In recent years, increased incidences of penicillin-resistant Streptococcus Pneumoniae (PRSP) strains and f3-lactamase-negative ampicillin-resistant (BLNAR) Haemophilus influenzae strains have been reported.We performed bacteriological studies on 29 Streptococcus Pneumoniae strains and 26 Haemophilus inft uenzae strains that were isolated in our outpatient department between September 1998 and August 1999. The mean age of patients from whom bacteria were isolated was 7.3years, while 14 of the

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... reptococcus Pneumoniae strains and 15 of the Haemophilus inf luenzae strains were isolated from patients under the age of 2years. The 29 Streptococcus Pneumoniae strains included 11 (37.9 %) penicillin-insensitive strains (PISP) and 10 (34.5%) PRSP.The combination of PISP and PRSP strains thus accounted for 72.4% of the total Streptococcus Pneumoniae isolates.Those PISP and PRSP strains were exposed to various oral antibacterial agents, and FRPM, CDTR and CFPN showed excellent antibacterial activity.The 26 Haemophilus influenzae strains did not include any ~i-lactamase producers, but 14 (53.8%) BLNAR strains were detected, representing a high frequency.Among the tested oral antibacterial agents, CDTR and CFPN showed excellent antibacterial activity against the BLNAR strains.FRPM showed an excellent MIC distribution in relation to the Streptococcus Pneumoniae strains, but its MICs for the Haemophilus inf luenzae strains were high. Among the currently used oral antibacterial agents, CDTR and CFPN showed excellent MICs for both the PRSP and BLNAR strains.