Summary. S. aureus is one of the world's most common pathogens of infectious diseases. It is known that the development of infection is facilitated by various factors and factors of virulence of staphylococci. Much less is known about their interaction with each other and the protective mechanisms of the host's immune system. The importance of immunocompetent cells in the development of the inflammatory process was the basis for studying the ability to phagocytose strains of Staphylococcus aureus isolated from the nasopharynx of children with measles. The aim of the study – to determine the ability to phagocytose Staphylococcus aureus strains isolated from children with measles by neutrophilic granulocytes and peripheral blood monocytes. Materials and Methods. The phagocytic response was assessed using the following indicators: phagocytosis activity or the percentage of phagocytic-active leukocytes, phagocytosis index – the average number of absorbed microbes per phagocyte. During the study, two groups were formed: group 1 – experimental (35 patients with measles); group 2 – control (samples of normal microflora from almost healthy people – 15 persons). The material from the oropharynx was taken with a sterile swab, examined by bacteriological method. The quantitative composition of bacteria was reflected in the number of colony forming units (CFU) in terms of dilution of the test material. Identification of microorganisms was performed according to standard schemes. Phagocytosis studies were performed by the method of Kost and Stenko. Results. During the study, it was found that neutrophilic granulocytes play an important role in the process of phagocytosis. Phagocytic activity of neutrophils isolated from children with measles and monocytes was less than 46.9 % and 38.8 % compared with the group of healthy individuals. There was also a decrease in the phagocytic index in phagocytic leukocytes relative to the culture of S. aureus isolated from children with measles: neutrophils – 31.7 %, monocytes – 38.6 %. Conclusions. The decrease in the phagocytic ability of Staphylococcus aureus culture isolated from children with measles by phagocytic cells in the experimental group is apparently due to the presence of virulence factors of the pathogen, which significantly inhibit phagocytosis and cause the ability of microorganisms to persist for a long time
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