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The globalization of the problem of the formation of bacterial strains poly- and pan-resistant to known antimicrobial drugs creates high risks in the healthcare sector. The threat of a return to the «pre-antibiotic» era dictates the need to search for alternative forms of antibacterial therapy. Phage therapy, based on the use of a natural, widely distributed in the environment, accessible antimicrobial agent, is again becoming relevant. The article highlights the mechanisms of antiviral protection of prokaryotes at various stages of interaction between the virus and the target cell. Revealing the secrets of the confrontation between bacteria and viruses, their co-evolution is necessary to increase the effectiveness of phage therapy and develop modern means of overcoming bacterial resistance to antimicrobial agents.

Aim. Тo study the molecular genetic characteristics of the tumor microenvironment and the mechanisms of cell death in resistant locally advanced breast cancer.Materials and methods. The study included 48 patients with breast cancer T2–4N0–3M0–1 (mean age 55.6 ± 9.8 years), and 29 patients of comparable age with breast fibroadenoma. According to the design of the study, patients were divided into groups: Group 1 included women with breast cancer resistant to neoadjuvant chemotherapy (n = 23), Group 2 – with breast cancer and a complete response to neoadjuvant chemotherapy (n = 25), control Group – with fibroadenoma (n = 29). The expression of markers CD4+, CD8+, CD20+, CD68+, tumor necrosis factor α (TNF-α), vascular endothelial growth factor A (VEGF A), Ang-2, matrix metalloproteinase 12 (MMP-12), inducible nitric oxide synthase (iNOS), bcl-2, p53, CD95 was assessed using immunohistochemistry.Results. When phenotyping immune cells, the following differences were obtained: in the tumor tissue of patients in Group 1, a significant decrease in the number of cytotoxic CD8+ cells was noted compared to Group 2 (p = 0.001) and control (p = 0.032). In Group 2, a significant increase in the number of CD68+ cells was revealed in relation to Group 1 (p = 0.027). The cytokine profile of the tumor microenvironment in Group 1 is characterized by statistically significant overexpression of TNF-α compared to Group 2 (p >0.001) and the control Group (p = 0.01). With regard to apoptotic factors, noteworthy is the significant decrease in the expression of bcl-2 and p53 in Group 1 compared to Group 2 (p = 0.001 and p = 0.02 accordingly).Conclusion. The presented results can serve as the basis for the creation of diagnostic algorithms that have predictive value regarding the effectiveness of NCT, and also to help identify new targets to justify the use of combined breast cancer treatments in the early stage.

Background. The B0/W148 subtype belongs to the L2phylogenetic lineage of Mycobacterium tuberculosis and is most common in the former Soviet Union. Test systems capable of detecting genetic variants of the pathogen are needed for effective epidemiological surveillance. Studying the genetic diversity of B0/W148 strains and finding molecular markers suitable for their genotyping are key steps in the development of such diagnostic tools.The aim of the work. To study the phylogenetic diversity of the B0/W148 subtype circulating in the territory of the Russian Federation and neighboring countries in order to identify unique clades and search for specific molecular markers suitable for their precise identification.Materials and methods. The study used DNA samples of B0/W148 strains (n = 34) isolated in different regions of the Russian Federation, as well as genomic data obtained from the SRA NCBI (Sequence Read Archive of the National Center for Biotechnology Information) (n = 419). Phylogenetic analysis and principal component analysis (PCA) of whole genome sequencing (WGS) data were used to analyze genetic diversity and to identify molecular markers. An evolutionary reconstruction of the age of the identified clades was carried out.Results. The analysis of the B0/W148 genomes (n = 453) revealed that they are divided into three phylogenetic clades: B – basal, M – minor and P – principal. It was found that specific mutations in the M and P clades allow for their differential diagnosis. The 4137219T>G mutation is unique for the M clade, and the 2241091C>T mutation is unique for the P clade. No characteristic mutations were found among the strains of B clade. In addition, unique mutation profiles in the genes responsible for drug resistance were identified for the clades.Conclusion. The study showed that B0/W148 strains represent a genetically heterogeneous population divided into B, M and P clades. M and P Clades have unique mutations that allow for their identification. It was also found that all clades are characterized by the presence of specific mutation profiles in drug resistance genes.

A clinical observation of a patient with Dravet syndrome caused by SCN1A gene mutation is presented. Dravet syndrome is a severe epileptic encephalopathy that occurs in early childhood, accompanied by seizure polymorphism, drug-resistant course and severe cognitive impairment. The current clinical case confirms the opportunity for drug controlled course of Dravet syndrome. A two-year remission was achieved using polytherapy with antiepileptic drugs. Currently, a complete remission during duotherapy with topiramate in combination with levetiracetam is sustained. The described clinical case also demonstrates preservation of cognitive functions: the child successfully acquires full general education program. It should be noted that upon early relief of epileptic seizures, no cognitive functions become affected.

Introduction. Fluoroquinolones remain the key second-line anti-tuberculosis drugs. The aim of the study was the molecular characterization of fluoroquinolone-resistant Mycobacterium tuberculosis strains from newly diagnosed tuberculosis patients in the Northwest of the Russian Federation. Materials and methods. The retrospective study collection included M. tuberculosis isolates isolated in 2015–2019 from previously untreated tuberculosis patients. Susceptibility to antituberculosis drugs (including the fluoroquinolone ofloxacin) was determined using the BACTEC MGIT960 or absolute concentration method. Mutations in the gyrA gene as a marker of resistance to fluoroquinolones, were detected by real-time PCR. Beijing genotype and its subtypes were detected by PCR and real-time PCR methods. Non-Beijing strains were spoligotyped. Results and discussion. Phenotypic resistance to ofloxacin was detected in 6.7% (40/599) of strains and in 17.4% (40/230) of MDR strains. 34 of 40 (85%) ofloxacin-resistant strains belonged to the Beijing genotype. 18 (45%) strains were assigned to the Russian epidemic subtype Beijing B0/W148 and 12 (30%) to Beijing Central Asian/Russian. The remaining 6 ofloxacin-resistant strains belonged to the Euro-American phylogenetic lineage. Mutations in the gyrA gene were found in 97.5% (39/40) of strains. The most common were mutations in codon 94 (69.2%, 27/39). The Asp94Gly substitution was identified in 57.5% (23/40) of ofloxacin-resistant strains and was dominant among Beijing (19/34) and non-Beijing (4/6) strains. The second most common substitution was Ala90Val (25%, 10/40). More than half of the ofloxacin-resistant strains, Beijing B0/W148 (10/18) and Central Asian/Russian (7/12), carried the Asp94Gly mutation. Conclusion. In the Northwest of Russia in 2016-2019, primary resistance of M. tuberculosis to fluoroquinolones was 6.7% in the total collection and 17.4% of MDR strains, and was mainly caused by the gyrA Asp94Gly and Ala90Val mutations. Beijing B0/W148 genotype was characterized by the largest proportion of fluoroquinolone-resistant strains.

Background. The increased antiretroviral therapy (ART) coverage of patients in the absence of routine drug resistance (DR) tests highlight the importance of HIV-1 drug resistance surveillance in Armenia. Aim. The aim of this study was a determination of the prevalence of HIV-1 DR on a large-scale cohort of HIV-infected citizens of the Republic of Armenia who had no experience of taking antiretroviral drugs. Materials and methods. The study was carried out on a cohort of more than 20% of PLHIV in the Republic of Armenia. The resulting 982 nucleotide sequences of the HIV-1 pol gene fragment, encoding the protease and reverse transcriptase region, as well as 367 sequences of the integrase gene, were analyzed using the Stanford University database and the CPR tool for the presence of drug resistance mutations and determination of the resistance level to ARV drugs. The HIV-1 subtype was determined using the Stanford University database and confirmed by phylogenetic analysis. Results. The overall prevalence of HIV DR to ARV drugs in naïve patients was 13.8%. Resistance to non-nucleoside reverse transcriptase inhibitors was 11.2%, nucleotide reverse transcriptase inhibitors — 1.4%, protease inhibitors — 2.0% and integrase inhibitors — 0.5%. The predominant genetic variant among viruses containing DR mutations was subtype B. Resistance was most often recorded among men who have sex with men living in Yerevan. Conclusion. In our study, prevalence of DR was high only for the NNRTI drugs. The results show that the first-line ARV drugs recommended in current national guidelines are highly likely to be effective. The analysis was carried out on a significant proportion of HIV-infected citizens of the Republic of Armenia, which increases the reliability and accuracy of the data obtained.

Background. Kemerovo Region has a high burden of tuberculosis (TB) with incidence rates twice the national average. The circulating variants of Mycobacterium tuberculosis significantly influence the TB epidemic process. Screening of epidemically significant variants of the pathogen in areas with a high burden of TB underlies epidemiological diagnosis and is necessary for the development of effective prevention measures. However, the population structure of M. tuberculosis in the Kemerovo Region — Kuzbass is poorly understood. Aims: to study genetic heterogeneity and phenotypic resistance to anti-tuberculosis drugs of M. tuberculosis strains in the Kemerovo Region. Materials and methods. The MIRU-VNTR genotyping of 163 M. tuberculosis strains isolated from TB patients in the Kemerovo Region in March–October 2022 was carried out. Cultivation of M. tuberculosis, drug susceptibility testing, and isolation of genomic DNA were carried out by standard methods. Genotypic identification was performed using MIRU-VNTR (24 loci) typing. In parallel, express genotyping was carried out: identification of isolates of the Beijing genotype (by RD105/207) and non-Beijing; subtyping Beijing using real-time PCR tests for detection of Central Asian Russian and B0/W148; identification of the non-Beijing group by real-tine PCR RT tests for LAM, S, Ural. Results. The isolates of the Beijing genotype (67.5%) were found to dominate both among newly diagnosed (64.4%) and previously treated patients (88.5%). MIRU-VNTR typing revealed 75 profiles, of which 94-32 (35.3%) and 100-32 (15.7%) were the most abundant and belonged to the Beijing genotype. Overall, 39.9% and 20.9% of isolates, respectively, were assigned to the Beijing Central Asian Russian and B0/W148 epidemic clusters, which differed significantly in MDR levels (50.8% and 85.3%, respectively; p = 0.005). The second most common were strains of the genetic family of the Euro-American lineage (L4) (31.9%): LAM (6.7%) Ural (7.4%) Haarlem (4.9%) and L4-unclassified (12.9%), MDR among of these minor genotypes was significantly lower than among Beijing genotype strains, and amounted to 11.5% (p 0.001). Strains from HIV-TB patients (56.4% of the total sample) carried an MDR profile more often (54.8%) compared to TB cases without HIV infection (35.2%) (p = 0.005), which may be due to higher proportion of Beijing genotype strains in the HIV-TB group (75.0% vs. 57.7%; p = 0.026). Complete comparability of the SNP analysis (in-house tests) to identify the main genotypes and epidemically significant Beijing subtypes was shown, which made it possible to characterize 75.5% of the sample by the express method. Conclusions. The molecular genetic screening carried out in the Kemerovo Region revealed the heterogeneity of the M. tuberculosis population, which was dominated by strains of the Beijing genotype, with the frequency of subtypes comparable with other territories of the Siberian Federal District.

The aim of the study was to determine the correspondence between the carbapenemase genotype and the phenotypic antimicrobial profiles of P. aeruginosa. Materials and methods. The study included 51 clinical isolates of P. aeruginosa, isolated from the patients with post-operative complications of the respiratory organs. The final identification of the obtained isolates was performed in the Riesbeck laboratory using MALDI-ToF (Bruker), followed by the determination of their sensitivity to antimicrobial drugs at the EUCAST Development Laboratory (Växjö, Sweden). Determination of the resistance genes was carried out by using polymerase chain reaction in real time (PCR-RF). The antimicrobial resistance index (ARI) was determined according to the method of G.V. de Socio. Statistical analysis was performed using the standard IBM SPSS Statistics software version 22.0 and GraphPad Prism Software 10.1.0. (USA, 2023). Results. 39 strains of P. aeruginosa (76.5%) showed polyresistance, and 26 of them (51.0%) were resistant to all antibiotics. According to research data, P. aeruginosa isolates most often carried the blaVIM gene. Genetically determined production of oxacillinase group -lactamase class D among clinical isolates of P. aeruginosa occurred somewhat less often. Based on the obtained results, four carbapenemase genetic resistotypes of P. aeruginosa as pathogens of respiratory tract complications in critically ill patients were established. We detected the antimicrobial resistance index (ARI) based on the phenotypic characteristics of P. aeruginosa at the level of 0.690.39. The phenomenon of statistically reliable correlation of the ARI of microorganisms by phenotypic characteristics with their carbapenemase genetic resistotypes was established. Conclusions. 76.5% of strains of P. aeruginosa show polyresistance, and 51.0% of them are resistant to all antibiotics. Four different carbapenemase genetic resistotypes of P. aeruginosa as pathogens of respiratory tract complications in critically ill patients were established. There is the phenomenon of statistically reliable correlation of the ARI of microorganisms by phenotypic characteristics with their carbapenemase genetic resistotypes.

Introduction. Rearrangement of molecular pathways and activation of bypass signaling determine the progression of tumor cell resistance to various drugs. Study of the common features of resistant formation mechanisms is essential for breast and other cancer beneficial treatments.Materials and methods. The present work was performed on estrogen receptor α ERα-positive (ERα – estrogen receptor α) McF-7 breast cancer cells, established sublines resistant to the mTOR inhibitor rapamycin or antiestrogen tamoxifen, and ERα-negative MDA-MB-231 breast cancer cells. Methods used include MTT test, transient transfection, immunoblotting, real-time polymerase chain reaction and methylation analysis by bisulfite pyrosequencing.Results. We have shown that the resistance of breast cancer cells to targeted and hormonal drugs is associated with the suppression of DNA methyltransferase 3A (DNMT3A) and respective changes in DNA methylation; DNMT3A knockdown results in the partial resistance to both drugs demonstrating the pivotal role of DNMT3A suppression in the progression of cell resistance.Conclusion. Totally, the results obtained highlight the possible mechanism of tumor cell resistance to targeting/hormonal drugs based on the deregulation of DNMTs expression and demonstrate direct connection between DNMT3A suppression and resistance progression.

Tuberculosis is an infectious disease, with many forms and localizations, caused by Mycobacterium tuberculosis, which can affect any organs and tissues of the body. The paper presents a clinical case of tuberculosis of multiple locations, with the presence of resistance of M. tuberculosis to anti-tuberculosis drugs (moxifloxacin, amikacin, bedaquiline), manifesting with sluggish lymphadenopathy of the submandibular lymph nodes in a child who arrived in russia from Pakistan.

Introduction. The genome variability of genetic variants of El Tor cholera agent has led to the emergence of strains carrying mutations in various genes associated with epidemically important pathogen properties. This situation requires an assessment of the trends in these changes in order to predict the pathogenic potential of previously unknown variants and promptly develop new tools for their diagnostics and prevention. The purpose of this work was to analyze the dynamic changes in pathogenicity and drug resistance genes of V. cholerae El Tor genetic variants from endemic countries and Russia. Materials and methods. We analyzed complete genome nucleotide sequences of 104 V. cholerae El Tor strains from the NCBI Gen Bank and European Nucleotide Archive databases, as well as those obtained by us. The nucleotide sequences were analyzed using the UGEN v. 45.1 software. The dendrogram was constructed using maximum parsimony algorithm in BioNumerics v.7.6 software package based on the multiple alignment generated using the Snippy 4.6.0 program. Results. Genomic sequences of 103 strain genovariants isolated on the territory of nine endemic countries of Asia and Africa, as well as in Russia in 1991-2022, have been compared. It is shown that the process of genovariant genome changing was multistage and occurred due to the continuous accumulation of point mutations in key (ctxB and tcpA) and additional (rtxA) genes of pathogenicity and core genes of antibiotic resistance (gyrA, parC and carR), as well as a deletion in SXT element. The most important was the change in the ctxB gene and the emergence of new genovariants with the ctxB7 allele, which replaced the previously prevalent strains. Analysis of altered genome regions of 83 strains from endemic regions has revealed eight genotypes, while the strains (21 isolates) imported to Russia belonged to only five of them including highly virulent strains with the ctxB7 allele and lost PolR biovar-specific feature due to carR gene mutation. The established close phylogenetic relatedness of genovariants from Russia with strains from endemic Asian countries confirms their importation from this region. Conclusion. The sequential occurrence and accumulation of mutations in the pathogenicity and drug resistance genes in the genome of genovariants in endemic regions have been shown, which leads to a change in their epidemically important features. The importation of new highly virulent genovariants into Russia has been established, which indicates the need for an ongoing assessment of changes in the genome of this pathogen for the timely development of adequate means of gene diagnostics and prevention.

Despite the advances in pharmacology, there are still some patients with drug-resistant inoperable epilepsy. Individual ketogenic diet might be an effective measure to prevent seizures. A ketogenic diet must be used only after consulting a dietitian, since it has contraindications and may cause complications. This article focuses on the mechanism of action of the ketogenic diet, indications and contraindications to it, and also describes our experience of using ketogenic diet in a patient with structural focal epilepsy and a typical history of the disease, side effects of antiepileptic drugs, and low compliance of antiepileptic therapy.

Data on the role of regulatory T lymphocytes (Treg) in the immunopathogenesis of tuberculosis are actively accumulating in the current literature. The overwhelming effect of Treg cells on the proliferation, functional activity of Th1 lymphocytes and antigen-presenting cells allows to consider this population as a possible target of modulation of the immune response in patients with tuberculosis. The Notch signaling pathway participates in the regulation of FoxP3 transcription factor expression and, therefore, is capable of supporting suppressor activity of Treg lymphocytes. A key role in the functioning of the Notch signaling cascade belongs to the enzyme γ-secretase that cleaves the intracellular domain of the receptor (Notch ICD), with the subsequent formation of a complex that regulates cell differentiation. The actively studied inhibitor of γ-secretase is DAPT – N-[N-(3.5-difluorophenacetyl)-L-alanyl]-S-phenylglycine tert-butyl ester). Mononuclear leukocytes isolated from the blood of patients with drug-sensitive and drug-resistant pulmonary tuberculosis by gradient centrifugation before the start of anti-tuberculosis therapy were used as the material for the study. The cells were cultured under conditions of stimulation with Mycobacterium tuberculosis antigens CFP10-ESAT6 or with the addition of γ-secretase inhibitor (DAPT) at doses of 5 μM/L and 10 μM/L in combination with CFP10-ESAT6 at 37 °C and 5% CO2 for 72 h to the incubation medium. The number of Treg lymphocytes was assessed by flow cytofluorimetry by determining the expression of the CD4 surface receptor (FITC) and the intracellular transcription factor FoxP3 (PE). In intact cell cultures of pulmonary tuberculosis patients, the relative number of Treg lymphocytes was statistically significantly (p < 0.001) higher than that of healthy donors. Stimulation of cells with CFP10-ESAT6 antigens was accompanied by an increase in the proportion of CD4+FoxP3+ cells in both groups of tuberculosis patients. Addition of γ-secretase inhibitor at a concentration of 5 μM/L to the incubation medium did not lead to statistically significant changes in the number of Treg lymphocytes. The increase in DAPT concentration up to 10 μM/L was accompanied by a decrease in the number of Treg lymphocytes in comparison with the corresponding indices upon stimulation with CFP10-ESAT6 antigens in all groups of the subjects. Regardless of cultivation conditions, the number of CD4+FoxP3+ cells in patients with drug-resistant mycobacteria exceeded their number in patients with drug-sensitive pulmonary tuberculosis. Inhibition of the Notch signaling pathway by a γ-secretase inhibitor (DAPT) at a concentration of 10 μM/L contributed to a decrease in the number of Treg lymphocytes in patients with drug-sensitive and drug-resistant pulmonary tuberculosis. Reduction of Treg lymphocyte number by γ-secretase inhibitor confirms the importance of Notch signaling cascade as a potential target for correction of Treg lymphocytes immunosuppressive activity and pathogenetic therapy of tuberculosis.

Background. Tuberculosis (TB) infection remains relevant as one of the leading public health problems in Russia.The aim. To characterize the dynamics and trends of epidemiological manifestations of TB infection in the Omsk region.Materials and methods. An observational descriptive-evaluative epidemiological study was carried out in the Omsk region from 2009 to 2021. The data available in the Federal statistical observation forms NN 7, 8, and 33, and results of the bacteriological study of patients with respiratory TB were analyzed.Results. In the Omsk region, an improvement in the epidemiological situation was observed from 2009 to 2021. It was associated with a decrease in TB prevalence by 3.7 times (from 325.6 to 86.7), mortality – by 5.8 times (from 21.1 to 3.6), incidence – by 2.7 times (from 130.7 to 48.4 per 100,000). At the same time, proportion of microscopy/culture-positive patients infected with multidrug-resistant Mycobacterium tuberculosis strains increased from 9.2 to 29.8 % among all patients, and from 15.5 to 30.6 % among newly diagnosed patients. There was a trend towards an increase in the number of cases with primary extensive drug resistance of M. tuberculosis. The incidence of tuberculosis associated with HIV infection has increased 10 times and reached 15.6 per 100,000 population.Conclusions. In the Omsk region, there is a change in the structure of M. tuberculosis strains with a predominance of multiple and extensive drug resistance along with decrease in TB incidence and mortality. New approaches are needed to organize the system of epidemiological surveillance and control of TB infection.

The development of sequencing technologies and bioinformatic analysis made it possible to conduct molecular and epidemiological studies, in which nucleotide sequences of the human immunodeficiency virus (HIV) are used as information added to the patient profile. From a practical perspective, studies of prevalence of HIV drug resistance (HIVDR) are of the highest significance. To promote such studies, different countries use databases that serve as repositories of genetic and epidemiological information. The Russian HIVDR database (https://hivresist.ru/) was created in 2009. Nevertheless, it was characterized by limited applicability for a long time. Since 2021, after the regulatory documents had been revised and updated, the entry of HIVDR research results into the Russian HIVDR database has been mandatory. Therefore, the priority attention has been given to upgrading the database and improving its functional capabilities. Different methods have been developed to enter clinical, epidemiological and genetic data. At the time of this study, the Russian database HIVDR contained 10,626 unique records about patients and 13,126 nucleotide sequences deposited by 10 institutions. The following functions have been provided for data analysis: quality control of the epidemiological and clinical information about a patient, quality control of nucleotide sequences, contamination check, subtyping, detection of DR mutations, identification of viral tropism and generation of standardized reports. The efforts toward further development of the Russian HIVDR database will be focused on designing tools for detection and analysis of molecular clusters, adaptation to routine application for epidemiological surveillance of HIV infection.

Creation of synergistic combinations of antifungal and antiseptic agents can be considered as one of the promising strategies for reducing the spread of drug resistance in pathogenic fungi.Aim. The aim of this work was to study the synergistic antifungal activity of amphotericin B (AMB) and antiseptic miramistin (MST) in their combined use to fight against drug-resistant Candida isolates. Material and methods. One AMB-resistant C.albicans strain (MIC 3.1 µg/ml), sensitive to MST, two isolates of C.albicans with different level of resistance to MST and AMB (MIC 1.6–6.3 µg/ml), and one MST-resistant C.lusitaniae isolate susceptible to AMB (MIC 0.4 µg/ml) were studied. Isolates’ susceptibility to AMB and MST alone was determined by broth microdilution method and time–kill assay, respectively. Individual anti-candida activity of test combinations of 0.001% MST with AMB in 10 or 50 µg/ml concentrations was studied using quantitative time–kill assay.Results. A significant decrease in the growth of all the isolates treated with both test combinations of MST and AMB in comparison with individual medication treatment was observed at each time interval studied (15–60 minutes). As part of the combination, MST exhibited significant synergy with AMB in sublethal concentration of 10 µg/ml against all the isolates. Treatment of the fungi with a combination of MST with AMB in 50 µg/ml concentration caused complete inactivation of all the isolates after 30 minutes. Under these conditions, AMB exhibited separate antifungal activity.Conclusion. These findings suggest the possible effective use of miramistin in combination with amphotericin B against multi-drug resistant isolates of the genus Candida.

Objectives. To analyze the significance of age, sex, social and medical risk factors for the relapses development of respiratory tuberculosis with a drug-resistant form of the causative agent. Material and methods. A retrospective analysis of 190 medical cards of inpatients over the past 5 years treated in the health care institution “Bogushevskaya Regional Tuberculosis Hospital” was carried out. Such indicators as age, sex, social and medical risk factors influencing the development of respiratory tuberculosis were analyzed. Results. Among these medical histories there were 172 of male patients, which made up 90.5%, and 18 of female patients (9.5%). The age of male patients suffering from recurrent respiratory tuberculosis (RT) was from 40 to 59 years, while that of women more frequently averaged from 30 to 39. People from rural areas had tuberculosis more often compared to urban residents. The analysis of the educational level showed that RT relapse was more common in those who had secondary and general secondary education and accounted for 65.8% of the entire sample. Among them 64% of persons were neither in registered nor in civil marriage. In women this index made up 66.6%. The body mass index (BMI) of patients was below the norm (

Fungi are opportunistic microorganisms that colonize all biotopes of the human body, including intestinal. In case of emerging adverse environmental factors (HIV infection, other immunodeficiencies, antibiotic therapy), these microbial representatives begin active reproduction, which might require prescribing antimycotics. Frequent use of the latter in clinical practice induces the development of drug resistance to antifungal drugs, which may impact on effectiveness of both the treatment of fungal infections and other diseases. The purpose of the study was to assess the pattern and spectrum of drug resistance of Candida genus in the intestinal biotope of patients with respiratory tuberculosis and identify risk factors for developing total fungal drug resistance to antimycotic drugs. Material and methods. There were enrolled 21 patients with respiratory tuberculosis. Pattern of the fungal species diversity for the Candida genus isolated from faeces was evaluated, and the spectrum of relevant drug resistance to antimycotic drugs was determined. Patients (n = 21) were divided into 2 groups: with (n = 10) and without (n = 11) total resistance to antimycotics, after which the main risk factors for its development were identified. Results. Members of the Candida genus were isolated from all patients examined, wherein pure cell cultures were characterized by high level of antimycotics resistance. Resistance to three drugs was noted in 1 culture (4.8%), to four in 10 cultures (47.6%), also found in 10 cultures to the entire drug panel (47.6%). During statistical processing, the data were obtained on affecting formation of total resistance to antimycotics of concomitant pathology of the gastrointestinal tract, the presence of a clinically significant dyspeptic syndrome, a history of antimycotic therapy, HIV infection with severe immunodeficiency, and some decrease in the peripheral blood CD4+ lymphocyte count. Conclusion. Fungi of the Candida genus isolated from tuberculosis patients were characterized by high level of resistance to antimycotics. Total resistance was observed in 47.6% of patients. In addition, the major fungi colonizing the intestines of tuberculosis patients were found to be Candida albicans species. The risk factors for the development of total antifungal resistance included: chronic enterocolitis, dyspeptic syndrome, peripheral blood CD4+ lymphocyte count lower than 350 cells/l, and history of antimycotic therapy.

The human immunodeficiency virus (HIV) is currently one of the most pressing global health problems. Since its discovery in 1978, HIV has claimed the lives of more than 35 million people, and the number of people infected today reaches 37 million. In the absence of highly active antiretroviral therapy (HAART), HIV infection is characterized by a steady decrease in the number of CD4+ T-lymphocytes, but its manifestations can affect the central nervous, cardiovascular, digestive, endocrine and genitourinary systems. At the same time, complications induced by representatives of pathogenic and opportunistic microflora, which can lead to the development of bacterial, fungal and viral concomitant infections, are of particular danger. It should be borne in mind that an important problem is the emergence of viruses resistant to standard therapy, as well as the toxicity of the drugs themselves for the body. In the context of this review, of particular interest is the assessment of the prospects for the creation and clinical use of drugs based on small interfering RNAs aimed at suppressing the reproduction of HIV, taking into account the experience of similar studies conducted earlier. RNA interference is a cascade of regulatory reactions in eukaryotic cells, which results in the degradation of foreign messenger RNA. The development of drugs based on the mechanism of RNA interference will overcome the problem of viral resistance. Along with this, this technology makes it possible to quickly respond to outbreaks of new viral diseases.

The high prevalence of pharmacoresistant epilepsy requires the use of nonpharmacological, including surgical approaches to the treatment of this disease. The surgical methods currently used to treat epilepsy (resection, stimulation, and disconnection) carry certain risks of developing intra- and postoperative complications. The technique of magnetic resonance-guided focused ultrasound (MRgFUS) may be an alternative to traditional neurosurgical interventions. Currently, MRgFUS is successfully used in the treatment of essential tremor and Parkinson’s tremor. As the literature data show, the use of focused ultrasound is a promising method in the treatment of epilepsy. It has been reported about successful FUS application for neuromodulation in animal epilepsy models. Studies related to FUS ablation of epileptogenic foci, neuromodulation in humans with epilepsy are currently underway. The technique of locally increased permeability of the blood-brain barrier after FUS, used for the treatment of brain oncological diseases and neurodegenerative disorders is also of interest in the targeted delivery of antiepileptic drugs. However, some experimental works are contradictory, and the lack of large-scale studies of MRgFUS in patients with epilepsy requires further investigation of this technique and its effectiveness.

HIV infection is incurable, but effective antiretroviral therapy (ART) makes it possible to achieve an undetectable viral load (VL), to preserve the function of the immune system and to prevent the patients health. Due to the constant increase in the use of ART and the high variability of HIV, especially in patients receiving so-called suboptimal therapy for various reasons, the incidence of drug resistance (DR) is increasing. In turn, the presence of DR in an HIV-infected patient affects the effectiveness of therapy, which leads to a limited choice and an increase in the cost of treatment regimens, disease progression and, consequently, an increased risk of death, as well as transmission of infection to partners. The main problems of drug resistance, its types and causes, as well as factors associated with its development are considered. The main drug resistance mutations for each of the drug classes are described.

Objective: To study the frequency and structure of primary and secondary drug resistance in M. tuberculosis (MTB) and risk factors for primary multidrug/rifampicin resistance (MDR/RR) in MTB before (Group I: 2018-2019) and during the COVID-19 pandemic (Group II: 2019-2020) in Dushanbe in patients with pulmonary tuberculosis (PTB). Methods: A cohort retrospective study included all patients with PTB tested for susceptibility to anti-tuberculosis drugs (ATD). Odds ratio (OR), 95% confidence interval (95% CI), and p-value were used to determine the significance of the association between frequency and drug susceptibility spectrum (DSS) in groups I and II; risk ratio (RR) was applied to assess a possible association between exposure and outcome. Results: The study included 559 newly diagnosed and 87 previously treated patients. Primary MDR/RR MTB was found in 21.1%, secondary – in 39.8% of patients: in group I, patients with primary MDR/RR MTB constituted 22.4%, secondary – 34.7%; in group II, the prevalence of secondary MDR/RR MTB was found to be three times higher than that of the primary resistance (OR=2.97; 95% CI=1.67-5.27, p

An important problem of our time is the resistance of bacteria to antimicrobial drugs. Surface water bodies accumulate all kinds of antibiotic-resistant bacteria found in the catchment area.The aim. To compare the antibiotic resistance of enterobacteria isolated from freshwater ecosystems of the Murmansk and Ryazan regions.Methods. Isolation was performed by the disk-diffusion method. For species identification, the “Rapid-entero 200 M” test system was used. Sensitivity was determined to 19 antibacterial drugs by the disk diffusion method in accordance with the requirements of MUK 4.2.1980-04 and Clinical guidelines (2014). Data interpretation was carried out using EUCAST v. 7.0 (2017) criteria and the WHONET software package.Results. In 2016, 771 isolates of enterobacteria were isolated from the water bodies of the Ryazan region, 323 isolates from the Murmansk region. The results showed that enterobacteria were found in all surveyed surface water bodies. Citrobacter (36 %), Escherichia coli (21 %) and Providencia (21 %) dominated in the Ryazan region, while Citrobacter (35 %) and Enterobacter (21 %) dominated in the Murmansk region. Enterobacteria resistant to one or more antimicrobials dominate in both regions. The phenotype of multiple drug resistance (MDR) was found in 82.62 % of isolates in Ryazan and 95.98 % in Murmansk regions. The extreme resistance phenotype (XDR) was more common among enterobacteria isolated from water bodies of the Ryazan region. In both districts, there was a fairly high level of resistance to beta-lactam antibiotics. In both regions, the quinolones were the most effective group for inhibiting the growth of enterobacteria.Conclusion. The results of the study show that the spread of antibiotic-resistant isolates of enterobacteria in freshwater ecosystems occurs everywhere, but in northern waters this process is slower.

Objective: To assess an implementation study (IS) aimed at improving the epidemiological surveillance of tuberculosis (TB) and drug-resistant TB (DRTB) in Dushanbe during the COVID-19 pandemic. Methods: IS assessment was carried out according to the RE-AIM framework and WHO recommendations for reporting on IS. To assess the effectiveness of the action taken, official statistics and reports from the City Center for Protection of Population from Tuberculosis were used. Results: IS was a qualitative study. The study was supported by the WHO Special Program for Research and Training in Tropical Diseases (TDR). A multidisciplinary team led by the Dushanbe City Health Department has undertaken the following measures: introduction of a system of weekly epidemiological surveillance for TB at the primary health care (PHC) level from the second week of 2021; involvement of students of basic and advanced field epidemiology programs (FETP) in the assessment of the TB epidemiological surveillance system; tracking of registered patients with laboratory confirmation of TB; application of data from the quarterly reports in tracking the diagnostic trends and evaluation of the effectiveness of DR-TB treatment. All materials received were documented and used to train TB doctors and PHC workers. Only 66% of TB doctors were involved in capacity building in Dushanbe PHC: 24.4% of PHC workers were trained in the basics of TB diagnosis and treatment. Stabilization of TB and DR-TB rate was achieved in 2021 compared to 2020 (morbidity growth rates were 2.7% and 11.9%, respectively); effectiveness of treatment of TB with preserved sensitivity of M. tuberculosis (MBT) to anti-TB drugs in the 2020 cohort increased, but efficacy of DR-TB treatment in the 2019 cohort decreased. Conclusion: IS has identified major barriers to achieving the TB elimination goals. Although the data indicate stabilization of TB and DR-TB incidence rates and increased effectiveness of drug-sensitive TB treatment in Dushanbe, further monitoring and achievement of sustainable results are required.

Background. Bedaquiline is currently a drug of choice in therapy for extensively and multidrug-resistant tuberculosis. It is indicated for children from a 6-year age and young adults as part of a combination chemotherapy, in compliance with the medical council’s (MC) regulation on active extensively and multidrug-resistant tuberculosis.Clinical Cases Description. The article describes the clinical cases of bedaquiline treatment of extensively drug-resistant tuberculosis in сhildren. Patient B., 16 yo, was routinely admitted to a children’s ward of the Orenburg Regional Clinical Antituberculosis Dispensary with the preliminary diagnosis: exudative pleurisy-complicated S1,2 infiltrative focal tuberculosis of left lung. Mycobactérium tuberculósis (MBT) (-). Complaints of cough, painful chest at deep breath, 37.3°C-elevated body temperature. Chest X-ray: left focal shadows in S1,2, intensive homogeneous darkening due to pleural effusion from diaphragm to anterior segment of rib III. An urgent pleural puncture was performed to sample fluid for MBTculture and PCR resistance tests to streptomycin and rifampicin. The patient was treated with anti-tuberculosis drugs according to the IV chemotherapy regimen. Taking into account the MBTculture results, the Medical Board took the decision to start using the V chemotherapy regimen with the inclusion of up to 180 doses of bedaquiline. The patient received anti-TB drugs according to chemotherapy regimen IV. Based on the pleural fluid PCR tests, the MC prescribed a conversion to chemotherapy regimen V with adding bedaquiline up to 180 doses. After 7 months of positive dynamics, the patient was transferred to continuation phase at a children’s sanatorium. Patient S., 10 yo, was routinely admitted to a children’s ward of the Orenburg Regional Clinical Antituberculosis Dispensary with the diagnosis: two-sided bronchopulmonary intrathoracic lymph nodes tuberculosis (ILNTB), calcification phase, MBT (-), follow-up care level I. Given the child’s triple contact with tuberculosis carriers, including extensively drug-resistant (XDR) tuberculosis, the MC prescribed antibacterial drug chemotherapy IF regimen V with adding bedaquiline up to 180 doses: pyrazinamide (Z), prothionamide (Pto), para-aminosalicylic acid (PAS), cycloserine (Cs), bedaquiline (Bq) concurrently with vitamins and hepatoprotectors (ZPtoPASCsBq). After 4 months of positive dynamics, the patient was transferred to anti-bacterial therapy continuation phase 4 (ZPtoCsPAS) for up to 12 months at a children’s sanatorium.Conclusion. The clinical cases presented demonstrate the efficacy of bedaquiline in adolescents having extensively drug-resistant focal pulmonary tuberculosis and intrathoracic lymph nodes tuberculosis. The prescription of bedaquiline in this age cohort requires careful justification and a monitoring of adverse reactions and antituberculosis chemotherapy complications.

Background and aim. Pseudomonas aeruginosa is considered as a notorious pathogen due to its multidrug resistance and life threatening infections. We investigated the relationship between type III secretion toxins, biofilm formation, and antibiotic resistance among clinical P. aeruginosa isolates. Methods. A total of 70 genetically distinct clinical P. aeruginosa isolates were characterized for antibiotic resistance by disk diffusion assay. Biofilm formation was evaluated by microtiter plate method and presence of four exo genes (exoS, exoU, exoT and exoY) was investigated by PCR. A p-value < 0.05 was regarded statistically significant. Results. The most effective antibiotics were Meropenem and Piperacillin. Multidrug resistance was more prevalent in the ciprofloxacin-resistant isolates than in the susceptible isolates. The most frequently identified exo was exoS (37.1%). Genotype exoS/exoT was found in 4 isolates, while genotype exoU/exoT was not found. Prevalence of exoS was generally higher in the susceptible isolates than in the resistant isolates. A significant association was found between the formation of strong biofilm and resistance to antibiotics (p < 0.05). Prevalence of exoY and exoU was higher in the non-strong biofilm producers compared to the strong biofilm producers. Conclusion. Our study revealed formation of strong biofilm along with antibiotic resistance and the presence of exo genes in P. aeruginosa isolates. Knowledge of virulence gene profiles and biofilm formation may be useful in deciding appropriate treatment.

Introduction. Mycobacterium tuberculosis is the causative agent of tuberculosis. Drug susceptibility testing is performed by phenotypic and molecular tests. Commonly used for phenotypic drug susceptibility testing is the automated BACTEC system in a liquid culture medium. Drug susceptibility by line probe molecular tests was introduced almost 15 years ago. Recently whole genome sequencing (WGS) analysis of M. tuberculosis strains demonstrated that genotyping of drug-resistance could be accurately performed. Several software tools were developed.Our study aimed to perform whole-genome sequencing on phenotypically confirmed multi-drug resistant (MDR) M. tuberculosis strains, to identify drug-resistant mutations and to compare whole-genome sequencing profiles with line probe assay and phenotypic results.Materials and methods. We performed analysis on 34 MDR M. tuberculosis Bulgarian strains. Phenotypic drug susceptibility testing was performed on the BACTEC system. For molecular testing of drug susceptibility to first- and second-line tuberculostatics, we applied line probe assay Geno Type MTBDR plus v.1.0 и Geno Type MTBDR sl v.1.0. Sequencing was performed on MiSeq. Generated FASTQ files were analyzed for known drugresistant mutations with the software platform Mykrobe v.0.8.1.Results. All three methods — phenotypic analysis using the BACTEC system, genetic analysis of strains applying the Geno Type test and Mykrobe software gave comparable sensitivity/resistance results for the studied strains. All phenotypically proven rifampicin and isoniazid-resistant strains were 100% confirmed using Mykrobe software. The C-15T mutation is a marker for isoniazid resistance in strains of the SIT41 spoligotype. We observed a 75% (21/28) agreement between BACTEC and Mykrobe for ethambutol resistance. Phenotypically, 87% (n = 27) of the strains are resistant to streptomycin, but only 59% (n = 19) are proven by Mykrobe software. Comparing phenotypic and genotypic resistance to ofloxacin, amikacin and kanamycin, we observed 100% coincidence of results.Conclusions. Whole-genome sequencing approach is relatively expensive and laborious but useful for detailed analysis such as epidemiological genotyping and molecular drug susceptibility testing.

The review is devoted to the appearance of resistance of a slowly developing disease leprosy to antimicrobial therapy (AMP), primarily recommended by the World Health Organization. The main danger of drug resistant leprosy is in the difficulty of identifying, since the causative agent of the disease is not cultivated on artificial media, and the methods for diagnosing drug resistance that are currently used take a long time. The drug resistance of the Mycobacterium leprae strain even to individual components of combination drug therapy result to the development of symptoms of the disease despite undergo anti-leprosy therapy, which in turn can cause the patient to become disabled. Currently, in the Russian Federation, there is no approved test for detecting Mycobacterium leprae DNA, and the determination of genetic determinants of resistance is carried out by sequencing genome regions determined by WHO recommendations: small gyrA, folP and rpoB genes loci. At the same time, modern studies in endemic regions reveal an increased level of Mycobacterium leprae strains resistant to individual components of combined drug therapy. The use of next generation sequencing (NGS) has made it possible to identify additional genetic determinants of leprosy resistance to the components of combination drug therapy. The current situation is relevant to antimicrobal drug resistance surveillance by using of quick identification systems for most frequent genetic resistance determinants of Mycobacterium leprae. The literature search was carried out using keywords in the Scopus, PubMed and RSCI databases.

Mycoplasma genitalium is a clinically significant intracellular bacterium from the family of genital mycoplasmas; it absolutely dominates in persistent/recurrent nongonococcal urethritis, causes chronic inflammatory diseases of the urogenital organs which dictates the necessity of treating this infection. The study presents observations of 2 patients with chronic recurrent urethritis caused by multiple drug resistant strains of M. genitalium. None of the administered schemes of antibacterial treatment covered in the international protocols on treatment of M. genitalium infection allowed to achieve clinical or microbiological cure in these patients. Practicing doctors require development and improvement of nucleic acid amplification methods with antimicrobial testing for M. genitalium resistance and new antimicrobial drugs with improved chemical and pharmacological characteristics for treatment of patients with intracellular urogenital infections.

Objective: To identify allergic reactions (AR) to anti-tuberculosis drugs (ATD) in patients with multidrug-resistant tuberculosis (MDR-TB). Methods: Total of 50 patients with MDR-TB, suspected to develop AR, were enrolled in the study. The patients received standard chemotherapy. The leukocyte lysis sensitization test (LLST) was used to detect delayed-type hypersensitivity. Peripheral blood samples were used to perform 331 tests for AR to nine ATD: isoniazid (H), pyrazinamide (Z), ethambutol (E), levofloxacin (Lfx), cycloserine (Cs), prothionamide (Pt), capreomycin (Cm), p-aminosalicylic acid(PAS) and pyridoxine (B6 ). Study design: retrospective. Results: Tests for AR were positive in 39 patients (78.0%), weakly positive – in 10 patients (20.0%), negative – in 1 patient (2.0%). Analysis of AR prevalence in MDR-TB patients showed that Cs (60.0%), Pt (52.1%), PAS (52.8%), H (54.5%), and Lfx (52.2%) caused AR more frequently than the other ATD. AR to Cm (38.3%), Z (37.8%), E (41.0%), and B6 (38.7%) showed comparable prevalence. Most frequently the patients demonstrated AR to the two ATD (12 patients, 24.0%). Conclusion: AR were detected in 98.0% of 50 examined MDR-TB patients with suspected drug allergy (DA). Cs proved to be the most allergenic drug among others (60.0%). Most frequently the MDR-TB patients demonstrated AR to the two ATD (24.0% of patients).

Epilepsy is a chronic condition that consists of a transient disorder of brain function manifested by recurrent and unprovoked seizures affecting approximately 50 million people worldwide. Antiepileptic treatment is aimed at possible improvement the quality of life by reducing epilepsy seizures with the lowest possible side effects. One of the newest broad spectrum antiepileptic drug (AED) for the treatment of wide range of epilepsies – focal, partial, myoclonic, tonic-clonic and primary generalized seizures that can be used in both children and adults is levetiracetam. Levetiracetam is believed to bind to SV2A (synaptic vesicle protein 2A) in the brain, prevent the release of calcium stores from neurons and inhibit GABA and glycine activity. Due to the unique mechanism of action, high bioavailability (in both oral and intravenous administration), rapid absorption, metabolism based on the hydrolysis of acetamide groups in the blood (independent of the liver) and the lack of activity of the resulting metabolites, the drug is considered to be safe and effective in reducing and stopping seizures. In this review, we present the latest reports on the effectiveness of levetiracetam and its potential in the treatment of epilepsy in children and adults.

Rapid tests detecting Mycobacterium tuberculosis and drug resistance which are universally implemented in medical practice has dramatically improved the diagnosis of rifampicin-resistant tuberculosis and shortened turnaround time thus enabling early etiotropic therapy. However, permanently increasing drug resistance of M. tuberculosis makes treatment less effective. Furthermore, long treatment courses are required due to low sterilizing activity of treatment regimens used for drug-resistant tuberculosis which leads to greater toxic effects, reduces patients’ adherence to treatment and consumes resources of medical care systems. Current phthisiology needs new effective medications and short treatment regimens, otherwise elimination of tuberculosis by 2050 is impossible. This review summarizes the information about treatment of drugresistant TB, including repurposed drugs, new medications and treatment regimens.

Glioblastoma multiform^ is one of the most aggressive malignancies, wich standard of treatment not changed over the past decade, and the average life expectancy from diagnosis to death does not exceed two years in the most optimistic trials. The review examines the features of the glioblastoma microenvironment, its genetic heterogeneity, the development of recurrent glioblastoma, the formation of drug resistance, the influence of the blood-brain barrier and the brain lymphatic system on the development of immunotherapy and targeted therapy. Molecular subgroups of glioblastomas with an assumed prognostic value were analyzed. It was determined that numerous relationships between glioblastoma cells and the microenvironment are aimed at ensuring tumor progression, and also cause a state of reduced effector function of T cells. Data on the development of future molecular-targeted therapies for four types of cancer cells based on their different properties and response to therapy are summarized: primary GSC, RISC cells, and proliferating and postmitotic non-GSC fractions. The penetration of blood-brain barrier with chemotherapeutic drugs and antibodies currently remains the main limitation in the treatment of glioblastoma. The resulting analysis of the causes is reduced to the following conclusions. A detailed understanding of the evolutionary dynamics of tumor progression can provide insight into the related molecular and genetic mechanisms underlying glioblastoma recurrence. The most promising methods of treatment for glioblastoma are combined therapy using immune checkpoint inhibitors in combination with new treatment methods -vaccine therapy, CAR-T-cell therapy and viral therapy. A deeper study of the mechanisms of drug resistance and acquisition resistance, biology and subcloning clonal populations of glioblastoma and its microenvironment, with active consideration of combined trips to the treatment will increase the survival rate of patients, and may lead to stable remission of the disease.

The aim of the study: to analyze the prevalence of resistance mutations to elsulfavirine and to evaluate the effectiveness of it among HIV-infected treatment-naïve patients in real clinical practice.Materials and methods. The study included 578 patients with HIV infection, which divided into 3 groups. The first group is 354 HIV-infected treatment-naïve patients for whom HIV-1 nucleotide sequences were obtained as part of routine drug resistance testing. The second study group included 111 HIV-infected treatment-naïve patients, tested for drug resistance before the antiretroviral therapy containing elsulfavirine. The third study group included 113 HIV-infected treatment-naïve patients, each of whom was assigned a treatment regimen containing elsulfavirine without prior drug resistance testing. The observation period for patients of the second and third groups who received treatment was 24 weeks. To assess the effectiveness of antiretroviral therapy in patients, viral load, CD4+ T-cell counts, and adherence to therapy were assessed. HIV-1 subtypes and drug resistance mutations were determined using the Stanford HIV Resistance Database (v. 8.9-1). To clarify the results of subtyping, phylogenetic analysis of nucleotide sequences was carried out using the MEGA program (v. 6.0).Results. The prevalence of mutations associated with decreased susceptibility to elsulfavirine among HIV-infected treatment-naïve patients was 1.7% and 4.5% for the first and second groups of patients, respectively. All of the patients have only single resistance mutations which, according to the results of preclinical studies, cannot cause drug resistance. The use of elsulfavirine in real clinical practice among treatment-naïve patients has demonstrated good virological and immunological efficacy of the drug. As a result of 24 weeks of therapy in patients of the second group, no treatment ineffectiveness, and the development of drug resistance were observed. Among the patients of the third group, 6 patients (5.3%) have the virological failure of therapy associated with the resistance to the used drugs. All patients with virological failure had a resistance mutation profile associated with a high level of drug resistance to one of the drugs in the treatment regimen, lamivudine. Additionally, 1 patient had a combination of mutations that reduce susceptibility to elsulfavirine, and 4 patients had mutations that can reduce susceptibility to elsulfavirine in combination with other mutations.Conclusion. The low prevalence of mutations associated with a decrease in susceptibility to elsulfavirine and the absence of combinations of mutations make it possible to predict the successful use of this drug for Russian treatment-naïve patients. Reported cases of virological failure of antiretroviral therapy are difficult to interpret in the context of elsulfavirine due to the lack of an exact list of mutations and their combinations, and associations with the degree of resistance to it. This study describes for the first time the mutation profiles in patients with virological failure of therapy containing elsulfavirine and demonstrates the necessity of the further study of drug resistance profile to drug in vitro and in vivo.

The tumor microenvironment is composed of extracellular matrix proteins, mostly collagen, and a wide range of tumor-associated cells, including fibroblasts, neutrophils, macrophages, and blood vessels. These components play a crucial role in supporting tumor growth and proliferation, especially at the early stages of metastasis, as well as determine the physiology of tumor cells. Within the tumor microenvironment, the interaction between tumor cells and tumor-associated cells does not only lead to tumor growth and metastasis, but also induces the epithelial-mesenchymal transition and angiogenesis and contributes to the development of drug and radiation treatment resistance. Ion channels and transporters are the important elements in the drug resistance of tumor cells. Advancing our understanding of the tumor microenvironment and its processes encouraging tumor progression is of paramount importance for creating effective targeted antitumor drugs of high specificity, i.e., drugs suppressing stromal and immune components of the tumor microenvironment, as well as at extracellular matrix, angiogenic factors, ion channels and transporters. In this review, we describe the main processes and interactions taking place in the tumor microenvironment and influencing the efficacy of antitumor therapy. We also take a look at stromal and immune cells involved in the tumor development and factors mediating the drug resistance in patients with cancer.

INTRODUCTION. The high prevalence of mutations in the SARS-CoV-2 genome raises particular concerns about the resistance of the virus to current antiviral therapy, including inhibitors of the main protease, or 3C-like protease (3CLpro), and RNA-dependent RNA polymerase (RdRp).AIM. This study aimed to analyse the prevalence, spectrum, and causes of SARS-CoV-2 mutations conferring resistance to approved and pipeline RdRp and 3CLpro inhibitors on the basis of clinical, virological, and genotypic data.DISCUSSION. The authors have analysed the prevalence of SARS-CoV-2 mutations conferring resistance to antivirals (RdRp inhibitors, including remdesivir and molnupiravir, and 3CLpro inhibitors, including paxlovid) in 2021–2024. The results suggest that certain mutations existed prior to the use of these antivirals. The prevalence of resistance-conferring mutations does not exceed 0.5% of the global population. However, the results of clinical and experimental studies demonstrate the possibility of a more than 200-fold reduction in susceptibility to medicinal products and, in particular, the emergence of multidrug-resistant variants. This is especially important for immunocompromised patients. SARS-CoV-2 can persist in such patients for many months, during which spontaneous or selection-driven mutations can render antiviral therapy ineffective. This would create a risk of spreading drug-resistant variants and/or a risk of adverse outcomes for patients.CONCLUSIONS. As COVID-19 treatment coverage increases, there may be a rise in drug-resistant variants of the virus. The presented data indicate the need for genomic epidemiological surveillance, including an analysis of potential targets for medicinal products based on clinical observations. In the future, surveillance data may determine the treatment strategy and the need to develop new antivirals (RdRp and protease inhibitors) adjusted to resistant SARS-CoV-2 variants.

Influenza is a worldwide public health problem. Annually, this infection affects up to 15% of the world population; and about half a million people die from this disease every year. Moreover, influenza A and B viruses tend to garner most of the attention, as these types are a major cause of the epidemics and pandemics. Although the influenza virus primarily affects the respiratory tract, it may also affect the cardiovascular and central nervous systems. Several antiviral drugs, that target various stages of viral reproduction, have been considered effective for the treatment and prevention of influenza, but some virus strains become resistant to these medications. Thus, new strategies and techniques should be developed to overcome the antiviral drug resistance. Recent studies suggest that new drugs based on RNA interference (RNAi) appear to be a promising therapeutic approach that regulates the activity of viral or cellular genes. As it is known, the RNAi is a eukaryotic gene regulatory mechanism that can be triggered by a foreign double-stranded RNA (dsRNA) and results in the cleavage of the target messenger RNA (mRNA). This review discusses the prospects, advantages, and disadvantages of using RNAi in carrying out a specific treatment for influenza infection. However, some viruses confer resistance to small interfering RNAs (siRNA) targeting viral genes. This problem can significantly reduce the effectiveness of RNAi. Therefore, applying siRNAs targeting host cell factors required for influenza virus reproduction can be a way to overcome the antiviral drug resistance.

There has been a sharp increase in the number of diseases associated with potentially pathogenic microorganisms of the genus Mycobacterium, which differ from Mycobacterium tuberculosis. These bacteria are known as atypical mycobacteria or nontuberculosis mycobacteria (NTM), and the diseases they cause are called mycobacteriosis. NTMs include more than 20 species of acid-resistant microorganisms that are widespread in the environment and that are not members of the M. tuberculosis complex. However, the role of certain types of NTMs in the pathogenesis of human diseases is rather ambiguous. The aim of the paper was to analyse the current rise in the incidence of NTM diseases, as well as the main areas of research on early diagnosis of mycobacteriosis and the detection and testing of drug susceptibility of these microorganisms. The paper summarises current views on NTM species differences, their prevalence and pathogenicity for humans and animals. The authors analysed the main efforts aimed at diagnosis and treatment of NTM diseases. The paper cites the results of the study of NTM susceptibility/resistance to anti-tuberculosis drugs. The diagnosis of mycobacteriosis remains extremely difficult, mainly because of the similarity of the clinico-radiological evidence with that of tuberculosis. Detection of NTM multiple and extensive drug resistance to the majority of anti-tuberculosis drugs complicates the treatment of the NTM disease. Further study of various aspects of NTM diseases is especially important given the increase in the incidence and prevalence of mycobacteriosis all over the world, challenging differential diagnosis, and detection of NTM extensive drug resistance.

Efficacy of remaxol In complex chemotherapy of generalized drug resistant tuberculosis was studied on mice. Mycobacterium tuberculosis 5419 SPBNIIF isolated from a patient with freshey diagnosticated pulmonary tuberculosis resistant to isoniazid (10 mcg/ml), rifampicin (40 mcg/ml), streptomycin (10 mcg/ml) and ethionamide (30 mcg/ml) was used in the experiments. The main polychemotherapy included 4 antituberculosis drugs in the highest therapeutic doses: isoniazid, amikacin, ethambutol and tavanic, the treatment course was 8 weeks. Remaxol was administered in a dose of 25 ml/kg intraperitoneally 5 times a week (14 injections). Significant activating effect of remaxol on the tension of the lung tissue local immunity was revealed by changes in the granuloma cell composition (from mainly epitheliod to mainly lymphoid) and by more frequent large lymphohistiocytic infiltrates. The use of remaxol also greatly increased the absorptive and digestive activity of the peritoneal macrophages phagocytosis, inhibited in the process of the experimental tuberculosis development.

The fungal strain INA 01108 producing antibiotic substances with broad spectrum of antibacterial activity was isolated from the natural environment. By the morphological characteristics and DNA analysis it was shown to belong to Ascomycetes of Sordariomycetes. In submerged culture the strain produced at least four antibiotics. The major component of them was identified as eremophilane-type sesquiterpene eremoxylarin A. Eremoxylarin A is effective in vitro against grampositive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin group glycopeptide antibiotics resistant Leuconostoc mesenteroides VKPM B-4177. The efficacy and toxicity of eremoxylarin A was determined on a murine staphylococcal sepsis model. The dose of 6.25 mg/kg provided 100% recovery and survival of the animals, while the dose of 3.12 mg/kg was close to the ED50. The chemical structure of eremoxylarin A allows to modify the antibiotic and such studies may be relevant to design a less toxic derivative without loss of the valuable antimicrobial properties.

Tamoxifen is the first target agent with a high-end position in breast cancer therapy till now. In recent years experimental researches revealed new biological effects of tamoxifen on tumor cells. The present study continues the theme of the review published in 2012, where a plenty of tamoxifen effects besides interaction with estrogen receptors was discussed. Thus, there is described a wide range of the drug targets which are the key points of signal cascades activating the cell proliferation and determining the course of the growth of the cancer and its sensitivity to chemotherapy. Also clinical trials of tamoxifen based on existing of targets besides the estrogen receptors are reviewed. Furthermore, the data on the antiviral, antibacterial, antifungal and antiparasitic activities of tamoxifen are indicated.

An actual problem of analysis of probiotic lactobacilli resistance to antibiotics and other drugs used in the treatment of gastro-intestinal disturbances has been for the first time solved. The levels of resistance of 19 strains of Lactobacillus (14 strains of L.fermentum, 4 strains of L.plantarum and 1 strain of L.rhamnosus) isolated from commercial probiotics and sour milk products to 14 antibiotics of various nature, i.e. в-lactams, aminoglycosides, macrolides, clindamycin, vancomycin, rifampicin, ciprofloxacin, tetracycline and chloramphenicol were determined. All the isolates were practically susceptible to the drugs of the first line antihelicobacterial therapy, i.e. amoxicillin and clarithromycin, that makes inexpedient the parallel use of the probiotics containing the above lactobacilli in the treatment of gastritis and gastric ulcer, despite the lactobacilli antagonism with respect to Helicobacterpylory. Lactobacilli are as well resistant to mesalazin and can be used for correction of dysbiosis in inflammatory affections of the intestine.

Febrile infection-related epilepsy syndrome (FIRES) is an exceedingly rare disorder that affects 1 in 1.000.000 children. However, we believe that FIRES is more common, since many cases remain undiagnosed. The exact pathogenesis of this clinical syndrome is still poorly understood. There are several theories of its development, including immune, genetic, and inflammatory-mediated ones. FIRES is known to have dismal outcomes with a death rate of up to 30 % in the acute phase and subsequent development (often immediately after the acute phase) of refractory epilepsy and mental retardation in 66–100 % of survivors. Despite the increasing number of publications, the problems of timely diagnosis and treatment of such patients have not yet been addressed. We describe 6 patients presumed to have had FIRES. The most common outcomes included drug-resistant epilepsy, as well as cognitive and behavioral disorders. Continuing seizures and epileptiform activity on the electroencephalogram trigger cognitive and behavioral disorders. The analysis of treatment outcomes indicates that combinations of carbamazepine / oxcarbazepine with other antiepileptic drugs are most effective.

Among the members of the large group of non-tuberculous mycobacteria (comprising more than 180 species), M. avium subsp. hominissuis (MAH) is the most significant causative agent of pulmonary infection in immunocompetent individuals as well as disseminated infection in immunocompromised hosts, e.g. human immunodeficiency virus (HIV)-positive patients. Due to increased incidence rate of mycobacteriosis, especially in HIV infection, much still need to be learnt about the MAH genetic control and virulence mechanisms. Deciphering the genome contents of the M. avium strain 104 (isolated from an AIDS patient with disseminated MAH disease) allowed to compare genome sequences of M. avium strains to gain insights into genomic diversity associated with variable hosts and environments. Comparative genome analysis of MAH strains isolated from patients with pulmonary and disseminated forms of mycobacteri-osis revealed differences in the structure of the genome, affecting the key virulence genes. This review provides current data on the genetic determinants of MAH virulence associated with the initial phase of infection. Several mycobacterial virulence-associated gene families, such as mce (mammalian cell entry), mmp (mycobacterial membrane proteins), pe/ppe and esx expressed by MAH during human infection are thought to be crucial for adhesion, entry, survival, and reproduction inside host macrophages. The genetic mechanisms of MAH survival in human macrophage cell culture as well as mice exposed to toxic effects of reactive oxygen, nitric oxide, bactericidal proteins (cathelicidin) are discussed. The MAH survival in the latency-like state is important for pathogen dissemination. Some genetic and phenotypic features of MAH (absence of a cord factor, presence of plasmids, potential to “switch” morphological types of colonies) are compared with M. tuberculosis. In addition, we summarized current state of MAH drug discovery, a role of MAH intrinsic multidrug resistance, genetic control, as well as mechanisms underlying formation of resistance to various groups of antibiotics in MAH strains.

Fungal infections in these days have the major risk for patients who receive immunosuppressive therapy and suffer from immunodeficiency conditions during their long stay in a hospital. The literature review is dedicated to Candida auris that was firstly isolated in 2009. Later it was reported that this fungus is the cause of nosocomial infections which mortality rate reaches 72%. C. auris has multi-drug resistance and it can survive for a long time in the environment. The lack of sensitivity of diagnostic tests for this fungus detection is the main problem in clinical practice. This leads to inappropriate management and increases the risk of mortality due to infection. C. auris was included in the group of infectious agents that has the highest danger to public health according to the recent report of the Centre for Disease Control (USA).

Introduction. Adamantanthane-type drugs such as rimantadine and amantadine have long been used to treat diseases caused by influenza A virus. However, as a result of the mutations, influenza viruses have become resistant to aminoadamantans. The target for these drugs was the protein channel M2. Influenza A virus M2 viroporin in the protein shell forms fairly specific ion channels with a diameter of about 11 Å, specializing in transporting protons inside the viral particle (virion). Restoration of the antiviral properties of adamantanthane-type drugs consists in the selection of advanced functional groups bound by the carbocycle to find new sites of binding to the protein target M2. The рurpose of the study is to identify the antiviral properties of new adamantanum derivatives to the pandemic strain of influenza A virus in vitro. Material and methods. Compounds of aminoadamantans with amino acids and other organic molecules were obtained by classical peptide synthesis methods. The structure of the compound was tested by means of physical and chemical methods. Antiviral properties of synthetic compounds were studied in vitro on monolayer MDCK cells infected with pandemic strain of influenza A/California/07/2009 virus in two schemes of administration of investigated compounds and virus. Results. The reference strain of the influenza virus A/California/07/2009(H1N1) was sensitive to the compounds under test in varying degrees. The antiviral activity of the compounds was expressed in a 50% inhibitory concentration (IС50) ranging from 0.5 to 2.5 мкM, which is generally a good indicator for the Rimantadine/Amantadine resistant strain. Discussion. The values of the IС50 for compounds introduced two hours before contact with the virus were slightly higher than those for single-moment introduction of the substance and virus. The effect of increasing the inhibitory concentration in the prophylactic scheme of compounds was valid for all compounds of the experiment. Conclusion. The presented synthetic compounds are active against the variant of influenza A virus resistant to Rimantadine and Amantadine preparations. The obtained compounds can be used as model structures for creation of a new drug of direct action against advanced strains of influenza A virus.

Objective. Mono-resistant tuberculosis is the resistance to one of the first-line anti-tuberculosis drug, excluding the rifampicin, and poly-resistant tuberculosis means the resistance to more than one first-line anti-tuberculosis drug (izoniazid, rifampicine, streptomycine, ethambutol, with the exception of the combination of izoniazid and rifampicine. The study was conducted to assess the main peculiarities of the patients with mono-resistant and poly-resistant tuberculosis and their treatment outcome. Material and methods. A cross-sectional, analytical, and retrospective study was performed, which included 124 new cases with mono-resistant and poly-resistant tuberculosis, diagnosed during 2014-2019. The patients were distributed into two groups: the 1st group included 85 (68.5%) cases with mono-resistant tuberculosis and the 2nd group – 39 (31.5%) cases with poly-resistant tuberculosis. Results. Among 85 cases from the 1st group, 69 (81.2%) cases were resistant to streptomycine, 15 (17.5%) to izoniazid, and 1 (1.2%) to ethambutol. Among 39 cases of the 2nd group: 32 (82.0%) were resistant to izoniazid + streptomycine and 7 (18.0%) to isoniazid + ethambutol + streptomycine. The peculiarities of the patients did not show statistical differences in terms of the men/female rate and the affected age groups. Most of them had a socially-economical vulnerable state and high-risk factors. Patients were more frequently detected through the passive case-finding. No differences, according to the localization and extensibility, between the groups were established. The treatment success was registered in 66 (77.6%) cases of the 1st group and 31 (79.5%) cases of the 2nd group. The death occurred in 10 (11.8%) cases of the 1st group and 6 (15.4%) cases of the 2nd group. Conclusions. Within the mono-resistance predominated resistance against the streptomycine and in poly-resistance was noted the resistance against the isoniazid + streptomycine. No differences in general characteristics, social-economical status, high-risk factors, localization, and extensibility of tuberculosis were found. The treatment outcome was suboptimal with a high rate of death in both groups. Individualized approach should be used in all patients for the improvement of the treatment outcome.

Introduction. The emergence of influenza virus strains with drug resistance to antiviral drugs requires finding new compounds, potential direct-acting inhibitors. Аdamantane compounds drugs used since the 1960s have lost their activity the resulting due to resistance. Only neuraminidase inhibitors such as zanamivir and oseltamivir have been approved by WHO for influenza treatment. The Russian pharmaceutical drug Arbidol (Umifenovirum) is actively used in Russia. This drug is used to treat influenza in Russia, China and most post-Soviet republics. This work presents a new derivative of aminoadamantane - dichlorohydrate L-histidyl-1-adamantayl ethylamine (2HCl*H-His-Rim), which showed a high level of inhibition of strains of influenza virus A in vitro. Objectives. Comparison of antiviral properties of the new synthetic low-molecular inhibitor of influenza A virus replication and Arbidol drug pharmacy. Methods. The compound 2HCl*H-His-Rim was obtained by classical peptide synthesis methods. It was identified by methods of mass spectrometry, infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Its antiviral properties have been studied in vitro for monolayer of cells Vero-E6 infected with a high-virulent strain of A/duck/Novosibirsk/56/06 (H5N1) influenza virus at various injection schemes of the investigated compounds. The results. The antiviral activity of the 2HCl*H-His-Rim compound against the highly pathogenic strain of the influenza A/H5N1 virus was slightly higher than for the known pharmacy drug arbidol. Discussion. The difference in antiviral activity of these two compounds is explained by different mechanisms of action on the viral particle. Conclusion. The 2HCl*H-His-Rim compound can be recommended as a candidate for preclinical and clinical trials in order to obtain an etiotropic antiviral drug based on it, due to its high efficacy and economic and synthetic availability. The synthetic compound 2HCl*H-His-Rim acts on influenza A virus variants resistant to Rimantadine and Amantadine.

Ovarian cancer is the fifth most common cancer affecting women and the most lethal cancer among the gynecological cancers. Because of the lack of specific symptoms and no special screening tools, it is recognised in an advanced stage. In addition, drug resistance in ovarian cancer is so frequent, that genes and cross-talks between some important pathways are still analysed. In this review, the major and recently identified molecular mechanisms of drug resistance, including platinum, taxane, bevacizumab and PARPi resistance mechanisms in ovarian cancer from relevant literature have been investigated.