[The present-day epidemiology: challenges of public health and possibilities to settle them: the publications review].

Actually, the epidemiology is a dynamically developing medical science located at the intersection of social and biological branches of knowledge and bio-informatics. The new sources of data, the new methods create unique opportunities for epidemiologist. The number of epidemiological studies carrying out at the junction of several adjacent disciplines is increasing that requires harmonious interaction of specialists of different branches of medical knowledge. The change of the structure of global mortality towards chronic non-communicable diseases significantly affected the vector of epidemiological studies. Many interventional epidemiological projects are targeted to evaluation of effectiveness of new methods of prevention of cardiovascular, metabolic and oncological diseases. However, in recent years, the fight against unremembered infections affecting about 1 billion of people and taking away lives of 0.5 million people annually gained new importance. The current COVID-19 pandemic also affected epidemiology of communicable and chronic non-communicable diseases. Great attention is also currently attended to studying influence of social, economic and environmental factors on human health. The increase of average life expectancy of population contributes to development of epidemiology of the elderly. The new projects are initiated in the field of pharmacoepidemiology targeted to studying effectiveness of medications. The review of national and foreign publications considering current trends and achievements in the field of epidemiology. The reference retrieval engines such as PubMed, Google Scholar, CyberLeninka were used. The current directions of epidemiological research are analyzed. The challenges and development prospects of development of modern epidemiology are highlighted.

[Primary diffuse meningeal melanomatosis: a literature review and a case report]. / Pervichnyi diffuznyi melanomatoz myagkoi mozgovoi obolochki: obzor literatury i sobstvennoe nablyudenie.

Primary melanocytic tumors of the central nervous system (CNS) are extremely rare and account for only 1% of all melanomas and 0.05% of primary brain tumors. In case of diffusely invasive lesions of the pia mater with a tumor of melanocytic origin (without signs of extracranial metastases), the tumors are classified as primary diffuse meningeal melanomatosis (PDMM). The latter is an extremely rare subtype of CNS malignant tumor with an incidence rate of 1 in 20 million people. Despite the development of neuroimaging techniques, today a morphological examination remains the main and most accurate method for verifying CNS melanocytic tumors. The paper describes a fatal case of PMMD manifested as epileptic syndrome, with a rapidly progressive course.

[Chordoma as a neurosurgical pathology]. / Khordoma kak neirokhirurgicheskaya patologiya.

OBJECTIVE: Assess the significance of chordoma as a neurosurgical pathology, taking into account the latest edition of the WHO classification of soft tissues and bone tumors (2020). MATERIAL AND METHODS: An analysis of 28 chordomas was carried out. All chordomas were histologically verified, including using immunohistochemical markers of notochordal differentiation (S100, EMA, keratin, brachiuria protein). RESULTS: Patients with chordomas accounted for 0.25% of the total number of neurosurgical patients. The vast majority (27) of chordomas had a cranio-vertebral localization. Sacral localization (S3-S5) of the tumor was detected in 1 patient. In 4 (15%) cases, operations were performed for the recurrence of chordoma. The tumors tended to grow into the structures of the skull, overgrown the vessels and nerves, and compress the adjacent brain structures. This was manifested by pain syndrome, neurological symptoms, impaired liquorodynamics. According to histopathological criteria, 27 (96%) cases of tumors were classified as conventional (usual) chordoma type, among them 7 corresponded to the chondroid subtype of the chordoma. In 1 case (4%), a dedifferentiated chordoma was detected. CONCLUSION: Chordoma, due to its axial localization, naturally involves adjacent structures of the nervous system, has clinically significant neuropathological manifestations, and often provides direct indications for a special neurosurgical approach. This requires its consideration not only as a bone, but also as a neurosurgical oncological pathology, along with other non-meningothelial (mesenchymal) tumors of the CNS.

[Isolated sarcoidosis of the brain]. / Izolirovannyi sarkoidoz golovnogo mozga.

Sarcoidosis is a granulomatous multisystem disease of unclear etiology. Among the many local lesions of different localization, lesions of the central and peripheral nervous system (neurosarcoidosis) are distinguished as particularly unfavorable manifestations of the disease. Only in rare cases, neurosarcoidosis can manifest as isolated or primary. Biopsy remains the gold standard for the diagnosis of neurosarcoidosis. However, significant difficulties remain in verifying the diagnosis, especially with an isolated variant of the lesion A rare case of isolated neurosarcoidosis with a primary focus in the right hemisphere of the brain is described. The data of histological, histochemical and immunohistochemical examination of the surgical material are presented.

Antibodies against carbamylated proteins: prevalence and associated disease characteristics in Belgian patients with rheumatoid arthritis or other rheumatic diseases.

Objectives: Anti-carbamylated protein antibodies (anti-CarP) are reported to be associated with increased disease activity and with more severe joint damage in rheumatoid arthritis (RA) patients. The present study investigated the presence of anti-CarP in various rheumatic diseases, and their specific clinical significance in RA, in Belgian rheumatology patients.Method: We tested sera from 254 RA patients, 56 healthy controls, and 153 patients with different rheumatic conditions: juvenile idiopathic arthritis (JIA), axial spondyloarthritis, systemic sclerosis, and Sjögren's syndrome (SS). An in-house enzyme-linked immunosorbent assay was used to detect immunoglobulin G antibodies against carbamylated foetal calf serum.Results: Anti-CarP were detected in 88 RA patients (34.6%), of whom 82% were also positive for anti-citrullinated protein antibodies (ACPAs) and 81% were also rheumatoid factor (RF) positive. Of note, 11 anti-CarP single-positive patients were detected (4.3%). The previously reported association with joint erosions was not detected. However, in ACPA- and RF-negative RA patients, the presence of anti-CarP was associated with higher disease activity and disability. Fifteen per cent of JIA patients and 30% of SS patients also tested positive for anti-CarP and their antibody levels did not differ significantly from those of anti-CarP-positive RA patients. Anti-CarP levels were, however, significantly higher in ACPA- or RF-positive patients.Conclusion: Anti-CarP antibodies were detected in the sera of a cohort of Belgian RA patients. Moreover, they were also detected in primary SS patients and in JIA patients. In the seronegative subset of RA patients, anti-CarP antibodies showed prognostic value.

[Morphological evaluation of the effectiveness of fluorescence navigation with chlorin e6 in surgery for malignant gliomas]. / Morfologicheskaya otsenka effektivnosti fluorestsentnoi navigatsii s khlorinom e6 v khirurgii zlokachestvennykh gliom.

OBJECTIVE: To evaluate the effectiveness of fluorescence navigation with chlorin e6 in surgery for malignant gliomas based on surgical material morphological and immunohistochemical data. MATERIAL AND METHODS: The surgical material obtained from patients with high-grade (Grade III-IV) anaplastic glioma was examined. Along with histological examination, the proliferation marker Ki-67, the cell cycle transcription factor protein p53, and vascular endothelial growth factor (VEGF) were determined. RESULTS: A significant direct correlation was found between the expression of Ki-67, p53, and VEGF and the fluorescence intensity of tumor tissues (p<0.05). CONCLUSION: The technique of fluorescence navigation using chlorin e6 in comparative morphopathological analysis has confirmed its effectiveness in surgery for malignant gliomas.

[Structural heterogeneity of epileptic foci in local drug-resistant epilepsy]. / Strukturnaya geterogennost' epilepticheskikh ochagov pri lokal'noi farmakorezistentnoi epilepsii.

BACKGROUND: To study etiopathogenesis is one of the most important tasks of modern neurology. Various types of structural changes occur in drug-resistant epilepsy (DRE); however, they are described as distinct phenomena. OBJECTIVE: To provide a comprehensive characterization of structural changes in the cortex and adjacent white matter in the electrophysiological activity zone (in the epileptic focus) in patients undergoing surgery for DRE. MATERIAL AND METHODS: Biopsy material of fragments of the temporal lobe and hippocampus from 16 patients aged 21 to 54 years (mean age, 25 years) with DRE were intraoperatively obtained at the Prof. A.L. Polenov Russian Research Institute of Neurosurgery. The investigators studied histological sections stained with H&E, toluidine blue according to the Nissl method and the Spielmeyer method, as well as the results of immunohistochemical reactions with glial fibrillary acidic protein (GFAP), vimentin, and neurofilaments (NF) (Dako antibodies, Denmark). RESULTS: Histological examination revealed a set of heterogeneous changes, reflecting the complex pathogenetic interactions that developed during the formation of an epileptic focus. Structural brain damage involved both gray and white matter. Focal cortical dysplasia was diagnosed in 14 (87.5%) cases; white matter neuronal heterotopia in 100%; neuronal reactive and destructive changes in 100%; epileptic leukoencephalopathy (vascular demyelination, microcysts, sclerosis and dystonia, gliosis) in 100%, cortical atrophy in 12.5%, and hippocampal sclerosis in 20% (in 2 out of the 10 examinees). CONCLUSION: The morphopathological heterogeneity in the structure of epileptic foci reflects the complexity of etiopathogenetic interactions, the polymorphism of epileptic manifestations, and the individual nature of formation of the epileptic system, which requires an integral approach to understanding the pathogenesis and morphogenesis of formation of the epileptic system and provides a direction for a personalized approach to epilepsy treatment.

PCR-based detection of EGFR, ALK, KRAS and BRAF mutations in Russian patients with lung adenocarcinoma: a single-center experience.

In contrast to other countries with predominantly white populations, Russian smoking-related lung cancers (LC) are mainly squamous cell carcinomas and approximately half lung adenocarcinomas (AdCa) are not related to tobacco consumption. Given that smoking significantly influences the probability of presence of actionable mutations in LC, one would expect that Russian lung AdCa patients would differ from other white populations in distribution of EGFR, ALK, KRAS and BRAF mutations. Herein, 2,336 consecutive lung AdCa cases, including 1,203 patients with known smoking status, were subjected to sequential testing for the above mutations. One quarter of lung AdCa patients carried either EGFR or ALK mutation with combined prevalence of 42% in those who had never smoked but only 8% in smokers. There was only a moderate difference in KRAS mutation frequency between ever- and never-smokers in EGFR/ALK-negative cases (31% vs. 23%), and this was mainly attributed to increased prevalence of G12C substitution in the former group. The occurrence of BRAF V600E mutation was 1.7% and 4% in EGFR/ALK/KRAS mutation-negative ever- and never-smokers, respectively. ALK testing of 470 EGFR-mutated tumors revealed only 1 (0.2%) instance of translocation. Similarly, KRAS testing identified 1 (1.25%) mutation in 80 EGFR-mutated AdCa and none in 48 ALK-rearranged AdCa. Therefore, concurrent actionable mutations in lung adenocarcinoma are exceptionally rare and sequential gene testing can be regarded as a reliable option.

Signal Immune Reactions of Macrophages Differentiated from THP-1 Monocytes to Infection with Pandemic H1N1PDM09 Virus and H5N2 and H9N2 Avian Influenza A Virus.

In culture of THP-1 cells differentiated into macrophages with PMA (THP-PMA macrophages) infected with influenza viruses of subtypes H1, H5 and H9, we measured the expression of TLR7 and RIG1 receptor genes, sensors of viral RNA and ribonucleoprotein, and the levels of production of inflammatory cytokines IL-1ß, TNFα, IL-10, and IFNα. The sensitivity and inflammatory response of THP-PMA macrophages to pandemic influenza A virus H1N1pdm09 and avian influenza H5N2 and H9N2 viruses correlate with the intracellular level of their viral RNA and activation of the RIG1 gene. Abortive infection is accompanied by intensive macrophage secretion of TNFα, IL-1ß, and toxic factors inducing cell death. Activity of endosomal TLR7 receptor gene changed insignificantly in 24 h after infection and significantly decreased in 48 and 72 h under the action of H5N2 and H9N2, which correlated with manifestation of the cytopathogenic effect of these viruses. H5N2 and H9N2 avian viruses in THP-PMA macrophages are strong activators of the expression of the gene of the cytoplasmic RIG1 receptor 24 and 48 h after infection, and the pandemic virus H1N1pdm09 is a weak stimulator of RIG1 gene. Avian influenza H5N2 and H9N2 viruses are released by rapid induction of the inflammatory response in macrophages. At the late stages of infection, we observed a minor increase in IL-10 secretion in macrophages and, probably, the polarization of a part of the population in type M2. The studied influenza A viruses are weak inductors of IFN in THP-PMA macrophages. In the culture medium of THP-PMA macrophages infected with H9N2 and H5N2 viruses, MTT test revealed high levels of toxic factors causing the death of Caco-2 cells. In contrast to avian viruses, pandemic virus H1N1pdm09 did not induce production of toxic factors.

[The microbiological monitoring as a basis of epidemiological control and anti-microbial therapy in conditions of multi-type hospital.]

The study was carried out to investigate features of microbiota and resistance to antibiotics of agents isolated from bio-material of patients in the conditions of multi-type hospital. The microbiological analysis was applied to 6148 samples using optimal set of corresponding techniques (classical tests, chromogenic mediums, immune serological, Maldi-Tof mass spectrometry). The resistance to antibiotics was established by using disk diffusion test (EUCAST 2016, Adagio analyzer). The leading role in etiology of pyoinflammatory processes belongs to E. coli, coagulase-negative staphylococci, enterococci, C. albicans. In the department of contaminated surgery among leaders are S. aureus, opportunistic enterobacteria, hemolytic streptococci, non-fermentative gram-negative microorganisms. In the department of traumatology and orthopedics first place was for representatives of enterobacteria family headed by E. coli, then follows S. aureus and after that other types of microorganisms. The main representatives of microorganisms, isolated from patients of the department of anesthesiology and reanimation, occurred blue pus bacillus, S.aureus, Klebsiella. In the department of therapy first place was for pneumoccocus and yeast-like fungi genus Candida. The resistance to antibiotics of main microflora differs depending on perspective of profile departments. It is extremely important to examine accurately for detection of agent of disease and to establish sensitivity to antibiotics of various groups.

[AVIAN RECOMBINANT VIRUS H5N1 INFLUENZA (A/VIETNAM/1203/04) AND ITS ESCAPE-MUTANT m13(13) INDUCE EARLY SIGNALING REACTIONS OF THE IMMUNITY IN HUMAN LYMPHOCYTES].

The innate immune receptors TLR4, TLR7, TLR8, and RIG1 recognized the structures of the influenza viruses in human lymphocytes and were activated by the recombinant avian influenza virus A/Vietnam/1203/04 and its escape-mutant m13(13) during early period of interaction. The stimulated levels are not connected with viral reproduction. Donor cells with the low constitutive immune receptors gene expression levels showed higher stimulation. Inflammation virus effects resulted in. increasing production of TNF-alpha and IFN-gamma by lymphocytes. Signaling gene reactions of the parent and mutant viruses endosomal as well as cytoplasmic receptors are very similar. The mutant virus A/Vietnam/1203/04 (HA S145F), stimulated an increase in the transcription level of the membrane receptor gene TLR4 and a decrease in the level of activation of TNF-alpha gene. Further studies of natural influenza virus isolates are necessary to estimate the role of HA antigenic changes on immune reactions in humans.

CHOLESTASIS OF PREGNANCY.

The article presents data concerning the prevalence, clinical manifestations, methods of diagnostics, treatment and prevention of cholestasis of pregnancy, as well as the case management depending on the gestation and the cholestasis severity. A clinical case of a typical course of cholesrasis of pregnancy is presented.

PANCREATITIS IN PREGNANCY: CASE MANAGMENT.

The purpose of the review is to summarise the current data on chronic and acute pancreatitis with the goal to improve the diagnostics and treatment of women during pregnancy, which complicates differential diagnosis of hepatopancreatobiliary system pathology. The features of the incidence, etiology, parhogenesis and evaluation of the severity of the clinical manifestations of acute pancreatitis in pregnant women are given, It is emphasis that the most frequent its reason is the gallstones following by the biliary pancreatitis. The experience of use in pregnant patients imaging methods - endoscopic ultrasound, magnetic resonance cholangiopancrearography and endoscopic retrograde cholangiopancreatography, as well as treatments that include endoscopic sphincterotomy, stone extraction from the common bile duct and laparoscopic cholecystectomy. The recommendations are based on expert opinions and are not supported by randomized controlled trials. Nevertheless more active clinical management allows to diagnose and treat effectively pancreatitis, including biliary etiology, which contributes to a sharp decline in maternal and perinatal mortality.

Analysis of three genomes within the thermophilic bacterial species Caldanaerobacter subterraneus with a focus on carbon monoxide dehydrogenase evolution and hydrolase diversity.

BACKGROUND: The Caldanaerobacter subterraneus species includes thermophilic fermentative bacteria able to grow on carbohydrates substrates with acetate and L-alanine as the main products. In this study, comprehensive analysis of three genomes of C. subterraneus subspecies was carried in order to identify genes encoding key metabolic enzymes and to document the genomic basis for the evolution of these organisms. METHODS: Average nucleotide identity and in silico DNA relatedness were estimated for the studied C. subterraneus genomes. Genome synteny was evaluated using R2CAT software. Protein conservation was analyzed using mGenome Subtractor. Horizontal gene transfer was predicted through the GOHTAM pipeline (using tetranucleotide composition) and phylogenetic analyses (by maximum likelihood). Hydrolases were identified through the MEROPS and CAZy platforms. RESULTS: The three genomes of C. subterraneus showed high similarity, although there are substantial differences in their gene composition and organization. Each subspecies possesses a gene cluster encoding a carbon monoxide dehydrogenase (CODH) and an energy converting hydrogenase (ECH). The CODH gene is associated with an operon that resembles the Escherichia coli hydrogenase hyc/hyf operons, a novel genetic context distinct from that found in archetypical hydrogenogenic carboxydotrophs. Apart from the CODH-associated hydrogenase, these bacteria also contain other hydrogenases, encoded by ech and hyd genes. An Mbx ferredoxin:NADP oxidoreductase homolog similar to that originally described in the archaeon Pyrococcus furiosus was uniquely encoded in the C. subterraneus subsp. yonseiensis genome. Compositional analysis demonstrated that some genes of the CODH-ECH and mbx operons present distinct sequence patterns in relation to the majority of the other genes of each genome. Phylogenetic reconstructions of the genes from these operons and those from the ech operon are incongruent to the species tree. Notably, the cooS gene of C. subterraneus subsp. pacificus and its homologs in C. subterraneus subsp. tengcongensis and C. subterraneus subsp. yonseiensis form distinct clades. The strains have diverse hydrolytic enzymes and they appear to be proteolytic and glycolytic. Divergent glycosidases from 14 families, among them amylases, chitinases, alpha-glucosidases, beta-glucosidases, and cellulases, were identified. Each of the three genomes also contains around 100 proteases from 50 subfamilies, as well about ten different esterases. CONCLUSIONS: Genomic information suggests that multiple horizontal gene transfers conferred the adaptation of C. subterraneus subspecies to extreme niches throughout the carbon monoxide utilization and hydrogen production. The variety of hydrolases found in their genomes indicate the versatility of the species in obtaining energy and carbon from diverse substrates, therefore these organisms constitute a remarkable resource of enzymes with biotechnological potential.

Role of Protein Kinase Akt Activation in Protective Effect of Ganglioside GM1 on PC12 Cells Exposed to H2O2.

Micro- and nanomolar concentrations of ganglioside GM1 improved viability of neuronal PC12 cells under conditions of oxidative stress and reduced H2O2-induced ROS accumulation in these cells. These effects were more pronounced at micromolar concentrations. GM1 in concentrations of 100 nM and 10 µM significantly and substantially increased basal activity of protein kinase B (Akt) (the level of phosphorylated Akt form), but had virtually no effect on its expression in PC12 cells. In the presence of PI3K inhibitor LY294002 preventing protein kinase Akt activation, the protective effect of GM1 significantly decreased. These findings suggest that activation of protein kinase Akt by GM1 contributes to improvement of PC12 cell viability by this ganglioside.

[Granulomatous inflammation in the bed of resected cerebral cavernoma in a child, caused by a hemostatic agent].

OBJECTIVE: The study presents a clinical observation of foreign body granuloma, which is rare productive inflammation, developed on treatment with a hemostatic material upon removal of cerebral cavernoma. MATERIAL AND METHODS: A 4-year-old boy operated on for left parietal lobe cavernoma was diagnosed with a mass lesion during a follow-up MRI examination 4 months after surgery. The patient was re-operated in connection with suspected abscess formation. The pathological tissue was subjected to the histological and immunohistochemical examination. RESULTS: Inflammation was accompanied by the formation of foreign body granulomas, and, in some areas, had immune nature with signs of focal destructive vasculitis, delayed maturation of the granulation tissue, and disturbance of the current organization and encapsulation processes. It is worth noting that granulomatous inflammation around a hemostatic material in the brain has no specific features during introscopy and mimics an abscess or tumor recurrence. CONCLUSION: The use of hemostatic materials upon resection of cerebral cavernous malformations may cause formation of granuloma mimicking disease relapse or abscess in the long term period. To prevent granulomatous inflammation, removal of a hemostatic material, if possible, from the surgical field is recommended when reliable hemostasis is achieved.

[THE DIFFERENTIAL DIAGNOSTIC OF ANEMIA].

The article presents analysis of the publications' data of the recent years concerning regulation of iron metabolism and possibilities of application of indicators of iron metabolism in differential diagnostic of anemia. The original results of protein detection are described concerning bivalent transporter of metals and ferroportine under iron-deficiency anemia, anemia of chronic inflammatory diseases and autoimmune hemolytic anemia. The significance of these proteins in more profound comprehension of pathogenesis is demonstrated

[Relation of hydrophobicity index of microbial cells to their biofilm-forming ability].

By examining cell adhesion to n-hexadecane the hydrophobicity index of S. aureus, E. coli and P. aeruginosa was measured. It has been established that the increase in the hydrophobicity of the microbial cells reduces their ability to form a biofilm. It is shown that the divalent metal ions are capable of increasing the hydrophobicity index of microbial cells and reducing biofilm formation. It is concluded that it is necessary to use materials with a negatively charged surface for biofilm preventive measures.

[Grippol, Vaxigrip and influvac vaccines--inductors of innate and adaptive immunity factor genes in human blood cells].

AIM: Study the effect of inactivated influenza vaccines on the activity of innate and adaptive immunity genes (TLR3, TLR4 and B2M), RNA-interference Dicer1-gene, production of cytokines (antiviral IFN type I and II, regulatory IL10, IL17) and pro-inflammatory factors IL1-ß, TNFα. MATERIALS AND METHODS: Gene expression was determined by rRT-PCR with authors' primers in human blood cells treated with various doses of the vaccines. Concentration of cytokines by enzyme immunoassay was measured in cultural fluid using "Vector-best" kits. RESULTS: The studied vaccines have characteristic effects on genetic level. Grippol vaccine predominately stimulates TLR4 gene, activates TLR3, B2M and Dicer1 genes. Influvac vaccine mostly induces TLR3 gene and to a lesser extent TLR4 gene, does not influence the expression of B2M gene and inhibits Dicer1 gene. Vaxigrip split vaccine--the most potent stimulator of gene activity at low doses. Its main targets are TLR3 and B2M genes. All the inactivated vaccines--inductors of high level of IFNγ, low level of TNFα and do not induce IL17. Grippol additionally stimulates secretion of IL1-ß, and Vaxigrip - IFNα. Subunit vaccines Grippol and Influvac that contain purified influenza virus hemagglutinins induce IL10 synthesis in blood cells. CONCLUSION: Immunogenetic characteristics of the inactivated influenza vaccines administered nowadays are obtained.

The role of colonization with resistant Gram negative bacteria in the treatment of febrile neutropenia after stem cell transplantation.

INTRODUCTION: Febrile neutropenia (FN) is one of the most common complications of stem cell transplantation. The aim of this analysis was to evaluate the frequency of sepsis in patients with FN colonized with resistant Gram negative bacteria (Extended spectrum ß-lactamase positive, multidrug resistant (MDR) P. aeruginosa) and the choice of primary antibiotic in colonized patients. PATIENTS AND METHODS: This was a retrospective study analyzed data from patients who underwent hematopoietic stem cell transplantation from 01/2018 to 09/2022. Data were extracted from the hospital information system. RESULTS: Carbapenem as the primary antibiotic of choice was chosen in 10.9% of non-colonized +/-AmpC patients, 31.5% of ESBL+ patients, and 0% of MDR P. aeruginosa patients. Patients with FN and MDR P. aeruginosa colonization had a high prevalence of sepsis (namely 100%, p = 0.0197). The spectrum of sepsis appeared to be different, with Gram negative bacilli predominating in the ESBL+ group (p = 0.0123, OR 5.39 [95% CI 1.55-18.76]). Colonizer sepsis was present in 100% of sepsis with MDR P. aeruginosa colonization (p=0.002), all in allogeneic transplantation (p=0.0003), with a mortality rate of 33.3% (p=0.0384). The incidence of sepsis in patients with ESBL+ colonization was 25.9% (p=0.0197), with colonizer sepsis in 50% of sepsis cases (p=0.0002), most in allogeneic transplantation (p=0.0003). CONCLUSION: The results show a significant risk of sepsis in FN with MDR P. aeruginosa colonization, this state is almost exclusively caused by the colonizer. At the same time, a higher risk of Gram negative sepsis has been demonstrated in patients colonized with ESBL+ bacteria.