Digital Commons Network^™

Assay For Rifampicin Resistant M13 Rf Synthesis, Carol Bauer Wheeler

Loma Linda University Electronic Theses, Dissertations & Projects

We have developed a rapid assay which can detect the function of the origin of 0X174 complementary strand DNA in Ml3 by virtue of its ability to initiate the synthesis of M13 complementary strands in the presence of the antibiotic rifampicin. A segment of DNA carrying the sequence recognized by the replication protein n' has been isolated from bacteriophage ØX174 and cloned into an Ml3 bacteriophage vector. Protein n' is a component of the bacterial primosome, a multi-protein assembly which initiates the synthesis of primers during DNA replication in the bacterium Escherichia coli. The recognition site for n' on the …

Isolation And Characterization Of A Novel Motility Mutant In Salmonella Typhimurium, David Matthew Chacko

Loma Linda University Electronic Theses, Dissertations & Projects

A new mutant, BT40, isolated from mutagenized cultures of S. typhimurium was deficient in chemotaxis (Che^- phenotype) in tryptone semisoft agar, but had random motility with a tumbling frequency (37%) similar to that of the parental strain, ST23 (39%). In spatial assays accumulation of BT40 cells in capillary tubes containing attractants was decreased by 33%-59% compared to ST23, but BT40 had a normal response to attractants in temporal assays. The methylation level of the chemotactic proteins was decreased in BT40. At room temperature, the mean swimming speed was 11 μm/s for BT40 and 20 μm/s for ST23; more BT40 …

A Rapid Concentration And Identification Technique For Human Malaria Infections Using A Mouse Model, Donald D. Barton

Loma Linda University Electronic Theses, Dissertations & Projects

Red blood cells infected with malaria parasites experience a change in density making them lighter (less dense). This paper reports a new, rapid diagnostic technique using this change in density in the infected red blood cell. It is not only easy to use, but it is also compatible with the technological conditions found where the malaria problem is most acute - in many developing countries of the world. A small sample of blood drawn from a simple finger stick can be concentrated and examined microscopically for malaria parasites within 10 minutes. The thick film slide preparation, presently used, takes a …

Characterization Of A New Freshwater Methanogen, Methanogenium Wolfei Sp. Nov., Theodore B. Moore

Dissertations and Theses

A recently isolated freshwater methanogenium species, Methanogenium wolfei, is characterized. Cells were irregular cocci, measuring 1.5 to 2.0 micrometers in diameter. No motility was observed, but 1 to 2 flagella per cell were observed after staining with Gray's Flagella Stain. Colonies formed by this species were small, shiny, and green-brown in color. Formate or hydrogen plus carbon dioxide served as substrates for growth. The optimal temperature for growth was found to be 45 degrees centigrade with minimal growth below 30 degrees centigrade and above 55 degrees centigrade. The optimal pH for growth was determined to be 6.8. Optimal growth was …

A Study Of Transferable Antibiotic Resistance In Enteric Bacteria, Charles H. Regeski

Loma Linda University Electronic Theses, Dissertations & Projects

A group of 48 enteric bacteria was selected from a total of 170 at Loma Linda University Medical Center because of resistance to three or more antibiotics. They were examined to see if any of the antibiotic resistances were transferred by conjugation to either of two recipient bacteria. These were a restrictionless, antibiotic sensitive, azide resistant mutant of Escherichia coli K 12 designated E. coli 1228 and a similar phenotypic strain of Salmonella typhimurium LT2 designated LB 5000. Forty-three transferred one or more antibiotic resistances to either or both recipients, a frequency of 25.3% of the total bacteria and 89.6% …

Cryptosporidiosis In The Immunosuppressed Mouse And In Cell Culture, Mercy Prabhu Das

Loma Linda University Electronic Theses, Dissertations & Projects

Cryptosporidiosis is a parasitic infection primarily of animals that has been recently recognized as an important disease in immunocompromised humans. Most cases to date have occurred in patients with acquired immunodeficiency syndrome (AIDS). Persons with abnormal humoral or cellular immune function, and even normal subjects, have also been affected.

To determine whether or not mice, when experimentally immunosuppressed, would develop cryptosporidiosis, a test was designed using the AKR/J strain. This strain was selected because, it was previously reported that it was the strain shown to respond most readily to the production of disease caused by the opportunistic protozoan, Pneumocystis carinii …

Cellular Immunity In Children With Down Syndrome (Trisomy-21), Roger Lee Noble

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Individuals with Down syndrome (US) suffer from increased incidence of respiratory infections and lymphoblastic leukemia, and a death rate that is particularly high in the first 5 years of life. Relatively few studies have probed immune parameters in young US children. Primary immune defects in DS may be masked by a degree of immune maturity in adults, and hygienic factors may have an effect on immune capability throughout the years. A study of young children can give clearer evidence of the actual primary immune defects in DS.

Blood samples were drawn from 20 DS children under 6 years old and …

Observations On The Adherence Of Bacteroides Bivius To Female Genital Tract And Oral Epithelial Cells, Susan V. Meade

Master's Theses

No abstract provided.

Factors Affecting Germ Tube Formation In Candida Albicans, Walter A. Tatarowicz

Master's Theses

No abstract provided.

Isolation And Characterization Of The Crossreactive Antigenic And Allergenic Components In Callistemon Citrinis And Melaleuca Quinquenervia Pollen By Immunochemical Methods, Brett E. Stanaland

Retrospective Theses and Dissertations

No abstract provided.

Dissection Of Microphage Activation Using T Cell Hybridoma Derived Lymphokines, William S. Futch Jr.

Theses and Dissertations

Macrophage phenotype/function can be modulated by various T-cell lymphokines (LK). The alteration of macrophage phenotype is a result of LK concentration, duration of exposure, and the level of macrophage activation when obtained from in vivo sources through elicitation by either sterile irritants or immune cellular mechanisms. In order to dissect macrophage activation into discrete signals T cell hybridomas were constructed by fusing HAT sensitive BW5147 cells with nylon-wool purified, con A stimulated T cells. The resulting T cell hybrids were screened for their ability to: (a) protect macrophages from the cytopathic effect of Naegleria; (b) induce class II MHC gene …

Fecal Coliform Membrane Filtration Recovery Techniques, Pamela Rose Rinebold

Masters Theses

Researchers over the years have been trying to improve recovery techniques for fecal coliform bacteria. Improved techniques would provide better estimates of the number of fecal coliform bacteria as well as better estimates of fecal contamination with potential pathogenicity of food and water.

Stressed, but viable, fecal coliform bacteria if placed under the appropiate conditions, can recover, thus presenting the possibility of inadequate disinfection. Chlorine sanitization, as done in potable and wastewater treatment, is one such method of stressing bacteria.

Techniques of recovery were studied using presumably unstressed and chlorine stressed samples. Phase one of this study was the comparison …

Response Of A Nitrifying Biofilm To Copper, Denise Moldroski Mott

Masters Theses

In pure cultures of Nitrosomonas, copper is known to cause a stimulation of nitrification at low levels (≤ 0.03 mg Cu⁺²/1) and an inhibition affect at higher levels (≥ 0.05 mg Cu⁺²/1). Nitrifying activated sludges are much more tolerant of copper showing only 75% inhibition at 150mg Cu⁺²/1. The purpose of this paper was to determine the copper sensitivity of a nitrifying biofilm grown in a continuous flow trickling filter system.

A continuous flow trickling filter system was built using limestone chips for the biofilm substrate. The biofilm was established from secondary effluent. …

Partial Characterization Of The Extracellular Polysaccharides Produced By Mutants Of Rhizobium Leguminosarum And Rhizobium Trifolii, Lendell L. Cummins

Masters Theses

Extracellular polysaccharides (EPS) are suspected to be involved in some aspect of the Rhizobium-legume symbiotic process. Extracellular polysaccharides produced by R. leguminosarum and R. trifolii mutants were isolated and partially characterized by gas chromatography, column chromatography, double diffusion, polyacrylamide gel electrophoresis, and immunoelectrophoresis.

The R. leguminosarum mutants, derived from strain 128C53, all are deficient in EPS production (exo-). Strain ANU54 is missing the symbiotic plasmid, while plasmid-containing strains ANU54 pJB5JI and ANU54 pBR1AN nodulate (nod+) peas and clover respectively, but do not fix nitrogen (fix-).

R. leguminosarum mutants produce an EPS that is similar to parental LPS in composition. …

A Comparison Of The Acidic Extracellular Polysaccharides From Rhizobium Trifolii Mutants Affected In Trifolium Repens Root Hair Curling, Brian Andrew Hanley

Masters Theses

The compositions and sugar linkages of the acidic extracellular polysaccharide (EPS) from several Rhizobium trifolii mutants were compared. These mutants were derived from a wild type Rhizobium trifolii, ANU843, and are unable to cause normal root hair curling, Hac-, or nodulate clover, Nod-. Three of the mutants contain a Tn5 insertion in a 5.3 kb BglII fragment of the symbiotic plasmid (pSym). A fourth mutant is missing the pSym, which includes much of the 5.3 kb BglII fragment, both of these deletions result in Hac-Nod- phenotypes. When the 5.3 kb BglII fragment is cloned (pRT150) and reinserted into the …