RESUMO
We investigated the susceptibility to antibacterials, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes, and the serotypes against 377 strains of Streptococcus pneumoniae isolated from medical facilities in Gifu and Aichi prefectures between June 2008 and April 2009. These results were compared with those against 160 strains of S. pneumoniae isolated in 2004. Referring to CLSI (M100-S17), the overall incidence of penicillin-susceptible (PSSP), penicillin-intermediate (PISP) and penicillin-resistant (PRSP) S. pneumoniae was 143 (38%), 185 (49%) and 49 (13%) strains, respectively. PISP and PRSP were isolated higher in the material of nasal cavity and throat, and PRSP was isolated higher in the area of Chuno district. The number of gPSSP with 3 normal PBP genes, gPISP with 1 or 2 normal PBP genes and gPRSP with 3 abnormal genes was 23 (6.1%), 173 (46%) and 181 (48%) strains, respectively. The isolates with no macrolide-resistant gene, only mefA, only ermB, and both mefA and ermB were 28 (7.4%), 138 (37%), 166 (44%) and 45 (12%). The prevalent pneumococcal serotypes were type 19 (92 strains; 24%), following by type 23 (60 strains; 16%) and type 6 (56 strains; 15%). The 80% of pneumococcal serotypes of PRSP were serotype 19 and 6. The MIC90 of each antibacterial was as follows; 0.1 microg/mL for imipenem, panipenem and garenoxacin, 0.2 microg/mL for moxifloxacin, 0.39 microg/mL for meropenem and tosufloxacin, 0.78 microg/ mL for amoxicillin, clavulanic acid/amoxicillin, cefditoren and cefcapene, 1.56 microg/mL for benzylpenicillin, piperacillin, cefteram and levofloxacin, 3.13 microg/mL for cefotiam, flomoxef and pazufloxacin, 6.25 microg/mL for cefdinir, 12.5 microg/mL for norfloxacin and minocycline, > 100 microg/mL for clarithromycin, and these MIC90s were about the same as those in 2004.