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Biomedical subjects

A F Moroz

Publications and source records attributed to A F Moroz.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Antigenic complexes of Pseudomonas aeruginosa slime: their isolation and biological properties].

The possibility of using antigenic complexes contained in the extracellular slime of P. aeruginosa clinical strains belonging to different serological groups as the components of a chemical vaccine has been revealed. Animal experiments have demonstrated a high immunogenicity of these preparations, as well as their low toxicity. The use of slime antigens stimulates the production of specific antibodies exerting a protective action against infection with homologous P. aeruginosa strains.

Animals↗
PubMed1984

[Pyocin typing of Pseudomonas aeruginosa strains].

The possibility of using the typing of P. aeruginosa strains by their pyocins as one of the epidemiological markers in the study of P. aeruginosa hospital infections has been established. As this method of typing is characterized by certain variability, the authors propose that the method of the "cross analysis" of pyocins produced by P. aeruginosa strains be used simultaneously. This method is based on the following phenomenon: if the cultures to be compared are different, the pyocin produced by one strain suppresses the growth of the other one, and if the cultures are identical, no suppression of their growth by pyocins is observed.

Bacteriocins↗
PubMed1984

[Use of genetic and molecular characteristics of R plasmids as an epidemiological marker in an outbreak of hospital infection].

Antibiotic sensitivity of 38 strains of enteric bacteria, such as Serratia marcescens Klebsiella pneumoniae and others and Ps. aeruginosa isolated during an outbreak of meningitis in a premature infant resuscitation department was studied. It was shown that all the isolates were multiple resistant, most frequently to 7 antibiotics. All the resistance markers were transferred on conjugation, segregation of some markers being observed. Investigation of the plasmid composition of the clinical strains and transconjugants of E. coli revaled the presence of 2 plasmids with the molecular weights of 40 and 60 Md or one of them. The restriction analysis demonstrated that the plasmids with the same molecular weights isolated from different strains were identical. It was suggested that such plasmids originated from the same source and were distributed by conjugation. The possible part of R plasmids in epidemiological analysis of hospital infections is discussed: the possible part as an additional marker in determination of the infection source and the possible part through its ability to change the host cell phenotype, including the phage and bacteriocin types.

Conjugation, Genetic↗
PubMed1984

[Comparative evaluation of the pathological process in a model of acute experimental pneumonia in rats caused by Pseudomonas aeruginosa strains of various origin].

The experimental model of acute pneumonia induced by the intratracheal inoculation of rats with P. aeruginosa strains has been developed; the use of this model permits the quantitative evaluation of the contamination of respiratory organs with this microorganism, as well as the development of schemes for the antimicrobial therapy of P. aeruginosa infection. The correlation between the severity of experimental pneumonia induced by P. aeruginosa and the production of pathogenicity factors by these microorganisms has been revealed.

Acute Disease↗
PubMed1983

[Possible dependence of the results of phage typing Ps. aeruginosa strains on the presence of R plasmids].

The plasmid composition of 209 strains of Ps. aeruginosa was determined. The strains were isolated from patients, animals and environment in different geographical areas. The number of the plasmid-containing strains averaged 26.8 per cent. The molecular weights of the plasmids varied from less than 10 to more than 150 MD. 41 conjugative plasmids were transmitted to the recipients of Ps. aeruginosa RAO 303. 66 per cent of them had a restrictive effect on the development of phages used in genetic studies, epidemiological phage typing (Lindberg Collection), and medical practice. This resulted in the changing of the phage type of the host strain. Similar results were obtained in the studies with 10 standard R plasmids representing different incompatibility groups. No relation between the spectrum of the phage restriction, group specificity and the other properties of the plasmids was observed. About 50 per cent of the plasmids markedly lowered the sensitivity level of Ps. aeruginosa RAO 303 to the therapeutic pyocyanic phage. The systems of restriction and modification of DNA coded with plasmids were not detected. A possible changing of the phage type of Ps. aeruginosa strains under the effect of R plasmids should be considered in epidemiological assays and respective treatment measures.

Bacteriophage Typing↗
PubMed1983

[Role of Pseudomonas aeruginosa in the etiology of postoperative suppurative inflammatory complications in patients with chronic suppurative lung diseases].

The study of P. aeruginosa strains isolated from patients and various objects of the environment in one of the clinics of Yerevan, carried out by the methods of serotyping, pyocin typing and phage typing, has allowed the authors to establish the circulation of hospital strains and their role in the appearance of post-operative suppurative inflammatory complications in patients with chronic suppurative diseases. The study has also allowed them to reveal the sources of infection which is spread by patients serving either as its reservoirs or as intermediate hosts.

Chronic Disease↗
PubMed1983

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.

Animals↗
PubMed1983

[Morphological study of the organs and tissues of mice infected after a burn with a Pseudomonas aeruginosa strain and treated with a Pseudomonas aeruginosa polyvalent corpuscular vaccine and tobramycin].

The effect of tobramycin and polyvalent corpuscular Ps. aeruginosa vaccine on the infectious process in mice with grade III burns inoculated with Ps. aeruginosa 1312 was studied. The highest percentage of the survival (100 per cent) among the animals was observed, when the vaccine was applied locally every day for 7 days. With the use of tobramycin administered intramuscularly for 2 times 95 per cent of the animals survived. When the vaccine was administered subcutaneously, 96.6 per cent of the animals survived. Morphological investigation of the organs and tissues of the mice showed that the vaccine applications to the infected burns promoted rapid elimination of microorganisms in the wounds and prevented development of sepsis due to Ps. aeruginosa. At the same time early epithelization of the wounds was observed (by the 4th-7th day). Intramuscular injections of tobramycin and subcutaneous injection of vaccine also prevented development of sepsis due to Ps. aeruginosa and protected the animals from death. Still no epithelization of the wounds by that period was observed. Microscopic examinations revealed necrosis of the epiderma and derma elements and microbial swarms on the skin surface.

Animals↗
PubMed1983

[Use of an immunoenzyme method for detecting specific antibodies to Pseudomonas aeruginosa in patients with acute and chronic lung diseases].

ELISA in which P. aeruginosa slime preparations are used as antigens permits the detection of antibodies to this microorganism in the blood sera of patients with acute and chronic pulmonary diseases induced by P. aeruginosa. This assay makes it possible to find out the etiology of infection even before the results of bacteriological investigation are obtained.

Adolescent↗
PubMed1982

[Selective media for isolating Pseudomonas aeruginosa].

The comparative study of 4 selective media (medium containing N-cetylpyridinium chloride, acetamide agar, cetrimide agar, medium containing irgasane) showed that their use permitted one to enhance the isolation of P. aeruginosa, especially pigment-free forms, from pathological material and to reduce the time of their isolation by 24-48 hours. Of all the media subjected to testing medium containing N-cetylpyridinium chloride and acetamide medium proved to have the highest selectivity.

Bacteriological Techniques↗
PubMed1981

[Production and experimental testing of the polyvalency of corpuscular vaccine for the prevention of Pseudomonas aeruginosa infections II. Experimental testing of the immunogenicity of polyvalent corpuscular Pseudomonas aeruginosa vaccine].

Newly developed P. aeruginosa vaccine has been shown to be safe and apyrogenic for experimental animals. Immunization with the vaccine in a single injection of 0.5 ml has been found to ensure the protection of 80--98% of mice from lethal infection caused by virulent vaccine strains, with the exception of P. aeruginosa strain No. 1311, for 9 weeks. Immunity to P. aeruginosa strain No. 1311 develops only by day 56 after vaccination. No sharp correlation between the specific agglutinin level and the degree of protective effect induced by the immunization of animals with the polyvalent vaccine has been established. The vaccine has been shown to possess high immunogenicity in respect to clinical P. aeruginosa strains belonging to different serotypes (homo- and heterological vaccine strains).

Agglutinins↗
PubMed1981

[Use of ionizing radiation for sterilizing alginate dressings containing various antibacterial preparations].

The effect of various doses of ionizing radiation on activity of antibacterial drugs contained in polymer alginate coatings was studied. Sensitivity of P. aeruginosa, E. coli, Staph. aureus, Proteus and B. subtilis used as the test organisms to the drugs and their combinations after radiation sterilization was determined on liquid nutrient media with the method of serial dilutions and agar diffusion and the use of the respective reference antibiotics. The coatings were irradiated in an isotope unit with 60Co at a dose of 7 Krad/min. The data are indicative of the possible use of ionizing radiation for sterilization of pharmaceutical alginate coatings in trade packings. Combined effect of antimicrobial substances and ionizing radiation plays an important role in the efficiency of radiation sterilization. Sterility of the majority of the drugs was achieved after irradiation in doses of 0.5-1 Mrad. The bactericidal activity of gentamicin, mafenid, polymyxin M and neomycin contained in the alginate coatings sterilized with gamma-radiation in doses of 1-2.5 Mrad did not decrease immediately and 1 year after irradiation.

Alginates↗