Aim: To study cases of bacteremia caused by multidrug-resistant (MDR) and extremely-resistant (XDR) gram-negative bacteria in the departments of a multidisciplinary hospital.Material and Methods. Since 2017, a retrospective epidemiological study has been conducted to investigate cases of infections with bacteremia caused using gram-negative bacteria with multiple or extreme antibiotic resistance. The pathogens were identified using the MALDI-TOF MS method, the sensitivity to antibacterial drugs was determined using the automatic Phoenix system, the beta-lactamase genes were detected using real-time PCR on a GeneXpert analyzer.Results. In 2017, bacteremia caused by MDR and XDR pathogens was detected in 42 and 76 patients, in 2018 — in 57 and 81 patients, in 2019 — in 65 and 111 patients, respectively. During three years of observation, the most frequent XDR microorganisms were, in descending order, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa. In 2019, among 11 K.pneumoniae strains, class D carbapenemase (OXA-48) was detected in 5 cases (45.5%), 3 strains produced NDM metallo-carbapenemase, and 3 strains had a combination of NDM and OXA-48 enzymes. Infections caused by MDR and XDR pathogens were characterized by high mortality. Thus, the relative risk of death in patients with XDR infection was 1.33 times higher than in patients from the MDR group (95% CI 1.04-1.69, P<0.05) in 2019. The duration of hospital stay also increased: in the XDR group — up to 29.5 days, in the MDR group – up to 16.4 days, with an average length of hospitalization of 6.0 bed-days in 2019.Conclusions. K.pneumoniae and A.baumannii with extreme antibiotic resistance are the main causative agents of severe late nosocomial infections in immunosuppressed patients. Nosocomial infections with bacteremia caused by gram-negative bacteria with the XDR phenotype and resistant to carbapenems are characterized by a high mortality rate (from 72 to 80%), and increase the duration of hospitalization by more than 4 times.

Aim. To study the adaptive mechanisms of structural and functional changes in a single kidney after nephrectomy for kidney cancer. Materials and Methods. A total of 179 operations of two types were performed: nephrectomy and kidney resection in patients with cancerous lesions. Postoperative ultrasound was performed size control and dopplerography of the vessels of the contralateral single kidney, monitoring-control of blood pressure. Results. In case of kidney resection, the adaptive mechanisms controlling the volume of functioning tissue are preserved. The load on the organ remains minimal and physiological, and is not redistributed, blood pressure remains close to baseline. Nephrectomy does not lead to functional changes in a single kidney, but to adaptive and pathophysiological structural damage as a result of increased plasma pressure, organ reboot, its vicarious hypertrophy, which is accompanied by venous edema of interstitium as a pressure factor on the tissue, increased tone of arterioles, the development of secondary organ ischemia, circulatory hypoxia and increased blood pressure. All this fits into the clinical picture of hypertensive nephropathy. Conclusions. The potential risk of hypertension and hypertensive nephropathy in patients undergoing nephrectomy, compared with patients after organ-saving surgery, is significantly higher. One of the most important manifestations of hypertension in the elderly is a violation of the structure and function of target organs, which include: the brain, heart, blood vessels, kidney. Nephrectomy forms a pathological vicious circle, contributing to the development and further progression of renal and cardiovascular failure.

Up to 70% of patients hospitalized for COVID-19 need respiratory support, up to 10% need high-flow oxygen therapy, non-invasive and invasive ventilation. However, standard methods of respiratory support are ineffective in 0.4-0.5% of patients. In case of potentially reversible critical refractory respiratory failure that patients may require ECMO. Management of patients with extremely severe COVID-19 associates with numerous clinical challenges, including critical illness, multiple organ dysfunction, blood coagulation disorders, requiring prolonged ICU stay and care, use of multiple pharmacotherapies including immunosuppressive drugs. Pharmacological suppression of immunity is associated with a significant increase in the risk of secondary bacterial and fungal infections. Currently, data on epidemiology of secondary infections in patients with COVID-19 undergoing ECMO is limited.Aim. To study the prevalence and etiology of secondary infections associated with positive blood cultures in patients with extremely severe COVID-19 requiring ECMO.Materials and methods. A single-center retrospective non-interventional epidemiological study including 125 patients with extremely severe COVID-19 treated with ECMO in April 2020 to December 2021.Results. Out of 700 blood culture tests performed in 125 patients during the study, 250 tests were positive confirming bacteremia/fungemia. Isolated pathogens varied depending on the duration of ECMO: gram-positive bacteria (primarily coagulase-negative staphylococci) dominated from the initiation of ECMO support; increased duration of ECMO associated with an increasing the proportion of pathogens common in ICU (Klebsiella pneumoniae and/or Acinetobacter baumannii with extensively drug resistant and pan-drug resistant phenotypes, and vancomycin-resistant Enterococcus faecium). When ECMO lasted more than 7-14 days, opportunistic pathogens (Candida species, Stenotrophomonas maltophilia, Providencia stuartii, non-diphtheria corynebacteria, Burkholderia species and others) prevailed as etiological agents.Conclusion. Longer duration of ECMO resulted in increasing the rates of infectious complications. In patients undergoing ECMO for more than 14 days, the microbiological landscape becomes extremely diverse, which hampers choosing an empirical antimicrobial therapy. Since potential pathogens causing secondary infections in patients during ECMO are difficult to predict, rapid identification of rare opportunistic pathogens and their sensitivity profile, followed by targeted administration of antimicrobials, seems most beneficial.

The article is devoted to the discussion of the advantages of assessing the environmental comfort of the climate, based on the natural features of the climate and the bioclimatic conditions of the territory. The study assessed the ecological comfort of the climate in the city of Taganrog on the basis of the developed original sequence of performing three stages of assessing the totality of bioclimatic indicators with the final calculation of the values of the integral indicator of the bioclimatic comfort of the climate. The results of the assessment showed, according to the average long-term climatic data, the presence of sub-comfortable climates with a tendency to transition to comfortable climate conditions in the warm period of the year. The cold season was distinguished by uncomfortable conditions according to long-term average climatic data. Modeling calculations of the possible risk to the health of city residents in the presence of concentrations of suspended solids in the surface air layer, together with carbon monoxide, exceeding the maximum one-time values by more than 7 times, showed that the development of possible resorptive or carcinogenic effects in these circumstances will occur in 1/3 the population of the city. The prospects for the assessment of the ecological comfort of the climate, which allow in the future to adequately calculate the magnitude of environmental risks to public health caused by pollution of the surface air layer, are shown.