Ability of Microorganisms, Causing Respiratory Infections in Children, to Form Biofilms in vitro
Authors:   Kharkiv National Medical University. 4, Nauky Avenue, Kharkiv 61022, Ukraine, Isaieva H. O. , Mishyna M. M. ,   Kharkiv National Medical University. 4, Nauky Avenue, Kharkiv 61022, Ukraine, Mozgova Y. A. ,   Kharkiv National Medical University. 4, Nauky Avenue, Kharkiv 61022, Ukraine, Gonchar M. O. ,   Kharkiv National Medical University. 4, Nauky Avenue, Kharkiv 61022, Ukraine, Logvinova O. L. ,   Kharkiv National Medical University. 4, Nauky Avenue, Kharkiv 61022, Ukraine, Basiuk M. A. ,   Municipal Office Commercial Enterprise Kharkiv Regional Council Regional Children's Clinical Hospital. 5, Ozerianskaya St., Kharkiv 61093, Ukraine
Published: February 2021

The purpose of the study was to detect ability to form biofilms by microorganisms that cause respiratory tract infections. Materials and methods. The study involved 97 strains of microorganisms. Microorganisms were isolated from children with respiratory tract infections. All strains, isolated from patients, were able to form biofilms. There were 44 strains of S. aureus (from patients with pneumonia – 13 strains, from patients with other respiratory diseases – 31), 34 strains of S. pneumoniae (pneumonia – 27 strains, other respiratory diseases – 7), 13 strains of K. pneumoniae (pneumonia – 6 strains, other respiratory diseases – 7), 6 strains of P. aeruginosa (pneumonia – 5 strains, other respiratory diseases – 1). Children were treated at the pulmonary department and intensive care unit in Kharkiv Regional Children's Clinical Hospital. Results and discussion. The optical density of primary biofilms formed by Gram-positive microorganisms was 1.33±0.24 Units of OD, and their secondary biofilms was 0.32±0.10 Units of OD. In patients with pneumonia optical density of primary biofilms of Gram-positive microorganisms was 1.48±0.21 Units of OD and of secondary biofilms was 0.30±0.08 Units of OD. Optical density of primary biofilms of Gram-positive microorganisms in patients with other respiratory infections was 1.18±0.15 Units of OD, of secondary biofilms was 0.35±0.12 Units of OD. The optical density of primary biofilms formed by Gram-negative microorganisms was 2.01±1.03 Units of OD, optical density of secondary biofilms was 1.06±0.42 Units of OD. In patients with pneumonia optical density of primary biofilms of Gram-negative microorganisms was 2.57±0.87 Units of OD, of secondary biofilms was 1.21±0.50 Units of OD. Optical density of primary biofilms of Gram-negative microorganisms in patients with other respiratory infections was 1.24±0.66 Units of OD, of secondary biofilms was 0.84±0.11 Units of OD. Conclusion. Gram-negative microorganisms in general formed more massive biofilms compared with Gram-positive microorganisms. Among all microorganisms P. aeruginosa formed the thickest primary and secondary biofilms. Strains of P. aeruginosa isolated from patients with pneumonia formed the thickest primary and secondary biofilms. Strains of S. aureus isolated from patients with other respiratory infections formed most massive primary biofilms, strains of K. pneumoniae formed the hardest secondary biofilms in this group