The culture filtrates of non-cholera vibrios (NAG vibrios) which possessed toxic activity were concentrated, precipitated with (NH4)2SO4 and fractionated on a column of Sephadex G-100. Three fractions were obtained. The first fraction contained mainly lipopolysaccharide which possessed no enterotoxic activity measured by the fluid accumulation in the ligated rabbit ileal loop as well as no activity in the skin permeability test. However, it was toxic for mice after i.v. administration (LD50: 600 microgram per mouse). The second fraction contained one antigenic protein and revealed four bands in the region of albumin migration distance in polyacrylamide electrophoresis. The size of the molecules from the second fraction was estimated by the elution volume from the G-100 Sephadex and polyacrylamide electrophoresis at approximately 50,000-70,000 daltons. This fraction had marked proteolytic activity. The third fraction contained proteins. In biological experiments only the second fraction possessed the enterotoxic activity identical to that of the original filtrate. The coexistence of the permeability and hemorrhagic factor in this material was proven by means of the rabbit skin test and a fast toxic effect for infant mice after intragastric inoculation. The enterotoxic activity characteristic of cholera enterotoxin was demonstrated in the ligated ileal loop of rabbit only after administration of 5-10 fold concentrated culture filtrate and the second fraction.

Animals↗

PubMed1977

Experimental Toxigenicity of NAG Vibrios.

Some strains of NAG vibrios isolated from the stool of patients with diarrhoeal disease as well as from surface water caused an accumulation of fluid in the ligated rabbit gut loop. 5-fold concentrated sterile culture filtrates of some strains were found positive in this test as well. The volume of the accumulated fluid in gut loops injected with live cultures as well as with concentrated culture filtrates was apparently smaller than the volume accumulated after injection of non-concentrated V.cholerae culture filtrates. This points to the fact that the NAG vibrio strains belong to weaker producers of enterotoxin than the cholera vibrios. The culture filtrates of all investigated strains contained the skin toxin which was of increased vascular permeability in the skin of rabbits. Besides this, a hemorrhagic effect was found in the filtrates. The skin toxin of NAG vibrios appears to be more heat resistant than the toxin of cholera vibrios. The presence of the skin toxin in culture filtrates, however, does not correlate with the enteropathogenicity of NAG vibrio strains.

Animals↗

PubMed1975

Investigation of the role of Vi antibodies and antibodies of IgA type in the low specific bactericidal activity of the serum in typhoid carriers.

Absorption of sera of typhoid carriers with Vi antigen resulting in the decrease of gamma A antibodies led to a significant increase in the specific bactericidal activity of the serum. On the basis of these findings the authors discuss the origin and the cause of the low values of this activity in sera of typhoid carriers and the possible meaning of this phenomenon in the pathogenesis of typhoid carriership.

Antibodies, Bacterial↗

PubMed1975

Typhoid gamma G, gamma M and gamma A antibodies in persons with different relation to the typhoid infection.

A study has been made of the differences in specific antibodies in three classes of immunoglobulins in sera of persons with different relation to the typhoid infection. The amount of specific antibodies was calculated from the differences in the levels of serum IgG, IgM and IgA before and after absorption with purified O, Vi and H antigens. The concentration of each immunoglobulin class was determined by means of single radial immunodiffusion. The results showed a significant decrease of IgA in the sera of typhoid carriers and IgM in the sera of patients with typhoid fever and persons with typhoid history after the absorption with the above mentioned antigens. The amount of eliminated antibodies in IgA class of the sera from typhoid carriers was 2.4 time higher as compared with the sera of non-carriers with typhoid history. The level of gamma M antibodies was 2.2 time higher in the sera of patients with typhoid fever and 2.8 time higher in the sera of persons with typhoid history than in the sera of typhoid carriers. In the IgG class no significant differences were observed.

Absorption↗

PubMed1974