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Objective. Introduction. Selective digestive decontamination of the digestive tract (SDD) with non-absorbable antibiotics is considered a promising approach to reduce the risk of infections in critically ill patients. However, the widespread circulation of multidrug-resistant microorganisms, including carbapenemresistant Klebsiella pneumoniae and Pseudomonas aeruginosa, significantly reduces the efficacy of conventional SDD regimens based on colistin monotherapy. The key reason for failures is the wide «mutant selection window» – a range of antibiotic concentrations insufficient to suppress the growth of resistant subpopulations.

Objective. To investigate the bacterial and fungal microbiota of the lower respiratory tract in hospitalized patients with tuberculosis and HIV coinfection. Materials and Methods. A total of 378 sputum samples from 147 patients at the Novosibirsk Tuberculosis Research Institute (Ministry of Health of the Russian Federation) were collected and analyzed between 2021 and 2024. Sputum samples were obtained according to standardized protocols to minimize contamination with upper respiratory tract microflora and ensure representativeness of the lower respiratory tract biota.

Objective. To identify associations between functional polymorphisms in genes of the immune, endothelial, and coagulation systems and the severity and outcomes of sepsis to validate genetic risk predictors. Materials and Methods. This single-center prospective study included 124 patients aged of 1 month to 28 years with hematological malignancies, in whom 152 cases of sepsis were recorded. Genotyping of 20 polymorphic variants in 16 genes was performed using capillary Sanger sequencing.

Objective. To study structure of pathogens of community-acquired urinary tract infections (UTI) in children and adolescents under 18 years of age subpopulation of the Krasnoyarsk region as well as the activity of antimicrobials against the leading pathogen in order to optimize local empirical therapy of UTI. Materials and Methods. A total of 298 urine cultures were analyzed (164 in 2023 and 134 – in 2024). The urinalyses were obtained from children and adolescents with community-acquired UTI who hospitalized to the Krasnoyarsk Regional Clinical Center for Maternal and Child Health in 2023–2024.

Objective. To study pharmacokinetics (PK) and develop a pharmacokinetic/pharmacodynamic (PK/PD) model of linezolid for preterm infants, based on therapeutic drug monitoring (TDM) data. Materials and Methods. The PK/PD analysis included data from therapeutic drug monitoring (TDM) of 24 premature infants, taking into account the repeated TDM procedure – a total of 27 occasions and 54 measurements of linezolid concentration. Quantitative determination of linezolid concentrations in the blood plasma of patients was carried out using the analytical method of measurement by HPLC-UV previously developed on the basis of the educational and scientific laboratory for the study of drug safety at the Department of General and Clinical Pharmacology of the RUDN University in the City Clinical Hospital No.

Objective. To study etiological structure of respiratory tract infections in patients with primary ciliary dyskinesia (PCD) across different age groups. Materials and Methods. A total of 173 patients with a confirmed diagnosis of PCD from various regions of the Russian Federation were examined from 2023 to 2025. The patients were divided into 4 age groups: children (0–6 years) – 42 patients; children (7–12 years) – 42 patients; adolescents (13–17 years) – 43 patients; adults (18 years and older) – 46 patients.

Objective. To analyze the current taxonomic structure of the genus Stenotrophomonas based on genomic data, taking into account limitations associated with nomenclatural validation processes. Materials and Methods. A reference dataset was constructed using taxonomic information from LPSN (List of Prokaryotic names with Standing in Nomenclature) and genome assemblies retrieved from the NCBI database. Pairwise average nucleotide identity (ANI) and average amino acid identity (AAI) values were calculated. Species delineation was performed using the commonly accepted threshold of ANI ≥ 95%.

Objective. To provide a genetic characterization based on whole-genome sequencing (WGS) data of S. aureus isolates identified in one intensive care unit (ICU) during the COVID-19 pandemic. Materials and Methods. WGS on Illumina MiSeq was performed, generating twenty S. aureus sequences isolated from patients and environmental surfaces. Bioinformatic analysis included typing, identification of antimicrobial resistance (AMR) determinants, virulence factors, plasmid replicons, and phylogenetic analysis. Results. Significant genetic diversity was revealed, comprising four clonal complexes (CCs): CC15 – 6⁄20 (30%), CC8 – 3⁄20 (15%), CC22 – 2⁄20 (10%), and CC97 – 2⁄20 (10%); while 7⁄20 (35%) of isolates had an indeterminate CC.

Objective. To assess quality of bacterial detection using 16S rRNA gene sequencing with accredited control materials designed for external quality control of PCR studies. Materials and Methods. Control materials obtained as part of the ISI «FSVOK» program: «DNA detection of Mycoplasma hominis, Ureaplasma spp., Ureaplasma urealyticum, Ureaplasma parvum by PCR (STI)», were analyzed by 16S rRNA gene sequencing. The control sets of samples were presented with lyophilized solutions of M.

Objective. To compare microbiota profiles of sputum and bronchial washes in patients with pulmonary tuberculosis obtained using PCR and to assess clinical significance of obtained microbial profiles. Materials and Methods. We compared the results of sputum and bronchial washes using PCR-based test systems «Backscreen UPM» and «Femoflor 16» (DNA-Technology, Russia) in 51 patients with pulmonary tuberculosis. Results. The analysis revealed that the following dominant taxa of microorganisms were detected both in sputum and bronchial washes in the majority of patients: representatives of the genera Streptococcus, Veillonella, Prevotella, and Haemophilus.