Microbiology Commons^™

Infectious Keratitis Associated With Contact Lens Use, Misty Dawn Harvey

All-Inclusive List of Electronic Theses and Dissertations

In March 2006, ophthalmologists noticed increased Fusarium keratitis in patients wearing soft contact lenses; the etiology was that of Fusarium solani. By May of 2006, CDC reported receiving a total of 130 confirmed cases of Fusarium keratitis across 26 states and one territory; of the 118 who could identify the lens solution they had used, 64% reported using Bausch & Lomb's ReNu with Moistureloc ©,while 18% reported using only non-Bausch & Lomb products. The association between Fusarium keratitis and ReNu with Moistureloc was not clear. Nevertheless, Bausch & Lomb withdrew Moistureloc solutions worldwide. In earlier laboratory tests using standard methods …

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 …

Spatial And Temporal Patterns In The Microbial Diversity Of A Meromictic Soda Lake In Washington State, Pedro A. Dimitriu, Holly C. Pinkart, Brent M. Peyton, Melanie R. Mormile

All Faculty Scholarship for the College of the Sciences

The microbial community diversity and composition of meromictic Soap Lake were studied using culture-dependent and culture-independent approaches. The water column and sediments were sampled monthly for a year. Denaturing gradient gel electrophoresis of bacterial and archaeal 16S rRNA genes showed an increase in diversity with depth for both groups. Late-summer samples harbored the highest prokaryotic diversity, and the bacteria exhibited less seasonal variability than the archaea. Most-probable-number assays targeting anaerobic microbial guilds were performed to compare summer and fall samples. In both seasons, the anoxic samples appeared to be dominated by lactate-oxidizing sulfate-reducing prokaryotes. High numbers of lactate- and acetate-oxidizing …

The Application Of Bacteriophage For The Elimination Of Pathogenic Bacteria In Compost, Spencer Heringa

All Theses

The demand for organically grown produce is rapidly rising in the United States, resulting in a resurgence of natural fertilizers, such as animal waste, being used in agriculture. Currently, there are guidelines set by the USDA for the proper processing of fecal materials through composting; however food-borne illnesses associated with fresh-produce have become more and more common. Research is being conducted toward developing more effective treatments of fecal waste to reduce the survival of harmful bacteria. One possible form of treatment is through the use of bacteriophages that are able to 'seek and destroy' specific bacteria. The objectives of this …

Sequencing, Sub-Cloning, Expression And Purification Of 2-Hydroxychromene-2-Carboxylate Isomerase From Sphingomonas Paucimobilis Epa505, Aaron Brown

All Theses

Polyaromatic hydrocarbons (PAHs) are ubiquitous toxic pollutants that are slow to degrade naturally and costly to remediate artificially. Several species of bacteria have been shown to degrade PAHs, including Sphingomonas paucimobilis EPA505. The aerobic bacterial catabolism of the PAH naphthalene has been studied in several PAH metabolizing bacteria but never in EPA505. This study addresses this deficiency by identifying and characterizing one of the genes for naphthalene metabolism--nahD. NahD codes for the enzyme 2-hydroxychromene-2-carboxylate (HCCA) isomerase, which is the fourth of six enzymes in the upper catabolic pathway of naphthalene.
In this study, the gene nahD is identified …

Time Trends In The Incidence Of Cancer Cervix In Karachi South, 1995-2002, Yasmin Bhurgri, Shahid Pervez, Naila Kayani, Muneeza Afif, Imran Tahir, Kauser Nazir, Ahmed Usman, Naveen Faridi, Hadi Bhurgri, Jawaid Malik, Imtiaz Bashir, Asif Bhurgri, Rashida Ahmed, Sheema H Hasan, Mohammad Khurshid, S. M. H. Zaidi

Department of Pathology and Laboratory Medicine

Introduction:The objective of the study was to determine the trends of cancer cervix in Karachi South during an eight (1995-2002) year period. Methododology: Cancer cervix cases recorded at Karachi Cancer Registry during 1st January 1995 to 31st December 2002 were analyzed. Trends were studied by analyzing the age standardized incidence rates (ASR)s in 2 time periods, 1995-97 and 1998-2002.

Results:

Cancer cervix ranked sixth in the 1995-97 period the age standardized incidence rate (ASR) world and crude incidence rate (CIR) per 100,000 were 6.81 and 3.22. It reached the fifth ranking in the 1998-2002 period with an ASR and …

Long-Term Persistence Of Mumps Antibody After Receipt Of 2 Measles-Mumps-Rubella (Mmr) Vaccinations And Antibody Response After A Third Mmr Vaccination Among A University Population, Anand Date, Moe H. Kyaw, Alison M. Rue, Julie Klahn, Leann Obrecht, Terry Krohn, Josh Rowland, Steve Ruben, Thomas J. Safranek, William J. Bellini, Gustavo H. Dayan

Nebraska Center for Virology: Faculty Publications

Background. High attack rates among vaccinated young adults reported during the 2006 mumps outbreak in the United States heightened concerns regarding mumps vaccine failure.

Methods. Serum specimens from university students and staff were tested for mumps immunoglobulin (Ig) G by enzyme immunoassay (EIA). A subset of participants vaccinated for ≤5 years and ≥15 years were tested by neutralizing antibody (NA) assay. Persons seronegative by EIA were offered a third dose of measles-mumps-rubella vaccine (MMR3), and serum specimens were obtained 7–10 days and 2–3 months after its administration.

Results. Overall, 94% (95% confidence interval [CI], 91%–96%) of the 440 participants were …

Emergence Of Carbapenem Resistant Gram Negative And Vancomycin Resistant Gram Positive Organisms In Bacteremic Isolates Of Febrile Neutropenic Patients: A Descriptive Study., Seema Irfan, Faiza Idrees, Vikram Mehraj, Faizah Habib, Salman Adil, Rumina Hasan

Department of Pathology and Laboratory Medicine

Background:This study was conducted to evaluate drug resistance amongst bacteremic isolates of febrile neutropenic Patients with particular emphasis on emergence of carbapenem resistant Gram negative bacteria and vancomycin resistant Enterococcus species.

Methods:

A descriptive study was performed by reviewing the blood culture reports from febrile neutropenic Patients during the two study periods i.e., 1999-00 and 2001-06. Blood cultures were performed using BACTEC 9240 automated system. Isolates were identified and antibiotic sensitivities were done using standard microbiological procedures.

Results:

Seven twenty six febrile neutropenic Patients were admitted during the study period. A total of 5840 blood cultures were received, off …

Rules Of Engagement: Interspecies Interactions That Regulate Microbial Communities, Ainslie Little, Courtney Robinson, S Peterson, Kenneth Raffa, Jo Handelsman

Department of Biology Faculty Publications

Microbial communities comprise an interwoven matrix of biological diversity modified by physical and chemical variation over space and time. Although these communities are the major drivers of biosphere processes, relatively little is known about their structure and function, and predictive modeling is limited by a dearth of comprehensive ecological principles that describe microbial community processes. Here we discuss working definitions of central ecological terms that have been used in various fashions in microbial ecology, provide a framework by focusing on different types of interactions within communities, review the status of the interface between evolutionary and ecological study, and highlight important …

Comparison Of Dna Pyrosequencing With Alternative Methods For Identification Of Mycobacteria, Loree C. Heller, Michael Jones, Ray H. Widen

Bioelectrics Publications

Identification of mycobacterial clinical isolates by pyrosequencing within the hypervariable A region of the 16S rRNA gene was compared to other identification methods. For >90% of isolates, these identifications correlated to the level of complex or species. For identification of many mycobacteria, pyrosequencing offers an inexpensive alternative to traditional sequencing.

Oxidative Stress-Mediated Anticancer Activity Of Novel Ahr Modulators Af & 5f203, Lancelot S. Mclean

Loma Linda University Electronic Theses, Dissertations & Projects

Estrogen receptor positive (ER+) breast cancer tends to respond to anti-estrogen agents such as Tamoxifen. Approximately 40% of ER+ breast cancer is resistant to these agents and those that initially respond often acquire resistance. Estrogen receptor negative (ER-) breast cancer remains largely unresponsive to these agents. It is therefore vital to discover drugs that are potent in both forms of breast cancer. Aminoflavone, (5-amino-2, 3-fluorophenyl)-6,8-difluoro-7-methyl-4H-l-benzopyran-4-one; AF; NSC 686288) and 5F203, (2-[-Amino-3-methy phenyl]-5-flurobenzothiazole) are novel anticancer candidate agents that display potent in vitro and in vivo anti-proliferative activity against select human tumor cells with a unique anticancer activity profile in the …

Effect Of Short Exposure Of Naoci/Edta On E. Faecalis In Extracted Human Teeth, Rylan N. Gustafson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this project was to study the antibacterial effect of the short exposure of 5.25% NaOCl and 17% EDTA on eight strains of Enterococcus faecalis in extracted human teeth. The crowns of 240 single rooted teeth were removed and the canals were instrumented to ISO 0.36. The canals were irrigated with 5.25% NaOCl and 17% EDTA, autoclaved and separated into eight groups of 30 teeth consisting of 20 experimental teeth, 5 positive and 5 negative controls. Each group was inoculated with one of eight different strains of E. faecalis in BHl broth and incubated for four weeks. The …

Novel Binding Domains Mediate Binding Of Hpv 16 E6 To Fadd And Procaspase 8, Sandy S. Tungteakkhun

Loma Linda University Electronic Theses, Dissertations & Projects

To evade the host response to infection, viruses have developed means to survive and propagate. HPV 16, a causative agent of cervical cancer and of some cases of oropharyngeal cancers, is one example. We have reported that the early viral protein E6 binds to proteins necessary for propagation of the apoptotic signal following receptor/ligand interactions, such as those mediated by FADD DED and procaspase 8 DED. E6 expression leads to the dose-dependent accelerated degradation of FADD and the protection of E6-expressing cells from Fas-induced apoptosis. Surprisingly, the splice isoforms of E6, E6_large and E6*, affect the stability of procaspase …

Mechanisms Of T Helper Cell Modulation In A Simulated Space Radiation Environment, Asma Rizvi

Loma Linda University Electronic Theses, Dissertations & Projects

Exposure to solar particle events (SPEs) poses the most serious threat to astronaut health. Due to this radiation environment, exploration of the solar system beyond Earth’s orbit entails many risks for the crew on these deep space missions. Depression or dysfunction of the immune system is a major concern due to its high radio-sensitivity; potential consequences include overwhelming infection, development of cancer, fibrosis, and poor wound healing. Astronauts are also exposed to low dose/low dose rate (LDR) radiation. A three month stay at the international space station exposes them to ~ 0.05 Gy of radiation.

C57BL/6 mice received LDR gamma-radiation …

Candida Albicans Tup1 Is Involved In Farnesol-Mediated Inhibition Of Filamentous-Growth Induction, Bessie W. Kebaara, Melanie L. Langford, Dhammika H. M. L. P. Navarathna, Raluca Dumitru, Kenneth W. Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

Candida albicans is a dimorphic fungus that can interconvert between yeast and filamentous forms. Its ability to regulate morphogenesis is strongly correlated with virulence. Tup1, a transcriptional repressor, and the signaling molecule farnesol are both capable of negatively regulating the yeast to filamentous conversion. Based on this overlap in function, we tested the hypothesis that the cellular response to farnesol involves, in part, the activation of Tup1. Tup1 functions with the DNA binding proteins Nrg1 and Rfg1 as a transcription regulator to repress the expression of hypha-specific genes. The tup1/tup1 and nrg1/nrg1 mutants, but not the rfg1/rfg1 mutant, failed to …

Bacteriophages That Infect Bacillus Bacteria (Anthrax), Michael H. Walter

Patents (University of Northern Iowa)

The invention provides bacteriophages that infect Bacillus bacteria, including Bacillus anthracis, and compositions containing the bacteriophages. The invention also provides methods for using the bacteriophages of the invention to prevent and treat infection of an organism by Bacillus bacteria. Methods and materials to decontaminate a surface or an organism that is contaminated with Bacillus bacteria or Bacillus spores is also provided.

Analysis Of Cis-Elements That Facilitate Extrachromosomal Persistence Of Human Papillomavirus Genomes, Daraporn Pittayakhajonwut, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) are maintained latently in dividing epithelial cells as nuclear plasmids. Two virally encoded proteins, E1, a helicase, and E2, a transcription factor, are important players in replication and stable plasmid maintenance in host cells. Recent experiments in yeast have demonstrated that viral genomes retain replication and maintenance function independently of E1 and E2 [Angeletti, P.C., Kim, K., Fernandes, F.J., and Lambert, P.F. (2002). Stable replication of papillomavirus genomes in Saccharomyces cerevisiae. J. Virol. 76(7), 3350-8; Kim, K., Angeletti, P.C., Hassebroek, E.C., and Lambert, P.F. (2005). Identification of cis-acting elements that mediate the replication and maintenance of human …

Antigen Trafficking Within Chlamydia Trachomatis-Infected Polarized Human Endometrial Epithelial Cells., David Kelley Giles

Electronic Theses and Dissertations

Chlamydia trachomatis serovars D-K are the leading cause of bacterially-acquired sexually transmitted infections in the United States. As an obligate intracellular pathogen, C. trachomatis infects columnar epithelial cells of the genital mucosae and can cause deleterious sequelae such as pelvic inflammatory disease, infertility, and ectopic pregnancy. Several chlamydial antigens reach the host cell cytosol prior to the natural release of chlamydiae at the end of the developmental cycle. While some of these extra-inclusion antigens traffic to the host cell surface, others remain intracellular where they are proposed to influence vital host cell functions and antigen trafficking and presentation. The research …

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.

Recent Applications Of Chemical Imaging To Pharmaceutical Process Monitoring And Quality Control, A. A. Gowen, Colm O'Donnell, Patrick J. Cullen, S. Bell

Articles

Chemical Imaging (CI) is an emerging platform technology that integrates conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Vibrational spectroscopic methods, such as Near Infrared (NIR) and Raman spectroscopy, combined with imaging are particularly useful for analysis of biological/pharmaceutical forms. The rapid, non-destructive and non-invasive features of CI mark its potential suitability as a process analytical tool for the pharmaceutical industry, for both process monitoring and quality control in the many stages of drug production. This paper provides an overview of CI principles, instrumentation and analysis. Recent applications of Raman and NIR-CI to pharmaceutical …

Integration Host Factor Positively Regulates Virulence Gene Expression In Vibrio Cholerae, Emily Stonehouse, Gabriela Kovacikova, Ronald K. Taylor, Karen Skorupski

Dartmouth Scholarship

Virulence gene expression in Vibrio cholerae is dependent upon a complex transcriptional cascade that is influenced by both specific and global regulators in response to environmental stimuli. Here, we report that the global regulator integration host factor (IHF) positively affects virulence gene expression in V. cholerae. Inactivation of ihfA and ihfB, the genes encoding the IHF subunits, decreased the expression levels of the two main virulence factors tcpA and ctx and prevented toxin-coregulated pilus and cholera toxin production. IHF was found to directly bind to and bend the tcpA promoter region at an IHF consensus site centered at position 162 …

Escherichia Coli And Antibiotic Resistance To Tetracycline Antibiotics, Taylor L. Dodgen

Senior Honors Theses

Escherichia coli cells growing under ideal conditions are able to complete one reproduction cycle in as little as every twenty minutes. Since so many generations are able to be observed, one should theoretically be able to observe thousands of generations and determine evolution’s effects over a short period of time. In this experiment, E. coli K12 cells were cultured under ideal growth conditions but in the presence of antibiotics as a selective environmental stress in order to select for resistance. This was accomplished by serially passing colonies that were in close contact with two different, but similar antibiotics over a …

Porcine Reproductive And Respiratory Syndrome Virus Infects Mature Porcine Dendritic Cells And Up-Regulates Interleukin-10 Production, Lilian Flores-Mendoza, Erika Silva-Campa, Monica Resendiz, Fernando A. Osorio, Jesus Hernandez

Nebraska Center for Virology: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) infects mature dendritic cells (mDCs) derived from porcine monocytes and matured with lipopolysaccharide. The infection of mDCs induced apoptosis, reduced the expression of CD80/86 and major histocompatibility complex class II molecules, and increased the expression of interleukin-10, thus suggesting that such mDC modulation results in the impairment of T-cell activation.

Kaposi’S Sarcoma-Associated Herpesvirus Transactivator Rta Promotes Degradation Of The Repressors To Regulateviral Lytic Replication, Zhilong Yang, Zhangcai Yan, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) RTA is an important protein involved in the induction of KSHV lytic replication from latency through activation of the lytic cascade. A number of cellular and viral proteins, including K-RBP, have been found to repress RTA-mediated transactivation and KSHV lytic replication. However, it is unclear as to how RTA overcomes the suppression during lytic reactivation. In this study, we found that RTA can induce K-RBP degradation through the ubiquitinproteasome pathway and that two regions in RTA are responsible. Moreover, we found that RTA can promote the degradation of several other RTA repressors. RTA mutants …

Chlorella Viruses Evoke A Rapid Release Of K+ From Host Cells During The Early Phase Of Infection, Monika Neupartl, Christine Meyer, Isabell Woll, Florian Frohns, Ming Kang, James L. Van Etten, Detlef Kramer, Brigitte Hertel, Anna Moroni, Gerhard Thiel

Nebraska Center for Virology: Faculty Publications

Infection of Chlorella NC64A cells by PBCV-1 produces a rapid depolarization of the host probably by incorporation of a viral-encoded K⁺ channel (Kcv) into the host membrane. To examine the effect of an elevated conductance, we monitored the virus-stimulated efflux of K⁺ from the Chlorella cells. The results indicate that all 8 Chlorella viruses tested evoked a host specific K⁺ efflux with a concomitant decrease in the intracellular K⁺. This K⁺ efflux is partially reduced by blockers of the Kcv channel. Qualitatively these results support the hypothesis that depolarization and K⁺ efflux are …

Louis Pasteur’S Views On Creation, Evolution, And The Genesis Of Germs, Alan L. Gillen, Frank Sherwin

Faculty Publications and Presentations

“There is no remembrance of men of old, and even those who are yet to come will not be remembered by those who follow.” Ecclesiastes 1:11 (NIV)

In past years revisionist historians have been rewriting the worldview of Christians who have made some of the major discoveries in biology and medicine. It appears that postmodern revisionists are rewriting history to support their agenda of a more “secular” explanation to science. The Judeo-Christian worldview is not politically correct in most universities. This is true in regard to past scientists such as Louis Pasteur who believed in creation. According to reliable, primary …

Isolation And Characterization Of Vibrio Tubiashii Outer Membrane Proteins And Determination Of A Toxr Homolog, Broderick Eribo

Department of Biology Faculty Publications

Outer membrane proteins (OMPs) expressed by Vibrio tubiashii under different environmental growth conditions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and PCR analyses. Results showed the presence of a 38- to 40-kDa OmpU-like protein and ompU gene, a maltoporin-like protein, several novel OMPs, and a regulatory toxR homolog.

Mutual Inhibition Between Kaposi’S Sarcoma-Associated Herpesvirus And Epstein-Barr Virus Lytic Replication Initiators In Dually-Infected Primary Effusion Lymphoma, Yanjun Jiang, Dongsheng Xu, Yong Zhao, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Background: Both Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) are members of the human gamma herpesvirus family: each is associated with various human cancers. The majority of AIDS-associated primary effusion lymphoma (PEL) are co-infected with both KSHV and EBV. Dually-infected PELs selectively switch from latency to lytic replication of either KSHV or EBV in response to chemical stimuli. KSHV replication and transcription activator (K-RTA) is necessary and sufficient for the switch from KSHV latency to lytic replication, while EBV BZLF1 gene product (EBV-Z) is a critical initiator for induction of EBV lytic replication.

Methodology/Principal Findings: We show K-RTA and …

Precipitating Factors Of Hepatic Encephalopathy In Patients With Chronic Liver Disease At Civil Hospital Karachi, Dileep K Rohra, Jaipal, Ameer A Khowaja, Khalid Mahmood, Kanya Lal Ahuja

Department of Biological & Biomedical Sciences

No abstract provided.

Hsp40 Facilitates Nuclear Import Of The Human Immunodeficiency Virus Type 2 Vpx-Mediated Preintegration Complex, Xiaogang Cheng, Michael Belshan, Lee Ratner

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 2 (HIV-2) Vpx is required for nuclear translocation of the viral preintegration complex (PIC) in quiescent cells. In order to decipher the mechanism of action of Vpx, a cDNA library was screened with the yeast two-hybrid assay, resulting in the identification of heat shock protein 40, Hsp40/DnaJB6, as a Vpx-interactive protein. Interaction with Vpx was confirmed by glutathione S-transferase (GST) pull-down and coimmunoprecipitation assays. Overexpression of Hsp40/DnaJB6 enhanced Vpx nuclear import, whereas overexpression of a nuclear localization mutant of Hsp40/DnaJB6 (H31Q) or down-regulation of Hsp40/DnaJB6 by small interfering RNA (siRNA) reduced the nuclear import of Vpx. …