Abstract
Organisms isolated from rhinopharyngeal fluid obtained from pediatric patients with upper respiratory tract bacterial infection were examined for β-lactamase production and susceptibility of anti-microbial drugs to estimate the direct pathogen as well as the β-lactamase-producing indirect pathogen, and to consider the preferable first choice antimicrobial drugs for the treatment of these patients. The predominant organisms which were estimated as the direct pathogen were Streptococcus pneumoniae and Haemophilus influenzae; 29.5% of the S. pneumoniae were penicillin-intermediate S. pneumoniae and penicillin-resistant S. pneumoniae, and 13.8% of the H. influenzae were β-lactamase-producing strains. The main organisms which were estimated as the indirect pathogen were Moraxella subgenus Branhamella catarrhalis and Staphylococcus aureus which produced β-lactamase. These organisms were often isolated concomitantly with S. pneumoniae or H. influenzae. The predominant patterns of isolated bacteria were S. pneumoniae plus M.(B.) catarrhalis and H. influenzae plus M.(B.) catarrhalis, these two patterns accounted for 32.6% of all patients. Thus it is suggested that the main indirect pathogenic factor in pediatric patients with upper respiratory tract bacterial infection is β-lactamase which is produced by M.(B.) catarrhalis. In the patients in whom an indirect pathogen is involved, the rate of elimination of S. pneumoniae and H. influenzae was significantly higher in those treated with clavulanic acid/amoxicillin than in those treated with amoxicillin.
