Microbiology Commons^™

A Twin-Cysteine Motif In The V2 Region Of Gp120 Is Associated With Siv Envelope Trimer Stabilization, Christopher Bohl, Dane Bowder, Jesse Thompson, Levon Abrahamyan, Sandra Gonzalez-Ramirez, Youdong Mao, Joseph Sodroski, Charles Wood, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

The V1 and V2 variable regions of the primate immunodeficiency viruses contribute to the trimer association domain of the gp120 exterior envelope glycoprotein. A pair of V2 cysteine residues at 183 and 191 (‘‘twin cysteines’’) is present in several simian immunodeficiency viruses, human immunodeficiency virus type 2 (HIV-2) and some SIV_cpz lineages, but not in HIV-1. To examine the role of this potentially disulfide-bonded twin-cysteine motif, the cysteine residues in the SIVmac239 envelope glycoproteins were individually and pairwise substituted by alanine residues. All of the twin-cysteine mutants exhibited decreases in gp120 association with the Env trimer, membrane-fusing activity, and …

Hiv-1 Env C2-V4 Diversification In A Slow-Progressor Infant Reveals A Flat But Rugged Fitness Landscape, S. Abigail Smith, Charles Wood, John T. West

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type-1 (HIV-1) fitness has been associated with virus entry, a process mediated by the envelope glycoprotein (Env). We previously described Env genetic diversification in a Zambian, subtype C infected, slow-progressor child (1157i) in parallel with an evolving neutralizing antibody response. Because of the role the Variable-3 loop (V3) plays in transmission, cell tropism, neutralization sensitivity, and fitness, longitudinally isolated 1157i C2-V4 alleles were cloned into HIV-1_NL4-3-eGFP and -DsRed2 infectious molecular clones. The fluorescent reporters allowed for dual-infection competitions between all patient-derived C2-V4 chimeras to quantify the effect of V3 diversification and selection on fitness. ‘Winners’ …

‘‘Megavirales’’, A Proposed New Order For Eukaryotic Nucleocytoplasmic Large Dna Viruses, Philippe Colson, Xavier De Lamballerie, Natalya Yutin, Sassan Asgari, Yves Bigot, Dennis K. Bideshi, Xiao-Wen Cheng, Brian A. Federici, James L. Van Etten, Eugene V. Koonin, Bernard La Scola, Didier Raoult

Nebraska Center for Virology: Faculty Publications

The nucleocytoplasmic large DNA viruses (NCLDVs) comprise a monophyletic group of viruses that infect animals and diverse unicellular eukaryotes. The NCLDV group includes the families Poxviridae, Asfarviridae, Iridoviridae, Ascoviridae, Phycodnaviridae, Mimiviridae and the proposed family ‘‘Marseilleviridae’’. The family Mimiviridae includes the largest known viruses, with genomes in excess of one megabase, whereas the genome size in the other NCLDV families varies from 100 to 400 kilobase pairs. Most of the NCLDVs replicate in the cytoplasm of infected cells, within so-called virus factories. The NCLDVs share a common ancient origin, as demonstrated by evolutionary reconstructions that trace approximately 50 genes encoding …

Seroprevalence Of Brucellosis In Livestock Within Three Endemic Regions Of The Country Of Georgia, Eliso Mamisashvili, Ian T. Kracalik, Tinatin Onashvili, Lela Kerdzevadze, Ketevan Goginashvili, Tamar Tigilauri, Marina Donduashvili, Marina Nikolaishvili, Irma Beradze, Marina Zakareishvili, Maka Kokhreidze, Makvala Gelashvili, Nino Vepkhvadze, S. Elizabeth Rácz, Philip H. Elzer, Mikeljon P. Nikolich, Jason K. Blackburn

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Brucellosis is the one of most common livestock zoonoses in Georgia, resulting in significant economic losses. Livestock were sampled in three regions of Georgia (Kakheti, Kvemo Kartli, Imereti). Districts that historically reported high numbers of brucellosis related morbidity were selected for serological, bacteriological and molecular surveys. Surveying efforts yielded samples from 10,819 large and small ruminants. In total, 735 serological tests were positive on Rose Bengal and 33 bacterial isolates were recovered and identified as Brucella melitensis or Brucella abortus by microbiology and AMOS-PCR. A Bayesian framework was implemented to estimate the true prevalence of the disease given an imperfect …

A World Review Of Fungi, Yeasts, And Slime Molds In Caves, Karen J. Vanderwolf, David Malloch, Donald F. Mcalpine, Graham J. Forbes

International Journal of Speleology

We provide a review of fungi, yeasts, and slime molds that have been found in natural solution caves and mines worldwide. Such habitats provide frequent roost sites for bats, and in eastern North America the environmental conditions that support white-nose syndrome, a lethal fungal disease currently devastating bat populations. A list of 1029 species of fungi, slime moulds, and yeasts in 518 genera have been documented from caves and mines worldwide in 225 articles. Ascomycota dominate the cave environment. Most research has been conducted in temperate climates, especially in Europe. A mean of 17.9±24.4SD fungal species are reported per study. …

Diversity And Biosynthetic Potential Of Culturable Aerobic Heterotrophic Bacteria Isolated From Magura Cave, Bulgaria, Iva Tomova, Irina Lazarkevich, Anna Tomova, Margarita Kambourova, Evgenia Vasileva-Tonkova

International Journal of Speleology

Biocapacity of bacteria inhabiting karstic caves to produce valuable biologically active compounds is still slightly investigated. A total of 46 culturable heterotrophic bacteria were isolated under aerobic conditions from the Gallery with pre-historical drawings in MaguraCave, Bulgaria. Phylogenetic analysis revealed that most of bacterial isolates affiliated with Proteobacteria (63%), followed by Actinobacteria (10.9%), Bacteroidetes (10.9%), and Firmicutes (6.5%). A strong domination of Gram-negative bacteria (total 81%) belonging to nine genera: Serratia, Pseudomonas, Enterobacter, Sphingobacterium, Stenotrophomonas, Commamonas, Acinetobacter, Obesumbacterium, and Myroides, was observed. Gram-positive isolates were represented by the genera Bacillus, Arthrobacter, and Micrococcus. One isolate …

La Serreta Endokarst (Se Spain): A Sustainable Value?, Antonia D. Asencio, Teodoro Espinosa

International Journal of Speleology

La Serreta endokarst (SE Spain), which UNESCO declared a World Heritage Site in 1998, was considered a sanctuary with cave art and one of the most important archaeological sites in the Mediterranean region for both the remains it hosts and the spectacular karstic landscape at the site.

To coincide with the 40th anniversary of its discovery, the La Serreta cave-chasm was adapted for public use with the intention of showing visitors the remains, which date back to prehistoric times. The solution included attempts to minimize contact with the valuables in the cave in order to alter the existing remains as …

The Effects Of Uv Light On The Antimicrobial Activities Of Cave Actinomycetes, Devon Rule, Naowarat Cheeptham

International Journal of Speleology

The goal of this study was to determine whether actinomycetes isolated from a volcanic cave in western Canada could produce novel antimicrobial compounds against six multidrugresistant pathogens when exposed to UV light. One hundred and seventy-six actinomycete strains isolated from Helmcken Falls Cave, Wells Gray Provincial Park, BC, were screened against six pathogens using the “plug assay” in UV light and no light conditions. Of the 176 strains tested, 100 or 57% of the cave actinomycete strains had antimicrobial activities against the pathogens in 124 different instances: 35 instances when exposed to UV and no light, 30 when exposed to …

Free-Living Amoebae In Sediments From The Lascaux Cave In France, Angela M. Garcia-Sanchez, Concepcion Ariza, Jose M. Ubeda, Pedro M. Martin-Sanchez, Valme Jurado, Fabiola Bastian, Claude Alabouvette, Cesareo Saiz Jimenez

International Journal of Speleology

The Lascaux Cave in France is an old karstic channel where the running waters are collected in a pool and pumped to the exterior. It is well-known that water bodies in the vicinity of humans are suspected to be reservoirs of amoebae and associated bacteria. In fact, the free-living amoebae Acanthamoeba astronyxis, Acanthamoeba castellanii, Acanthamoeba sp. and Hartmannella vermiformis were identified in the sediments of the cave using phylogenetic analyses and morphological traits. Lascaux Cave sediments and rock walls are wet due to a relative humidity near saturation and water condensation, and this environment and the presence of abundant bacterial …

Cure From The Cave: Volcanic Cave Actinomycetes And Their Potential In Drug Discovery, Naowarat (Ann) Cheeptham Dr., Tara Sadoway, Devon Rule, Kent Watson, Paul Moote, Laiel C. Soliman, Nicholas Azad, Kingsley Donkor, Derrick Horne

International Journal of Speleology

Volcanic caves have been little studied for their potential as sources of novel microbial species and bioactive compounds with new scaffolds. We present the first study of volcanic cave microbiology from Canada and suggest that this habitat has great potential for the isolation of novel bioactive substances. Sample locations were plot ted on a contour map that was compiled in ArcView 3.2. Over 400 bacterial isolates were obtained from the Helmcken Falls cave in Wells Gray Provincial Park, British Columbia. From our preliminary screen, of 400 isolates tested, 1% showed activity against extended spectrum ß-lactamase E. coli, 1.75% against Escherichia …

Understanding The Posttranslational Regulation Of The Response Regulator Rcsb And Acetyl Phosphate As An Acetyl Group Donor In E. Coli, Linda Hu

Dissertations

The observation that Nepsilon-lysine acetylation occurs on a hundreds of proteins in bacteria is a recent discovery. To study the mechanisms that regulate acetylation and to determine if acetylation affects physiology, I studied the Escherichia coli response regulator and transcription factor RcsB, which was reported to be acetylated in vitro. To monitor RcsB activity, I measured transcription from the rprA promoter, which requires RcsB. I confirmed that RcsB is activated by phosphorylation through the Rcs phosphorelay and acetyl phosphate and showed that acetyl phosphate could phosphorylate RcsB. However, a mutant that accumulates acetyl phosphate (ackA) exhibited reduced rprA transcription instead …

Prevalence Of Drug Resistance Associated Mutations In Plasmodium Vivax Against Sulphadoxine-Pyrimethamine In Southern Pakistan, Afsheen Raza, Najia K. Ghanchi, Muhammad Shahzeb Khan, Mohammad Asim Beg

Department of Pathology and Laboratory Medicine

Background: In Pakistan, Plasmodium vivax and Plasmodium falciparum co-exist and usage of sulphadoxine-pyrimethamine (SP) against P. falciparum exposes P. vivax to the drug leading to generation of resistant alleles. The main aim of this study was to investigate frequency distribution of drug resistance associated mutations in pvdhfr, pvdhps genes and provide baseline molecular epidemiological data on SP-associated resistance in P. vivax from southern Pakistan.
Methods: From January 2008 to May 2009, a total of 150 samples were collected from patients tested slide-positive for P. vivax, at the Aga Khan University Hospital, Karachi, or its collection units located in Baluchistan and …

Bacteriostatic Effects Of Sucralose On Environmental Bacteria, Arthur Phillip Omran Jr.

UNF Graduate Theses and Dissertations

Sucralose is a zero calorie sweetener developed and manufactured by Tate and Lyle Sweetener Company in the 1980’s. They sell the sweetener compounded with maltodextrin and dextrose under the brand name Splenda®. Sucralose was developed as a low cost artificial sweetener that is non-metabolizable in humans and can withstand changes in pH and temperature. It is not degraded by the waste water treatment process. Since the molecule can withstand heat, acidification and microbial degradation it is accumulating in the environment, and has been found in waste water, estuaries, rivers and the Gulf Stream. The highest concentration of environmental sucralose detected …

Expression And Characterization Of The Major Capsid Protein (Mcp) Of A Giant Marine Virus: Cafeteria Roenbergensis Virus, Sayan Chakraborty

Open Access Theses & Dissertations

The oceans play significant roles in maintaining the climate on Earth and providing nutrients to the whole biosphere. Oceanic microbes produce approximately half of the Earth's oxygen. It has been shown that the populations of microbial communities in oceans are largely regulated by viral infection and thus affect the marine ecosystem. Cafeteria roenbergensis Virus (CroV) is a giant marine virus with a linear, double stranded, and AT-rich DNA genome. The genome of CroV has a size of 744kb and encodes for 544 predicted genes. CroV derived its name from its host, a unicellular marine zooplankton Cafeteria roenbergensis (Cro) that is …

Role Of Post-Translational Modifications In The Hiv Cofactor Activity Of Ledgf/P75, Denisse Adriana Gutierrez

Open Access Theses & Dissertations

see document.

Validation Of N-Myristoyltransferase As Potential Chemotherapeutic Target In Chagas Disease, Linda Herrera

Open Access Theses & Dissertations

The protozoan parasite Trypanosoma cruzi is the etiological agent of Chagas disease, a problem endemic to Central and South America. In recent years, this neglected infectious disease has become a global health concern. The only clinically available drugs for the chemotherapy of Chagas disease have important disadvantages such as, high toxicity, strain resistance and variable efficacy. Therefore, there is an urgent need for the development of new antichagasic agents. The enzyme N-myristoyltransferase (NMT) has been characterized in a range of eukaryotes, from Saccharomyces cerevisae to Homo sapiens. Moreover, NMT has been shown to be essential in protozoan parasites, including Leishmania …

The Threat Of Domestic Bioterrorism: Fact Or Fiction, Stacy M. Langston

Open Access Theses & Dissertations

The threat of a domestic bioterrorist attack can be a daunting issue to cover. Using the analytic technique What If? Analysis a scenario was created for a domestic bioterrorism attack in Houston, TX. Indicators were developed to determine how to mitigate and respond to the attack. Recommendations were provided following the attack that can be used to prevent future attacks that were conducted in the scenario. Having a hindsight view of an attack is the best way to prevent and respond to the attack.

Sumoylation Exerts Minimal Effects On The Splicing Regulatory Activity Of The Influenza A Virus Non-Structural Protein Ns1, Griselda Melendez

Open Access Theses & Dissertations

One of the greatest challenges facing the development of a universal treatment for influenza infection is the virus's ability to mutate rapidly and produce new antigenic properties. Targeting the viral components of one strain does not ensure that the treatment will be effective with a newly developed strain. One alternative would be to develop therapies that target cellular factors the virus depends on for survivability. One of these factors is the cellular SUMOylation system. We have previously demonstrated that the Small Ubiquitin-like MOdifier (SUMO) interacts with the influenza virus by SUMOylating several viral proteins and by affecting the interferon blocking …

Composition Of Non Volatile Oils And Antimicrobial Activities Of Extracts From Monanthotaxis Discolor, And An Undescribed Uvariondedron Species, Ds Parmena, Ca Mgina, Cc Joseph

Tanzania Journal of Science

The chemical compositions of non volatile oil extracts from two Annoneceous plant species Monanthotaxis discolor and an undescribed Uvariodendron species which are endemic to Eastern Arc Mountains, Tanzania were determined by GC-MS. The biological activities of extracts and fractionated samples were also determined. Both methanol and dichloromethane extracts of the root bark of M. discolor showed mild antimicrobial activity and had positive brine shrimp test (BST). The BST test for dichloromethane extract of M. discolor root bark were LC50 41.794 μg/ml and that of methanol extract showed LC50 13.560 μg/ml. The petroleum ether and dichloromethane extracts of root bark of …

Measuring Population Transmission Potential For Hiv: An Alternative Metric Of Transmission Risk In Men Who Have Sex With Men (Msm) In The Us, Colleen F. Kelley, Eli S. Rosenberg, Brandon M. O'Hara, Paula M. Frew, Travis Sanchez, John L. Peterson, Carlos Del Rio, Patrick S. Sullivan

Environmental & Global Health Faculty Research

Background Various metrics for HIV burden and treatment success [e.g. HIV prevalence, community viral load (CVL), population viral load (PVL), percent of HIV-positive persons with undetectable viral load] have important public health limitations for understanding disparities. Methods and Findings Using data from an ongoing HIV incidence cohort of black and white men who have sex with men (MSM), we propose a new metric to measure the prevalence of those at risk of transmitting HIV and illustrate its value. …See full text for complete abstract.