摘要:

Several workers have shown that laboratory animals are protected from penicillin-resistantStaphylococcus aureusinfections by antiserum toBacillus cereuspenicillinase in conjunction with benzylpenicillin. This paper shows that antiserum to staphylococcal penicillinase has the same effect. Concentrated penicillinase from a single strain of staphylococcus was used to prepare a rabbit antiserum. Groups of rabbits were injected intravenously with lethal doses of the same strain of staphylococcus. They were either given no treatment or were treated with penicillin only, antiserum only, or combined penicillin and antiserum. Antiserum was given in a single dose or in multiple doses. Throughout the 3-week observation period, the mortality in the group of rabbits receiving combined treatment was significantly less than in any other group. It was concluded that it might be possible to use antistaphylococcal penicillinase serum in the treatment of penicillin-resistant staphylococcal infection.

ISSN:0008-4166    

DOI:10.1139/m64-063

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

A modified fermentation tube was devised by introducing a glass rod in the small inverted Durham tube to keep its mouth away from the bottom of the outer main tube, thus providing the maximum opportunity for gas collection. A medium containing autoclavable growth factors was developed, which, when added to the main tubes with a few particles of cooked meat, allowed growth of fastidious anaerobes. Each ingredient was shown to be free of any fermentable substance that might lead to gas formation. The fermentation tubes were incubated in an anaerobic jar.

ISSN:0008-4166    

DOI:10.1139/m64-064

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Of 664Salmonellacultures isolated during 1962 from a variety of sources in Canada, 56 (8.4%) were resistant to one or more of the antibiotics tetracycline, chloramphenicol, and ampicillin. Of the 38 serotypes studied,S.typhimuriumandS.heidelbergshowed a much higher proportion of strains resistant to tetracycline than did the other serotypes. The incidence of resistant strains among 335 cultures from man was 6.9%; among 74 strains from poultry, 35.1%; while among 52 strains from other animal sources only 5.8% were resistant.

ISSN:0008-4166    

DOI:10.1139/m64-065

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

It has been shown that the fixed rabies virus (strain Louis Pasteur) could be propagated in dog salivary glands cells cultivated in vitro. The titers of the supernatant medium have increased gradually upon passages. This virus is able to induce the formation of intracytoplasmic inclusions bodies and will destroy the cells in which it multiplies only after more than 20 successive passages. Still, this cytopathogenic effect, even after 26 passages, appears late and is only partial; it is possible that this effect may become constant upon further adaptation to the cells. Nevertheless, one may already conclude that following numerous passages from cells to cells an important modification has taken place in the virus-cells relationships.The virus which has undergone a limited number of passages from cells to cells brings on a chronic infection of these cells which persists for the entire life of the cells. The titers of the virus harvested in the culture medium remain stable as long as the cells grow abundantly. Finally the maximum titer is reached on the fifth day after inoculation in the case of a primoculture and on the third day in the case of a chronically infected culture.Heat is a very important factor in limiting the virulence titer of the virus.

ISSN:0008-4166    

DOI:10.1139/m64-066

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Antibody production by spleen cells in vitro permits the study of a unique property of cells, the synthesis of a specific, quantitatively detectable protein. Under certain conditions allantoic fluid containing Newcastle disease virus (NDV), as well as centrifugally purified NDV, when added to a suspension culture of spleen cells from previously immunized rabbits, produced detectable changes in the amount of radioactively labelled antibody produced. NDV also inhibited glycine-C14incorporation into the TCA-insoluble protein fraction of spleen cells.This inhibition was parallel to the loss of cell viability. No detectable increase of infectious virus or haemagglutination titer was noted. It is suggested that the inhibitions shown were due to the cytotoxic effect of the virus, which appeared to require the infectious virus particle.

ISSN:0008-4166    

DOI:10.1139/m64-067

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

S.typhispheroplasts were produced by growing typhoid organisms in a liquid semisynthetic medium containing 1.5 to 2.0% glycine. The addition of traces of magnesium and glucose concentrations of 0.5 to 2.0% was required for optimal growth conditions. These cells were considered to be of the transition L form since they reproduced as spheroplasts as long as they were grown in the glycine medium, but unlike a true L organism they reverted to the normal bacillary form when subcultured to glycine-free medium.The lytic susceptibility ofS.typhispheroplasts was studied. They were found to be resistant to a number of detergents, alcohols, and enzymes. They could, however, be broken up by osmotic shock and were lysed by trypsin, pancreatic lipase, and, best of all, by Dornavac(R), a commercial preparation of pancreatic desoxyribonuclease which, in addition, contains traces of other enzymes, such as trypsin and lipase. Studies towards the production of an enzyme-lysed sphero-plast vaccine for the prevention of typhoid are now in progress.

ISSN:0008-4166    

DOI:10.1139/m64-068

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

A rapid slide test for the detection of Vi antibodies, using spheroplasts ofSalmonella typhi(Vi I, Bhatnagar strain) as the test antigen, has been described. The spheroplasts, grown in a semisynthetic medium containing 1.5% glycine, maintained their antigenic sensitivity for periods of at least 1 month when stored in the cold in the growth medium preserved with 1:5000 Thimerosal.Comparative tests were carried out with the spheroplast slide technique, agglutination tests using intact Bhatnagar cells and Vi-antigen-sensitized red cells, and flocculation tests of Vi-antigen-sensitized bentonite particles. The slide test proved to be specific and reproducible and was as sensitive as the test tube hemagglutination test for both rabbit and human sera. The intact cell agglutination technique and the bentonite flocculation test were relatively insensitive.

ISSN:0008-4166    

DOI:10.1139/m64-069

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

The serological activity of glycine-induced spheroplasts and normal intact cells ofSalmonella typhiwas assessed. No major differences could be detected in the somatic O and in the Vi antigens of spheroplasts and intact cells. The only major change associated with transformation of normal typhoid organisms into spheroplasts seems to be associated with the flagellar antigen. Spheroplasts evoked a high H agglutinin response in immunized rabbits but were poorly agglutinated by standard H antiserum.The immunogenic ability of the spheroplasts to protect mice from the typhoid challenge was about five times higher than that of intact cells and the toxicity was reduced at least 10-fold.

ISSN:0008-4166    

DOI:10.1139/m64-070

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

For the study of in vitro antibody production, methods have to be established which are sensitive and specific enough to demonstrate minute amounts of antibodies.Spleen cell suspensions from hyperimmunized rabbits (secondary phase) were incubated in completely synthetic medium. The amount of antibody in the culture fluid supernatants was assayed by the following methods: Neutralization ofC.perfringenstoxin using a modified lecitho-vitellin test. The test could demonstrate as little as 0.0015 antitoxic units (AU)/ml. In tissue culture systems antitoxin titers up to 0.1 AU/ml were observed. Neutralization of the dermonecrotic and lethal action of diphtheria toxin. This method detected 0.001 AU/ml. In experiments with tissue cultures antitoxin titers of 0.25 AU/ml could be demonstrated.Antibodies labelled with C14glycine were used in other experiments. To demonstrate labelled antibodies the coprecipitation method was used.Our experiments showed that antibodies produced in vitro can(a) inhibit the lecithinase activity ofC.perfringenstoxin,(b) neutralize the dermonecrotic and lethal action of diphtheria toxin, and(c) participate in precipitation.

ISSN:0008-4166    

DOI:10.1139/m64-071

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Mononuclear leucocytes harvested from the peritoneal cavities of rats recovered from infection withPasteurella tularensis, and from those immunized with a killed vaccine, conferred significant resistance against this organism when transferred to normal recipients. It was determined that a minimum of 3.7 × 107leucocytes/rat was required for protection and that only intact cells were effective in providing immunity. The immune response was shown to be specific for tularemia, and was of the passive type, disappearing between 15 and 18 days following cell transfer.

ISSN:0008-4166    

DOI:10.1139/m64-072

出版商:NRC Research Press    

年代:1964

数据来源: NRC