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Evaluation Of Survival And Recovery Characteristics Of Bifidobacteria As Indicators Of Fecal Pollution Of Water, John Elmer Ravenscroft Jr. Dec 2000

Evaluation Of Survival And Recovery Characteristics Of Bifidobacteria As Indicators Of Fecal Pollution Of Water, John Elmer Ravenscroft Jr.

Graduate Theses, Dissertations, and Problem Reports

The examination of aquatic environments for bacterial indicator organisms has proven to be a useful and well-established practice for the purpose of monitoring microbiological water quality. An ideal indicator of fecal pollution should be present in sufficient density to allow detection, present simultaneous with pathogen(s), incapable of aftergrowth in external aquatic environments, easy to enumerate, and exclusively of fecal origin. Unfortunately, none of the indicator organisms presently in use today meet all of these requirements. Bifidobacteria show promise as indicators of fecal pollution in water with the additional ability of potentially distinguishing between fecal pollution of human and animal origin. …


Induction Of Myosin Cross-Reactive Antibody And Cytolytic T Cell Responses In Mice With Streptococcus Pyogenes, Cynthia Ann Cunningham Aug 2000

Induction Of Myosin Cross-Reactive Antibody And Cytolytic T Cell Responses In Mice With Streptococcus Pyogenes, Cynthia Ann Cunningham

Graduate Theses, Dissertations, and Problem Reports

Impetigo and pharyngitis are two common suppurative infections in man elicited by Streptococcus pyogenes that lead to autoimmune complications in susceptible individuals. Although the underlying mechanisms for the onset of post-streptococcal autoimmunity have yet to be established, experimental information gained thus far suggests that the resultant pathology is a consequence of immunological cross-reactivity between streptococcal antigens, namely the anti-phagocytic factor M protein and host proteins, specifically myosin. Experimental animal model systems developed to date have predominantly relied on the immunization of adult animals with M protein emulsed in adjuvant. In the laboratory we have undertaken studies with mice to examine …


Structural Determinants Of Murine Leukemia Virus Reverse Transcriptase That Are Important For Template Switching, Fidelity, And Drug Resistance, Evguenia S. Svarovskaia Aug 2000

Structural Determinants Of Murine Leukemia Virus Reverse Transcriptase That Are Important For Template Switching, Fidelity, And Drug Resistance, Evguenia S. Svarovskaia

Graduate Theses, Dissertations, and Problem Reports

Retroviruses exhibit high mutation rates. High mutation and recombination rates increase variation within a viral population and result in production of drug-resistant mutants and/or mutants that can escape a host immune response. Mutations are introduced into the viral genome by error-prone reverse transcriptase (RT), a virally encoded enzyme that converts single-stranded viral RNA into double-stranded DNA. In the current study we are trying to understand what structural determinants of RTs are important for fidelity, frequency of template switching, and drug-resistance. First, we developed an in vivo assay and performed mutational analysis of manne leukemia virus (MLV) RT to identify structural …


Structural Determinants Of Murine Leukemia Virus (Mlv) Reverse Transcriptase (Rt) Important For Fidelity And Drug Resistance In Vivo, Elias Konstantine Halvas Aug 2000

Structural Determinants Of Murine Leukemia Virus (Mlv) Reverse Transcriptase (Rt) Important For Fidelity And Drug Resistance In Vivo, Elias Konstantine Halvas

Graduate Theses, Dissertations, and Problem Reports

Error-prone DNA synthesis by retroviral reverse transcriptases (RTs) is a major contributor to variation in retroviral populations generating mutants that exhibit altered host tropisms, resistance to antiviral drugs, and the ability to escape the host's immune system. To identify structural elements of murine leukemia virus (MLV) RT important for fidelity and drug-resistance in vivo, we developed a D17-based encapsidating cell line (ANGIE P) which is designed to express the amphotropic MLV envelope. ANGIE P cell line also contains an MLV-based retroviral vector (GA-1), which encodes a wild-type bacterial beta-galactosidase gene (lacZ) and a neomycin phosphotransferase gene. Transfection of ANGIE P …


Foodborne Pathogens In Poultry Production And Post-Harvest Control, Rajesh R. Nayak May 2000

Foodborne Pathogens In Poultry Production And Post-Harvest Control, Rajesh R. Nayak

Graduate Theses, Dissertations, and Problem Reports

A comprehensive ecological survey was conducted from April 1997 to June 1999 on four turkey flocks (F5-F8) to identify the preharvest sources of Salmonella colonization. Generic E. coli and total coliforms were enumerated as indicators of fecal contamination in F7 and F8. Turkey cecal and crop contents, litter, drinkers, air, feed, feeder contents, and environmental swabs were sampled and tested for Salmonella and E. coli. Salmonella was isolated from 13% of litter, 11% of turkey ceca, 10% of drinkers, and 5% of swabs. Escherichia coli and total coliforms were detected in 45 and 53% of samples, respectively. Salmonella heidelberg was …


Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning Feb 2000

Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning

Department of Biological Sciences Publications

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.


Cyanonews (Vol. 15, No. 1, July 2000), Jeff Elhai Jan 2000

Cyanonews (Vol. 15, No. 1, July 2000), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.


Characterization Of The Interactions Within The Ccr4 -Not Complex And The Interactions Between Adr1 And Tfiid Components, Yongli Bai Jan 2000

Characterization Of The Interactions Within The Ccr4 -Not Complex And The Interactions Between Adr1 And Tfiid Components, Yongli Bai

Doctoral Dissertations

The mechanisms of transcriptional regulation are well conserved from yeast to human cells. Most genes are regulated at the transcriptional level, particularly, at the transcription initiation step. In Saccharomyces cerevisiae at least one transcriptional activator, ADR1, and one transcription complex, CCR4-NOT, participate in the activation of the ADH2 gene. The core 1 x 106 dalton CCR4-NOT complex consists of CCR4, CAF1, the five NOT proteins (NOT1-NOT5), and three other uncharacterized proteins. Deletion of NOT3, NOT4, or NOT5 did not affect the association of CCR4 with CAF1 in the gel filtration analysis. In contrast, NOT2 inactivation caused partial destabilization of the …


Creation And Characterization Of 25 Kda Outer Membrane Protein (Omp25) Deletion Mutants In Brucella Species., Matthew David Edmonds Jan 2000

Creation And Characterization Of 25 Kda Outer Membrane Protein (Omp25) Deletion Mutants In Brucella Species., Matthew David Edmonds

LSU Historical Dissertations and Theses

The genus Brucella is composed of Gram-negative, facultative intracellular pathogens that impact man and animals. Brucella species express a 25 kDa major outer membrane protein termed Omp25. To determine the role of Omp25 in virulence, mutants were created in Brucella abortus (BA25), Brucella melitensis (BM25), and Brucella ovis (BO25) that contain disruptions in the omp25 gene (Deltaomp25 mutants). In the murine brucellosis model, each Deltaomp25 mutant was attenuated when compared to the virulent parental strain. To assess the ability of the B. abortus and B. melitensis mutants to colonize and induce abortions in the ruminant host, cattle and goats in …


Defining Anuran Malformations In The Context Of A Developmental Problem, Carol U. Meteyer, Rebecca A. Cole, Kathryn A. Converse, Douglas E. Docherty, Mark Wolcott, Judy C. Helgen, Richard Levey, Laura Eaton-Poole, James G. Burkhart Jan 2000

Defining Anuran Malformations In The Context Of A Developmental Problem, Carol U. Meteyer, Rebecca A. Cole, Kathryn A. Converse, Douglas E. Docherty, Mark Wolcott, Judy C. Helgen, Richard Levey, Laura Eaton-Poole, James G. Burkhart

Journal of the Iowa Academy of Science: JIAS

This paper summarizes terminology and general concepts involved in animal development for the purpose of providing background for the study and understanding of frog malformations. The results of our radiographic investigation of rear limb malformations in Rana pipiens provide evidence that frog malformations are the product of early developmental errors. Although bacteria, parasites and viruses were identified in these metamorphosed frogs, the relevant window to look for the teratogenic affect of these agents is in the early tadpole stage during limb development. As a result, our microbiological findings must be regarded as inconclusive relative to determining their contribution to malformations …


Isolation And Characterization Of Newly Emerging Coronaviruses In Acute Respiratory Tract Diseases Of Cattle., Xiaoqing Lin Jan 2000

Isolation And Characterization Of Newly Emerging Coronaviruses In Acute Respiratory Tract Diseases Of Cattle., Xiaoqing Lin

LSU Historical Dissertations and Theses

A total of 411 G clone cell-dependent virus strains recently were isolated from nasal, trachea and lung samples in etiological investigations of acute respiratory tract diseases of vaccinated cattle, including shipping fever pneumonia. The virus infectivity titers reached up to 1.2 x 10 7 plaque forming units per gram of lung tissues of fatal cases. These viral agents were isolated in the 1st G clone cell passage without trypsin enhancement, and induced cell fusion. They have a restricted hemagglutination pattern, agglutinating only rat and mouse erythrocytes. Majority of them has receptor-destroying enzyme activities. They are round and enveloped with a …


Host And Parasite Interactions Among Three Symbionts: Pocket Gophers, Chewing Lice, And Endosymbiotic Bacteria., David Lee Reed Jan 2000

Host And Parasite Interactions Among Three Symbionts: Pocket Gophers, Chewing Lice, And Endosymbiotic Bacteria., David Lee Reed

LSU Historical Dissertations and Theses

This study investigates the patterns of cophylogeny documented between pocket gophers (Rodentia: Geomyidae) and their ectoparasitic chewing lice (Phthiraptera: Trichodectidae). The first two chapters investigate the mechanisms that reinforce cospeciation in this system. Chapter one examines whether mammalian hair diameter is a resource tracked by chewing lice, and thus reinforces the patterns of cospeciation. I found that hair diameter of pocket gophers is correlated with gopher body size and the body size of the ectoparasitic chewing lice. Hair diameter also is correlated with size of the rostral groove, which chewing lice use to grasp hair shafts of pocket gophers. In …


Biological And Molecular Properties Of Sweet Potato Leaf Curl Virus., Pongtharin Lotrakul Jan 2000

Biological And Molecular Properties Of Sweet Potato Leaf Curl Virus., Pongtharin Lotrakul

LSU Historical Dissertations and Theses

In 1994, a sweet potato sample showing leaf curl symptoms was collected from the field in Louisiana. When graft-inoculated, Ipomoea setosa reacted with mild upward leaf curling while I. aquatica reacted with a bright yellow mottle. The putative virus was transmitted by the sweet potato whitefly, Bemisia tabaci biotype B, and it was designated the United States isolate of Sweet potato leaf curl virus (SPLCV-US). Four independent Southern blot hybridizations using the DNA-A of different begomoviruses as probes confirmed the presence of begomovirus-like DNA in the infected plants. Fibrillar inclusions and granular aggregates of geminivirus-like particles were observed in the …