[Changes in the serum acid phosphatase activity of guinea pigs poisoned with C1 perfringens type A toxin and a mixture of toxin and a broth culture filtrate]

It was shown in experiments on guinea pigs that the injection of C1. perfringens type A toxoid induced an increase in acid phosphatase activity of animal blood serum. The action of the toxoid increased under the effect of C1. butyricum cultural filtrate, which gave rise to an earlier enhancement of the specific activity of the enzyme as compared to the injection of the toxoid alone. Increased activity of acid phosphatase may play a pathogenetic role in cases of anaerobic infection caused by association of C1. perfringens and C1. butyricum.

Shigellosis and Escherichia coli diarrhea: relative importance of invasive and toxigenic mechanisms

Shigellae and dysentery-like Escherichia coli must invade the epithelium of the colon to cause disease which can present as dysentery, diarrhea, or both. This paper addresses the possible role of a Shigella dysenteriae-like (Shiga-like) toxin in the pathogenesis of shigellosis and E. coli diarrheal diseases. The possibility for such a role is suggested by the following observations: 1) diarrhea, considered to be a result of secretion of water by the small bowel, is frequently observed in shigellosis, a large bowel disease. 2) Even though shigellae do not invade the jejunum of monkeys fed Shigella flexneri, jejunal secretion is seen in animals with diarrhea. 3) The Shiga toxin of S. dysenteriae has enterotoxic activity and other serotypes of shigellae produce Shiga-like toxins. 4) E. coli 015 RDEC-1 causes a diarrheal disease and frequently death in young rabbits. This organism neither produces E. coli enterotoxins nor is it invasive, but it may produce low levels of a Shiga-like toxin.

Diarrhea and colitis associated with antimicrobial therapy in man and animals

Antimicrobial agent-induced ileocecitis of laboratory animals and colitis of man share common features. The significance of a newly described toxin in these two entities, the apparent source of the toxin (Clostridium difficile) and characteristics of the toxin are reviewed. Methods of toxin detection, isolation and rapid identification of C. difficile, and possible modes of therapy for antimicrobial agent-associated colitis of man are discussed.

Clindamycin-induced colitis

The hamster model of enterocolitis after the administration of clindamycin was used to study various drugs used in treatment of the disease in humans. Current evidence strongly suggests toxigenic, clindamycin-resistant Clostridium difficile is a cause of the disease in hamster and man. This organism is susceptible to vancomycin and metronidazole, and the disease could be prevented in the hamster so long as the antibiotics were given orally. A fatal colitis almost invariably ensued once they were discontinued. Administration of cholestyramine significantly prolonged survival of hamsters, but did not pervent death or colitis. Corticosteroids or atropine-diphenoxylate (Lomotil) did not alter the disease. The hamster model may be useful in studying other kinds of treatment of this disease.

[Staphylococcal toxic epidermal necrolysis]

Staphylococcal toxic epidermal necrolysis is a well defined disease and can be ideally reproduced in a mouse model. It is due to the action of a staphylococcal exotoxin (exfoliatin) which is produced by phage group2 staphylococci. Exfoliatin acts on a hitherto unknown target site which is likely to be located in the cell membrane of keratinocytes of the subgranular layer. Sensitivity to exfoliatin is common to only few mammals and appears to be genetically determined. Exfoliatin leads to loss of intercellular adherence resulting in acantholysis; cellular morphology and function remains unimpaired. The action of exfoliatin on the epidermis is not influenced by serum factors nor by the mesenchyme. It is also not age dependent although adult humans as well as adult mice do not develop systemic disease. This is due to suppression of growth of staphylococci and rapid renal excretion of exfoliatin in the mature, immunologically competent organism.

[Changes in the lymph nodes of adrenalectomized rats with staphylococcal poisoning]

Histological changes in lymph nodes and dynamics of 11-oxycorticosteroid levels in blood were studied in intact and adrenalectomized rats under staphylococcal intoxication. At early stages (up to 24 h) after staphylotoxin or staphylococcal injection, stress reaction of the organism, which produces a rise of corticosteroid level in blood, was demonstrated to play the major role in aplasy of the lymphoid tissue. At later stages, when the level of corticosteroids decreases, the lymphoid tissue begins to restore. In adrenalectomized rats, aplasy of the lymphoid tissue begins at later stages (in 3--4 days) because of a decreased amount of corticosteroids in blood. From the data obtained a suggestion is made that under intoxication, devastation of the lymphoid tissue occurs via mediated and direct action of the toxin.

[Effect of aminazin on changes in the electrical activity of the cerebral cortex under the influence of the toxin C1. perfringens type A]

Experiments on cats revealed that injection of chlorpromazine (3 mg/kg of body weight, intramuscular) one hour prior to the Cl. perfingens toxin type A injection prevented the appearance of desynchronization of the electrical activity of the cerebral cortex usually observed during the first phase of intoxication. Chlorpromazine injection postpones the appearance of the electrical activity depression phase during the second phase and prolonged the animals' life span from 1.5 to 2 times. The effect of chlorpromazine was apparently connected with the block of the adrenergic structures of the brain stem reticular formation.

[Effect of alcoholic intoxication on the body's natural resistance to exposure to infectious and toxic agents]

The influence of alcoholic intoxication on the resistance of albino mice to bacterial toxins and staphylococcus cultures was investigated. Five-day administration of 40% ethyl alcohol to the animals was accompanied by a significant increase of their resistance to the intoxication caused by C1. perfringens toxins and staphylococcus. Thirty-day alcoholic intoxication promoted a marked reduction of albino mice resistance to the both toxins used and the staphylococcus cultures.

[Changes in the electric activity of the cerebral cortex in poisoning caused by Cl. perfringens toxin type A]

The electrical activity of the cerebral cortex was recorded in cats under mild nembutal anesthesia (15-20 mg/kg of body weight) during the development of Cl. perfringens, type A, toxin poisoning (the toxin was injected intramuscularly in a dose of 100 MLD per kg of body weight). Two phases of the changes in the electrical activity of the cerebral cortex were noted. The first phase was attended by the desynchronization of the electrical activity, persistence of the induced potentials and of the reaction of the rhythm reconstruction to the rhythmic light stimulus. No desynchronization occurred under conditions of preliminary section of the midbrain (on the mesencephalic preparation), this indicating the involvement of the reticular formation into the pathological process and pointing to its role in the desynchronization effect. A profound depression of the electrical activity of the brain, depression of induced potentials and disturbance of the reaction of the rhythm reconstruction occurred during the second phase.