摘要:

Passive protection againstAeromonas salmonicida, the causative agent of furunculosis in fishes, was produced in juvenile coho salmon by administration of serum from adult rainbow trout containing antibodies actively produced by intra-abdominal vaccination.The levels of natural (or residual) agglutinins againstA.salmonicidaand those produced by vaccination are shown for two age-groups of rainbow trout.Oral vaccine administered in the diet of juvenile coho salmon failed to produce either agglutinating antibody or protection against experimental infection under the conditions employed.

ISSN:0008-4166    

DOI:10.1139/m65-053

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

A new method of removing the bacterial population from surfaces has been developed for use in laboratory and field studies. The method is based on the impingement of a spray of washing solution against a circumscribed area of surface; the number of bacteria in the resultant suspension is subsequently determined by plating. The equipment developed for this procedure is simple to use, portable, and does not injure the test surface. In comparative tests using chicken skin and slices of lean beef and pork fat, inoculated uniformly withPseuiomonas fluorescens, recoveries obtained with the spray technique were superior to those obtained with conventional methods.

ISSN:0008-4166    

DOI:10.1139/m65-054

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Bone marrow, spleen, liver, and thymus cells of the guinea pig were incubated in Eagle"s minimal essential medium which contained glycine-2-C14. Flasks were removed from the water bath at 0, 6, 18, 24, and 48 hours and their contents were homogenized, centrifuged, and concentrated. Experiments were carried out with the concentrated supernatant samples to determine whether or not they contained proteins with properties similar to those of complement (C′) proteins. Titrations for hemolytic activity revealed that bone marrow cells produced C′2, C′3, and C′4; spleen cells synthesized C′2 and liver slices produced C′2. Liver supernatant samples also contained C′3 activity, but proteins associated with C′3 actiyity seemed to be released rather than synthesized by liver slices. We were unable to demonstrate C activity with thymus cell supernatants. Heat inactivation (56 °C for 30 minutes), as well as EDTA inhibited the hemolytic activity of supernatant samples.Further experiments showed that these supernatant proteins were fixed to antigen–antibody complexes and to aggregated gamma-globulin. The fixation was inhibited by guinea pig serum. Immunoelectrophoresis and gel-diffusion showed that proteins synthesized in vitro migrated as beta-globulins and were antigenically similar to C′ proteins.

ISSN:0008-4166    

DOI:10.1139/m65-055

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The spheroplast-inducing activity of glycine in solid and semisolid media was studied, particularly with reference to growth, reversion to the bacillary state, and properties of the spheroplasts. The combination of 3% NaCl, 1.75% glycine, 10% horse serum, 2% dextrose, and 0.01 MMgSO4∙7H2O was optimal for L colony formation.Resistance to glycine induction was apparent by the third generation in glycine-containing media, while the absence of the inducer invariably resulted in mass reversion.Glycine-induced spheroplasts were essentially similar to the parent bacilli in virulence, antigenicity, phage type, antibiotic sensitivity, and biochemical fermentations. These forms are not filtrable through membrane filters. It is suggested that the term "L" form should be applied to these spheroplasts, even though stability was not one of their characteristic

ISSN:0008-4166    

DOI:10.1139/m65-056

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

BS-C-1 cells, cultivated in a simple medium designated M-E, were found to be suitable for a plaque assay of polio and measles viruses. In the plaque assay both low- and high-passage levels of the BS-C-1 cell line were highly susceptible to measles virus but titers of polioviruses were lower in the high-passage cells. Low-passage cells, preserved and stored at −196 °C for prolonged periods, are recommended for the titration of polio and measles viruses.

ISSN:0008-4166    

DOI:10.1139/m65-057

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The amoebae ofTetramitus rostratusgrowing withEscherichia coliwere inoculated into a yeast peptone broth and a potassium phosphate buffer solution, and flagellate formation was studied. In both, the numbers of flagellates formed and their proportional incidence increased with the number of amoebae inoculated. In buffer the numbers of flagellates reached a peak at 10 hours, and in broth at 23 hours.Comparisons between the buffer and broth, using the same inoculum, indicated that population density is only one factor governing flagellate formation, since this transformation was greater in buffer for a given population.Replacement ofE.coliwith four other monoxenic associates indicated that bacterial flora makes little difference in buffer on flagellate transformation, as flagellates were formed with all four genera. A search for a "flagellating substance" produced in the medium or within the cells was not successful.

ISSN:0008-4166    

DOI:10.1139/m65-058

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Dark-field and electron microscopic studies of budding yeast cells have shown an extension of a wall of full thickness, rather than a break in the wall, when the bud emerges. The bud appears as a minute bulge and grows steadily, not explosively, during which time both it and the mother cell are enclosed within a single wall. The wall maintains essentially a constant thickness throughout the growth of the bud, and at maturity both the wall and the cytoplasm of the two cells are separated by a cleavage wall which is laid down between them.

ISSN:0008-4166    

DOI:10.1139/m65-059

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

D-Cycloserine not only strongly inhibited growth of anErwiniaspecies, but, at levels allowing some growth, inhibited cell division. The resulting long cells often showed thickening or swelling. Several agents were able to prevent this effect.D-Alanine, at a level that overcame growth inhibition completely, still allowed considerable elongation to take place. To overcome division inhibition completely required an approximately 300-fold higher concentration than that completely overcoming growth inhibition under the conditions used. Similar results were obtained withL-alanine, but at a given concentration it was less effective thanD-alanine. Pantoyl lactone partially overcame growth inhibition, and, at higher levels which reduced growth, completely overcame division inhibition. Pyridoxal overcame growth inhibition to a large extent, but increased elongation and damage to cells. Pantoyl lactone andL-alanine showed a high degree of synergism in overcoming both growth and division inhibition byD-cycloserine. Pantoyl lactone plusD-alanine, or pyridoxal plus eitherD- orL-alanine also showed such a synergism, but to a lesser extent. The significance of these findings with regard to known enzyme inhibitions ofD-cycloserine is discussed.

ISSN:0008-4166    

DOI:10.1139/m65-060

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

It is well known that the beta hemolysin ofStaphylococcus aureusis unable to cause lysis of erythrocytes at 37 °C but will do so when the temperature is lowered. Sheep erythrocytes sensitized to partially purified beta lysin were, however, lysed at 37 °C by NaCl at concentrations less but not greater than 0.80–0.85%. Increasing acidity rather than increasing alkalinity was also effective in causing lysis of erythrocytes at this temperature. These observations suggest that the beta lysin-sensitized red cells are much more sensitive to osmotic swelling than are normal cells.Kinetic studies of the effect of time, lysin concentration, pH, and temperature on sensitization of sheep erythrocytes to beta lysin indicate that the reaction may be enzymatic. This concept is further supported by the Mg++ion requirement of the beta lysin and its sensitivity to the action of trypsin.

ISSN:0008-4166    

DOI:10.1139/m65-061

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Inhibition of growth of a wine yeast in shaken liquid culture by polybutene emulsions was shown to depend solely on the concentration and type of emulsifier used. The toxicity of various emulsifiers was examined, mainly at concentrations of 200–600 p.p.m. In general, the anionic alkyl aryl sulfonates were toxic, and the non-ionic alkyl aryl polyether alcohols were non-toxic. As the concentration was increased, the toxic materials were first fungistatic, then fungicidal. Two blended emulsifiers used in agricultural sprays gave very steep dosage–response curves.

ISSN:0008-4166    

DOI:10.1139/m65-062

出版商:NRC Research Press    

年代:1965

数据来源: NRC