In 2001 and 2004-2005, in cooperation with clinics in the Johnan area in Tokyo, we conducted studies to evaluate bacteria isolated from epipharynx of acute otitis media patients aged 10 years old or younger. In this presentation, we report a comparison between the findings of these two studies. In addition, the results of evaluating of gene mutations in isolated bacteria and the efficacy of Cefrerm Pivoxil (CFTM-PI) in the treatment of otitis media will be discussed.
In 2001, 191 strains of bacteria were isolated from a total of 123 ears. These isolates included 78 strains of Streptococcus pneumoniae (PSSP 37 strains, PISP 38 strains, PRSP 3 strains), 59 strains of Haemophilus influenzae (BLNAS 49 strains, BLNAR 10 strains) and 54 strains of Moraxella catarrhalis. Among Streptococcus pneumoniae isolated, 52.6% were drug-resistant strains, and 16.9% of Haemophilus influenzae, showed resistance. During the study conducted between 2004 and 2005, 223 strains were isolated. These isolates included 73 strains of Streptococcus pneumoniae (PSSP 28 strains, PISP 28 strains, PRSP 17 strains), 67 strains of Haemophilus influenzae (BLNAS 43 strains, BLNAR 20 strains, BLPAR 3 strains, BLPACR 1 strain) and 61 strains of Moraxella catarrhalis. 61.6% of Streptococcus pneumoniae and 35.8% of Haemophilus influenzae were drug-resistant strains. On the evaluation of gene mutations, 70 strains of Streptococcus pneumoniae showed gene mutations; especially, pbp2x mutations were observed in all of the strains. As for Haemophilus influenzae, there were 32β-lactamase-non-producing strains and 4β-lactamase-producing strains both with pbp mutations. In the evaluation of efficacy, CFTM-PI showed good antimicrobial activity with MIC of 0.25-1μg/mL against both pbp mutated strains of Haemophilus influenzae. The approved dosage for CFTM-PI is 9-18mg/kg, and it has a rather wide range. In the treatment of pediatric acute otitis media, if penicillin administration is not effective, CFTM-PI seems to be a useful option considering the potential of Haemophilus influenzae infection and the possibility of doubling the dosage.
