Bacterial Biofilm and Peculiarities of Its Formation in Plague Agent and in Other Pathogenic Yersinia

This paper represents a review of the current literature data concerning general principles of bacterial biofilm formation, stages of biofilm production and its structural and functional organization, as well as the data concerning involvement of different enzyme systems with the process of biofilm functioning. Carried out is the analysis of the data on the peculiarities of biofilm formation by pathogenic Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica. Displayed are the data on the role of hmsHFRS-operon genes, located in pigmentation chromosomal region of Y. pestis, in the process of biofilm structure formation, and the data on its regulation by hmsP and hmsT genes. Summarized are the results of the recent years' investigations devoted to the genetic determinancy of the plague agent biofilm formation processes, and in particular to the involvement of genes encoding synthesis of lipopolysaccharide (waaA, yrbH and gmhA) and polyamines (speA and speC), as well as rcsA and phoP-phoQ regulatory genes with biofilm formation procedures. Represented are the results of our own investigations concerning the studies of peculiarities of biofilm formation by plague agent strains of different subspecies on the abiotic surfaces and on the nematode model - Caenorhabditis elegans. Discussed is the role of the biofilm in the complex life span of the plague agent. Noted is biofilm significance not only for facilitation in plague transmission by fleas, but also for Y. pestis preservation in the environment, out of the organism of a warm-blooded host

Studies of Biofilm Formation in Non-Pigmented and Plasmid-Deprived Mutants of <I>Yersinia pestis</I> on Biotic Surfaces, <I>in vivo</I> and <I>in vitro</I> Conditions

In non-pigmented and plasmid-deprived mutants – isogenic variants of highly virulent Yersinia pestis 231 strain – studied is the mechanism of biofilm formation on biotic surfaces, both in vitro (on the laboratory model of nematode Caenorhabdiitis elegans) and in vivo (inside the alimentary tract of Nosopsyllus laeviceps flea). It is determined that spontaneous loss of ability to form biofilms and generate pigmented colonies in the mutants is probably caused not only by the deletion of the whole chromosome pigmentation fragment, but also by a point(single base) mutation in structural hms operon. It is demonstrated that the absence of pCad, pFra or pPst plasmids does not have an impact on the ability of plasmid-deprived mutants to form biofilm on the cuticle of nematode C. elegans

Biofilm Formation in <i>Yersinia pestis</i> Strains of the Main and Non-Main Subspecies and <i>Yersinia pseudotuberculosis</i> on the Model of <i>Caernorabditis elegans</i>

Biofilm formation by Yersinia pestis strains of the main and non-main subspecies and Yersinia pseudotuberculosis was studied on the model of Caernorabditis elegans. It was shown that plague agent strains that did not form pigmented colonies on a medium with Congo red (Pgm-) did not produce biofilm at the head and neck surfaces of nematode. Pgm+ strains of the main and non-main subspecies of plague microbe are able to form biofilm at cuticle of nematode C. elegans, the expression of this feature being unequal in various strains

Comparative Characteristics of Antioxidative Enzymes of <i>Yersinia pestis</i> Strains of Different Subspecies and <i>Yersinia pseudotuberculosis</i> Strains

Comparative electrophoretic investigation was carried out to study antioxidative enzymes (superoxide dismutase, catalase and peroxidase) in strains of Yersinia pestis, Yersinia pseudotuberculosis, Escherichia coli and Salmonella typhimurium. It was shown that Yersinia antioxidative enzymes are different from E. coli and S. typhimurium enzymes in electrophoretic motility. Their expression depends on cultivation temperature and plasmid content. Peculiarities of catalase-peroxidase expression were determined in strains of plague etiological agent of Ulegei subspecies, in strains of pseudotuberculosis etiological agent of IV serovar and in strains isolated from humans

Structural and Functional Analysis of <i>nap</i> Operon Genes in <i>Yersinia pestis</i> Strains of Different Subspecies

Carried out was structural and functional analysis of nap genes coding for a significant diagnostic feature - nitrate reduction in main and non-main subspecies of Yersinia pestis. The presence of a single nucleotide substitution (A for T in position 631) in gene napA was determined to be the reason for the lack of nitrate reduction in part of the main subspecies strains. Other mutation - single nucleotide substitution G for A in position 1021 of napA is not the reason for absence of this diagnostic feature in non-main subspecies and biovar microtus as this substitution is present in denitrifying and non­denitrifying strains

Hormonal factors of virus-associated cancer of the cervix uteri

Objective: to study the urinary levels of estrogen metabolites as a diagnostic criterion in patients with cancer of the cervix uteri (CCU) associated with human papillomavirus (HPV) infection to provide a rationale for the use of pathogenetic therapy in the combination treatment of CCU.Subjects and methods. The study enrolled 26 patients with Stages I-IV CCU who were treated at the Department of Gynecology, Tomsk Research Institute of Oncology. The patients’ mean age was 45.6±1.3 years (range 24 to 72 years), the patients of reproductive age ac- counted for 50%. Tumor was staged in accordance with the FIGO classification. Genotyping was carried out on 12 oncotropic types, by estimating the viral load by polymerase chain reaction. Urinary estrogen metabolite levels were measured in all patients.Results. In the female patients, the urinary level of the metabolite 2-OHE1 responsible for normal cell growth was 8.95±2.9 ng/mg, which was significantly below the values in healthy women (19.7±1.2 ng/mg). The level of the metabolite 1