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Biomedical subjects

J Karolcek

Publications and source records attributed to J Karolcek.

At least 19 recordsLinked to original sources
PubMed1987

Partial purification and biological activity of the enterotoxic component of Pseudomonas aeruginosa.

From an Pseudomonas aeruginosa strain isolated from feces of a patient with clinical manifestation of diarrhoeal disease a filtrate from the culture in proteose peptone broth was prepared. After concentration, the culture filtrate was separated on Sephadex G-100 column in four fractions. The first high molecular fraction (F1) represented components of relative molecular mass exceeding 100,000, the second fraction those about 58,000, the third fraction those about 23,000 and the fourth one was composed from low molecular components of molecular mass lower than 10,000. In biological tests, the most marked reactions were caused by the third fraction. It caused a fluid accumulation in the rabbit ileal loop test, reactions in the rapid and delayed skin tests and in the mouse foot edema test. Besides these activities the third fraction caused also a hemolytic, proteolytic and elastase activity. A clear cytotoxic effect of this fraction was seen on Vero, Y1 and CHO cell lines. It was also found, that after heating (100 degrees C/10 min) both, the enterotoxic and hemolytic activities were lost.

Animals↗
PubMed1985

Toxic exoproducts of citrobacter freundii.

A strain of Citrobacter freundii isolated from the feces of a patient with diarrhoea was examined for growth kinetics and toxic exoproduct formation using the complete (BHI) and synthetic culture media. It was found that the test organism in synthetic medium grew distinctly slower than in BHI. Fractionations on Sephadex G-100 column yielded 3 fractions from the complete medium culture filtrate and 2 fractions from the culture filtrate obtained from synthetic medium. The first culture filtrate fractions (F1) were represented by components of the molecular weight over 100,000, the respective second fractions (F2) from complete and synthetic medium were of the molecular weights of about 40,000 and 10,000. In the early skin test on rabbits the toxicity of culture filtrates and their fractions manifested itself by an increased permeability of blood vessels, in the late skin test by a hemorrhagic reaction associated with dilatation of blood vessels and induration of the skin tissue. In a test on mouse foot pad all separated filtrate fractions gave a positive edematous reaction. In cultured Vero cells samples of synthetic medium fractions gave a distinct cytotoxic reaction. Immunochemically, the presence of LPS in culture filtrates as well as some variations in the antigenicity of components from the complete and synthetic medium fractions were found. Apart from LPS some additional high-molecular-weight components were also present in the toxic complex of both first filtrate fractions (F1). Much more attention should be given to analysis of these first fraction complexes as well as to toxinogenicity of second fractions (F2) using some additional tests.

Bacterial Toxins↗
PubMed1984

Toxinogenic potential of Proteus mirabilis strains.

Live bacterial suspensions, original as well as concentrated filtrates of Proteus mirabilis cultures caused positive reaction in the rapid skin test (vascular permeability reaction) and also in the delayed test (combination of haemorrhagic reaction, dilatation of vessels and induration) as well as in the test of mice-foot edema. The test on suckling mice did not prove the presence of thermostable enterotoxin. After separating the concentrated culture filtrates the biologic activity appeared in fraction 1 (relative molecular mass over 100 000) concerning the delayed skin test and in the fraction 2 (relative molecular mass approx. 40 000) in the rapid skin test. The activity localized in the fraction 1 can be ascribed to a lipopolysaccharide. The fraction 2 with an expressed activity in the rapid skin test showed also cytotoxic and proteolytic activity. In both fractions the presence of active antigen substances with different mobility and different antigen specificity was demonstrated.

Animals↗
PubMed1983

Biological activities of enterotoxin from Vibrio cholerae non-01.

The specific antiserum 54(2) prepared in rabbits by combined intraperitoneal and intravenous immunization with the enterotoxin from Vibrio cholerae non-01 was found to neutralize the enterotoxin biologic activity expressed by rabbit skin vascular permeability and hemorrhage factors. The inhibition of biologic activity was also observed when using antiserum to choleragen, but choleragen could not be neutralized by specific serum 54(2). The enterotoxin was also inactivated when heated at 100 degrees C for 10 min, but heating at 56 degrees C for 30 min had no influence on its biologic activity. The enterotoxin from Vibrio cholerae non-01 was found to elevate concentration levels of cAMP in the epithelial cells of the rabbit intestine and this elevation was comparable with that produced by the filtrate of Vibrio cholerae 569 B culture. The culture filtrate from Vibrio cholerae non-01 exhibited a similar activity. The Vibrio cholerae non-01 enterotoxin as well as the original culture filtrate were found to be cytotoxic for Vero cells.

Adenylyl Cyclases↗
PubMed1982

Bound and spontaneously released toxic products of NAG vibrios cultivated in minimal synthetic media.

Properties of toxic substances released spontaneously and by ultrasonic disintegration from NAG vibrio cells cultivated in minimal synthetic medium were compared. The released material was separated on the AMICON ultramembranes, dialysed and fractionated on the column of Sephadex G-100. This procedure revealed three fractions released by ultrasonic disintegration. The culture released spontaneously only one fraction separated by the above mentioned procedure. The molecular weight estimated by the elution from calibrated G-100 column of the fractions released by the ultrasound was a follows: first fraction (H1) over 100,000, second fraction (H2) 25,000-30,000 and third one (H3) below 10,000. The molecular weight of the spontaneously released fraction (F1) was over 100,000. The biological activity of the fractions was tested by the rabbit skin test and by the rabbit ligated ileal loop test. The fractions H1, H2 and F1 were positive in both while the fraction H3 was negative. Fraction F1 was inactivated at 56 degrees C while at 100 degrees C its activity was restored. In agar gel diffusion test, the presence of endotoxin in fraction F1 was proved by means of specific antiserum. Results show that the toxic substances of enterotoxin nature are bound also to cell structures. They reveal the biological activity qualitatively and quantitatively different of the spontaneously released substances. Besides the endotoxin also other cell components can contribute to these effects.

Animals↗
PubMed1982

Ecology and importance of bacterial' species of the family Vibrionaceae.

The bacterial species of the family Vibrionaceae, particularly the species of the genus Aeromonas (A. hydrophila and A. punctata and their subspecies were found to be relatively common in the running surface water in Czechoslovakia (the occurrence of A. salmonicida species was not studied). The strains of the so-called NAG-vibrios (Vibrio cholerae unrelated to the cholera vibrio 0 group 1) were also relatively frequent, but the positive isolates of Plesiomonas shigelloides were sporadic. The above described bacterial species occurred also in municipal sewage water and the strains of the Aeromonas genus were identified even in the drinking water of some wells and in foods. In the biological specimens from the human sources, namely in the feces of patients with diarrheal diseases, in secreta from the respiratory pathways, in the urine and occasionally in other material, there prevailed strains of the genus Aeromonas, especially A. hydrophila subsp. hydrophila and A. punctata subsp. caviae. Among the isolates from foods A. punctata subsp. caviae predominated. Positive isolates of the Aeromonas strains from the intestinal contents of cattle, domestic animals and some synantropic birds were rare. Importantly, a relatively great part of the isolates obtained from various sources (including the strains isolated from well water and foods) showed enterotoxigenic properties. The enterotoxigenicity was also observed in a great number of NAG-vibrio strains and in strains of Plesiomonas shigelloides. The occurrence of vibrios in the examined animal species was sporadic.

Aeromonas↗
PubMed1982

Toxic factors of Aeromonas hydrophila and Plesiomonas shigelloides.

In detail, exoproducts of Aeromonas hydrophila and Plesiomonas shigelloides were studied on the pathogenesis of diarrhoea. Enterotoxin, hemolysin and a cytotoxic factor were found in a fraction of culture filtrates of Aeromonas hydrophila with a molecular weight of approximatley 60,000. Apart there from a cytotoxic factor was also found in a fraction with molecular weight above 100,000. This fraction contained also endotoxin which was hemolytic, too. Enterotoxic activity was expressed by an accumulation of fluid in the ligated ileal loop and by increased vascular permeability in the skin of rabbit. Activation of adenylate cyclase was not found. Cytotoxic activity was represented by hemorrhagic reaction in the skin of rabbit, in some cases by sanguinous and mucous fluid in the ligated ileal loop and by significant morphological alterations on Vero cells leading to the death of cells. Culture filtrates of Plesiomonas shigelloides show only very low activity in biological experiments. Separation and purification steps led to a more concentrated and active material.

Aeromonas↗