Microbiology Commons^™

An Investigation Of The Subtype Diversity Of Clinical Isolates Of Irish Clostridium Difficile Ribotypes 027 And 078 By Repetitive-Extragenic Palindromic Pcr, Denise Drudy, K. Solomon, S. Murray, L. Scott, S. Mcdermott,, A. Martin, C. O’Donoghue, M. Skally, K. Burns, L. Fenelon, F. Fitzpatrick,, L. Kyne, S. Fanning

Articles

A repetitive-extragenic palindromic PCR (rep-PCR) subtyping method (DiversiLab) in conjunction with ribotyping, toxinotyping and antimicrobial-susceptibility testing was used to detect subtypes within Clostridium difficile ribotypes 027 and 078. Clinical isolates of ribotypes 027 (toxinotype III) (n530) and 078 (toxinotype V) (n523) were provided by health-care facilities across the Republic of Ireland over 2 months in 2006 and 1 month in 2009. Ribotype 027 isolates were significantly more related to each other (9 different subtype profiles) when compared to ribotype 078 isolates (14 different profiles) (P50.001; cut-off .90 % similarity). Almost half of ribotype 078 isolates (45.5 %) showed no relationship …

Robust Rnai-Based Resistance To Mixed Infection Of Three Viruses In Soybean Plants Expressing Separate Short Hairpins From A Single Transgene, Xiuchun Zhang, Shirley Sato, Xiaohong Ye, Anne E. Dorrance, Thomas Jack Morris, Thomas E. Clemente, Feng Qu

Nebraska Center for Virology: Faculty Publications

Transgenic plants expressing double-stranded RNA (dsRNA) of virus

origin have been previously shown to confer resistance to virus infections

through the highly conserved RNA-targeting process termed RNA silencing

or RNA interference (RNAi). In this study we applied this strategy to

soybean plants and achieved robust resistance to multiple viruses with a

single dsRNA-expressing transgene. Unlike previous reports that relied

on the expression of one long inverted repeat (IR) combining sequences

of several viruses, our improved strategy utilized a transgene designed to

express several shorter IRs. Each of these short IRs contains highly conserved

sequences of one virus, forming dsRNA of …

The Zambia Children's Ks-Hhv8 Study: Rationale, Study Design, And Study Methods, Veenu Minhas, Kay L. Crabtree, Ann Chao, Janet M. Wojcicki, Adrian M. Sifuniso, Catherine Nkonde, Chipepo Kankasa, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

The epidemic of human immunodeficiency virus in Zambia has led to a dramatic rise in the incidence of human herpesvirus-8 (HHV-8)–associated Kaposi's sarcoma in both adults and children. However, there is a paucity of knowledge about the routes of HHV-8 transmission to young children. The Zambia Children's KS-HHV8 Study, a large, prospective cohort study in Lusaka, Zambia, was launched in 2004 to investigate the role of household members as a source of HHV-8 infection in young children and social behaviors that may modify the risk of HHV-8 acquisition. This cohort is distinct from other epidemiologic studies designed to investigate HHV-8 …

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 im- munocompetent BALB/c mice. Mice immunized with first-generation Ad5 expressing …

Species D Adenoviruses As Oncolytics Against B-Cell Cancers, Christopher Y. Chen, Julien S. Senac, Eric A. Weaver, Shannon M. May, Diane F. Jelinek, Philip Greipp, Thomas Witzig, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Purpose: Oncolytic viruses are self-amplifying anticancer agents that make use of the natural ability of viruses to kill cells. Adenovirus serotype 5 (Ad5) has been extensively tested against solid cancers, but less so against B-cell cancers because these cells do not generally express the coxsackie and adenoviral receptor (CAR). To determine whether other adenoviruses might have better potency, we "mined" the adenovirus virome of 55 serotypes for viruses that could kill B-cell cancers.

Experimental Design: Fifteen adenoviruses selected to represent Ad species B, C, D, E, and F were tested in vitro against cell lines and primary patient B-cell cancers …

Tetherin Inhibits Prototypic Foamy Virus Release, Fengwen Xu, Juan Tan, Ruikang Liu, Dan Xu, Yue Li, Yunqi Geng, Chen Liang, Wentao Qiao

Nebraska Center for Virology: Faculty Publications

Background: Tetherin (also known as BST-2, CD317, and HM1.24) is an interferon- induced protein that blocks the release of a variety of enveloped viruses, such as retroviruses, filoviruses and herpesviruses. However, the relationship between tetherin and foamy viruses has not been clearly demonstrated.

Results: In this study, we found that tetherin of human, simian, bovine or canine origin inhibits the production of infectious prototypic foamy virus (PFV). The inhibition of PFV by human tetherin is counteracted by human immunodeficiency virus type 1 (HIV-1) Vpu. Furthermore, we generated human tetherin transmembrane domain deletion mutant (delTM), glycosyl phosphatidylinositol (GPI) anchor …

Western Australia's Biosecurity, Department Of Agriculture And Food, Western Australia, Department Of Environment And Conservation, Western Australia, Department Of Fisheries, Western Australia, Forest Products Commission, Western Australia

Biosecurity published reports

Biosecurity is the protection of the economy, environment and human health from the negative impacts of pests, weeds and diseases, including the management of invasive species if they become established (definition adopted by AusBIOSEC).

This requires steps to prevent the entry of harmful organisms, as well as the timely and efficient management of them if they do enter.

Biosecurity threats range from catastrophic diseases such as Foot and Mouth Disease, which causes rapid and widespread animal deaths, to more subtle and slower spreading problems such as invasive weeds, mussels that foul vessel hulls and fungus-induced dieback disease of trees. These …

Mechanisms Of Adenovirus Membrane Permeabilization, Oana Maier

Dissertations

For a successful infection to occur, a virus must first penetrate host cell membranes to access intracellular sites of viral replication. Currently the mechanism through which adenovirus, a non-enveloped, dsDNA virus, disrupts the endosomal membrane during cell entry is not well characterized.

Recent studies suggest that adenovirus protein VI, which is released from the interior of the capsid during cell entry, has all of the in vitro membrane lytic activity of the virion. We found that protein VI binds membranes via an amino-terminal 80 residue α-helical domain. Critical to this interaction are conserved hydrophobic and basic lysine residues within this …

Cofactors In Coronavirus Entry, Ana Shulla

Dissertations

Viruses have evolved complex ways to penetrate host barriers and cause disease. One of the most important barriers the virus has to cross is the cellular membrane. Enveloped viruses accomplish this task by viral glycoprotein-mediated binding to host cells and fusion of virus and host cell membranes. For the coronaviruses, viral spike (S) proteins execute these cell entry functions. In my dissertation research I focused on understanding the coronavirus spike proteins as well as other cofactors required for S-mediated entry into cells.

The S proteins are set apart from other viral and cellular membrane fusion proteins by their extensively palmitoylated …

Analysis Of Risk Factors Associated With Asymptomatic Colonization Of Methicillin Resistant Staphylococcus Aureus (Mrsa) Among Community College Students, Marilynn Kish-Molina

Walden Dissertations and Doctoral Studies

The bacterium Staphylococcus aureus has been an important human ailment for centuries, and with the overuse of antibiotics, methicillin resistant Staphylococcus aureus (MRSA) has emerged as a deadly, costly pathogen worldwide. Healthy carriers can become sick or can spread MRSA without symptoms. The amount of asymptomatic colonization among healthy college students and risk factors for colonization by MRSA are not well understood. According to the epidemiologic triangle model, the host (students who take antibiotics or have a history of skin infections), the infectious agent (MRSA) and the environment (direct contact with people, animals, or objects that may harbor MRSA) all …

Optimization Of Application Of Delactosed Whey Permeate Treatment To Extend The Shelf-Life Of Fresh Cut Tomato Using Response Surface Methodology., Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan

Articles

Optimization of delactosed whey permeate (DWP) treatment for fresh-cut tomato was accomplished by evaluating different quality, nutritional and microbial markers. Response surface methodology was applied to obtain polynomial model equations. DWP concentration (0 - 5 %) and storage (0 - 10 days) were used as independent factors in order to optimize the process. The analyses showed that increases in DWP concentration extended the quality of the fresh-cut tomato significantly (p3 % were scored unacceptable by the sensory panel due to perceived off-odours. DWP treatment also improved retention of ascorbic acid and lycopene over storage. The total aerobic counts and yeast …

Modulation Of Alpha-Subunit Visit-Dg Sequence Residues Ser-347, Gly-351 And Thr-349 In The Catalytic Sites Of Escherichia Coli Atp Synthase., Laura Elaine Brudecki

Electronic Theses and Dissertations

Binding of inorganic phosphate (P_i) in ATP synthase catalytic sites is a crucial step for the synthesis of adenosine-5'-triphosphate (ATP). ATP is the fundamental means of cellular energy in almost every organism, and in order to gain insight into the regulation of ATP catalysis, critical amino acid residues responsible for binding P_i must be identified. Here, we investigate the role of highly conserved α-subunit VISIT-DG sequence residues αSer-347, αGly-351, and αThr-349 in P_i binding. Mutations αS347A/Q, αG351Q, αT349A/D/R, βR182A, and αT349R/βR182A were generated via site directed mutagenesis. Results from biochemical assays showed that αSer-347 is required …

Discovery And Characterization Of An Antibiotic From The Soil Bacterium Bacillus Sp., Thomas S. Barber

Electronic Theses and Dissertations

Many important antibiotics have become nearly obsolete due to the rise of antibiotic resistant pathogens. Rhodococcus, an actinomycete related to the prolific antibiotic producing genus Streptomyces, harbors over 30 genes for secondary metabolism that could be involved in antibiotic production. Several antibiotics have already been reported for Rhodococcus, suggesting the genus may be a good source for new inhibitory compounds. Fifty four soil bacteria were isolated using enrichment culture techniques (including 37 Rhodococcus) and screened for antibiotic producers. BTHX2, a species of Bacillus was found to have activity against Micrococcus luteus and Rhodococcus erythropolis. BTHX2 …

H-Ns Binding And Repression Of The Ctx Promoter In Vibrio Cholerae, Emily A. Stonehouse, Robin R. Hulbert, Melinda B. Nye, Karen Skorupski, Ronald K. Taylor

Dartmouth Scholarship

Expression of the ctx and tcp genes, which encode cholera toxin and the toxin coregulated pilus, the Vibrio cholerae O1 virulence determinants having the largest contribution to cholera disease, is repressed by the nucleoid-associated protein H-NS and activated by the AraC-like transcriptional regulator ToxT. To elucidate the molecular mechanism by which H-NS controls transcription of the ctxAB operon, H-NS repression and binding were characterized by using a promoter truncation series, gel mobility shift assays, and DNase I footprinting. Promoter regions found to be important for H-NS repression correlated with in vitro binding. Four main H-NS binding regions are present at …

Campylobacter Ureolyticus: An Emerging Gastrointestinal Pathogen?, Susan Bullman, Daniel Corcoran, James O'Leary, Brigid Lucey, Deirdre Byrne, Roy D. Sleator

Department of Biological Sciences Publications

A total of 7194 faecal samples collected over a 1-year period from patients presenting with diarrhoea were screened for Campylobacter spp. using EntericBios, a multiplex-PCR system. Of 349 Campylobacter-positive samples, 23.8% were shown to be Campylobacter ureolyticus, using a combination of 16S rRNA gene analysis and highly specific primers targeting the HSP60 gene of this organism. This is, to the best of our knowledge, the first report of C. ureolyticus in the faeces of patients presenting with gastroenteritis and may suggest a role for this organism as an emerging enteric pathogen.

Ultraviolet Light As An Adjunct Treatment To Pasteurization For Microbial Reduction In Milk Intended For Extended Shelf Life, Jacob Zonneveld

Dairy Science

The objective of this study was to determine whether ultraviolet light treatment of milk could be used in adjunct with pasteurization and to determine whether the microbial count in bulk tank raw milk was sufficient enough to receive significant results. Samples were collected from a bulk tank filled with 1600 gallons of raw Holstein and Jersey milk from the Cal Poly Dairy throughout the course of a week. Control (library) samples were also taken from the raw milk tank and stored without air or agitation for comparison. These samples were plated each day and examined 24 and 48 hours after …

Analysis Of The Clear Plaque Phenotype Of The Bacteriophage Hk75, Phani Chandrika Kunapuli

Masters Theses & Specialist Projects

The growth of bacteriophage HK75 is inhibited by specific mutations in the zinc binding domain of the host RNA polymerase beta prime subunit. It shares this rare property with bacteriophage HK022 and other phages that use RNA mediated antitermination to promote early gene expression. Recent genomic analysis of HK75 and HK022 has confirmed the relatedness of these two phages and place HK75 in the lambdoid family of bacteriophages. Lambdoid phages are temperate and can adopt a lytic or lysogenic lifestyle upon infection of a suitable host. However, HK75 only forms clear plaques and thus appears to be defective in its …

Maporal Hantavirus Β-Integrin Utilization And Sensitivity To Favipiravir, Kristin K. Buys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hantaviruses are members of the Bunyaviridae family of viruses. Pathogenic hantaviruses are the etiologic agents of hemorrhagic fever with renal syndrome (HFRS), a disease principally endemic in the Old World, and hantavirus pulmonary syndrome (HPS), a disease primarily restricted to the Americas. Maporal virus (MPRLV), a recently isolated hantavirus, has been found to cause disease in hamsters that resembles HPS in humans. However, the virus has not been linked to human cases of HPS. Considerable evidence suggests that β-integrin usage mediating infection may serve to distinguish hantaviruses pathogenic to humans from nonpathogenic, but this receptor usage pattern information is not …

Kinetic, Mechanistic, And Structural Investigation Of Features Controlling Stereoselectivity Of (R)- And (S)-Hydroxypropyl Com Dehydrogenases From Xanthobacter Autrophicus Strain Py2, Dariusz Adam Sliwa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enantiopure alcohols are valuable intermediates in fine organic synthesis, in particular for preparation of biologically active compounds. The necessity of preparing single enantiomer drugs in an optically pure form has triggered much research, especially in the pharmaceutical industry. The biocatalytical production of chiral alcohols by alcohol dehydrogenase enzymes is characterized by the asymmetric reduction of the corresponding ketones, usually with high degree of stereoselectivity. The commercial value of the enzymes as stereoselective biocatalysts has been a significant driving force in understanding features that control their mechanism of catalysis and stereoselectivity. This work focuses on two enantiocomplementary dehydrogenase enzymes ((R …

Two-Phase Partitioning System Using Elvax 40w Polymer For The Biodegradation Of Aqueous Phenols, Amit Suresh Ghode

Masters Theses & Specialist Projects

A solid-liquid two phase partitioning system (TPPS) is a new technology platform for destroying toxic organic compounds. TPPS have traditionally been operated by using an immiscible organic phase which partitions organic compounds into the aqueous phase. TPPS using an immiscible organic phase suffers from several limitations such as the organic phase could be biodegradable and hence only certain compatible microbial strains could be used. This therefore, eliminates the desired use of mixed microbial populations for efficient degradation. A solid-liquid two phase partitioning system, in which solid polymeric beads replace liquid organic phase, appears to have benefits over the traditional liquid-liquid …