[Detection rate of enterotoxigenic Staphylococcus aureus isolated from children with intestinal disbacteriosis].

Detection rate of enterotoxigenic Staphylococcus aureus isolated from faeces of 62 children aged from 3 months old to 7 years old with intestinal dysbacteriosis was studied by indirect hemagglutination assay and enzume immunoassay. It was shown that strains of S.aureus producing staphylococcal enterotoxin A (SEA) are prevailed (40.3%) in children with disturbances of intestinal microflora while staphylococcal enterotoxin B (SEB)-producing strains were detected in 20.9% of children. Amount of produced enterotoxin varied for SEA from 125 ng/ml to 2000 ng/ml and for SEB--from 125 ng/ml to 250 ng/ml. Inverse dependence of detection rate of enterotoxin-producing strains in faeces on age of children was established. The most number of enterotoxigenic strains of S.aureus was detected in infants. These data point to expediency of determination of enterotoxin-producing ability of S. aureus strains isolated from children with dysbacteriosis as measure of danger of this microorganism for children's health and indication for adequate actions for its elimination.

[Isolation of different variants of Pseudomonas aeruginosa anatoxin and their characteristics]. / Poluchenie razlichnykh variantov anatoksina Pseudomonas aeruginosa i ikh kharakteristiki.

The conditions for the detoxification of the crude preparations of P. aeruginosa exotoxin A, obtained by the cultivation of strain PA-7 in Martin's broth, have been studied, and the schemes for obtaining nontoxic, stable, specifically antigenic preparations of toxoid from exotoxins A with different degrees of purification have been developed. Toxoid obtained by formalin treatment on the level of a crude preparation with its subsequent purification and additional detoxification with formalin in the presence of lysin has been shown to possess high immunogenic potency. The preparation has been found to induce immune response and to ensure the protection of experimental animals challenged not only with the lethal dose of exotoxin A, but also with P. aeruginosa toxigenic and protease-producing strains.

[Protective properties of anatoxin obtained from a homogeneous preparation of Pseudomonas aeruginosa exotoxin A]. / Protektivnye svoistva anatoksina, poluchennogo iz gomogennogo preparata ékzotoksina A Pseudomonas aeruginosa.

The protective properties of formulated toxoid obtained from the highly purified preparation of P. aeruginosa exotoxin A have been studied in the test of the active immunization of mice. The study has revealed that the preparation when introduced in 1 or 2 injections in a dose of 15 micrograms, shows faint protective potency with respect to P. aeruginosa strains differing in virulence. Immunization with this toxoid in 3 and 4 injections has been found to ensure 60-100% and 50-60% protection of mice infected with P. aeruginosa toxigenic and proteolytic strains respectively. Immunization with toxoid has been found to induce the appearance of short-term antibacterial immunity which loses its capacity to protect the immunized animals, challenged with both toxigenic and proteolytic P. aeruginosa strains, as early as on day 28. The immunization of mice with toxoid in 4 injections has been shown to induce the development of antitoxic immunity capable of neutralizing up to 150 LD50 of purified exotoxin A.

[Exotoxin A production during Pseudomonas aeruginosa PA-7 cultivation in Martin's broth]. / Produktsiia ékzotoksina A pri kul'tivirovaniia Pseudomonas aeruginosa PA-7 na bul'one Martena.

The activity of exotoxin A in culture filtrates prepared from cultures obtained by growing P. aeruginosa strains PA-7 and PA-103 in Martin's broth containing iron at a concentration of 0.08 microgram/ml, 0,05 M sodium glutamate and 1% of glycerin has been shown to be 1.5 times higher than that in filtrates prepared from cultures obtained by growing the above strains in a medium containing soybean tryptic digestion (USA). The optimun conditions for the production of exotoxin A by these strains are achieved during their cultivation in a fermenter at a temperature of 32 degrees C for 18 hours with simultaneous stirring (800 r. p. m.) and oxygenation (450 m3/h). Under these conditions the biological activity of the filtrates is 200 LD50/ml, their ADP-ribosyltransferase activity is 9500 c. p. m. and a sharply defined precipitation line appears in the double diffusion test in gel with monospecific antiserum to purified toxin, used in a dilution of 1:8.

[The assessment of the toxigenicity of clinical strains of Pseudomonas aeruginosa by an immunoenzyme method using nitrocellulose filters]. / Otsenka toksigennosti klinicheskikh shtammov Pseudomonas aeruginosa immunofermentnym metodom s ispol'zovaniem nitrotselliuloznykh fil'trov.

The enzyme immunoassay (EIA) on nitrocellulose filters was adapted for the detection of exotoxin A in 104 P. aeruginosa strains isolated from patients and the environment in surgical wards in hospitals of Moscow and Alma-Ata. The method was shown to be highly sensitive: it permitted the detection of 5.ng of P. aeruginosa exotoxin A. The screening of 104 P. aeruginosa clinical strains by means of EIA on nitrocellulose filters revealed that these strains exotoxin A in 88.5% of cases.

[The proteolytic activity of the contents of the normal large intestine and in microecological disorders]. / Proteoliticheskaia aktivnost' soderzhimogo tolstoi kishki v norme i pri mikroékologicheskikh narusheniiakh.

The proteolytic (caseinolytic) activity of fecal supernatants obtained from 52 practically healthy children and 220 children with the etiologically undetermined (unclear) diagnosis of gastrointestinal tract dysfunction has been studied. As revealed in this study, in cases of bacteriologically confirmed microecological disturbances in the intestine, accompanied by the activation of opportunistic microflora, the caseinolytic activity of fecal supernatants increases. The determination of the level of the caseinolytic activity of fecal supernatants on solid culture media as a rapid method, specially intended for the diagnosis of dysbiotic states of the gastrointestinal tract, is proposed.

[The safety, reactogenicity and antigenic activity of a Pseudomonas aeruginosa anatoxin studied in volunteers]. / Izuchenie bezopasnosti, reaktogennosti i antigennoi aktivnosti anatoksina Pseudomonas aeruginosa na dobrovol'tsakh.

The safety, reactogenicity and immunogenic activity of P. aeruginosa toxoid were studied in 46 volunteer donors. Systemic reactions to the injection of the preparation were absent in all vaccinees, in 2 subjects (4.3%) insignificant reactions at the site of injection in the form of hyperemia, sized 13-14 mm and disappearing within 48 hours, were registered. The preparation was found stimulate humoral immunity, which was manifested by an increase in the number of B-rosette-forming lymphocytes and the level of antitoxic IgG in the blood of the vaccinees. Besides, immune sera obtained from the blood of the volunteers were found to possess protective properties.

[The protective properties of the lysosomal form of Pseudomonas aeruginosa anatoxin in a test of its active protection of experimental animals]. / Izuchenie protektivnykh svoistv liposomal'noi formy anatoksina Pseudomonas aeruginosa v teste aktivnoi zashchity éksperimental'nykh zhivotnykh.

The protective activity of the liposomal form of P. aeruginosa toxoid and intact phosphatidylethanolamine liposomes has been evaluated in mice with experimental P. aeruginosa infection. It has been revealed that the liposomal form of P. aeruginosa toxoid, introduced in a single injection, ensures the formation of more intense and prolonged immunity in comparison with that induced by the toxoid adsorbed on aluminum hydroxide. This investigation has revealed that intact phosphatidylethanolamine liposomes also possess protective properties, protecting 10-36.7% of the animals from infection with P. aeruginosa toxigenic strain.

[Pharmacokinetics of gentamicin after its regional endolymphatic and lymphotropic administration to dogs]. / Farmakokinetika gentamitsina pri regionarnom éndolimfaticheskom i limfotropnom ego vvedenii sobakam.

It was shown that intralymphatic+ inguinal administration of gentamicin provided its high concentrations in central lymph, blood and ++para-aortic lymph nodes and increased the antibiotic levels in the abdominal organs 2.33 to 6.66 times as compared with its intramuscular administration while lymphotropic retroperitoneal administration of gentamicin provided more prolonged maintenance of the antibiotic therapeutic concentrations in lymph of the thoracic lymphatic duct, central blood, ++para-aortic lymph nodes and the abdominal organs in comparison to its intramuscular administration. Intralymphatic+ inguinal administration of drugs providing the highest concentrations in all the organs of the abdominal cavity and the ways of the infection penetration is useful in therapy of severe inflammatory diseases of the abdominal organs inclined to generalization and lymphotropic retroperitoneal administration of drugs is useful in therapy of less severe purulent inflammatory processes in the abdominal cavity.

[Accumulation of gentamicin in biological fluids, organs and tissues during regional lymphotropic therapy with antibiotics]. / Nakoplenie gentamitsina v biologicheskikh zhidkostiakh, organakh i tkaniakh pri limfotropnoi regionarnoi antibiotikoterapii.

Gentamicin distribution in biological fluids, organs and tissues, lymph nodes was studied on 70 dogs. Three administration routes were compared: lymphotropic, intramuscular and regional subcutaneous. The lymphotropic route for the drug administration was recommended not long ago. It was shown that the lymphotropic route provided the antibiotic accumulation mainly in some of the abdominal organs as compared to intramuscular administration. Regional lymphotropic administration of the antibiotic to the experimental animals resulted in higher gentamicin levels in the regional lymph nodes and regional organs as compared to the levels observed after the antibiotic regional subcutaneous administration in the same doses.

Characteristics, isolation and role in the infectious process of Pseudomonas aeruginosa protease.

Pseudomonas aeruginosa produces the extracellular enzyme protease, which plays an important role in the development of the infectious process caused by this microorganism. Protease is produced in three types, I, II and III, with protease II being responsible for 75% of the total proteolytic activity of protease. The molecular mass of protease II has been determined by different methods; the values obtained are 23000 and 39500. This discrepancy may be associated with an autodigestion of the enzyme or with the presence in the periplasm of its producer of a nonactive precursor whose activation may lead to a change in the molecular mass. Pseudomonas aeruginosa protease is capable of cleaving high-molecular proteins into low-molecular ones, which are taken up by the microbial cell and serve as a source of nutrition. When injected into the bloodstream of animals, purified protease produces haemorrhagic lesions in internal organs; its subcutaneous injection provokes haemorrhage in the skin and subcutaneous tissues. Manifestation of high P. aeruginosa virulence on a model of burnt mouse skin requires that not only exotoxin A but also protease be produced. The protease is immunogenic and has, in toxoid form, been used experimentally in a multicomponent vaccine.

[Antibacterial activity of a number of preparations and their combination with a proteolytic enzyme against the microflora of burn and surgical wounds]. / Antibakterial'naia aktivnost' riada preparatov i ikh kombinatsii s proteoliticheskim fermentom v otnoshenii mikroflory ozhogovoi i khirurgicheskoi ran.

Antibacterial activity of antibiotics (azlocillin, tobramycin and piperacillin), antiseptics (metacid, chlorhexidine and quinosoline) and some other drugs (dioxidine and mafenide acetate) against the main representatives of the burn and surgical wound microflora, i. e. Staphylococcus, P. aeruginosa, Proteus, Providencia, Serratia, Klebsiella and E. coli was studied. Tobramycin and piperacillin were highly active against P. aeruginosa, Staphylococcus and Proteus. It was shown that in the presence of terrilytin, a proteolytic enzyme the activity of the combinations of chlorhexidine with dioxidine or mafenide acetate against all microorganisms occurring in burn and surgical wounds markedly increased.

[Suppresion of the R-factor transduction transmission of antibiotic resistance markers in E. coli by distamycin A]. / Podavlenie transduktsioonoi peredachi markerov antibiotikorezistentnosti R-faktorov E. coli distamitsinom A

Some mechanisms of inhibition by distamycin A of transduction of antibiotic resistance markers of R-factors (RI drd and R222) with the moderate phage PI kc in E. coli were studied. The kinetics of the transduction of the R-factor markers was investigated in comparison with the stages of interaction of PI kc phage particles with bacterial cells of E. coli K-12 carrying the R-factors such as RI and R222 -- phage PI kc -- E. coli C6000. Later the effect of distamycin A on transduction of the above R-factors was studied using the same system. It was shown that distamycin A in concentrations of 75 gamma/ml suppressed the transduction of the R-markers when added to the transduction mixture simultaneously with the phage. The transduction rate decreased 15 times if the drug was added 5 minutes after beginning of the phage contact with the recipient culture. Addition of distamycin A at the 20th minute of the experiment induced no inhibition of the transduction of the R-factor markers. Preliminary 18-hour exposure to distamycin A of the recipient culture and phagolysates possessing transduction capacity resulted in decreased rates of the transduction of the antibiotic resistance markers 35 to 40 times. No inhibitory effect of distamycin A on the process of phenotypic manifestation of the antibiotic resistance markers of the R-factors was noted. The experiments showed that distamycin A affected the early stages of interaction of the transducing particles with the recipient culture, possibly the process of penetration of the transducing DNA of the R-factors into the cells of the recipient culture.

[Search for antimicrobial agents and their various combinations that are effective in relation to the main microfloral representatives in the burn wound]. / Poiski antimikrobnykh sredstv i razlichnykh ikh kombinatsii, éffektivnykh v otnoshenii osnovnykh predstavitelei mikroflory ozhogovoi rany.

Activity of 10 antibiotics, 6 surface active substances, 1 antioxidant and boric acid against P. aeruginosa, E. coli, Pr. vulgaris and Staph. aureus most frequently vegetating in burn wounds was studied. It was found that gentamicin had the highest antibacterial effect on the above organisms. Polymyxin M had a pronounced antimicrobial action on P. aeruginosa and E. coli. A significant antibacterial effect with respect to Staph. aureus, E. coli and Pr. vulgaris was observed with the use of the drugs of the nitrofuran line, i.e. salaful, furagin and furacillin. These drugs were not active against P. aeruginosa. A high antimicrobial effect with respect to all of the test-microbed used was recorded with methacyl, a surface active substance. To show the synergistic effect on the microbes most frequently vegetating in burn wounds, the antibacterial action of the drug combinations was studied. The synergistic effect (16 to 100 times) was observed with the use of polymyxin M combination with mafenide, carbenicillin with gentamicin, methacide with fenozan. The microorganisms tested were resistant to boric acid. On the basis of the study the most effective drugs and their combinations were chosen for their addition to the algipores (polymer coatings) used in treatment of burns infected with the above microbes.