One hundred and fourteen strains of Moraxella species isolated from marine fishery sources were investigated to determine the cause of this organism's predominance in seafood. The nutritional requirements, effect of pH, NaCl concentration, and temperature on growth, utilization of carbohydrates, protein, and lipid, resistance to 12 antibiotics, sensitivity to phenethyl alcohol (PEA), production of PEA, and a study of the deoxyribonucleic acids (DNA) of the Moraxella strains were performed. Two strains of Moraxella had a requirement for biotin; most other strains, however, had no requirement for growth factors. The majority of strains had a multiple amino acid requirement which was satisfied by seven amino acids: leucine, isoleucine, valine, alanine, glycine, serine, and hydroxyproline. All strains grew in broth in the pH range of 6.9 to 8.8, with pH limits for growth by any strain being 4.9 to 10.4. All strains grew in the presence of 6% NaCl, with most strains tolerating up to 10%. Ninety five percent of strains tested grew at 5°C and no strain grew at 37°C or above. Thirty percent of all Moraxella strains were able to produce acid from glucose. Xylose and arabinose were oxidized by 17.5 and 1.7% of strains, respectively. Sucrose, fructose, lactose, and galactose were not oxidized. Seven percent of strains were weakly proteolytic while lipolytic activity was not observed in any strain. All Moraxella strains were sensitive to tetracycline (Tc), chlorotetracycline (Ct), oxytetracycline (Ot), streptomycin (St), neomycin (Nm), kanamycin (Km), and nalidixic acid (Na). Half of all strains were resistant to chloramphenicol (Ch) and nitrofurazone (Nf), 36% were resistant to ampicillin (Am), and 70% were resistant to sulfathiazole (Su). Thirty one strains (27.2%) were resistant to 3 IU of penicillin G (Pe), thus, being classified as atypical Moraxella. Atypical Moraxella strains were significantly more resistant to Ch and Am. Moraxella strains were more resistant to PEA than were other gram negative bacteria of fishery origin. At a concentration of 0.82 mmoles PEA/1iter, Moraxella strains were not affected; however, an Arthrobacter strain of marine origin was totally inhibited and marine Pseudomonas strains showed an extended lag period. Moraxella strains produced PEA in concentrations ranging from undetectable to 3.25 mmoles per liter. PEA production was strain dependent and substrate dependent and was not the direct function of the cell concentration. Moraxella strains tested showed a guanine plus cytosine mole percent (G+C mole %) between 42.8 to 44.4. No relationship was observed between G+C mole % and other parameters: penicillin resistance, proteolytic ability, PEA production, or acid production from glucose oxidation. Four factors appear to allow Moraxella to predominate in seafood: NaCl tolerance, the ability to grow at low temperatures, a simple nutritional requirement, and production of PEA. / Graduation date: 1979

Digitized by Kansas Correctional Industries

In order to gain a better understanding of this microorganismand its role in human pathogenesis, a physical map of Moraxella catarrhalis type strain ATCC25238 was constructed using pulsed field gel electrophoresis (PFGE) in combination with Southern hybridization techniques. Restriction endonucleases Not I, Rsr II, and Sma I were used to digest the chromosomal DNA. An overlapping circular map was generated by cross-hybridization of isolated radiolabeled fragments of Moraxella catarrhalis genomic DNA to dried PFGE gels. The number and location of the 16S and 23S ribosomal RNA genes were determined by digestion with l-Ceul enzyme and by Southern hybridization. Virulence-associated genes, the gene for β-lactamase, and housekeeping genes were also placed onto the physical map.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / "May 1998." Typescript. Vita. Includes bibliographical references (leaves 71-76). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves: 71-76). Also available on the Internet.

<I>Moraxella catarrhalis</I> is a gram-negative diplococcus which until recently was thought to be a harmless commensal. Increasing awareness has established the pathogenic nature of this organism and it is now recognised as a major cause of otitis media in children, exacerbations of chronic bronchitis in elderly patients and an occasional cause of invasive disease. <I>M. catarrhalis</I> is spread nosocomially especially in respiratory wards containing elderly patients. This study evaluated four methods for typing nosocomially spread isolates:- immunoblotting with normal human serum (NHS), and three DNA fingerprinting methods. The most discriminatory method found was restriction endonuclease analysis (REA) using <I>Taq</I> I, although immunoblotting with NHS and pulsed-field gel electrophoresis (PFGE) using <I>Sma</I> I sub-divided isolates grouped together by the other methods. PFGE using <I>Not</I> I only confirmed groupings made by other methods. A study of <I>M. catarrhalis</I> and phenotypically similar organisms was performed using comparisons of partial 16S rDNA sequence. 16S rDNA of <I>M. catarrhalis</I> strains from disparate geographical locations was found to be extremely conserved <I>M. catarrhalis</I> 16S rDNA was very similar to that of other <I>Moraxella</I> species whilst <I>Moraxella</I> species were found to be generally distinct from the <I>Neisseria</I> and <I>Kingella</I> species studied. These results confirm <I>M. catarrhalis</I> as a genuine member of the <I>Moraxellae</I>.

Dissertation (Ph.D.)--University of Toledo, 2009. / ["In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomedical Sciences."] Title from title page of PDF document. Bibliography: p. 80-112.

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2004. / Vita. Bibliography: 214-244.

Thèse (M.Sc.)--Université Laval, 2000. / Bibliogr.: f. 64-79. Publié aussi en version électronique.

The enzyme, aspartate transcarbamoylase (ATCase) from Moraxella (Branhamella) catarrhalis, has been purified. The holoenzyme has a molecular mass of approximately 510kDa, harbors predominantly positive charges and is hydrophobic in nature. The holoenzyme possesses two subunits, a smaller one of 40 kDa and a larger one of 45 kDa. A third polypeptide has been found to contribute to the overall enzymatic activity, having an approximate mass of 55 kDa. The ATCase purification included the generation of cell-free extract, streptomycin sulfate cut, 60 °C heat step, ammonium sulfate cut, dialysis and ion, gel-filtration and hydrophobic interaction chromatography. The enzyme's performance throughout purification steps was analyzed on activity and SDS-PAGE gradient gels. Its enzymatic, specific activities, yield and fold purification, were also determined.