Microbiology Commons^™

Ecology Of Vibrio Parahaemolyticus And Vibrio Vulnificus In The Coastal And Estuarine Waters Of Louisiana, Maryland, Mississippi, And Washington (United States), Crystal N. Johnson, John C. Bowers, Kimberly J. Griffitt, Vanessa Molina, Rachel W. Clostio, Shaofeng Pei, Edward Laws, Rohinee N. Paranjpye, Mark S. Strom, Arlene Chen, Nur A. Hasan, Anwar Huq, Nicholas F. Noriea Iii, D. Jay Grimes, Rita R. Colwell

Faculty Publications

Vibrio parahaemolyticus and Vibrio vulnificus, which are native to estuaries globally, are agents of seafood-borne or wound infections, both potentially fatal. Like all vibrios autochthonous to coastal regions, their abundance varies with changes in environmental parameters. Sea surface temperature (SST), sea surface height (SSH), and chlorophyll have been shown to be predictors of zooplankton and thus factors linked to vibrio populations. The contribution of salinity, conductivity, turbidity, and dissolved organic carbon to the incidence and distribution of Vibrio spp. has also been reported. Here, a multicoastal, 21-month study was conducted to determine relationships between environmental parameters and V. parahaemolyticus …

A Plant Virus Substrate Induces Early Upregulation Of Bmp2 For Rapid Bone Formation, Pongkwan Sitasuwan, L. Andrew Lee, Peng Bo, Erin N. Davis, Yuan Lin, Qian Wang

Faculty Publications

Many nanoscale materials have been developed to investigate the effects on stem cell differentiations via topographical and chemical cues for applications in tissue engineering and regenerative medicine. The use of plant viruses as cell supporting substrates has been of particular interest due to the rapid induction of bone marrow derived mesenchymal stem cells (BMSCs) towards osteogenic cells. In this study, the role of Tobacco mosaic virus (TMV) and its early effects on osteoinduction with particular emphasis on the regulation of bone morphogenetic protein-2 (BMP2) was examined. We observed that the cells on the virus substrate immediately aggregated and formed bone-like …

Human Pathogen Shown To Cause Disease In The Threatened Elkhorn Coral Acropora Palmata, Kathryn Patterson Sutherland, Sameera Shaban, Jessica L. Joyner, James W. Porter, Erin K. Lipp

Faculty Publications

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments …

Electrospinning Fabrication, Structural And Mechanical Characterization Of Rod-Like Virus-Based Composite Nanofibers, Laying Wu, Jianfeng Zang, L. Andrew Lee, Zhongwei Niu, Gary C. Horvatha, Vaughn Braxtona, Arief C. Wibowo, Michael A. Bruckman, Soumitra Ghoshroy, Hans-Conrad Zur Loye, Xiaodong Li, Qian Wang

Faculty Publications

Tobacco mosaic virus (TMV) was electrospun with polyvinyl alcohol (PVA) into continuous TMV–PVA composite nanofibers to form a biodegradable nonwoven fibrous mat as an extracellular matrix (ECM) mimetic. Morphological characterizations by electron microscopyshowed that the addition of varying amounts of TMV resulted in homogeneous nanofibers without phase separation and did not change the diameter of the composite nanofibers. The orientation of TMV in as-spun fibers could be readily controlled and post-processing of the nonwoven TMV–PVA mat significantly improved its water resistance. In addition, tensile tests were performed on individual nanofibers, which revealed that the TMV–PVA composite nanofibers achieved a comparable …

Alteration Of Microbial Communities Colonizing Leaf Litter In A Temperate Woodland Stream By Growth Of Trees Under Conditions Of Elevated Atmospheric Co2, John J. Kelly, Amit Bansal, Jonathan Winkelman, Lori R. Janus, Shannon Hell, Marie Wencel, Patricia Belt, Kevin A. Kuehn, Steven T. Rier, Nancy C. Tuchman

Faculty Publications

Elevated atmospheric CO₂ can cause increased carbon fixation and altered foliar chemical composition in a variety of plants, which has the potential to impact forested headwater streams because they are detritus-based ecosystems that rely on leaf litter as their primary source of organic carbon. Fungi and bacteria play key roles in the entry of terrestrial carbon into aquatic food webs, as they decompose leaf litter and serve as a source of nutrition for invertebrate consumers. This study tested the hypothesis that changes in leaf chemistry caused by elevated atmospheric CO₂ would result in changes in the size and …

The Pentameric Vertex Proteins Are Necessary For The Icosahedral Carboxysome Shell To Function As A Co2 Leakage Barrier, Fei Cai, Balaraj B. Menon, Gordon C. Cannon, Kenneth J. Curry, Jessup M. Shively, Sabine Heinhorst

Faculty Publications

Background

Carboxysomes are polyhedral protein microcompartments found in many autotrophic bacteria; they encapsulate the CO₂ fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) within a thin protein shell and provide an environment that enhances the catalytic capabilities of the enzyme. Two types of shell protein constituents are common to carboxysomes and related microcompartments of heterotrophic bacteria, and the genes for these proteins are found in a large variety of bacteria.

Methodology/Principal Findings

We have created a Halothiobacillus neapolitanus knockout mutant that does not produce the two paralogous CsoS4 proteins thought to occupy the vertices of the icosahedral carboxysomes and related microcompartments. Biochemical …

Transcriptome Analysis Of Frog Virus 3, The Type Species Of The Genus Ranavirus, Family Iridoviridae, Sai Majji, V. Thodima, R. Sample, D. Whitley, Y. Deng, J. Mao, V. Gregory Chinchar

Faculty Publications

Frog virus 3 is the best characterized species within the genus Ranavirus, family Iridoviridae. FV3's large (similar to 105 kbp) dsDNA genome encodes 98 putative open reading frames (ORFs) that are expressed in a coordinated fashion leading to the sequential appearance of immediate early (IE), delayed early (DE) and late (L) viral transcripts. As a step toward elucidating molecular events in FV3 replication, we sought to identify the temporal Class Of Viral messages. To accomplish this objective an oligonucleotide microarray containing 70-mer probes corresponding to each of the 98 FV3 ORFs was designed and used to examine viral gene expression. …

Controlled Assembly Of Rodlike Viruses With Polymers, Tao Li, Laying Wu, Nisaraporn Suthiwangcharoen, Michael A. Bruckman, Dayton Cash, Joan S. Hudson, Soumitra Ghoshroy, Qian Wang

Faculty Publications

A practical method to assemble rodlike tobacco mosaic virus and bacteriophage M13 with polymers was developed, which afforded a 3D core–shell composite with morphological control.

The Role Of Msa In Staphylococcus Aureus Biofilm Formation, Karthik Sambanthamoorthy, Antony Schwartz, Vijayaraj Nagarajan, Mohamed O. Elasri

Faculty Publications

Background

Staphylococcus aureus is an important pathogen that forms biofilms. The global regulator sarA is essential for biofilm formation. Since the modulator of sarA (msa) is required for full expression of sarA and regulates several virulence factors, we examined the capacity of the msa mutant to form biofilm.

Results

We found that mutation of msa results in reduced expression of sarA in biofilm and that the msa mutant formed a weak and unstable biofilm. The msa mutant is able to adhere to surfaces and begins to form biofilm but fails to mature indicating that the defect of the …

Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, Jianhua Rong, L. Andrew Lee, Kai Li, Brandon Harp, Charlene M. Mello, Zhongwei Niu, Qian Wang

Faculty Publications

Fibrillar M13 bacteriophages were used as basic building blocks to generate thin films with aligned nanogrooves, which, upon chemical grafting with RGD peptides, guide cell alignment and orient the cell outgrowth along defined directions.

Decline In A Dominant Invertebrate Species Contributes To Altered Carbon Cycling In A Low-Diversity Soil Ecosystem, Byron J. Adams, J. E. Barrett, Ross A. Virginia, Diana H. Wall

Faculty Publications

Low-diversity ecosystems cover large portions of the Earth's land surface, yet studies of climate change on ecosystem functioning typically focus on temperate ecosystems, where diversity is high and the effects of individual species on ecosystem functioning are difficult to determine. We show that a climate-induced decline of an invertebrate species in a low-diversity ecosystem could contribute to significant changes in carbon © cycling. Recent climate variability in the McMurdo Dry Valleys of Antarctica is associated with changes in hydrology, biological productivity, and community composition of terrestrial and aquatic ecosystems. One of the greatest changes documented in the dry valleys is …

Comparative Phylogeography Of Codistributed Species Of Chilean Liolaemus (Squamata: Tropiduridae) From The Central-Southern Andean Range, Byron J. Adams, Pedro F. Victoriano, Juan Carlos Ortiz, Edgar Benavides, Jack W. Sites

Faculty Publications

In this study, we used a recently developed supertrees method to test for shared phylogeographical signal in partially overlapping geographical ranges of lizards of the genus Liolaemus from the Andean Range in south-central Chile. We reconstruct mtDNA gene trees for three partially codistributed species (Liolaemus tenuis, L. lemniscatus and L. pictus), and our sampling effort is sufficient to allow statistical tests of shared signal between the combinations L. tenuis-L. pictus, and L. tenuis-L. lemniscatus. For both combinations, standardized maximum agreement subtrees scores showed statistically significant signal for shared pattern in regions of overlap, as evaluated by randomization tests (P < 0.001 and < 0.05, respectively). The matrix representation with parsimony tree obtained from the combination of the three different gene trees revealed concordant phylogeographical associations of all species, and was consistent with the geographical association of intraspecific haploclades with three Chilean bioclimatic zones. A multidimensional scaling analysis of several climate variables showed highly significant differences among these zones, which further suggests that they may have contributed to similar patterns of intraspecific divergence across all three species. In the mesomorphic zone in Central Chile, the species L. tenuis and L. lemniscatus may have codiverged in response to shared orogenic vicariant events, which likely predominated over climatic events associated with cycles of glacial advance and retreat. In the hygromorphic zone in southern Chile, however, glacial cycles likely predominated in structuring the phylogeographical histories of L. tenuis and L. pictus, although important ecological differences between these two caution against broad generalizations at this point.

Differential Resource Allocation In Deer Mice Exposed To Sin Nombre Virus, Eric Wilson, Erin M. Lehmer, Christine A. Clay, Stephen St. Jeor, Denise M. Dearing

Faculty Publications

The resource allocation hypothesis predicts that reproductive activity suppresses immunocompetence; however, this has never been tested in an endemic disease system with free-ranging mammals. We tested the resource allocation hypothesis in wild deer mice (Peromyscus maniculatus) with natural exposure to Sin Nombre Virus (SNV). Immunocompetence was estimated from the extent of swelling elicited after deer mice were injected with phytohemagglutinin (PHA); swelling is positively correlated with immunocompetence. After livetrapping deer mice, we determined their reproductive state and SNV infection status. Males were more likely to be seropositive for SNV than females (37% vs. 25%) and exhibited 10% less swelling after …

Inhibitory Effects Of Estrogen Receptor Beta On Specific Hormone-Responsive Gene Expression And Association With Disease Outcome In Primary Breast Cancer, Chin-Yo Lin, Anders Strom, Li Say Kong, Silke Kietz, Jane S. Thomsen, Jason B. S. Tee, Vinsensius B. Vega, Lance D. Miller, Johanna Smeds, Jonas Bergh, Jan-Ake Gustafsson, Edison T. Liu

Faculty Publications

The impact of interactions between the two estrogen receptor (ER) subtypes, ER(alpha) and ER(beta), on gene expression in breast cancer biology is not clear. The goal of this study was to examine transcriptomic alterations in cancer cells co-expressing both receptors and the association of gene expression signatures with disease outcome. Methods: Transcriptional effects of ER(beta) overexpression were determined in a stably transfected cell line derived from ER(alpha) -positive T-47D cells. Microarray analysis was carried out to identify differential gene expression in the cell line, and expression of key genes was validated by quantitative polymerase chain reaction. Microarray and clinical data …

Tandem Repeat Regions Within The Burkholderia Pseudomallei Genome And Their Application For High Resolution Genotyping, Richard A. Robison, Jana M. U'Ren, James M. Schupp, Talima Pearson, Heidie Hornstra, Christine L. Friedman Clark, Kimothy L. Smith, Rebecca R. Leadem Daugherty, Shane D. Rhoton, Ben Leadem, Shalamar Georgia, Michelle Cardon, Lynn Y. Huynh, David Deshazer, Steven P. Harvey, Daniel Gal, Mark J. Mayo, David Wagner, Bart J. Currie, Paul Keim

Faculty Publications

The facultative, intracellular bacterium Burkholderia pseudomalle is the causative agent of melioidosis, a serious infectious disease of humans and animals. We identified and categorized tandem repeat arrays and their distribution throughout the genome of B. pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of 31 isolates including B. pseudomallei, B. mallei and B. thailandensis in order to identify loci with varying degrees of polymorphism. A subset of these tandem repeat arrays were subsequently developed into a multiple-locus VNTR analysis to examine …

Vertical Transmission Of A Phylogenetically Complex Microbial Consortium In The Viviparous Sponge Ircinia Felix, Susanne Schmitt, Jeremy B. Weisz, Niels Lindquist, Ute Hentschel

Faculty Publications

Many marine demosponges contain large amounts of phylogenetically complex yet highly sponge-specific microbial consortia within the mesohyl matrix, but little is known about how these microorganisms are acquired by their hosts. Settlement experiments were performed with the viviparous Caribbean demosponge Ircinia felix to investigate the role of larvae in the vertical transmission of the sponge-associated microbial community. Inspections by electron microscopy revealed large amounts of morphologically diverse microorganisms in the center of I. felix larvae, while the outer rim appeared to be devoid of microorganisms. In juveniles, microorganisms were found between densely packed sponge cells. Denaturing gradient gel electrophoresis (DGGE) …

Morphological And Molecular Analyses Of Microorganisms In Caribbean Reef Adult Sponges And In Corresponding Reproductive Material, Susanne Schmitt, Markus Wehrl, Niels Lindquist, Jeremy B. Weisz, Ute Hentschel

Faculty Publications

Caribbean reef sponges were surveyed for the presence of microorganisms in the mesohyl tissue of adult sponges and the respective reproductive material (embryos, larvae). A clear correlation was found in that high microbial abundance (HMA) sponges always contained microorganisms in their reproductive stages. In contrast, low microbial abundance (LMA) sponges did not contain microorganisms in their reproductive stages. Based on these data, Ircinia felix Duchassaing and Michelotti, 1864 was chosen as a model organism for the molecular analysis of microorganisms within the adult sponge and its larvae and juveniles. Denaturing gradient gel electrophoresis (DGGE) of eubacterial 16S rDNA sequences revealed …

Enzymes As Feed Additive To Aid In Responses Against Eimeria Species In Coccidia-Vaccinated Broilers Fed Corn-Soybean Meal Diets With Different Protein Levels, J. Parker, E. O. Oviedo Rondon, Beatrice A. Clack, S. Clemente-Hernandez, J. Osborne, J. C. Remus, H. Kettunen, H. Makivuokko, E. M. Pierson

Faculty Publications

This research aimed to evaluate the effects of adding a combination of exogenous enzymes to starter diets varying in protein content and fed to broilers vaccinated at day of hatch with live oocysts and then challenged with mixed Eimeria spp. Five hundred four 1-d-old male Cobb-500 chickens were distributed in 72 cages. The design consisted of 12 treatments. Three anticoccidial control programs [ionophore (IO), coccidian vaccine (COV), and coccidia-vaccine + enzymes (COV + EC)] were evaluated under 3 CP levels (19, 21, and 23%), and 3 unmedicated-uninfected (UU) negative controls were included for each one of the protein levels. All …

Computational Promoter Analysis Of Mouse, Rat, And Human Antimicrobial Peptide-Coding Genes, Chin-Yo Lin, Manisha Brahmachary, Christian Schonbach, Liang Yang, Enli Huang, Sin Lam Tan, Rajesh Chowdhary, S. P. T. Krishnan, David A. Hume, Chikatoshi Kai, Jun Kawai, Piero Carninci, Yoshihide Hayashizaki, Vladimir B. Bajic

Faculty Publications

Mammalian antimicrobial peptides (AMPs) are effectors of the innate immune response. A multitude of signals coming from pathways of mammalian pathogen/pattern recognition receptors and other proteins affect the expression of AMP-coding genes (AMPcgs). For many AMPcgs the promoter elements and transcription factors that control their tissue cell-specific expression have yet to be fully identified and characterized. Results- Based upon the RIKEN full-length cDNA and public sequence data derived from human, mouse and rat, we identified 178 candidate AMP transcripts derived from 61 genes belonging to 29 AMP families. However, only for 31 mouse genes belonging to 22 AMP families we …

A Phylogeny Of Belonolaimus Populations In Florida Inferred From Dna Sequences, Byron J. Adams, U. Gozel, K. B. Nguyen, R. N. Inserra, R. M. Giblin-Davis

Faculty Publications

The D2-D3 and ITS regions of rDNA from 33 Florida populations of Belonolaimus spp. were sequenced and subjected to phylogenetic analysis. Our objective was to derive a theoretical evolutionary framework for interpreting phenotypic differences as they relate to the taxonomy of the genus. The most striking aspect of the phylogenetic analysis is that none of the three nominal species (B. longicaudatus, B. euthychilus, and B. gracilis) are monophyletic. Additionally, two taxa appear to have discordant ITS and LSU sequences. Three major clades of B. longicaudatus exhibited discernible, overlapping, geographic foci from east to west across the peninsula. Morphological character states …

Multiplatform Genome-Wide Identification And Modeling Of Functional Human Estrogen Receptor Binding Sites, Chin-Yo Lin, Vinsensius B. Vega, Koon Siew Lai, Li Say Kong, Min Xie, Xiaodi Su, Huey Fang The, Jane S. Thomsen, Ai Li Yeo, Wing Kin Sung, Guillaume Bourque, Edison T. Liu

Faculty Publications

Transcription factor binding sites (TFBS) impart specificity to cellular transcriptional responses and have largely been defined by consensus motifs derived from a handful of validated sites. The low specificity of the computational predictions of TFBSs has been attributed to ubiquity of the motifs and the relaxed sequence requirements for binding. We posited that the inadequacy is due to limited input of empirically verified sites, and demonstrated a multiplatform approach to constructing a robust model. Results: Using the TFBS for the estrogen receptor (ER)alpha (estrogen response element [ERE]) as a model system, we extracted EREs from multiple molecular and genomic platforms …

Co-Variation In Soil Biodiversity And Biogeochemistry In Northern And Southern Victoria Land, Antarctica, Byron J. Adams, J. E. Barrett, Ross A. Virginia, Diana H. Wall, S. C. Cary, A. L. Hacker, J. M. Aislabie

Faculty Publications

Data from six sites in Victoria Land (72-77degrees S) investigating co-variation in soil communities (microbial and invertebrate) with biogeochemical properties show the influence of soil properties on habitat suitability varied among local landscapes as well as across climate gradients. Species richness of metazoan invertebrates (Nematoda, Tardigrada and Rotifera) was similar to previous descriptions in this region, though identification of three cryptic nematode species of Eudorylaimus through DNA analysis contributed to the understanding of controls over habitat preferences for individual species. Denaturing Gradient Gel Electrophoresis profiles revealed unexpectedly high diversity of bacteria. Distribution of distinct bacterial communities was associated with specific …

Effects Of Feed Additives And Mixed Eimeria Species Infection On Intestinal Microbial Ecology Of Broilers, M. E. Hume, S. Clemente-Hernandez, E. O. Oviedo Rondon

Faculty Publications

Evaluation of digestive microbial ecology is necessary to understand effects of growth-promoting feed. In the current study, the dynamics of intestinal microbial communities (MC) were examined in broilers fed diets supplemented with a combination of antibiotic (bacitracin methylene disalicylate) and ionophore (Coban 60), and diets containing 1 of 2 essential oil (EO) blends, Crina Poultry (CP) and Crina Alternate (CA). Five treatments were analyzed: 1) unmedicated uninfected control; 2) unmedicated infected control; 3) feed additives monensin (bacitracin methylene disalicylate) + monensin (Coban 60; AI); 4) EO blend CP; and 5) EO blend CA. Additives were mixed into a basal feed …

Investigating The Mechanism Of Acoustically Activated Uptake Of Drugs From Pluronic Micelles, Ghaleb A. Husseini, Christopher M. Runyan, William G. Pitt

Faculty Publications

This paper examines the mechanism of ultrasonic enhanced drug delivery from Pluronic micelles. In previous publications by our group, fluorescently labeled Pluronic was shown to penetrate HL-60 cells with and without the action of ultrasound, while drug uptake was increased with the application of ultrasound. Methods In this study, the amount of uptake of two fluorescent probes, Lysosensor Green (a pH-sensitive probe) and Cell Tracker Orange CMTMR (a pH-independent probe), was measured in HL-60 and HeLa cells. Results: The results of our experiments show that the increase in drug accumulation in the cells as a result of ultrasonication is not …

The Mycobactericidal Efficacy Of Orthophthalaldehyde And The Comparative Resistances Of Mycobacterium Bovis, Mycobacterium Terrae, And Mycobacterium Chelonae, Richard A. Robison, Adam W. Gregory, G. Bruce Schaalje, Jonathan D. Smart

Faculty Publications

Objectives: To assess the mycobactericidal efficacy of an agent relatively new to disinfection, ortho-phthalaldehyde (OPA) and to compare the resistances of three Mycobacterium species. Mycobacterium bovis (strain BCG) was compared with Mycobacterium chelonae and Mycobacterium terrae to investigate the feasibility of using either of the latter two species in tuberculocidal testing. M chelonae (a rapid grower) and M terrae (an intermediate grower) both grow faster and are less virulent than M bovis (a slow grower).