Resistance against Oral Antibiotics to Streptococcus pneumoniae Isolated from Adult Respiratory Tract Infections

Abstract

The resistance against oral antibiotics to Streptococcus pneumoniae (S. pneumoniae) isolated from adult patients with respiratory tract infections in the Kurume area in 1998 was studied. The frequency of resistant strains, which were isolated penicillin-intermediate S. pneumoniae and resistant S. pneumoniae (PISP, PRSP) were both 41.2%. We examined the minimal inhibitory concentrations (MIC) of oral antibiotics and the susceptibility ratio of the strains for the drugs based on the breakpoint MIC. The breakpoint MIC of pneumonia against oral β-lactam antibiotics to PISP, PRSP, which were determined by Japan Society of Chemotherapy, were high in the order of FRPM>CDTR, CFPN>CFTM>CFDN, CPDX. In the case of the new oral quinolones, DU6859a>SPFX>LVFX> CPFX showed good results, in this order. DU6859a showed the most significant inhibitory effect to PISP, PRSP (MIC₉₀ 0.06μg/ml). By serotyping the percentage of 19, 6, 23 was 42.9%, 21.4% and 14.3%.