Biomedical subjects

A G Ostle

Publications and source records attributed to A G Ostle.

7 recordsLinked to original sources

PubMed1987

Vaccination of cattle with Mycoplasma bovoculi antigens: evidence for field immunity.

Cattle previously exposed to Mycoplasma bovoculi developed a high serum IgG and cellular responses detected by ELISA and lymphocyte blastogenesis respectively, when immunized with three M. bovoculi antigen preparations (two non-ionic detergent extracts and a killed whole organism). Similar responses to the detergent immunogen were observed in colostrum-deprived calves free of M. bovoculi. Following ocular challenge with live M. bovoculi all animals including the control group cleared the organism. However the organism colonized the eyes of the colostrum-deprived calves. These observations indicate that previous exposure to M. bovoculi confers immunity to reinfection and that none of the vaccines provided a protective activity against the organism.

Animals↗

PubMed1986

Mycoplasma bovoculi infection increases ocular colonization by Moraxella ovis in calves.

To determine whether infection with Mycoplasma bovoculi increases ocular colonization of cattle eyes with Moraxella bovis and other bacteria, colonization of ocular gram-negative bacteria were measured in eyes of cattle infected with Mycoplasma bovoculi. Strains of Moraxella ovis were chosen because these are among the most commonly isolated species of gram-negative bacteria from cattle eyes. Five strains of M ovis were characterized biochemically and by pilus structure, permitting the recognition of 2 biotypes. All strains were tested in a mouse corneal pathogenicity model. One strain of each biotype was selected for testing in calves. All 5 strains were apathogenic for mice, and the 2 strains tested in cattle did not induce keratitis. Infection of calves with Mycoplasma bovoculi increased the amount and persistence of colonization with the strains of M ovis.

Animals↗

PubMed1986

Outer membrane protein antigens of Moraxella bovis.

Outer membranes were isolated from bovine isolates and type strains of Moraxella bovis, M phenylpyruvica, M lacunata, and M ovis by sodium N lauroyl sarcosinate extraction and differential centrifugation. Analysis of outer membranes from these organisms by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis revealed that all M bovis isolates shared a common polypeptide pattern that was readily distinguishable from other Moraxella spp. Nine major outer membrane protein bands were identified by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis analysis of M bovis. Immunoblotting of protein antigens of M bovis revealed several outer membrane proteins that seemed to be common antigens of all M bovis isolates.

Animals↗

PubMed1985

Immunogenicity of Moraxella bovis hemolysin.

Anti-Moraxella bovis hemolysin activity was observed in 35 cattle exposed to field infections of infectious bovine keratoconjunctivitis (IBK). All cattle in infected herds seroconverted with respect to antihemolysin whether or not clinical IBK was noted. Cattle previously exposed to IBK possessed higher antihemolysin titers than did younger, nonexposed cattle. Antihemolysin activity was noted in bovine sera up to 7 years after exposure to IBK. Sera from experimentally infected calves were found to possess antihemolytic activity against all 33 strains of M bovis tested. Antihemolytic activity could be demonstrated in random-bred mice inoculated with whole doxycycline-treated M bovis, frozen or lyophilized whole M bovis, and membrane fractions treated with sodium lauryl sarcosinate, Triton X 100, and Triton X 100 + EDTA, but not with formalin-treated whole M bovis.

Animals↗

PubMed1984

Moraxella bovis hemolysin.

Moraxella bovis hemolysin was readily filterable through polycarbonate membrane filters, but not through nitrocellulose filters. The hemolysin was filterable through polycarbonate filters with pore diameters of greater than or equal to 0.015 micron (APD). Of the hemolytic activity of cell-free filtrates, 74% could be pelleted by ultracentrifugation at 100,000 X g for 2 1/2 hours. Hemolytic activity could be demonstrated in preparations of outer membrane fragments isolated from log-phase cultures. Hemolysin in M bovis broth cultures reached a maximum concentration in late logarithmic phase (4.5 hours after inoculation) and declined thereafter. Hemolysin was inactivated by heat, trypsin, formalin, and lyophilization.

Collodion↗

PubMed1982

Nile blue A as a fluorescent stain for poly-beta-hydroxybutyrate.

Poly-beta-hydroxybutyrate granules exhibited a strong orange fluorescence when stained with Nile blue A. Heat-fixed cells were treated with 1% Nile blue A for 10 min and were observed at an excitation wavelength of 460 nm. Glycogen and polyphosphate did not stain. Nile blue A appears to be a more specific stain for poly-beta-hydroxybutyrate than Sudan black B.

Azotobacter↗

PubMed1979

Elution and inactivation of bacteriophages on soil and cation-exchange resin.

A variety of elution schemes was tested to determine the most effective procedure for eluting Arthrobacter bacteriophages from soil. A buffer solution of pH 8.0 was found to be the most satisfactory eluent. Bacteriophages were adsorbed to cation-exchange sites on soils, clays, and Dowex-50 resin and eluted. Eluted bacteriophages were detected by passive hemagglutination and plaque assay. Although bacteriophage antigen was successfully eluted, most recovered bacteriophages were noninfective. Inactivation was greatest in bacteriophages of Bradley group B and was associated with the elution process. Inactivation is believed to be caused by physical damage to bacteriophage tails upon elution. The significance of this inactivation relative to bacteriophage models for vertebrate viruses is discussed.

Journal Article↗