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Biomedical subjects

J B Wilson

Publications and source records attributed to J B Wilson.

At least 361 records · Page 20Linked to original sources
PubMed1968

Phage typing reactions on Brucella species.

The nature of the phage typing reactions on Brucella species was determined by rates of adsorption and infection, one-step growth experiments, and susceptibility to lysis from without. The highest rates of adsorption and infection were obtained on smooth B. abortus cultures, and large clear plaques were produced. One or a few phage particles per B. neotomae cell killed about one-half of the cells, but some went through an infective cycle and released mature phage that resulted in production of small clear plaques. With B. suis, more phage particles per cell were required to kill, replication did not occur, and plaques were not observed. Still greater numbers of phage particles were required to cause some inhibition of growth of B. melitensis lawns. Rough Brucella cultures and species, such as B. ovis and B. canis, were not affected by the highest concentrations of phage. B. abortus cultures of intermediate colonial morphology adsorbed phage, but only a few infected cells (after a delayed latent period) released mature phage. An infected culture or colony appeared normal until spontaneous phage mutants appeared which could penetrate the cell wall more effectively than the parent phage. The mutant phage multiplied more rapidly, and the colony changed to a sticky white form.

Adsorption↗
PubMed1968

Identification of the toxic component of Brucella abortus endotoxin and its labeling with radioactive chromate.

The evidence obtained from immuno-gel diffusion, centrifugation, and toxicity studies employing the serum iron assay proved that most of the toxicity in an ether-water brucella endotoxin preparation lies in the slow-diffusing component identified as the biologically active endotoxin. Subsequent destruction of the slow-diffusing component by acid hydrolysis resulted in a corresponding loss of toxicity. Chromate-51 was found to attach almost entirely on the slow-diffusing biologically active component and, hence, is a valid label for endotoxin derived from smooth Brucella abortus by the ether-water method.

Animals↗
PubMed1968

Antigenic relationship of the gram-negative organism causing canine abortion to smooth and rough brucellae.

The use of whole-cell antigens in agglutination and agglutinin-absorption tests showed that the organism causing abortion in dogs is similar to rough Brucella abortus, B. melitensis, and B. ovis, but different from smooth Brucella cultures. Water-soluble antigens obtained by ultrasonic treatment and examined by immuno-electrophoresis and gel diffusion show extensive cross-reactions within the genus Brucella, but little or no cross-reaction with similar antigens from other gram-negative genera in the family Brucellaceae. The dog organism showed near identity with rough and smooth Brucella cultures on the basis of immuno-gel diffusion tests with water-soluble antigens, but it lacked the lipopolysaccharide-endotoxin associated with the agglutinogen of smooth brucellae. These findings support the proposal of Carmichael and Bruner for the designation of a new species, "Brucella canis."

Abortion, Veterinary↗
PubMed1968

Taxonomic position in the genus Brucella of the causative agent of canine abortion.

The gram-negative organism causing abortion in dogs was examined in parallel with cultures representative of the Brucella species and with Bordetella bronchiseptica. The organism fits into the genus Brucella and most closely resembles B. suis on the basis of its growth characteristics. It is of rough colonial morphology and is agglutinated by antisera prepared against rough Brucella. In mouse toxicity tests, no endotoxic activity could be demonstrated. In contrast to most Brucella cultures, it does not utilize erythritol. Electron microscopy showed a cell wall structure similar to that of other gram-negative organisms. The question of whether the organism should be designated Brucella canis, as proposed by Carmichael and Bruner, or Brucella suis biotype 5 is discussed. The authors favor the designation Brucella canis because the organism lacks the lipopolysaccharide antigen associated with the smooth agglutinogen and endotoxin, and it does not utilize erythritol.

Abortion, Veterinary↗
PubMed1968

Surface antigens of smooth brucellae.

Surface antigens of smooth brucellae were extracted by ether-water, phenol-water, trichloroacetic acid, and saline and examined by immunoelectrophoresis and gel diffusion with antisera from infected and immunized rabbits. Ether-water extracts of Brucella melitensis contained a lipopolysaccharide protein component, which was specific for the surface of smooth brucellae and was correlated with the M agglutinogen of Wilson and Miles, a polysaccharide protein component devoid of lipid which was not restricted to the surface of smooth brucellae and was not correlated with the smooth agglutinogen (component 1), and several protein components which were associated with internal antigens of rough and smooth brucellae. Immunoelectrophoretic analysis of ether-water extracts of B. abortus revealed only two components, a lipopolysaccharide protein component, which was correlated with the A agglutinogen, and component 1. Component 1 from B. melitensis and B. abortus showed identity in gel diffusion tests, whereas component M from B. melitensis and component A from B. abortus showed partial identity with unabsorbed antisera and no cross-reactions with monospecific sera. Attempts to prepare monospecific sera directly by immunization of rabbits with cell walls or ether-water extracts were unsuccessful. Absorption of antisera with heavy fraction of ether-water extracts did not always result in monospecific sera. It was concluded (as has been described before) that the A and M antigens are present on a single antigenic complex, in different proportions depending upon the species and biotype, and that this component is a lipopolysaccharide protein complex of high molecular weight that diffuses poorly through agar gel. Components 1, A, and M were also demonstrated in trichloroacetic acid and phenol-water extracts. With all extracts, B. melitensis antigen showed greater diffusibility in agar than B. abortus antigens. After mild acid hydrolysis, B. abortus ether-water extract was able to diffuse more readily.

Agglutination Tests↗
PubMed1967

Antigenic relationship of Brucella ovis and Brucella melitensis.

Immune sera were prepared in rabbits by the injection of living and acetone-killed cells of Brucella ovis and smooth and rough B. melitensis. The use of whole-cell antigens in agglutination and agglutinin-absorption tests revealed little relationship between B. ovis and smooth B. melitensis, although there was extensive cross-agglutination between B. ovis and rough B. melitensis. The use of water-soluble antigens prepared from ultrasonically treated cells of the three strains revealed extensive cross-reactions in indirect hemagglutination, agar gel precipitation, and immunoelectrophoresis tests, as well as in allergic skin tests in rabbits. The most definitive results were obtained with the immunoelectrophoresis technique. B. ovis antigen produced at least 11 lines with its homologous serum. All were removed by absorption of the serum with rough B. melitensis antigen. All but three were removed by absorption with smooth B. melitensis antigen. Smooth B. melitensis antigen produced 11 lines with its homologous serum, and all but 3 were removed by absorption with B. ovis antigen. Rough B. melitensis produced nine lines with its homologous serum, and eight were removed by B. ovis antigen. The extensive cross-reactions between soluble antigens of B. ovis and B. melitensis are added evidence that B. ovis belongs in the genus Brucella.

Animals↗
PubMed1967

Differences between Brucella antigens involved in indirect hemagglutination tests with normal and tanned red blood cells.

Brucella antigens capable of sensitizing normal and tanned sheep red blood cells for indirect hemagglutination were compared with antigens involved in agglutination, gel diffusion, and immunoelectrophoresis. Hyperimmune rabbit sera, before and after absorption with various antigenic preparations from smooth and rough B. abortus, were used in the tests. Normal erythrocytes could be sensitized with an NaOH-treated ether-water extract (EW-T) of smooth Brucella. Tanned erythrocytes could be sensitized with a water-soluble extract from ultrasonically disrupted smooth or rough Brucella. The EW-T produced a single precipitation band and the water-soluble antigens produce 6 to 23 bands in immunoelectrophoresis with unabsorbed sera. After absorption of antisera with water-soluble extracts from smooth or rough Brucella cells or from smooth or rough cell walls, the hemagglutinins for sensitized tanned erythrocytes and the precipitins for water-soluble antigens were removed. Absorption with living smooth or rough Brucella cells or with EW-T did not remove these antibodies. The precipitins and hemagglutinins for the antigen EW-T, and agglutinins for smooth cells, were absorbed by smooth antigens but not by rough antigens. It appears that the antigens which sensitize tanned erythrocytes and diffuse through agar gels are present in both smooth and rough forms and may be situated in the cytoplasm or in the internal part of the cell wall, whereas the agglutinogen and the antigen which attaches to normal erythrocytes are surface antigens found only on the smooth Brucella cell.

Animals↗
PubMed1966

Spontaneous mutation and recombination among brucellaphages.

Merz, George S. (University of Wisconsin, Madison), and Joe B. Wilson. Spontaneous mutation and recombination among brucellaphages. J. Bacteriol. 91:2356-2361. 1966.-Two plaque morphology variants, as seen on Brucella abortus 544A, termed c (for clear plaque) and lc (for late-clearing plaque) were isolated from stocks of wild-type brucellaphage and from colonies of B. abortus 544A which had undergone an alteration in colonial morphology associated with the establishment of the phage carrier state. Single-burst experiments showed that the phage variants arise by spontaneous mutation of the wild-type phage during its replication on B. abortus strain R19. Two-factor crosses of independently occurring c mutant phages showed the presence of wild-type recombinants among the progeny. Control experiments showed that there are no strong selective forces against either wild-type or c mutant phage inherent in the cross-procedure. Other control experiments ruled out the possibility that wild-type phage in the cross-progeny resulted from either back mutation of the c mutants or the presence of wild-type phage among the input c mutants.

Bacteriophages↗
PubMed1965

Chemical composition and biological properties of the endotoxin of Brucella abortus.

Baker, Phillip J. (University of Wisconsin, Madison), and J. B. Wilson. Chemical composition and biological properties of the endotoxin of Brucella abortus. J. Bacteriol. 90:895-902. 1965.-The ability of endotoxin to induce hypoferremia in mice was used to measure the specific activity of various endotoxin preparations of Escherichia coli and Brucella abortus and to determine the endotoxin content of several strains of B. abortus differing in virulence for guinea pigs. The endotoxin preparations from E. coli possessed greater biological activity than those from B. abortus. The same types of B. abortus endotoxin preparations, whether obtained from strains of high or low virulence, had about the same activity. Although differences in endotoxin content were noted among several strains of B. abortus of different virulence, there appeared to be no correlation between endotoxin content and virulence. Chemical analyses of B. abortus and E. coli endotoxins, based upon nitrogen, phosphorus, fatty acid ester, fatty acid amide, total fatty acids, hexose, and hexosamine content, revealed differences in chemical composition; however, these differences could not be correlated with differences in biological activity. The same types of endotoxin preparations, whether obtained from strains of B. abortus of high or low virulence, were similar in chemical composition and in biological activity. A correlation between the ability of endotoxin to induce hypoferremia and its lethal effects in mice is suggested. In general, endotoxin preparations of high hypoferremic activity had low mouse ld(50) values.

Animals↗
PubMed1965

Hypoferremia in mice and its application to the bioassay of endotoxin.

Baker, Phillip J. (University of Wisconsin, Madison), and J. B. Wilson. Hypoferremia in mice and its application to the bioassay of endotoxin. J. Bacteriol. 90:903-910. 1965.-The ability of endotoxin to induce hypoferremia in mice was used for the bioassay of endotoxin. A marked depression in the serum-iron levels of mice occurred 12 hr after the intraperitoneal injection of 0.01 to 100 mug of Escherichia coli endotoxin; similar results were obtained with 1.0 to 100 mug of Brucella abortus endotoxin. This biological response to endotoxin appeared to be specific, reproducible, and dose-dependent. As heat-killed cells of B. abortus and E. coli were also able to induce hypoferremia, this bioassay could be employed for the determination of the endotoxin content of killed-cell preparations. Treatment of endotoxin by acid hydrolysis, acetylation, or pyridine-formic acid greatly diminished the hypoferremic response as well as its lethality for mice. Pretreatment of mice with Thorotrast had little effect upon the ability of endotoxin to induce hypoferremia; however, a stimulation of the activity of the reticuloendothelial system (RES) by treatment of mice with triolein markedly reduced the ability of endotoxin to induce hypoferremia. The relationship between the hypoferremic response to endotoxin and alterations in the activity of the RES are discussed.

Animals↗