Although Streptococcus pneumoniae (SP), Haemophilus influenzae (HI), and Moraxella
catarrhalis (MC) are major pathogenic bacteria of acute otitis media (AOM) in children, responsibility of their resistance
to antimicrobial agents for intractable AOM has not been cleared. In this study, cultured bacteria from the adenoid of
otitis-prone children were compared with those of children who had no apparent episodes of AOM to know the most
responsible pathogens for intractable AOM.
Sixty-eight children who had episodes of recurrent or persistent AOM were subjected to this study and 19
children without apparent episodes of AOM but with obstructive sleep apnea were taken as controls. Nasopharyngeal
swab specimens were obtained from the adenoid transorally during the adenoidectomy, instead of conventional transnasal
harvesting, to avoid contamination. Prevalence of SP, HI, and MC in each group was compared using the chi-squared or
Fischer's exact test, and p-values <0.05 were considered significant.
SP was identified in 60.3% of otitis-prone children and in 52.6% of control children, and this difference indicated
no statistically significance (p=0.54). HI was isolated from 77.9% of subjects and from 47.4% of controls, and the
difference revealed significant (p=0.009). Above all, beta-lactamase negative HI (BLNAR) was caught in 39.7% of the
study group, but in none of the control group (p=0.002). MC was identified in 32.4% and in 5.3%, individually, with
significant difference (p=0.04).
HI was more frequently isolated from otitis-prone children, and was considered to make AOM more
intractable. The pathogenic role of MC for AOM may be evident.