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PubMed1993

[Granule-accumulation in VERO cells used for determination of antitoxin titration by micro cell culture method: II. Nature of granules and influence on the potency testing of diphtheria toxoid].

Accumulation of granules occurs in VERO cells when mouse serum was added in high concentration. The nature of the granule and influence of the granule-accumulation on the potency testing of diphtheria antitoxin were studied. The concentration of triglyceride in VERO cells increased 15 folds after 24 hours of incubation by the addition of undiluted mouse serum. Kinetical study of the increase of triglyceride and electron microscope observation suggested that the accumulated granules might be oil droplets with an average diameter of 0.27 micron. The end point reaction of neutralization of diphtheria toxin by the standard antitoxin was analyzed by the addition of mouse serum to the micro cell culture using VERO cells. The mean values of the end point reactions in the cell cultures added with high concentrations of mouse serum were -2.324, -2.338 and -2.346, while that of the control group was -2.343. The variance of these mean values in the experiment and control groups were 0.0017, 0.0024, 0.0017 and 0.0021, respectively. A test of homogeneity of variance for these data showed no significant difference between them. Furthermore, antitoxin titer of the serum specimens of mouse immunized with diphtheria toxoids determined by the micro cell culture method were compared with that obtained by rabbit skin test; a high correlation between the antitoxin titers by the two techniques was recognized. The results were comparable with those of guinea-pig sera. From these results it is evident that little influence, if any, was observed in the potency testing of diphtheria antitoxin using VERO cells, in spite of the remarkable accumulation of granules.

Animals↗
PubMed1977

Purification and some properties of phospholipase C (alpha-toxin) of Clostridium perfringens.

1. Phospholipase C[EC 3.1.4.3] was purified from the culture filtrate of Clostridium perfringens by successive chromatographies on CM-Sephadex, DEAE-Sephadex, and Sephadex G-100. During the purification it was noted that, beside the monomer form of the enzyme which was purified, a part of the enzyme existed in active polymerized forms. 2. The purified preparation gave a single band on polyacrylamide gel electrophoresis and gave a single precipitin line in immunodiffusion with the National Standard gas gangrene (C. perfringens) antitoxin, indicating the homogeneity of the preparation. 3. The specific lecithin-hydrolyzing activity of the purified preparation was comparable to that of a preparation obtained by affinity chromatography, which had the highest specific activity previously reported. 4. The molecular weight of the purified enzyme was estimated to be 43,000 by SDS-polyacryl-amide gel electrophoresis, although the same preparation gave a molecular weight of 31,000 as determined by gel filtration on Sephadex G-150. From this and the above finding that a part of the enzyme exists in active polymerized forms, the discrepancy among reported values for the molecular weight of C. perfringens phospholipase C can be accounted for. 5. For maximum hydrolytic activity toward lecithin, the enzyme required sodium deoxycholate (SDC) and Ca2+ ions. In the presence of 6 mM Ca2+, the optimal molar ratio of SDC to lecithin for maximal hydrolytic activity was about 0.5 for dipalmitoyl lecithin and about 1.0 for egg lecithin. The effects of various divalent cations on the enzymatic hydrolysis were also investigated. 6. The effects of sodium deoxycholate and Ca2+ ions on the enzymatic hydrolysis are discussed, based on their possible roles in mixed micelle formation.

Antitoxins↗
PubMed1990

Carboxy-terminal peptides from the B subunit of Shiga toxin induce a local and parenteral protective effect.

Two synthetic peptides corresponding to overlapping sequences from the C-terminus of the B chain of Shiga toxin were prepared and characterized. These peptides consisted of residues 54-67 and 57-67 in the protein sequence. This region coincides with the major peak of surface area residues, as predicted from a computer-derived plot. For the purpose of immunization, the peptides were either conjugated with a protein or a synthetic carrier, or were polymerized. Polyclonal antibodies against these peptides derivatives, induced in rabbits, recognized the homologous peptides and cross-reacted with the intact toxin. These antibodies were capable of neutralizing the various biological activities of the toxin, namely the cytotoxic, enterotoxic and neurotoxic activities. Active immunization of mice with the peptide derivatives protected them from the lethal effect of the toxin. Moreover, oral immunization of rats led to inhibition of fluid secretion in ligated ileal loops into which toxin was injected. This effect was paralleled by the induction of high levels of specific anti-peptide IgA antibodies in the serum after bile duct ligation.

Administration, Oral↗
PubMed1985

Selective and differential medium for detecting Clostridium botulinum.

A selective and differential growth medium was developed for detection of Clostridium botulinum types A, B, and F. The medium consisted of peptone-glucose-yeast extract agar supplemented with cycloserine, 250 micrograms/ml; sulfamethoxazole, 76 micrograms/ml; and trimethoprim, 4 micrograms/ml as selective inhibitors and various types and levels of botulinal antibodies for type differentiation in the immunodiffusion reaction. Growth of proteolytic types of C. botulinum were not affected by the incorporation of the selective agents, but some nonproteolytic types were suppressed. Cross-reactions between types A and B were visually distinguishable, whereas cross-reactions between type F and Clostridium sporogenes did not occur at the optimum antibody titer. Optimum antibody titer varied with toxin type. The proposed selective differential medium should be valuable in isolating and typing of proteolytic C. botulinum types A, B, and F from samples containing mixed microbial populations.

Antitoxins↗
PubMed2001

Saccharomyces boulardii stimulates intestinal immunoglobulin A immune response to Clostridium difficile toxin A in mice.

Saccharomyces boulardii is a nonpathogenic yeast that protects against antibiotic-associated diarrhea and recurrent Clostridium difficile colitis. The administration of C. difficile toxoid A by gavage to S. boulardii-fed BALB/c mice caused a 1.8-fold increase in total small intestinal immunoglobulin A levels (P = 0.003) and a 4.4-fold increase in specific intestinal anti-toxin A levels (P < 0.001). Enhancing host intestinal immune responses may be an important mechanism for S. boulardii-mediated protection against diarrheal illnesses.

Animals↗
PubMed1993

Colony immunoblot assay of botulinal toxin.

Botulinal neurotoxin in and around colonies of Clostridium botulinum types A, B, and E and of toxigenic Clostridium butyricum was detected by an enzyme-linked immunoassay procedure whereby the toxin was transferred from the agar medium to a nitrocellulose support and the immobilized toxin was probed with type-specific antibodies. The method identified the toxin types of the colonies grown from a mixed inoculum of C. botulinum serotypes. The specificity of the antitoxins for type A and B toxins was improved by adsorption of the antitoxins with the antigens of heterologous type cultures.

Antibody Specificity↗
PubMed1985

Expression of the cloned toxic shock syndrome toxin 1 gene (tst) in vivo with a rabbit uterine model.

Toxic shock syndrome (TSS) toxin 1 (TSST1) is produced by strains of Staphylococcus aureus associated with TSS. Purified TSST1 induces in rabbits a shock-like illness with many features similar to TSS in humans. These symptoms were also induced by TSST1-producing bacteria in diffusion chambers implanted in the rabbit uterus. Naturally occurring TSST1+ strains and a TSST1- strain harboring a pE194-derived plasmid carrying the cloned TSST1 determinant tst gave the same symptoms. TSST1- strains and a TSST1- strain carrying a pE194-tst plasmid with a deletion of the tst gene had no effect in rabbits. The results with the plasmid-carrying TSST1+ and TSST1- strains, which were isogenic apart from tst, show that the toxin is responsible for the illness in rabbits and suggest that it is a major factor in the pathogenesis of TSS.

Animals↗
PubMed1984

[Antitoxic effect of leukocytic interferon in in vivo experiments].

Leukocyte interferon of various species origin (human, swine, mice) protected mice from the lethal dose of staphylococcal toxin. Endogenic mouse interferon and exogenic serum mouse interferon had no such effect. The suspension of waste leukocytes had also a protective activity. The results of the study evidence the presence of antitoxic factor in the leukocytes.

Animals↗