1998 Volume 46 Issue 4 Pages 148-155
One hundred and seventy six pediatric patients with upper respiratory tract bacterial infection were clinically evaluated for indirect pathogenicity by β-lactamase-producing organisms to consider the selection of antimicrobial drugs used to treat this infection. The patients included 41 with monomicrobial infections (23.3%) and 135 with polymicrobial infections (76.7%). The main bacteria isolated as the direct pathogen were Haemophilus influenzae and Streptococcus pneumoniae, while those isolated as the indirect pathogen were Moraxella subgenus Branhamella catarrhalis, and Staphylococcus aureus. Of all the patients evaluated, 130 (73.9%) suggested possible involvement of either direct or indirect pathogenicity by β-lactamase-producing organism. These selected patients were randomly treated with amoxicillin (AMPC) or clavulanic acid/amoxicillin (CVA/AMPC), and the effect on eradication of the direct pathogen and the clinical effect were assessed and compared between patients caused by a β-lactamase-non-producing organism [β-negative (-) infection] and those caused by a β-lactamase-producing organism [β-positive (+) infection]. No significant difference was observed between the two treatment groups in terms of the rate of eradication of the direct pathogen both on either day 3 or 7 after treatment in the β-negative patients, while those treated with CVA/AMPC showed a significantly better eradication rate in the β-positive patients. Patients with polymicrobial infection from which M.(B.) catarrhalis was isolated showed a result similar to that in the β-positive patients. No significant difference in the clinical effect was found between the two treatment groups, while those treated with CVA/AMPC tended to show a more favorable clinical effect on patients with polymicrobial infectionfrom whom M.(B.) catarrhalis was isolated. It is clear that the indirect pathogenicity by a β-lactamase-producing organism was involved in eradication of the direct pathogen, but further studies including evaluation of long-term prognosis seem to be required to determine its clinical significance.
