[The effect of cefaclor on the nasopharyngeal pathogens in children].

Nasopharyngeal specimens were taken from 29 children with acute otitis media, 14 children with chronic sinusitis at acute exacerbation and 2 children with streptococcal pharyngitis who had received cefaclor for 14 days. The study was designed to compare the microbiologic flora of the nasopharynx before the treatment of these diseases with that after the treatment. In this report the subjects were limited to the children who had not received antibiotics within 1 month. Pathogens detected on initial examination were 49 strains consisting of 40 strains of H. influenzae, 3 strains of S. aureus, 5 strains of S. pyogenes, and 1 strain of S. pneumoniae. Two strains were detected in 4 patients. Pathogens remained after treatment in 29 patient, with an unchanged number of pathogens in 12 patients, a decreased number in 14, and microbial substitution in 3. All of the remaining pathogens were H. influenzae, and minimum inhibitory concentration (MIC) changed in 5 of the 26 patients in whom H. influenzae was detected before and after treatment. In a patients with increased MIC, the strain changed from a sensitive strain with an MIC of lower than 3.13 micrograms/ml to a highly resistant strain with an MIC of 25.0 micrograms/ml or higher. By contrast, in 2 patients with decreased MIC, the strain changed from a highly resistant strain with an MIC of 12.5 micrograms/ml or higher to a sensitive strain with an MIC of lower than 3.13 micrograms/ml. In the other patient, MIC decreased to 3.13 micrograms/ml after it had increased from 3.13 micrograms/ml to 25.0 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)