Aetiological diagnosis of pneumonia in children seems difficult, while the identification of causative factor is of great significance as it determines the choice of appropriate treatment. It also reduces the time of hospitalisation as well as prevents permanent damage of respiratory organ and its chronic dysfunction in the future. Patients suffering from pneumonia with atelectasis confirmed by radiological investigation can be subjected to diagnostic- therapeutic bronchoscopy. Bronchial secretion sampled at that time and investigated bacteriologically may be the most helpful in the determination of the aetiology of pneumonia and drug-resistance of the pathogen. The study was a retrospective evaluation of the results of bacteriological and mycological analyses of the secretion from bronchial tree, sampled during bronchoscopy from children with pneumonia and coexistent atelectasis. Study assumptions included: assessment of bacterial flora, determination of the most frequent bacterial strains in infants and older children, analysis of correlation between the nature of secretion in bronchial tree and the result of bacteriological investigation. The study was based on 148 cases of children treated due to pneumonia with atelectasis, hospitalised between 1st January 1985 and 31 December 1995. PatientsÕ age ranged between 1 day Ð 15 years (mean age 27.3 months). The number of boys and girls in the study groups was similar. In the majority of cases (90%), bacteriological investigation of the secretion from bronchial tree revealed the presence of bacterial flora. Streptococci turned out to be the most frequent pathogen in children with pneumonia, while Streptococcus pneumoniae occurred significantly more often in infants and betahaemolytic streptococci gr. A prevail significantly among older children. Out of Gram-negative bacteria, E. coli is a significantly more frequent aetiological factor of pneumonia in infants, while Haemophilus sp. dominates significantly among older children. Irrespective of macroscopic nature of the secretion collected from bronchial tree (mucous, mucous-purulent, purulent secretion), its bacteriological investigation revealed the presence of pathogenic bacteria.

Keywords: children, Bacteria, bronchial secretion