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Biomedical subjects

L A Riapis

Publications and source records attributed to L A Riapis.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Frequency of genes speA, speB, and speC in Streptococcus pyogenes strains and the identification of the infective agent by polymerase chain reaction].

In cultures of S. pyogenes isolated from patients and carriers in different territories of the Russian Federation the genes of erythorogenic toxins A, B and C (speA, speB and specC) were detected. The possibility of the identification of S. pyogenes by means of PCR on the basis of primers to erythrogenic toxin B was determined. Gene speB was detected in all S. pyogenes cultures under study and proved to be species specific. Genes speA and speC were detected, respectively, in 29.4% and 9.35% of the S. pyogenes cultures under study. A test system for the identification of S. pyogenes on the basis of primers to gene speB was developed. The prospects for the detection of genes speA and speC for intraspecific typing of this infective agent were evaluated.

Bacterial Proteins↗
PubMedDate not supplied

[Molecular epidemiology of infectious diseases].

Data on molecular epidemiology of bacterial infections is summarized. The term definitions of "molecular epidemiology", "taxonomic species" are given, the limits and species structure of prokaryotes are described. The basic mechanisms of the prokaryotes variability in the epidemic process, as well as the possibilities and limitations of microbiological, molecular-biological and population--genetic typing methods, are characterized. The tactics of molecular-biological studies in analyzing the population structure on the global, regional and local levels is presented. The economic effectiveness of measures taken with due consideration of information on the clonal structure of causative agents of hospital infections is shown.

Bacterial Infections↗
PubMedDate not supplied

[Characterization of Escherichia coli strains O157:H7, isolated on the territories of the Central Federal District].

The characterization of E.coli strains O157:H7, isolated from humans and animals on some territories of the Central Federal District, is presented. Among the isolates from human outbreaks, related and, probably, related cultures prevailed, while among the isolates obtained from different animals mainly unrelated cultures have been detected. A conclusion has been made concerning the existence of several independent zoonotic reservoirs of E. coli O157:H7 infection on this territory. The advantages and drawbacks of the use of pulse electrophoresis in the characterization of E. coli O157:H7 are discussed. Grounds are given for the necessity of the patients examination with hemorrhagic enetrocolitis for the presence of E. coli O157:H7, as well as for the expediency of having a special item for the registration of this E. coli infection in relevant statistical forms.

Animals↗
PubMedDate not supplied

[Genotypic emm-typing of streptococcal cultures, group A, isolated from patients with different clinical manifestations of streptococcal infection in Moscow].

The results of the intraspecific typing of group A streptococci (SGA), isolated from patients with different manifestations of group A streptococcal infection, carried out in Russia for the first time, are presented. The genotypic method of emm-typing, based on sequencing the DNA area coding the variable part of the molecule of SGA M-protein was used. The data obtained in this study made it possible to follow changes in the pattern of SGA M-types in Moscow and the specific features of SGA in comparison with the analogous data on other territories. New emm-types of SGA circulating on the territory of Russia were detected and described.

Antigens, Bacterial↗
PubMedDate not supplied

[Complex typing of Salmonella typhimurium hospital strains].

A salmonellosis outbreak, caused by S. typhimurium, was investigated with the use of some microbiological and molecular-biological methods of typing. This investigation revealed that the outbreak was caused by the "outbreak" electrotype of the multi-resistant variant of the infective agent, found to have several plasmidovars. The possibilities and limitations of typing by sensitivity to antibiotics and plasmid DNA profile were shown. These methods of intraspecific typing were regarded as methods making it possible to establish the heterogeneity of S. typhimurium with the use of intraclonal markers.

Adolescent↗
PubMedDate not supplied

[Pulse-electrotypes of Listeria monocytogenes strains, isolated in Moscow].

The characterization of the pulse-electrotypes of L. monocytogenes, isolated in 2003-2004 in Moscow from different sources, is presented. Among the cultures, isolated from humans, one outbreak pulse electrotype was detected and from different objects in buildings where a wide variety of food products was produced several probably related and unrelated pulse-electrotypes were obtained. The conclusion was made that several independent L. monocytogenes clones existed on the territory of Moscow, and many products supplied to retail trade and public catering enterprises were contaminated with these clones. Pulse electrophoresis was shown to be the most effective method for intraspecific typing and the study of the molecular epidemiology of listeriosis. Grounds for the necessity to improve the microbiological diagnostics of L. monocytogenes infection are given.

Animals↗
PubMedDate not supplied

[Concept of a bacterial species and the evolution of the prokaryotic genome].

The present concepts of evolution and species delineation in prokaryotes are considered. Recently a considerable extension of knowledge on the processes of microevolution of medically significant bacteria was noted alongside with the importance of horizontal and lateral transfer of genes. The phylophenetic concept of species was considered in detail. The inclusion of the ecological criterion into a phylophenetic concept of a species is supposed to facilitate the development of more adequate notion on the evolution of bacteria, the improvement of species delineation in prokaryotes, their classification and nomenclature.

Bacteria↗
PubMedDate not supplied

[The screening and restriction analysis of the plasmid DNA of Salmonella enteritidis strains].

The screening and restriction analysis of plasmid DNA of 36 S. enteritidis strains, isolated in Moscow and Novomoskovsk (Tula Province) at the periods of outbreaks and sporadic diseases, have been made. The possibility of using plasmid screening as an additional method for the differentiation of S. enteritidis strains belonging to different sources of infection has been shown. The restriction analysis has confirmed the conservative character of the nucleotide sequence of the virulence plasmid with a molecular weight of 38 MD, which makes it difficult to use this method for epidemiological purposes.

Adult↗
PubMedDate not supplied

[The variability of a Pseudomonas aeruginosa population in the phase of parasitism on Tetrahymena pyriformis].

Types of interaction between P. aeruginosa and T. pyriformis have been studied. The study has revealed that phagocytizing protozoa are killed by P. aeruginosa in the process of their joint cultivation. The data obtained in this study indicate that in the process of interaction of these species phagocytosis-resistant cells are selected from heterogeneous microbial population. The use of this model is believed to be promising in the study of the fate of P. aeruginosa in abiotic and biotic environment.

Animals↗