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O V Agapova

Publications and source records attributed to O V Agapova.

5 recordsLinked to original sources
PubMedDate not supplied

[The pathogenicity enzymes of clinical strains of Klebsiella pneumoniae].

In 108 K. pneumoniae clinical strains isolated in pneumonia (32 strains), inflammatory processes of the urinary tracts (36 strains) and toxicoseptic states (40 strains) caseinolytic, gelatinase, phosphatase, lecithinase activities and the capacity for producing DNAase and RNAase were studied. The presence of caseinolytic activity was found in 38 cultures (35.1%), gelatinase activity in 37 cultures (34.2%) and lecithinase activity in 13 cultures (12.0%). The production of RNAase was noted in 74 strains (68.5%), DNAase in 56 strains (51.8%) and acidic phosphatase in 33 strains (30.5%). The role of the above-mentioned enzymes in the development of purulent inflammatory processes, as well as the importance of further studies, including those aimed at establishing the nature of the genetic control of the already known properties of the pathogen, are discussed.

Blood↗
PubMedDate not supplied

[Serine proteases of Gram-negative bacteria: structure, mechanisms of secretion, biological activity].

Current data on the characterization of bacterial serine proteases, forming the family of proteins with specific structural and functional features and secreted by type V (autotransport), are presented. The expression of many of these proteases is believed to be linked with pathogenicity of Gram negative bacteria, which necessitates their further study with a view to obtain more profound concepts. These enzymes have been shown to facilitate the bacterial colonization of the skin and mucous membranes. They are believed to be linked with the resistance of microorganisms to lysosomal proteolysis by phagocytes and their ensuing dissemination in the course of the infectious process. Serine proteases split coagulating factor V and enhance the permeability of blood vessels, thus inducing the hemorrhagic syndrome. The detailed study of serine proteases is closely linked with the prospects of the development of protease inhibiting preparations aimed at the suppression of the pathogenetic activity of proteases by their blocking or by affecting the mechanisms of their secretion.

Animals↗
PubMedDate not supplied

[Role of bacterial protease degrading secretory immunoglobulin A in Klebsiella persistence].

During the study of 186 K. pneumoniae clinical strains the presence of SIgA-protease activity was detected in 109 isolates (58.6%). The PCR test system permitting the detection of iga gene DNA in K. pneumoniae strains isolated in purulent inflammatory processes of different localization was developed. For the first time a conjugative plasmid with a mol. wt. of 100 MD was detected in K. pneumoniae clinical isolates. This plasmid controlled the capacity of inactivating SIgA, carried the markers of antibiotic resistance and was capable of expression in a wide circle of hosts belonging to the family Enterobacteriaceae. The results of in vitro experiments revealed that the strains containing plasmid SIgA were cytotoxic with respect to cells HEp-2 and more resistant to the digestive action of enzymes produced by the phagolysosomes of guinea pig peritoneal cells. As shown on the in vivo biological model with the use of the genetically linked pair of Salmonella typhimurium 274 vaccine strains, differing in SIgA-protease activity, plasmid pSigA ensured more prolonged survival of bacteria in mice in comparison with the nonplasmid variant. The study of SIgA-protease activity of K. pneumoniae strains circulating among patients with a view to the detection of clones causing the development of persistent infection was shown to have good prospects.

Animals↗