RESUMEN
AIM: To study microflora of lower respiratory tract of children from different age groups with cystic fibrosis during follow-up for determination of its variability and possible sources of infectious complications. MATERIALS AND METHODS: One hundred forty-one medical histories of patients from different age groups with cystic fibrosis living in various regions of Russian Federation were analyzed. Eighty-four children with cystic fibrosis living in Moscow and Moscow region treated as outpatients and inpatients were prospectively followed. For identification and characterization of microorganisms, microbiological, molecular biological, and statistical methods were used. RESULTS: It was demonstrated that chronic pseudomonas, staphylococcal or mixed infection was already diagnosed in 25% of children aged 1-4 years, and identified in 80% of patients to the age of 18 years. In two-thirds of cases association of microorganisms was identified, and in hospitalized patients these associations were comprised by 3-5 microorganisms in 60% of cases. Aside from main agents in associations (Pseudomonas aeruginosa and Staphylococcus aureus), representatives of Gram-negative nonfermentative microorganisms (Burkholderia cepacia, Stenotrophomonas maltophilia, Acinetobacter baumanii) were often identified that possibly determined by tropism of these species to lung tissue. CONCLUSION: Chronic mixed infection is characteristic for patients with cystic fibrosis. Identification of possible mechanisms of lung infection in patients with cystic fibrosis will allow to develop evidence-based system of prevention of infectious complications in these patients.