COLONIZATION PROPERTIES OF OPPORTUNISTIC BACTERIA ISOLATED FROM CHILDREN WITH PNEUMONIA

Aim. Evaluation of phenotypes and pathogenicity factors of 476 opportunistic bacteria isolated from respiratory samples of 973 children with community-acquired pneumonia and 365 children without respiratory infection symptoms. Materials and methods. Quantitative method of tracheal aspirate and nasopharyngeal swab seeding into certified nutrient media was used, identification was carried out according to standard techniques. Results. Adhesive, «anti-interferon», anti-lysozyme and inherent bactericidal activity of Escherichia coli and Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter spp. were established to ensure in combination with known aggression factors their colonization advantage compared with other pneumopathogens. Adhesion indexes of Gram-negative bacteria lower than 2.5 are shown as markers of invasive strains. Anti-lysozyme activity level lower than 2.14 g/ml and lack of «antiinterferon» activity characterize non-invasive opportunistic bacteria strains. Conclusion. The detected phenotypic features of opportunistic bacteria may be used in clinical practice for evaluation of etiologic importance of microorganisms isolated from tracheal aspirate in pneumonia patients.

opportunistic microorganisms, pneumonia, children, etiology, pathogenicity factors