摘要:

The influence of medium composition and cultivation time on the electrophoretic pattern of mycoplasma proteins has been investigated. It was found that media containing horse serum are unsuitable because increasing amounts of medium protein are harvested together with the mycoplasmas during incubation. The medium protein gives rise to unspecific electrophoretic bands which grow more numerous and intense during incubation. These disadvantages were not found in a medium containing PPLO serum fraction. An examination of the electrophoretic patterns of 25M. canis, 16M. edwardiiand 12M. spumansstrains demonstrated that interspecies differences were more pronounced than intraspecies variations. It is concluded therefore that the electrophoresis method may be used as an aid in the classification of mycoplasmas isolated from dogs.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02204.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

A method is presented for the isolation of153H DNA fromNeisseria meningitidis.The15N DNA separates from ordinary14N DNA ofN. meningitidiswhen analysed in analytical density centrifugation corresponding to a difference in buoyant density of approximately 0.013 g/cm3. The specific density of regularN. meningitidisDNA is found to be 1.7105 g/cm3. Analysis by preparative density centrifugation of cell extracts ofN. meningitidistransformed with15N3H DNA shows that the radioactivity taken up during transformation assumes a specific density very close to that of the recipient DNA. The absence of radioactivity corresponding to that of the donor DNA in these cell extracts supports the notion thatN. meningitidislacks a DNase insensitive site outside the membrane, and supports the hypothesis of a concomitant uptake and integration of homologous, exogenous DNA inN. meningitidistransformation.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02205.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Density gradient centrifugations of cell extracts fromNeisseria meningitidistransformed by15N3H DNA in the presence of acriflavin or ethidium bromide show that in spite of a substantial reduction of viable transformants in the presence of these drugs, the radioactivity taken up assumes a specific density indistinguishable from that of the DNA of the recipient cells. Thus DNA uptake and integration are inseparable steps inN. meningitidis.The genetically incompetent (cp‐) variant ofN. meningitidisis unable to integrate exogenous DNA into its chromosome. Furthermore it does not take up exogenous DNA to DNase insensitivity, neither homologous nor heterologous DNA. Exogenous DNA is only taken up by genetically competent (cp+)N. meningitidisif of homologous origin, and when it is integrated into the recipient chromosome in a transformation even

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02206.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Crossed immunoelectrophoresis with intermediate gel was used in an attempt to identify and quantitate precipitins againstPseudomonas aeruginosain sera from 33 patients with Cystic Fibrosis. A standard antigen‐antibody system containing 55 precipitates was used as reference. A total of 173 precipitins against Pseudomonas aeruginosa were found in 20 of the sera. 56 per cent of the precipitins representing 30 different precipitin specificities could be identified and quantitated in relation to the reference system. As much as 22 precipitins were found in one serum. In one serum, the simultaneous occurrence of 6Pseudomonas aeruginosaantigens and 15Pseudomonas aeruginosaprecipitins were demonstrated. Patients harbouring mucoid strains ofPseudomonas aeruginosain the respiratory tract were found to produce significantly more precipitins than other groups of subjects, and 23 out of the 30 different identifiedPseudomonas aeruginosaprecipitins were only found in this group of patients. Protective antibodies were not demonstrated. It is suggested that the mucoid strains ofPseudomonas aeruginosacharacteristic of patients with Cystic Fibrosis are selected in preference to the non‐mucoid strains by means of the patient's immune response. The persistent infection and the multiple precipitins produced against the bacteria by many of the patients raise the question whether the local immune reaction could enhance the destructive lesions of the respiratory tr

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02207.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

A passive hemagglutination method has been used to determine antibodies against type specific capsular polysaccharide in theKlebsiellagroup. Erythrocytes were coated with acidic capsular polysaccharide. Chromium chloride was used as the coupling reagent. The method has been tested on eleven serotypes.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02208.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Serological typing of 200S. aureusstrains from clinical specimens has been performed with the Oeding‐Haukenes factor sera. Since weak agglutinations were recorded, serologically reacting antigens were studied in immunofluorescence with FITC‐labelled type‐specific anti‐S. aureusF(ab')2‐fragments of IgG and IgM and TRITC‐labelled normal IgG to detect protein A by its reaction with the Fc‐part of IgG. Protein A was found to be unevenly distributed among theS. aureuscells derived from a single colony and, by trypsin digestion of the bacteria, type‐specific antigens were found to be masked by the common cell surface constit

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02209.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The antigenic pattern of a pneumococcal strain of serotype 27 used as model was studied by immunodiffusion methods and found to show a complex antigenic structure with a least 21 separate precipitinogens. Strains belonging to type 11, 28 and 29 contained most of the precipitinogens present in the model strain while the antigenic composition of type 3 strain differed more from this strain. Double diffusion studies of capsular polysaccharides prepared by conventional methods revealed the presence of contaminating C‐polysaccharide. Within the tested pH range 4–9 the capsular polysaccharides migrated toward the anode. The electrophoretic migration of the C‐polysaccharide varied with pH. At pH 4–5 it moved slowly toward the cathode which made it possible, by preparative electrophoresis, to obtain capsular polysaccharide free from the contaminating C‐polysaccharide. This procedure is suggested as a final step in isolation of capsular polysaccharides for serolog

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02210.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

567 strains ofStaphylococcus aureusisolated from a number of animal hosts were examined by agar gel precipitation for wall teichoic acids or other wall polysaccharides. The species was shown to be heterogeneous with regard to these constituents. Three groups could be distinguished: 1. The strains which had been classified biochemically as belonging to the human, bovine, hare and horse biotypes, and some of the swine strains, contained polysaccharide A. Of these, the horse strains contained polysaccharide Aαwhereas the other strains regularly contained polysaccharide Aß.Of the latter, a higher incidence of additional polysaccharide Aαdistinguished the human biotype from other biotypes. 2. The dog strains contained none of the reference polysaccharides but an unknown polysaccharide (P). 3. The pigeon and mink strains contained polysaccharide C. The occurrence of polysaccharide C in the biochemically least active biotypes is interesting, indicating a bridge towards the polysaccharide AßC group ofS. epidermi

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02211.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

BCG vaccinated hamsters, in contrast to non‐vaccinated, have been shown to be sensitive to tuberculin injected intraperitoneally. An introductory study showed that hamsters vaccinated with a strongly potent BCG strain were killed by tuberculin shock using about the same dose of purified tuberculin as in experiments on guinea pigs. In the main experiment, hamsters were vaccinated with vaccines prepared from BCG strains of weak, medium or strong potency, and injected with a large dose of tuberculin. It was demonstrated that the number of animals that died of shock was significantly different in the groups vaccinated with the three vaccines. Thus this method can be used for determination of the potency of a vaccine. The strains examined originated from the Danish strain of BCG received from Paris in 193

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02212.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Exudate collected from a strangulated loop of intestine in conventional and germfree rats has the property of inhibiting the opsonic and bactericidal activity of normal rat serum onEscherichia coli.Using release of radioactivity from32P‐labelledE. colias an indicator of bactericidal activity, the inhibitory property of strangulation fluid on serum bactericidal activity has been subjected to further studies. The inhibitory factor (FIB) resisted heat treatment for 30 min up to 100°C, and did not disappear following dialysis. Chromatography of strangulation fluid from germfree rats on Sephadex G‐100 indicated that FIB had a molecular weight higher than 100 000. Homogenates from intestinal mucosal cells contained FIB, while intestinal contents contained FIB of considerably stronger activity. The results indicated that high molecular substances of intestinal origin were responible for the FIB activity of rat strangulation f

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1973.tb02213.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY