[Multicenter surveillance of Pseudomonas aeruginosa strains for antimicrobials in Aichi prefecture in 2009].

We investigated the susceptibility to antimicrobials of 204 Pseudomonas aeruginosa strains isolated from 21 hospitals in Aichi prefecture from September to November 2009. MIC distributions of various antimicrobials were analyzed in terms of geographic region of isolation, patient status (outpatient or inpatient), and type of specimens that the strain was isolated from. The results were as follows. 1. Although more than 90% of strains were susceptible to all aminoglycosides and colistin, 80-90% of them were susceptible to beta-lactams and fluoroquinolones. MIC distributions of all antimicrobials measured were not significantly different between regions. 2. Only 1 strain (0.5%) was multi-drug resistant Pseudomonas aeruginosa (MDRP). Thirteen strains (6.4%) showed imipenem MIC > or = 16 microg/mL, and 16 strains (7.8%) showed ciprofloxacin MIC > or = 4 microg/mL. These strains tended to be more isolated from urine, respiratory tract specimens, or surgical specimens. 3. The MICs of tazobactam/piperacillin, panipenem, meropenem, doripenem, biapenem, sulbactam/cefoperazone, cefepime, and aztreonam were significantly higher in strains isolated from inpatients than in those from outpatients. MIC distributions of antimicrobials other than beta-lactams were not significantly different between situations where strains were isolated. 4. MIC distributions of piperacillin, all carbapenems, cefepime, gentamicin, and all fluoroquinolones were significantly different among samples from which strains were isolated. The strains isolated from blood showed lower MICs against all antimicrobials than those from other samples. No difference was found in MIC distributions when categorized according to bacteremic origin. The MICs were apparently elevated against beta-lactams, fluoroquinolones, and gentamicin in strains isolated from respiratory tract specimens, and against beta-lactams, and fluoroquinolones in strains isolated from urine. It was suggested that in P. aeruginosa surveillance, the results should be reported by stratifying with patient status, and type of specimens that the strain was isolated from and that regional surveillance should be useful with such stratification to establish antibiograms for empirical antimicrobial choice.

[Epidemiological analysis of Streptococcus pneumoniae in Gifu prefecture and the northern district of Aichi prefecture--2009].

High pathogenicity and drug resistance of Streptococcus pneumoniae are serious problem in clinical practice. Since 1999, we have conducted epidemiologic analyses of S. pneumoniae in Chubu district. We report the results of the analysis conducted in 2009. Three hundred and eight (308) S. pneumoniae isolates with a gene coding for autolysin lyt-A, which had been isolated from patients at 21 medical institutions in Gifu prefecture and the northern part of Aichi prefecture in 2009, were enrolled in this study. The strains were classified according to their drug resistance based on the presence of the pbp mutation, and examined for the presence of the two macrolide-resistance genes, ermB and mefA. Moreover, they were serotyped using type-specific antisera. The mean age of the patients from whom these S. pneumoniae strains were isolated, was 23.4 +/- 30.1 years old, and children aged 15 years old or less accounted for 66% of all the patients. Genotype penicillin-susceptible S. pneumoniae (gPSSP), genotype penicillin-intermediate S. pneumoniae (gPISP) and genotype penicillin-resistant S. pneumoniae (gPRSP) were 22 (7.1%), 131 (42.5%) and 155 (50.3%), respectively. The strains with mefA positive and ermB negative, mefA negative and ermB positive, and mefA positive and ermB positive were 80 (26.0%), 153 (49.7%), and 47 (15.3%), respectively. The MIC90 values of tebipenem (TBPM) and faropenem were 0.06 microg/mL and 0.5 microg/mL, respectively. TBPM showed the high bactericidal activity against gPRSP. In carbapenems, panipenem and biapenem exhibited higher bactericidal activities. Quinolone-resistant S. pneumoniae (QRSP) were isolated from 10 (3.2%). QRSP dominated 5 (7.9%) and 3 (1.5%) among the elderly (over 65 years old) and children, respectively. (As for the serotype, serotypes 6, 19 and 23 were 60 (19.5%), 62 (20.1%), and 44 (14.3%), respectively. Further epidemiologic studies on S. pneumoniae might be required also in the future, including the relationship between the serotype and drug resistance.