Species Spectrum and Biological Properties of Bacterial and Fungal Causative Agents of Health-care-associated Infections and in Vitro Study of Antimicrobial Activity Against Them Using 4-thiazolidinone Derivatives.

The study aims to characterize the structure and distribution of Healthcare-Associated Infections (HAIs) in Ukraine in recent years, features of the species spectrum of pathogens, and the spreading of antibiotic resistance, clinical and microbiological characteristics of HAIs, including those caused by rare pathogens of HAIs, as well as a search, synthesis, screening of new chemical compounds with antimicrobial and antifungal activity in order to introduce new prototypes of antimicrobial drugs.

According to the study design, and analysis of the data of the CDC of Ukraine on the registration of HAIs cases in Ukraine during 2009-2020 was conducted. As a result, for the first time in Ukraine, the registration of HAIs for the last 12 years was analyzed; according to the results, an average of 4,759 ± 710 cases of HAIs have been registered annually. The analyzed materials give grounds to claim a significant underestimation of the incidence of HAIs in the country.

According to the results of a comprehensive, dynamic, clinical, and laboratory-instrumental examination of 250 patients of 4 local hospitals' ICU departments, and based on microbiological and epidemiological criteria, the corresponding diagnosis was confirmed in 205 patients. Among persons with HAIs, 46.8% were men, and 53.2% were women. Among all cases of HAIs, 24.9% were children (including 8.8% newborns), 64.9% - people aged 18-60 years, older adults (> 60 years) were 10.2%. The most common nosologies were respiratory tract infections (36.6%) and urinary tract infections (34.1%). Most HAIs (58.6%) occurred from the 5th to the 14th day of hospital stay.

Three hundred eighty-nine biomaterials were taken, from which 309 strains of microorganisms were isolated, among which Gram-negative bacteria prevailed (51.5%), the species spectrum of which included representatives of 27 different species. Representatives of the genus Pseudomonas were the most isolated - 50 isolates, 16.2% of the total number of pathogens. Gram-positive microbiota is represented by 15 different species of pathogens, the most - members of the genus Staphylococcus - 52 isolates, which is 16.8% of the total number of pathogens. Among the fungi, 12 different species of pathogens were isolated, most of them Candida non-albicans - 20 isolates, which is 6.5% of the total number of pathogens.

For the first time in Ukraine, clinical cases caused by rare pathogens Raoultella (Klebsiella) terrigena and Vibrio metchikovii have been identified and described. Our reported cases were compared with the clinical cases described in the literature. It was shown that the isolate of R. terrigena has film-forming properties, more pronounced than the standard strain Raoutella terrigena ATCC 33257, and the rate of film formation exceeds the rate of film formation by staphylococci.