The aim: to study the stages of primary and secondary biofilms formation by the leading pathogens in children with pyelonephritis on congenital hydronephrosis background depending on child’s age. Materials and methods. Venflons, catheters, urine were used as material for microbiological study. Identification of microorganisms was provided with MICRO-LA-TESTÒID kits. Isolates were tested for ability to form biofilms in Petri dishes with d=40 mm. The morphological structure of the biofilms was studied by scanning electron microscopy. Results: The study of structural and functional features of biofilms formation by leading pathogens of in children with pyelonephritis on congenital hydronephrosis background depending on child’s age revealed a number of features and patterns. In addition to the classical stages of biofilms formation as 3D structure there was found a dissemination of planktonic cells with the release of bacteria or loss of single fragments that spread throughout the body and attach to the substrate with the formation of a new or secondary biofilm. In children under 3 years it was shown that the cocci attachment to the substrate appeared faster than in gram-negative rods and had appearance of separate structures. The longest stage of primary biofilms formation in young children was the co-aggregation. Detecting an ability to colonize with the formation of a secondary biofilm in isolates established that the longest stage was re-adsorption and the shortest was re-aggregation, which lasted 2 hours in all detected pathogens. In middle-aged children, the duration of adhesion stage was reduced by 1-2 hours compared with it in young children. Conclusions. Scientific data about the stages of biofilms formation by microorganisms, causative agents of pyelonephritis in children was updated. Adhesion stage of isolates from elder children with pyelonephritis on background of congenital hydronephrosis underwent faster in the formation of secondary biofilms than in primary, and it formed the possibility for chronic process and the development of recurrences. The duration of each stage in biofilms formation by causative agents of pyelonephritis in children with congenital hydronephrosis depended on the age of the child and the properties of microorganisms

Determination of the effect of Ag nanoparticles impregnated in medical polyethylene products together with the LED radiation of the red and violet spectra on the ability of microorganisms to form biofilms and on daily biofilms.

Assessment of the biological effect of Cu nanoparticles impregnated in polyethylene medical devices combined with the effect of LED radiation of the red and violet spectra on the ability of microorganisms to form biofilms and on daily biofilms.

The prevalence of polymorphism -1486T/C of the TLR-9 gene was studied in 44 patients with chronic Epstein-Barr virus infection (CEBV). The control group for the study of the polymorphisms prevalence of -1486T/C of the TLR-9 gene was 40 healthy donors. Three main genotypes of -1486T/C of the TLR-9 gene were identified based on the obtained results – TT, TC, CC. Investigation of the occurrence frequency of individual genotypes revealed the dominance of the TC genotype, compared with the homozygous TT and CC genotypes. The study of -1486T/C of the TLR-9 gene polymorphism frequency distribution for different genotypes demonstrated the specificity of changes in the TC genotype in patients with CEBV and the absence of such for the TT and CC genotypes. These results confirm the important role of the TLR-mediated signaling in the pathogenesis of the disease, which is necessary to determine the genetic background associated with the course of the disease and its possible consequences. These are the aspects that will further enable the identification of risk groups among such patients and provide timely therapy. The analysis of the results of the -1486T/C polymorphism of the TLR-9 gene revealed three main genotypes –TT, TC, CC. Investigation of the occurrence frequency of individual genotypes revealed the dominance of the genotype TC, compared with the homozygous genotypes of TT and CC. The study of frequency distribution of the polymorphism -1486T/C of TLR-9 for different genotypes demonstrated the specificity of changes in the TC genotype and the absence of suchin the TT and CC genotypes in patients with CEBV.Our study for the purpose of determining the 1486T/C polymorphism of the TLR-9, that is associated with chronic forms of CEBV infection, confirms the important role of TLR-mediated signaling in the pathogenesis of this disease, which is necessary to determine the genetic background associated with the course of the disease and possible consequences of CEBV. These aspects will further enable the identification of risk groups among such patients and provide timely therapy.Analysis of the results allowed establishing the following:1. The 1486T/C polymorphism of the TLR-9 gene is significantly more frequent in patients with CEBV than in the control.2. The frequency distribution of the -1486T/C polymorphism ofthe TLR-9 gene allowed the establishment of the association of the genotype TC with chronic forms of the EBV infection, which is very specific for this group of patients.