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The influence of staphylococcal enterotoxin of type A (SEA) and enterobacterial lipopolysaccharide (LPS) on the production of tumor necrosis factor alpha (TNF alpha), gamma-interferon and active forms of oxygen by mouse peritoneal cells was studied. Both SEA and LPS, when injected to animals, produced stimulating influence on the oxygen metabolism of phagocytizing cells. The highest toxic doses of LPS induced the maximal generation of oxygen radicals. Under the conditions of the development of lethal toxic shock, i.e. after the combined injection of SEA and LPS, the synergic activation of oxygen metabolism was observed, which was also manifested by the pronounced production of TNF alpha and the increased synthesis of gamma-interferon.

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The screening of Campylobacter clinical isolates in ELISA with the use of nitrocellulose filters as solid phase has revealed the possibility of the detection of enterotoxins. The capacity for producing thermolabile enterotoxin has been found in 75.9%, Shiga-like enterotoxin in 56.4% and both enterotoxins in 31.3% of the tested C. jejuni and C. coli strains. The influence of the enterotoxigenic capacity of the strains under study on the severity of Campylobacter infection and on its numerous clinical manifestations in children has been established.

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In the process of the submerged cultivation of E. coli gene engineering strain KS 1561 carrying hybridization plasmid controlling the synthesis of thermolabile enterotoxin LT. The dissociation of the initial strain with the formation of two populations with different properties was observed. One population was characterized by the capacity of fermenting lactose and had decreased activity on the production of LT; the other population, which was lactose-negative, was capable of its increased synthesis.

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The structure and functional specificity of thermostable toxins, their genetic determination, mechanisms of action and testing are reviewed. Amino acid sequences of the peptide toxins with the common amino acid residues on the C-end of their molecules are presented as well as the sequences of the functional groups underlying the biological activity. The data on the structure of precursors of enterotoxins, the genetic control of toxin production and location of the est-genes in the genome of bacteria are demonstrated. The nature of receptors binding enterotoxins, their effect on the guanylate-cyclase system are also described. The possibility of enterotoxins testing by different techniques (genetic, biological, immunological) are discussed.

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We investigated the level of reduced glutathione in mouse liver after injection of staphylococcal enterotoxin type A (SEA) and Serratia marcescens endotoxin (LPS). It was shown that SEA caused significant glutathione depletion. Glutathione level fell more under the combined treatment by both toxins. The data demonstrate a considerable role of antioxidant potential in the mechanism of enhanced sensitivity of animals to the lethal effect produced by LPS.

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The Escherichia coli strains (75) isolated from patients suffering from diarrhea were screened for ability to produce the temperature-labile or stable toxins (ST or LT) by the different techniques (the hybridization with DNA probes, biological, enzyme immunoassay). The majority of tested strains was shown to harbor the tox-genes controlling the synthesis of ST, LT or both enterotoxins. However, the phenotypic expression of the genes was registered in only some of the strains. The hybridization with the DNA probes is noted to be most perspective in the mass screening of toxigenic strains. The DNA probe used contained the fused estA-eltB genes that makes one able to detect the genes for both enterotoxins.

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The simple method is proposed for isolation and purification of staphylococcal alpha-toxin that permits one to obtain the homogeneous toxic protein with high activity. The time necessary for maximal toxin production at cultivation has been defined. The thermostability and interferonogenic characteristics of the obtained alpha-toxin were studied.

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The procedure for isolation and purification of Pasteurella multocida serovariant D toxin has been described. It includes the three steps of protein precipitation from cultural filtrates by 70% ammonium sulfate, chromatography of the concentrated material on Ultragel AcA44 gel-filtration on Sephracryl S-200. The proposed technique permits one the 155-fold purification of the preparation with 32.6% yield estimated by biological activity. The obtained purified preparation is homogeneous in polyacrylamide gel electrophoresis. The immunological methods also confirm the homogeneity of the preparation. The minimal dermonecrotic dose for guinea pigs of the purified 120 kDa toxin is 78 ng and LD50 for mice is 280 ng. Pasteurella multocida toxin is found to be a thermolabile protein sensitive to trypsin, glutaraldehyde and formaldehyde treatments.

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The aim of this study is production of monoclonal antibodies (MAB) to staphylococcal alpha-toxin (SAT). SAT was obtained from culture medium of S. aureus s. 0-15 with ion-exchange chromatography and chromatofocusing. SAT was conjugated with CH-sepharose 4B and used for in vitro immunization of spleen cells, extracted from intact BALB/c mouse.

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The antilysozyme activity of 184 meningococcal strains was studied. Such activity was found in all strains within the range 1-25 micrograms/ml, which was due to the heterogeneity of bacterial population. Strains varying in the total level of their lysozyme activity differed in the population structure by this sign. Preparations inhibiting antilysozyme activity could be differentiated according to the character of their action by the method of the population analysis. In the process of phagocytosis the selection of clones with a high level of antilysozyme activity was found to occur. The antilysozyme factor, heat resistant protein with a molecular weight of 10,000-30,000 D, was sensitive to trypsin.

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Type D purified staphylococcal enterotoxin and anti-enterotoxic serum to it were prepared. IgG isolated from the anti-enterotoxic serum by the affinity chromatography method was used to improve the specificity and sensitivity of the aggregate hemagglutination test (AHAT) and enzyme immunoassay (EIA). The developed AHAT and EIA variants intended for the indication of type D staphylococcal enterotoxin are characterized by a high resolution ability and strict specificity. The suggested methods are simple and may be used for the rapid diagnosis of staphylococcal toxin infections.

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A new method for isolation and purification of Vibrio cholerae non-01 cytolysin has been elaborated. It includes the steps of concentration by ammonium sulphate, ion exchange chromatography on DE-52-cellulose, gel filtration via ultragel AsA-44 and chromatography on Mono Q. Cytolysin is shown to be a 60 kD and pI 6.2 protein. It is not inactivated by thiol-restoring agents and induces the production of precipitating antibodies. In contrast to choleragen the protein cytolytically affects erythrocytes and cells of the line L-929. It also possesses the lethal and oedematous effect and demonstrates the enteropathogenic effect on nursing rabbits.

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The capacity of P. mirabilis and P. vulgaris strains isolated in acute enteric infections in children for producing enterohemolysin, a new type of hemolysin, has been shown. The relationship between the capacity of Proteus cultures for producing enterohemolysin and their capacity for inducing toxic secretory reaction on a ligated loop on the small intestine of rabbits in the absence of known thermostable and thermolabile antitoxin in bacteria.

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The recent data on staphylococcal alpha-toxin, its functions, methods for its purification, forms are presented in the review. The problem of a target for toxin molecule is discussed.

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The capacity of Proteus strains, isolated from patients with purulent inflammatory, urological and enteric infections, for the production of choleriform thermolabile enterotoxin was studied by means of the enzyme immunoassay (EIA) with the use of antitoxic serum to Escherichia coli enterotoxin. Out of 125 strains, 27 (21.6%) showed the capacity for producing choleriform thermolabile enterotoxin in EIA experiments. The results thus obtained indicate that EIA techniques can be used, in principle, for detecting the capacity of Proteus for the production of choleriform thermolabile enterotoxin.

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The present study investigated the effect of staphylococcal enterotoxin type A (SEA) and endotoxin Serratia marcescens (LPS) on the phagocytosis and killing of Staphylococcus aureus by mouse peritoneal macrophages. Two hours after enterotoxin intraperitoneal injection phagocytic and bactericidal activity were depressed. 24 hours later there was increased functional activity of macrophages by SEA and LPS, apart. But when two toxins were administered together (LPS four hours later enterotoxin) marked inhibition of bacterial killing was observed. When peritoneal macrophages were treated in vitro for 24 hours with the same toxins they were also markedly suppressed in bactericidal activity.

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Comparative study of mitogenic and interferonogenic properties of staphylococcal enterotoxins of different serotypes is done. It is revealed that preparations of enterotoxins are polyclonal mitogens and have interferon-inducing activity. It is stated that enterotoxin of D type has the highest mitogenic activity, which is shown by interferon-inducing activity of A type toxin.

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