Bunting, Zhengyao Xu, Elizabeth Bailes, Robert E. Sinden, Anthony A. Holder, Elizabeth F. Smith

Dartmouth Scholarship

Malaria, caused by the apicomplexan parasite Plasmodium, threatens 40% of the world's population. Transmission between vertebrate and insect hosts depends on the sexual stages of the life-cycle. The male gamete of Plasmodium parasite is the only developmental stage that possesses a flagellum. Very little is known about the identity or function of proteins in the parasite's flagellar biology. Here, we characterise a Plasmodium PF16 homologue using reverse genetics in the mouse malaria parasite Plasmodium berghei. PF16 is a conserved Armadillo-repeat protein that regulates flagellar structure and motility in organisms as diverse as green algae and mice. We show that …

Morphological Analysis Based On A Fractional Dynamic Model For Hyphal Growth, Jonathan Blackledge, Dan Barry

Conference papers

The development of methods capable of accurately characterising the morphology of filamentous microbes represents a significant challenge to biotechnologists. This is because the productivity of many industrial fermentation processes is heavily dependent on the morphological form adopted by an organism. It is therefore of significant value if a quantitative model and associated metric(s) for morphological forms determined by complex phenotypes can be determined non-invasively, e.g. through image analysis. Specific interest is in the quantification of the branching behaviour of an organism. This is due to the link between branching frequency, biomass and metabolite production. In this paper we present a …

Demographic And Clinical Features Of Dengue Fever In Pakistan From 2003-2007: A Retrospective Cross-Sectional Study., Erum Khan, Mehreen Kisat, Nabil Khan, Amna Nasir, Salma Ayub, Rumina Hasan

Department of Pathology and Laboratory Medicine

Background: Demographic features of dengue fever have changed tremendously in Pakistan over the past two decades. Small scale studies from all over the country have reported different aspects of individual outbreaks during this time. However, there is scarcity of data looking at the overall trend of dengue virus infection in the country. In this study, we examined annual trends, seasonality, and clinical features of dengue fever in the Pakistani population.
Methods: Demographic information and dengue IgM status of all patients tested for dengue IgM antibody at Aga Khan University Hospital from January 2003 to December 2007 were analyzed to look …

The Chlorella Variabilis Nc64a Genome Reveals Adaptation To Photosymbiosis, Coevolution With Viruses, And Cryptic Sex, Guillaume Blanc, Garry Duncan, Irina Agarkova, Mark Borodovsky, James Gurnon, Alan Kuo, Erika Lindquist, Susan Lucas, Jasmyn Pangilinan, Juergen Polle, Asaf Salamov, Astrid Terry, Takashi Yamada, David D. Dunigan, Igor V. Grigoriev, Jean-Michel Claverie, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Chlorella variabilis NC64A, a unicellular photosynthetic green alga (Trebouxiophyceae), is an intracellular photobiont of Paramecium bursaria and a model system for studying virus/algal interactions. We sequenced its 46-Mb nuclear genome, revealing an expansion of protein families that could have participated in adaptation to symbiosis. NC64A exhibits variations in GC content across its genome that correlate with global expression level, average intron size, and codon usage bias. Although Chlorella species have been assumed to be asexual and nonmotile, the NC64A genome encodes all the known meiosis-specific proteins and a subset of proteins found in flagella. We hypothesize that Chlorella might have …

Negative Dielectrophoretic Capture Of Bacterial Spores In Food Matrices, Mehti Koklu, Seungkyung Park, Suresh D. Pillai, Ali Beskok

Mechanical & Aerospace Engineering Faculty Publications

A microfluidic device with planar square electrodes is developed for capturing particles from high conductivity media using negative dielectrophoresis (n-DEP). Specifically, Bacillus subtilis and Clostridium sporogenes spores, and polystyrene particles are tested in NaCl solution (0.05 and 0.225 S/m), apple juice (0.225 S/m), and milk (0.525 S/m). Depending on the conductivity of the medium, the Joule heating produces electrothermal flow (ETF), which continuously circulates and transports the particles to the DEP capture sites. Combination of the ETF and n-DEP results in different particle capture efficiencies as a function of the conductivity. Utilizing 20 μm height DEP chambers, “almost complete” and …

Genome Sequence Of The Model Mushroom Schizophyllum Commune, Robin A. Ohm, Jan F. De Jong, Luis G. Lugones, Andrea Aerts, Erika Kothe, Jason E. Stajich, Ronald P. De Vries, Eric Record, Anthony Levasseur, Scott E. Baker, Kirk A. Bartholomew, Pedro M. Coutinho, Susann Erdmann, Thomas J. Fowler, Allen C. Gathmen, Vincent Lombard, Bernard Henrissat, Nicole Knabe, Ursula Kues, Walt W. Lily

Biology Faculty Publications

Much remains to be learned about the biology of mushroom-forming fungi, which are an important source of food, secondary metabolites and industrial enzymes. The wood-degrading fungus Schizophyllum commune is both a genetically tractable model for studying mushroom development and a likely source of enzymes capable of efficient degradation of lignocellulosic biomass. Comparative analyses of its 38.5-megabase genome, which encodes 13,210 predicted genes, reveal the species's unique wood-degrading machinery. One-third of the 471 genes predicted to encode transcription factors are differentially expressed during sexual development of S. commune. Whereas inactivation of one of these, fst4, prevented mushroom formation, inactivation of another, …

Time Will Tell: Community Acceptability Of Hiv Vaccine Research Before And After The "Step Study" Vaccine Discontinuation, Paula M. Frew, Mark J. Mulligan, Su-I Hou, Kayshin Chan, Carlos Del Rio

Environmental & Global Health Faculty Research

Objective This study examines whether men-who-have-sex-with-men (MSM) and transgender (TG) persons’ attitudes, beliefs, and risk perceptions toward human immunodeficiency virus (HIV) vaccine research have been altered as a result of the negative findings from a phase 2B HIV vaccine study. Design We conducted a cross-sectional survey among MSM and TG persons (N = 176) recruited from community settings in Atlanta from 2007 to 2008. The first group was recruited during an active phase 2B HIV vaccine trial in which a candidate vaccine was being evaluated (the “Step Study”), and the second group was recruited after product futility was widely reported …

Conidia But Not Yeast Cells Of The Fungal Pathogen Histoplasma Capsulatum Trigger A Type I Interferon Innate Immune Response In Murine Macrophages, Diane O. Inglis, Charlotte A. Berkes, Davina R. Hocking Murray, Anita Sil

Biology Faculty Publications

Histoplasma capsulatum is the most common cause of fungal respiratory infections and can lead to progressive disseminated infections, particularly in immunocompromised patients. Infection occurs upon inhalation of the aerosolized spores, known as conidia. Once inside the host, conidia are phagocytosed by alveolar macrophages. The conidia subsequently germinate and produce a budding yeast-like form that colonizes host macrophages and can disseminate throughout host organs and tissues. Even though conidia are the predominant infectious particle for H. capsulatum and are the first cell type encountered by the host during infection, very little is known at a molecular level about conidia or about …

Splice Factor Sfrs6: Regulation By P53 And Effect On Il-24 Splicing, Erin L. Schmidt

Loma Linda University Electronic Theses, Dissertations & Projects

Alternative splicing of RNA transcripts is emerging as a major mechanism for expanding the proteome. Splice pattern changes are found in numerous diseases and cancers, indicating the importance of tight control over this process. While the mechanism of splicing has been described in detail, it is less clear how a cell is able to modify its splicing patterns in response to different conditions. Our lab previously demonstrated that DNA damage can induce SFRS6, the gene coding for splicing factor SRp55, thereby leading to changes in the splicing patterns of several target genes related to survival and apoptosis. We also …

Bioluminescent Escherichia Coli Strains For The Quantitative Detection Of Phosphate And Ammonia In Coastal And Suburban Watersheds, Cristina V. Cardemil , '01, D. R. Smulski, R. A. Larossa, Amy Cheng Vollmer

Biology Faculty Works

Accumulation of phosphate and ammonia in estuarine systems and subsequent dinoflagellate and algal blooms has been implicated in fish kills and in health risks for fishermen. Analytic chemistry kits are used to measure phosphate and ammonia levels in water samples, but their sensitivity is limited due to specificity for inorganic forms of these moieties. An Escherichia coli bioluminescent reporter system measured the bioavailability of inorganic nutrients through fusion of E. coli promoters (phoA or glnAp2) to the luxCDABE operon of Vibrio fischeri carried either on the chromosome or on a multicopy plasmid vector, resulting in emission of light in response …

Distinct Macrophage Subpopulations Regulate Viral Encephalitis But Not Viral Clearance In The Cns, Christina D. Steel, Woong-Ki Kim, Larry Sanford, Laurie Wellman, Sandra Burnett, Nico Van Rooijen, Rochard P. Ciavarra

Biological Sciences Faculty Publications

Intranasal application of vesicular stomatitis virus (VSV) induces acute encephalitis characterized by a pronounced myeloid and T cell infiltrate. The role of distinct phagocytic populations on VSV encephalitis was therefore examined in this study. Ablation of peripheral macrophages did not impair VSV encephalitis or viral clearance from the brain, whereas, depletion of splenic marginal dendritic cells impaired this response and enhanced morbidity/mortality. Selective depletion of brain perivascular macrophages also suppressed this response without altering viral clearance. Thus, two anatomically distinct phagocytic populations regulate VSV encephalitis in a non-redundant fashion although neither population is essential for viral clearance in the CNS. …

Virus Silicification Under Simulated Hot Spring Conditions, James R. Laidler, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).

Jsphylosvg: A Javascript Library For Visualizing Interactive And Vector-Based Phylogenetic Trees On The Web, Samuel A. Smits, Cleber C. Ouverney

Faculty Publications, Biological Sciences

Background
Many software packages have been developed to address the need for generating phylogenetic trees intended for print. With an increased use of the web to disseminate scientific literature, there is a need for phylogenetic trees to be viewable across many types of devices and feature some of the interactive elements that are integral to the browsing experience. We propose a novel approach for publishing interactive phylogenetic trees.

Methods/Principal Findings
We present a javascript library, jsPhyloSVG, which facilitates constructing interactive phylogenetic trees from raw Newick or phyloXML formats directly within the browser in Scalable Vector Graphics (SVG) format. It is …

Quantification Of Aflatoxin B1 In Ready-To-Use Food Thickeners In South-East Geo-Political Zone In Nigeria, G. I. Okwu, Premila N. Achar, Santosh K. Sharma

Faculty Articles

A total of 150 ready to use food thickeners were randomly collected from various markets in both urban and rural settings. Four of the samples tested Achi (Brachystegia eurycoma), Akpalata (Afzelia africana), Ofor (Detarium microcarpum), and Ukpo (Mucuna flagellipes) were contaminated with fungal flora. The most common and prevalent fungi observed on incubated powdered form of food thickeners on media, were the Aspergillus group namely Aspergillus flavus, Aspergillus parasiticus and Aspergillus niger. Pure isolates of A. flavus and A. parasiticus from various food thickeners from open markets in Nigeria were screened for their potential to produce aflatoxin B-1 (AFB(1)) on …

Prevalence Of Staphylococcus Aureus And Staphylococcus Intermedius Among Pet Industry Employees And Transfer Of Erm Genes From S. Aureus To S. Intermedius Colonizing Healthy People, Xing Fu

Student Theses and Dissertations

Staphylococcus aureus is a ubiquitous opportunistic pathogen carried by humans. Staphylococcus intermedius is a zoonotic pathogen showing a potential to infect humans. Transfer of antibiotic resistance genes between bacteria accelerates the spread of antibiotic resistance. In this project, biochemical tests combined with PCR were employed to identify the colonization rates of S. aureus and S. intermedius in pet industry employees and the transfer of erythromycin rRNA methylase genes, ermA and ermC, between them. The colonization rates of S. aureus and S. intermedius were 24% and 2% respectively, which were low and indicates daily contact with animals may not facilitate the …