Fish, asymptomatically infected with Enteric Redmouth
Bacterium (ERMB), were tested for their ability to transmit
bacteria to non-infected fish. Unstressed carrier fish
were unable to transmit enough bacteria to cause
epizootics or produce carrier fish. However, when the
ERMB carriers were stressed with heat, sufficient bacteria
were shed to infect...
A laboratory-prepared hot-water extract of yeast is required
for vigorous growth of San Francisco sourdough bacteria (Lactobacillus
sanfrancisco) in pure culture. This requirement was examined
with the goal of determining what is unique about fresh yeast extractives
(commercial extractives exhibit much lower growth promoting
activity), and which components of fresh...
The myxozoan Ceratonova shasta is an intestinal parasite of salmon and trout that causes ceratomyxosis, a disease characterized by severe inflammation of the intestine that can lead to hemorrhaging, necrosis, and death of the fish host. The parasite is endemic to the Pacific Northwest of the United States and Canada,...
Corals have multiple roles in maintaining ocean health and are some of the world’s most diverse ecosystems. The coral animal is host to a multitude of taxa, including symbiotic dinoflagellate algae, fungi, bacteria, protists, and viruses. Environmental stressors and disease agents can perturb the delicate balance of the coral host...
Purpose: To compare target dose conformality and OAR sparing afforded by VMAT and HT for pancreatic cancer.
Materials and Methods: A retrospective planning study was performed in 18 patients. Total treatment dose was 59.4Gy. OAR and PTV mean doses, conformity indices, isodose volumes, and integral doses were compared. The relationship...
The vitamin B₁₂ concentrations in both the water and sediments
of Klamath Lake were found to vary significantly during a
one-year period. The patterns of B₁₂ distribution were remarkably
similar among the three main sites. In all cases there was an extremely
sharp gradation in concentration in relation to depth...
An interactive map of important watersheds in the United States was created for use as a teaching tool in an estuarine ecology class. Figures and explanations of important factors influencing river ecology were created using data downloaded from the U.S. Geologic Survey. This interface serves as a visualization of biological,...
The occurrence and distribution of fish viruses in Oregon were
determined by the examination of anadromous and fresh water salmonids.
Infectious pancreatic necrosis virus (IPNV) was isolated and
identified from asymptomatic adult coho (Oncorhynchus kisutch) and
chinook (0. tshawytscha) salmon returning to the Columbia River
system. Infectious pancreatic necrosis virus...
Selected secreted and cellular virulence factors of Aeromonas
salmonicida were examined. A protocol was developed for the
separation of two secreted proteases (P1 and P2 protease), and
a trout erythrocyte specific hemolysin (T-lysin) from
supernatants of cultures of the bacterium. Distinctions between
the proteases were demonstrated using molecular weight
determinations,...
The development of an effective infectious
hematopoietic necrosis virus (IHNV) vaccine depends on a
better understanding of the antigenic structure and
variation among isolates. Three objectives to elucidate
this were: (1) to generate a panel of antigenic
derivatives of the IHNV glycoprotein by monoclonal
antibody-mediated selection of neutralization-resistant
variant viruses,...
Coral reefs are diverse ecosystems and serve many purposes including preventing erosion on coastlines and acting as a source of food, income, and culture. Acropora cervicornis, a staghorn coral, has faced a significant 80-89% decline in the Caribbean, attributed to a poorly-characterized epizootic, White Band Disease (WBD). Previous studies showed...
Although IL-4 is a well-characterized multi-functional cytokine, its role as a survival factor in T cells is not completely understood. In an attempt to uncover IL-4-mediated survival, we studied caspase activation in primary mouse T lymphocytes undergoing death by neglect, activation-induced or steroid-induced cell death. Here, we identify the executioner...
Some positive-strand RNA plant viruses possess a transfer RNA-like structure (TLS) at the 3'-terminus of their genomic RNAs. The closest mimicry to tRNA is exhibited by the valylatable TLSs from tymoviruses and furo-like viruses, which are able to interact with key cellular tRNA enzymes: [CTP, ATP]:tRNA nucleotidyltransferase (CCA NTase), valyl-tRNA...
Disseminated neoplasia (DN) is a proliferative cell disorder that occurs in the
circulatory system of bivalves. The condition is progressive and lethal. At least 15
species of bivalves over a wide range of geographic locations have been reported to
contract DN. Prevalence levels of disseminated neoplasia can reach up to...
In this thesis, I studied the translation of dengue virus RNA using a luciferase reporter gene system in Vero cells. The dengue reporter mRNA construct, which harbors 5´-terminal viral nts and 3´-terminal nts, could be translated efficiently compared to an alpha globin reporter construct. The 5´-cap structure and 3´-untranslated region...
Agrobacterium tumefaciens, the causative agent of crown gall
disease, does not readily infect commercial varieties of alfalfa (Medicago sativa). Cloned virulence genes from the megaplasmid pTiBo542 have
been shown to enhance Agrobacterium host range and infectivity on
dicotyledonous plants. To obtain a gene transfer system for commercial
alfalfa cultivars, an...
Nitrification is the process within the global Nitrogen Cycle where ammonia (NH3) is oxidized to nitrate (NO₃⁻) and can be carried out by two distinct groups of bacteria. The ammonia-oxidizing bacteria (AOB) first oxidize NH₃ to nitrite (NO₂⁻), and second, the nitrite-oxidizing bacteria (NOB) oxidize NO₂⁻ to NO₃⁻. In aerobic...
In most environments, ammonia (NH₃) is oxidized to nitrate (NO₃⁻) via the intermediate nitrite (NO₂⁻). This is a microbe-driven process involving phylogenetically distinct types of microorganisms, namely, ammonia-oxidizing bacteria (AOB) and Thaumarchaea (AOA), and nitrite-oxidizing bacteria (NOB). Nitrosomonas europaea and Nitrobacter winogradskyi are the best studied AOB and NOB, respectively,...
The transcriptional promoter sequences for the Rhizobium meliloti
nitrogen fixation genes nifA and nifB were cloned to a β-galactosidase gene
fusion plasmid vector and transferred by homologous recombination to a
specialized transducing phage. The promoter fusions were then transduced
to a recombination deficient strain of Escherichia coli as single-copy
lysogens...
Seed germination is strictly defined as the physiological events before radicle
protrusion through the endosperm cap, the endosperm region adjacent to the radicle tip.
There are two opposing forces governing seed germination: the growth potential of the
embryo and the mechanical resistance of the endosperm cap. The endosperm cap cell...
We have used the sequence-specific endonucleases Eco RI, Sma I,
Bam HI, Hsu I and Hae III as identification tools in following the
conjugal transfer of the well studied R plasmids Sa, R388, RP4 and R6K.
Transfers were both intergenus and intragenus. Plasmid fingerprints
were generated from both single and...
From the formation of reservations, Native Americans have faced many
difficulties and continue to deal with cultural barriers today. Particularly within a medical
setting, there is a worldview disconnect between western medicine and traditional Native
healing. It would be useful to interview Native pupils to learn about their uses of...
Three isolates of Escherichia coli were labeled by their resistance
to sodium azide and, separately, to novobiocin, nalidix acid, and tetracycline.
The strains exhibited a high degree of persistence in the soil
environment and were recoverable on strain specific media at levels
within the 95% confidence interval of the numbers...
In this study of toxigenic and non-toxigenic strains of Clostridium
botulinum type E, attempts were made to induce toxin production
in non-toxigenic cultures by exposure to mutagenic agents
and to differentiate the organisms by immunodiffusion. First, cultures
of non-toxic Cl. botulinum type E were exposed to various
mutagenic agents in...
Vibrio marinus MP-1, an obligate psychrophilic marine
bacterium, was severely damaged when heat-shocked in the presence
of nutrients. Thermally induced leakage materials from cells tested
for in the medium were 260 mμ absorbing material (nucleic acids),
orcinol reacting material (RNA), ninhydrin reacting material (amino
acids), protein, malic dehydrogenase, and glucose-6-phosphate...
Some enzymes of the citric acid cycle and glycolytic pathway
in cell-free extracts of Vibrio marinus MP-1 were compared for
thermal lability. After one hour of moderate temperature exposure,
enzymes of both pathways rapidly lost catalytic activity. For all
but one enzyme, 50 percent remaining activity occurred near an
averaged...
Marine mammals are top predators that are essential for the health and function of our oceans. These top predators are often affected by various factors that can be detrimental to their populations. Therefore, there is a need to evaluate undetermined causes of deaths and to better understand known diseases in...
The Hawai’i County Band is based in Hilo, Hawai’i and was founded in 1883 by brothers Joaquin and Jules Carvalho. After the Kingdom of Hawai’i was overthrown in 1893, the band became known as the Hilo Portuguese Band and after the United States made Hawai’i a territory, the band became...
The terminal reactions in the biosynthetic pathway of methionine
in Saccharomyces cerevisiae were investigated in this study. Analyses
of a number of methionine auxotrophs for biochemical deficiences
established four mutant groups. It was observed from qualitative feeding
experiments that some auxotrophs were able to utilize S-adenosylmethionine
(AM) and S-adenosyl-homocysteine (AH)...
Pseudomonas aeruginosa is a ubiquitous environmental microbe, opportunistic pathogen, and a highly social organism. P. aeruginosa utilizes a wide array of cooperative behaviors to adapt to the environmental conditions around it. These behaviors include quorum sensing (QS), a form a cell-to-cell signaling that coordinates the expression of secreted products in...
The purpose of this research was to determine whether the transducing phage Pl picks up original bacterial chromosome segments and whether these segments are always the same size. The plan of approach was to grow the donor bacteria Escherichia coli C600 gal⁺ (galactose) in minimal media containing the heavy isotopes...
Previous studies of six Oregon public water supply systems revealed that greater proportions of the standard plate count (SPC) bacteria from distribution waters were multiple antibiotic resistant (MAR) compared to isolates from the corresponding source raw waters. In the present study, two of these water systems were examined further to...
Streptomycin resistance in both gram-positive and gram-negative bacteria is usually caused by a single mutation in the rpsL gene. The rpsL gene encodes the S12 protein of the ribosomal complex. The rpsL genes of various bacteria have consensus regions in their sequences. Primers were designed from these consensus pockets and...
The myxozoan parasite Ceratonova shasta threatens both juvenile and adult salmonid populations in the Pacific Northwest region of the United States, causing intestine necrosis and hemorrhaging, along with high mortality in some fish strains. It induces an inflammatory tissue response in susceptible strains of fish; understanding the interactions between C....
Bacterial contamination of food poses a great risk to human health worldwide. A
chromatophore cell-based biosensor, utilizing B. splendens erythrophore cells, is an
emerging technology that has shown potential to detect bacterial toxicity based on
function-dependent mechanisms. Previous studies have investigated the response of
erythrophore cells to foodborne pathogens, pesticides,...
An enzyme system was prepared from Saccharomyces cerevisiae,
strain MCC, which carries out the transfer of the methyl group from
S-adenosylmethionine or methionine to the side chain of yeast sterols.
The cell-free system has been shown to be incapable of synthesizing
ergosterol but carries out the synthesis of two as...
T cells are one of the key cells in the immune system. Although they are not the first line of defense against a pathogen, their functions can greatly enhance the phagocytosis and destruction of pathogens as well as the development of antibody responses. Furthermore, even when responding T cells have...
The majority of our modern understanding of bacterial pathogenesis is based on the strategy that involves screening bacterial genomes for the presence of the genes encoding pathogenic factors, and analysis of these genes via forward and reverse genetics. Chlamydiae represent a unique group of pathogenic bacteria in which it is...
RNA silencing plays a critical role in plant defense against viral infection. Plants use virusderived
small interfering RNA to target and silence invading viruses. The antiviral silencing
pathway can be broken down into three conceptual stages: initiation, amplification, and systemic
movement. The molecular mechanisms of silencing initiation are not well...
Salmonella is a bacterium responsible for several illnesses, including typhoid fever,
paratyphoid fever, and salmonellosis. It is commonly found in animal products, including
poultry. Determination of potential reservoirs of Salmonella contamination is important
to mitigate the risk of transmission and possible outbreaks. Outbreaks can negatively
impact the livelihood of local...
This study examined the effects of Roundup
[N-(phosphonomethyl) glycine] and N-Serve [2-chloro-6-
(trichloromethyl) pyridine] on nitrifying organisms in
static batch, perfusion soil columns, and a new continuous-flow
soil column system. The continuous-flow method is new
to nitrification studies and was shown to produce greater
nitrifier activity than either static batch...
Vaccinia virus gene expression is characterized by tight temporal
regulation. Viral early transcription begins within the cytoplasm upon
infection; three hours later, early genes are repressed, DNA replication
occurs and late gene expression commences. As an approach toward
understanding the mechanisms governing vaccinia late gene expression,
I have undertaken an...
Science is difficult for even its researchers to understand. Science journalists must understand scientific discoveries well enough to write clear, accurate explanations of scientific discoveries for laypeople. A sense of ethical judgment will help journalists ensure that their accounts are reliable and appropriate. Responsible science journalists will maintain a working...
The Oregon sockeye salmon virus (OSV) was isolated from
diseased sockeye salmon (Oncorhynchus nerka) fingerlings in 1958
by J. L. Fryer. Experimentation performed prior to the research
reported herein indicated that the OSV contained essential lipids, was
100 to 300 mμ in size, and possessed RNA (presumptively identified
by 5-bromodeoxyuridine...
Since the isolation of the Oregon sockeye salmon virus (OSV) in
1958, extensive investigations have been undertaken to characterize
the properties of this virus. The results of these investigations
have indicated that OSV is a single-stranded RNA virus which contains
essential lipids and has a density of 1.16 gm/cm³ in...
Prevailing concepts relating to the non-enzymatic gaseous
loss of nitrite from soil are thought to be inadequate as regards
to the mechanisms involved. The conventional explanation for
nitric oxide formation i.e., the acid decomposition of nitrite,
is held to be insufficient in substrates of only mild or slight
acidity. A...
Mycobacterium avium subspecies hominissuis (MAH) is an opportunistic pathogen that is ubiquitous in the environment and often isolated from faucets and showerheads. MAH mostly infects humans with an underlying disease, such as chronic pulmonary disorder (COPD), cystic fibrosis (CF), or are immunocompromised, though infections in patients without concurrent disease are...
The primary purpose of this investigation was to characterize
the lipids of the spores and vegetative cells of Cl. botulinum. A
second purpose was to explore the possibility that lipids might serve
as a means of differentiating the chiefly proteolytic Cl. botulinum
type B from the nonproteolytic Cl. botulinum types...
The Oregon strain of the agent of infectious hematopoietic necrosis (IHN) was isolated from fingerling sockeye salmon (Oncorhynchus nerka) by J. L. Fryer in 1958. Before the study reported herein no other virus had been recovered from any fish population in Oregon. Therefore, in July, 1971 a survey was initiated...
Myxozoa have been found worldwide; these parasites infect a wide variety of hosts, but have been found most often in fish. Carassius auratus (goldfish), a popular aquarium fish and a widespread invasive species, have been identified as an intermediate host for several myxozoan species. Some myxozoan parasites are pathogenic and...
Trypticase-Soy Broth (TSB) was inoculated with Streptococcus
diacetilactis, incubated at 21C for 24 hours and centrifuged to remove
the cells. When the spent TSB was inoculated with Staphylococcus
aureus, it allowed 99.8% less growth than fresh TSB. If the spent
TSB were supplemented with 0.08 μg/ml of niacinamide, this inhibition...
Biotic and abiotic processes at continent-ocean interfaces cycle a disproportionate mass of carbon and nutrients relative to their global surface area, and microbial activity is a principal determinant of organic and inorganic matter flux in these transition zones. Most studies using modern high-throughput ‘omics techniques to link microorganisms with costal...
Environmental swabs and meat samples from two of three seafood
processing plants sampled on the Oregon Coast were found to
contain Salmonella. Although these enteropathogens were not isolated
from the finished products, the danger of contamination is great
since the processing received by many seafoods is not designed to
yield...
Ten helminth-free sheep were given two doses of 10,000,
X-irradiated, H. contortus, third stage larvae 30 days apart. These
animals and a group of ten non-vaccinated sheep were challenged
with 50,000, normal, H. contortus, third stage larvae 60 days
following the second vaccination. Antibody levels were measured
in both groups...
The lagoons spanning Alaska’s Beaufort Sea coast provide a unique habitat for arctic wildlife. These lagoons and the food webs they support face extreme seasonality with nine months of ice cover followed by a spring thaw that pulses a large amount of freshwater and nutrients into the lagoons. Bacteria link...
Ceratonova shasta is a myxozoan parasite that affects populations of salmonid species in the Pacific Northwest and is the cause of enteronecrosis. It has a complex life cycle involving two hosts; a definitive annelid host, Manayunkia speciosa (polychaete), and an intermediate salmonid host. Klamath River M. speciosa are genetically variable...
Cooperative behaviors in bacteria are increasingly appreciated for their relevance to microbial ecology and utility as model systems for social evolution. One example is the secretion of siderophores, a structurally diverse group of compounds that chelate extracellular iron. Siderophore production is considered cooperative because the benefits can be shared with...
Methylthioadenosine (MTA) is a naturally occuring nucleoside formed during
the synthesis of polyamines in mammalian cells. MTA is rapidly catabolised
by MTA phosphorylase (MTAase), eventually yielding methionine and
adenine. MTAase has been shown to be active in all normal cells, but
deficient in some cells and tissues of malignant origin....
The modern world has presented many threats to the health and stability of ecosystems worldwide. One of the most biodiverse ecosystems, coral reefs, faces particularly strong pressures, and is already declining rapidly in complexity and area. Although the stressors that affect reefs are diverse, ranging from nutrient pollution to overfishing,...
Using X-ray computed tomography (CT) scanning to characterize the physical characteristics of soil and sediment cores allows scientists to observe and analyze stratigraphy without destroying the integrity of different layers. Microbiologists often work with geologists to characterize the microbial communities in such cores; however, X-rays are known to be destructive...
Aging is a complex biological phenomenon that alters many different physiological processes. Although many age-related phenotypes, such as neurodegeneration, weakening circadian rhythms, and inflammaging, are well-studied, the links between them are not. To elucidate these links we created an inflammation-like state in Drosophila melanogaster by overexpressing Relish (Rel), an NFκB...
Nearly 3000 juvenile Chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon captured in nearshore waters off the coasts of Washington and Oregon from 1999-2004 were tested for infection by Renibacterium salmoninarum, Nanophyetus salmincola, and skin metacercariae. First, three quantitative PCR primer/probe sets were compared for detection of R. salmoninarum; amplification...
Phytoplankton and microzooplankton comprise the base and the first link of the marine food web, respectively. These microbes are key drivers of marine carbon and nutrient cycles. Phytoplankton convert atmospheric CO₂ into organic carbon, and microzooplankton consume phytoplankton, packaging phytoplankton carbon into particulate forms that have a variety of fates:...
The transport response of four marine psychrophilic bacteria
to a variety of substrates was determined and related to environmental
conditions. Studies on pressure and temperature effects on glutamic
acid transport and utilization indicated that high pressures and
low temperatures inhibit glutamate transport, while permitting glutamate
respiration. Similar results were obtained...
Commercial inoculant products for subclover that are marketed in the Pacific Northwest were evaluated in field trials (supplemented by appropriate laboratory analysis) at four sites in southwest Oregon. The materials tested were Nitragin (Milwaukee, WI) and Northrup-King (Minneapolis, MN) peat-based inocula, and Celpril (Manteca, CA) inoculated, lime-pelleted subclover seed. Duplicate...
The marine psychrophilic bacterium Vibrio marinus MP-4
possessed a maximum temperature and hydrostatic pressure of
20 C and 425 atm for growth. The effects of temperatures of 21 and
25 C and hydrostatic pressures of 200, 400, 500, and 1,000 atm on
protein, RNA and DNA synthesis by V. marinus...
Neurofibromatosis type 2 (NF2) is a genetic disorder caused by the inactivation of the
merlin tumor suppressor gene. NF2 patients develop bilateral vestibular schwannomas
(VS) and other nervous system tumors with no effective drug treatment option. In
pathological conditions, including NF2, production of the oxidant peroxynitrite leads to
protein tyrosine...
Canine transitional cell carcinoma (TCC) has been shown to have a substantial inflammatory component. It exhibits genotypic and morphologic elements that resemble its human counterpart. Cyclooxygenases (COX) are key enzymes in the synthesis of proinflammatory molecules, such as prostaglandins. Excess prostaglandin production through cyclooxygenases may promote oncogenesis and progression of...
Koi herpesvirus (KHV) is a new emerging viral pathogen of koi and common carps. It has been demonstrated that KHV becomes latent in the white blood cells in the recovered koi. The latent KHV can be reactivated under stressful conditions, such as heat and injury, and the reactivated viruses can...
The within-host interactions that can occur as a result of mixed infections in wildlife likely influence the outcome of an infection. We investigated the infection frequency and outcome as well as the potential mechanisms regulating mixed infections with two Ceratonova shasta genotypes within the Chinook salmon host. Previous research in...
Plasma membranes from Saccharomyces cerevisiae were prepared by a new procedure involving lyticase treatment of the yeast cells. The plasma membranes were right-side out, closed vesicles of uniform appearance with a sterol to phospholipid molar ratio of 0.365. The thermotropic behavior of these plasma membranes from wild-type yeast and from...
The mechanisms of substrate recognition by regulatory proteases are not well understood. Presently, two opposing models have arisen to describe E. coil Lon's ability to discriminate between substrates: one suggests the N-terminus involvement while the second suggests the C-terminus involvement. In this project, the role of the C-terminal domain as...
Phytophthora cactorum lacks sterol synthesis capability. Nevertheless,
it exhibits vegetative growth in the total absence of sterol.
Supplementation of the growth medium with sterol, however, resulted in
a three-fold increase in cell yield. This increase was shown by whole
cell and cell free experiments to be the consequence of altered...
The mechanism of transsulfuration and the role of cystathionine
in the biosynthesis of methionine in yeast were investigated.
Saccharomyces were shown to accumulate cystathionine by use
of the ³⁵S labeled compound.
Cell-free extracts of the wildtype clone as well as methionine
auxotrophs were shown to cleave cystathionine. The enzymatically
produced...
Cyprinid herpesvirus 3 (CyHV-3), commonly known as koi herpesvirus (KHV), is a member of the Alloherpesviridae and is a deadly pathogen for koi and common carp, Cyprinus carpio. It causes severe gill necrosis and nephritis, dermal ulceration and hemorrhage, and mass mortality of up to 100% of affected fish. Fish...
When nitrate is used in a biological electron transport
system as the final acceptor of hydrogen to form water,
the system is characterized as "Nitrate Respiration." However,
the quantitative expression of the over-all participation
of NO₃⁻(0) in the oxidation of glucose by denitrifiers
such as Pseudomonas stutzeri deserves clarification.
In...
The bacteriophage receptor of lactococci was found on the cell
walls. A carbohydrate analysis of the cell walls from phage-resistant
mutants of L. lactis subsp. cremoris KR with reductions in phage binding
indicated that a loss of galactose correlated with a loss in binding
and infection of all phage tested:...
Our laboratory is exploring the mechanism of action of a novel broad spectrum antiviral, ST-669. This compound has activity against a variety of different viruses and the obligate intracellular bacterium, Chlamydia. In this study, we explored the effects of ST-669 when the cell cycle of the host cells was altered....
Methionine metabolism, leading to the biosynthesis of ethylene in Saccharomyces cerevisiae does not appear to involve S-adenosylmethionine (SAM) and aminocyclopropanecarboxylic acid (ACC), based on the lack of ethylene synthesis when both SAM and ACC were incubated in the presence and absence of cells. Thus, the mechanism leading to the formation...
The association of other materials with DNA has been studied
extensively in higher organisms and more recently in bacteria.
However, investigation of these complexes in bacteria have for the
most part been restricted to the study of a specific function this association
may serve, or a specific kind of association....
This research was initiated to investigate the effects of various
parameters on the immune response of juvenile coho salmon to Aeromonas
salmonicida. The antibody response and development of protective
immunity in juvenile coho salmon were followed after a single
intraperitoneal injection of formalin killed A. salmonicida cells emulsified
in Freund's...
The psychrophilic marine Vibrio sp., ANT-300, was able to utilize a variety of carbon sources that can be considered typical for the marine environment. The organism grew abundantly on glucose and serine. Chitin was hydrolyzed even when it was offered as the only carbon source, while no growth occurred on...