Meningococcus Toxin and Antitoxin
4
Citation
0
Reference
10
Related Paper
Citation Trend
Abstract:
Summary Live cultures, whole killed cultures, washed killed cultures, washings of live cultures, washings of killed cultures and toxin (meningococcus bouillon filtrate) have more or less of a similar effect when injected intracisternally in 250-gram guinea pigs. Experimental meningococcus antitoxin has a neutralizing effect against meningococcus toxin, the washings of killed cultures and to some degree against washed cultures, when mixed with these substances before injection, but shows no evidence of neutralizing live cultures or killed cultures when the mixtures are injected intracisternally. Antimeningococcic serum has evidenced some neutralizing effect against meningococcus toxin when the mixture of toxin and serum was injected intracisternally. Exposure for two hours at incubator temperature has no appreciable deleterious effect on the toxin or mixtures of toxin and antitoxin.Keywords:
Antitoxin
Data are presented on the detection in crude animal and human sera of Cl. perfringens phospholipase C (PLC) inhibitor. When the level of Cl. perfringens type A antitoxin is determined in the in vitro toxin neutralization test the inhibitor is found to decrease PLC activity in the test dose of experimental homologous toxin. The extent of decrease accounts for the variation of results obtained in the in vitro and in vivo toxin neutralization tests. The variation may be cancelled out by introducing a corresponding coefficient to calculate the level of alpha-antitoxin. It is suggested that the isolation and investigation of the PLC inhibitor will contribute to the development of preparations for treatment of gas gangrene due to Cl. perfringens type A.
Antitoxin
Clostridium perfringens
Gas gangrene
Cite
Citations (1)
Antitoxin
Tetanus antitoxin
Cite
Citations (194)
Bacterial toxin-antitoxin (TA) systems typically consist of a small, labile antitoxin that inactivates a specific longer-lived toxin. In Escherichia coli, such antitoxins are proteolytically regulated by the ATP-dependent proteases Lon and ClpP. Under normal conditions, antitoxin synthesis is sufficient to replace this loss from proteolysis, and the bacterium remains protected from the toxin. However, if TA production is interrupted, antitoxin levels decrease, and the cognate toxin is free to inhibit the specific cellular component, such as mRNA, DnaB, or gyrase. To date, antitoxin degradation has been studied only in E. coli, so it remains unclear whether similar mechanisms of regulation exist in other organisms. To address this, we followed antitoxin levels over time for the three known TA systems of the major human pathogen Staphylococcus aureus, mazEF, axe1-txe1, and axe2-txe2. We observed that the antitoxins of these systems, MazE(sa), Axe1, and Axe2, respectively, were all degraded rapidly (half-life [t(1/2)], approximately 18 min) at rates notably higher than those of their E. coli counterparts, such as MazE (t(1/2), approximately 30 to 60 min). Furthermore, when S. aureus strains deficient for various proteolytic systems were examined for changes in the half-lives of these antitoxins, only strains with clpC or clpP deletions showed increased stability of the molecules. From these studies, we concluded that ClpPC serves as the functional unit for the degradation of all known antitoxins in S. aureus.
Antitoxin
Cite
Citations (116)
Antitoxin
Neurotoxicity
Cite
Citations (12)
Quantitative Studies on the Neutralization of Pathogenic Agents in Tissues by Circulating Antibodies
Summary The neutralization of diphtheric toxin in the skin by intravenously injected antitoxin follows the law of multiple proportions provided that the antitoxin is given before the toxin. If the antitoxin is injected only two minutes after the toxin, neutralization no longer follows the law of multiple proportions, larger amounts of toxin requiring more antitoxin than calculated. From the above experimental observations it follows that when the injection of antitoxin precedes that of the toxin the latter is neutralized before combining with the tissue. The endpoint of titration is the same whether the antitoxin is injected immediately, 1, 2, and sometimes even 4 or 6 hours before the toxin is injected intracutaneously. The distribution of antitoxin between blood and skin, therefore, must reach equilibrium immediately after its intravenous injection. This rapid exchange of antibodies between blood and tissue is explained by the assumption that the cutaneous reaction will be negative when the toxin is neutralized in a molecular zone of fluid bordering on the tissue structures and that within this area the exchange takes place in no measurable time. The result of the cutaneous test under these experimental conditions, therefore, is independent of the velocity of the toxin-tissue reaction. The application of these conclusions to experiments with viruses is discussed.
Antitoxin
Cite
Citations (0)
Antitoxin
Polyclonal antibodies
Cite
Citations (10)
Neutralization of Clostridium difficile toxin by Clostridium sordellii antitoxin was studied by cytotoxicity assay in tissue culture. The sources of toxin were stools from two patients with pseudomembranous colitis and a culture filtrate of C. difficile isolated from one of the patients. C. sordellii antitoxin was available either in monovalent form or as gas gangrene polyvalent antitoxin. The potency of antitoxins against C. difficile determined by cytotoxicity assay did not correlate with the established values reported for mouse protection tests against C. sordellii toxin. An equivalent zone of optimal neutralization was demonstrated for stool toxin, and a slightly different one for culture toxin. The rate of neutralization appeared to be instantaneous, either at 24 or at 37 degrees C. The efficacy of antitoxin in preventing cytotoxicity in cultured cells preexposed to toxin decreased rapidly with preexposure time. The union between toxin and antitoxin could be readily dissociated by simple dilution or by ammonium sulfate precipitation followed by dissociated by simple dilution or by ammonium sulfate precipitation followed by dilution. Continued incubation of toxin-antitoxin mixture did not increase the firmness of the union; on the contrary, more dissociation occurred. The unusual looseness of the toxin-antitoxin union is probably relatd to lack of serological specificity or affinity. Based on these observations, a practical diagnostic method for antibiotic-induced colitis is outlined.
Antitoxin
Ammonium sulfate precipitation
Clostridium botulinum
Cite
Citations (80)
Quantitative Studies on the Neutralization of Pathogenic Agents in Tissues by Circulating Antibodies
Summary The amount of intravenously injected antitoxin which is necessary to neutralize 10 lethal doses of tetanus toxin, injected intracerebrally, differs in rabbits and guinea pigs even when the difference between the volumes of the plasma of the two animal species is taken into consideration. In the case of diphtheric toxin, however, the values are the same when a correction is made for the volumes of the plasma. The cerebral capillaries of the guinea pig and rabbit, therefore, must be equally permeable to antibodies, contrary to the conclusions existing in the literature. These results also show that the widely held opinion of the impermeability of the cerebral capillaries to antibodies is not tenable.
Antitoxin
Cite
Citations (4)
An atypical toxin variant of Clostridium botulinum (strain 657) was isolated from the feces of a 6-week-old female infant whose symptoms and clinical history were consistent with infant botulism. Toxin detected in the feces and the toxin produced by isolates from the feces and from two rectal swabs could be neutralized by type B botulinal antitoxin only at very high ratios of of antitoxin to toxin in the neutralization mixture. One international unit of type B antitoxin neutralized only about 10 lethal doses of 657 toxin as compared with approximately 10,000 lethal doses of conventional type B toxin from the Beans strain. Antitoxin prepared against 657 toxin was 10 times more effective against the conventional toxin than against the homologous toxin. Toxoid-antitoxin-binding studies indicate that both 657 toxin and type B toxin are heterogeneous and that both toxins may contain the same molecular variants, but that the proportions of the variants are different in each.
Antitoxin
Botulism
Clostridium botulinum
Toxoid
Cite
Citations (53)