Nowadays etiological significance of opportunistic pathogenic microorganisms, isolated from clinical material, significantly associated with the presence of pathogenicity factors (PF) in this group of microorganisms. One of the leading PF is adhesion, which is responsible for the initial stage of infection, i. e. the attachment of micro-organisms to the respective cells of macroorganism. Staphylococcus aureus is a germ with ubiquitous distribution. It plays a key role in the emergence of community-acquired inflammatory diseases of different localizations and is the leader in etiological structure of nosocomial infections. Most of these infections occur with the biofilms forma-tion, and the first stage of the biofilms formation is the adhesion of microorganisms to surfaces. The aim of the work was to study the adhesive properties of clinical strains of S. aureus, isolated from differ-ent ecological niches in multidisciplinary hospital. 323 strains of S. aureus were used as the object of study, 216 of them were isolated from clinical specimens from patients, 62 strains were isolated from environmental objects and 45 strains were isolated from the nasopharynx of medical staff of the multidisciplinary hospital. The study of adhesive activity of S. aureus strains was performed according to the V. I. Brilis method. The following criteria were used for the adhesive properties assessment: average adhesive characteristic (AAC), the coefficient of adhesion (CА) and the index of adhesiveness of microorganisms (IAM). Microorganisms were considered nonadherent if IAM was below than 1,76; with low adhesive properties if IAM was 1,76 to 2,5; with medium adhesive properties if IAM was 2,51 to 4,0, and with high adhesive properties if IAM was more than 4,0. It was established that almost all the S. aureus strains showed high and medium ability to react with human cells. The range of IAM for S. aureus strains, isolated from the patients was from 1,8 to 5,1, meanwhile 42,3% of the strains were with medium adhesive proper-ties, 35,5 % were highly adhesive and 22,2% were low adhesive. IAM of S. aureus strains isolated from hospital objects ranged from 2,3 to 6,7. Meanwhile 14,5% of the strains were low adhesive, 48,4% were medium adhesive and 37,1% of the strains were highly adhesive. IAM of S. aureus strains isolated from nasopharynx of medical per-sonnel ranged from 2,0 to 7,2. Among them 11,1% of the strains were low adhesive, 62,2% were medium adhesive and 26,7% were highly adhesive. IAM of the S. aureus strains isolated from environmental objects was 1,7 times greater than that of the strains isolated from patients, and 1,2 times greater than IAM of the strains isolated from medical staff (p <0,05). The highest AAC was observed in S. aureus strains isolated from hospital facilities, the AAC of these isolates was 1,9 times greater than that of strains isolated from clinical specimens from patients, and 1,4 greater than AAC of the isolates from medical staff (p <0,05). Thus, it was revealed that the strains isolated from the environmental objects significantly dominated among the S. aureus strains with high adhesive ability, and microbial adhesion is of the factors of persistence.
