From October 2002 to September 2003, we collected the specimen from 476 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 584 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 578 strains were examined. The breakdown of the isolated bacteria were: Staphylococcus aureus 77, Streptococcus pneumoniae 103, Haemophilus influenzae 95, Pseudomonas aeruginosa (non-mucoid) 61, P. aeruginosa (mucoid) 23, Klebsiella pneumoniae 36, 1 29, etc.
Of 77 S. aureus strains, those with 2μg/ml or less of MIC of oxacillin (MPIPC) [methicillin-susceptible S. aureus: MSSA] was 34 strains (44.2%) and those with 4μg/ml or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) was 43 strains (55.8%). Against MSSA, imipenem (IPM) and minocycline (MINO) had the most potent antibacterial activity and inhibited the growth of all the strains at 0.25μg/ml. Although clindamycin (CLDM) and aminoglycosides also had the potent activity, the resistant strains against those agents were detected. Cefotiam (CTM) inhibited the growth of all the strains at 1μg/ml without the low sensitive strains. Against MRSA, vancomycin (VCM) showed the most potent activity and inhibited the growth of all the strains at 2μg/ml. Arbekacin (ABK) also showed the relatively potent activity and inhibited the growth of all the strains at 4μg/ml. Carbapenems showed the most potent activities against S. pneumoniae and inhibited the growth of all the strains at 0.25-0.5μg/ml. Cefozopran (CZOP) also had a preferable activity (MIC₉₀: 1μg/ml) and inhibitedthe growth of all the strains at 2μg/ml. In contrast, the resistant strains for cefaclor (CCL), erythromycin (EM), CLDM, and tetracycline (TC) were detected in 50.5%, 76.7%, 50.5%, and 80.6% of all the strains, respectively.
Against H. influenzae, LVFX showed the most potent activity and inhibited the growth of 92 of all the strains (96.8%) at 0.063 ug/ml. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and non-mucoid) and inhibited the growth of all the strains at 2μg/ml. The antibacterial activity of CZOP was good and its MIC90 against mucoid and non-mucoid strains was 8 and 16μg/ml, respectively. CZOP and cefpirome (CPR) were the most potent against K. pneumoniae with 0.125μg/ml of MIC₉₀. Also, all the agents generally showed potent activities against M.(B.) catarrhalis and the MIC₉₀ of all drugs were 4μg/ml or less.
The approximately half the number (47.5%) of the patients with respiratory infection were aged 70 years or older. As for the incidence by the diseases, bacterial pneumonia and chronic bronchitis were the highest, being noted in 35.7 and 33.8% of all the patients, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. pneumoniae (22.6%). In contrast, S. aureus (16.6%) and P aeruginosa (13.7%) were relatively frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from all the patients were H. influenzae (24.5%) and S. pneumoniae (24.2%). In comparison of the isolated bacteria by pretreatment agents, P. aeruginosa was relatively frequently isolated from the patients pretreated with cephems or macrolides and H. influenzae was relatively frequently isolated from the patients pretreated with penicillins.

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The bacterial strains isolated from 491 patients diagnosed as having urinary tractinfections (UTIs) in 13 institutions in Japan were supplied between August 2002 and July 2003. The susceptibilities of them to many kinds of antimicrobial agents were investigated. Of them, 578 strains were estimated as causative bacteria and used for the investigation. The number of them was 578 strains consisting of 177 Gram-positive bacterial strains (30.6%) and 401 Gram-negative bacterial strains (69.4 %).
Against Staphylococcus aureus, vancomycin (VCM) showed a strong activity and prevented the growth of all strains with 1μg/mL. The susceptibility of Staphylococcus epidermidis to cephems including cefotiam (CTM) was relatively good. Against Enterococcus faecalis, ampicillin (ABPC), imipenem (IPM), and VCM showed the strongest antibacterial activity (MIC₉₀: 2-4μg/mL). In addition, the low sensitive strains (MIC: ≥256μg/mL) to clarithromycin (CAM) were detected at 48.3% but none to cefozopran (CZOP). The antibacterial activity of cephems to Escherichia coli was generally good, and especially CZOP and cefpirome (CPR) showed the highest activity (MIC₉₀: ≤0.125μg/mL). Quinolone resistant E. coli was detected at frequency of 13.5%, which was higher than that in the last year. The antibacterial activity of cephems to Citrobacter freundii was generally lowbut CZOP and CPR had a strong acitivity (MIC90: 0.25 and 0.5 μg/mL, respectively). The antibacterial activity of cephems to Klebsiella pneumoniae was good and especially cefmenoxime (CMX), cefixime (CFIX), flomoxef (FMOX), CPR, and CZOP showed stronger activity (MIC₉₀: ≤0.125μg/mL). Against Serratia marcescens, meropenem (MEPM) had the highest antibacterial activity followed by CPR and CZOP. Against Proteus mirabilis, CMX, ceftazidime (CAZ), CPR, MEPM, carumonam (CRMN), and levofloxacin (LVFX) showed the strongest activity (MIC90: ≤0.125μg/mL). Among other cephems, CZOP and CFIX were also strong (MIC₉₀: 0.25μg/mL). The antibacterial activity of the drugs to Pseudomonas aeruginosa wasgenerally low, and MIC₉₀ of all the drugs were ranged from 64 to≥256μg/mL except IPM and amikacin (AMK) having 16μg/mL. The antibacterial activity of CZOP was relatively good (MIC₅₀: 8μg/mL).

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A total of 615 bacterial strains isolated from 491 patients diagnosed as having urinary tract infections (UTIs) in 13 institutions in Japan were supplied between August 2002 and July 2003. Then, the clinical background of patients were investigated such as sex, age, and type of infections and kind of bacteria, frequency of bacteria isolation by age and infections, bacteria and infections by timing of antibiotics administration, and bacteria and infections by surgical procedures.
The bacterial strains were divided by the age and sex of the patients and the types of infections. In males, the number of patients aged less than 50 years was few and the complicated UTIs without indwelling catheter was observed most frequently. In the present time, the bacteria most frequently isolated were Escherichia coli. Pseudomonas aeruginosa and Enterococcus faecalis were also relatively frequently isolated. E. coli decreased and P. aeruginosa increased with the complication of the infections. E. faecalis tended to be isolated more frequently in the complicated UTIs than in the uncomplicated UTIs. With respect to the relation of these results to the age of the patients, in the uncomplicated UTIs, the isolation frequency of E. coli was the highest in all age groups, accounting for 70.8% in 20-49 years old. In the complicated UTIs without indwelling catheter, the isolation frequency of E. coli decreased with aging of the patients and was lower than that of E. faecalis in the patients aged 70 or more (18.3 vs 20.6%). In the complicated UTIs with indwelling catheter, the isolation frequency of E. coli was lower than in the uncomplicated UTIs in all age groups and P aeruginosa and E. faecalis were more frequently isolated. In comparison of causative bacteria in UTIs between before and after the administration of antibiotics, E. coli decreased and P aeruginosa increased after the administrationin any UTIs. In comparison of causative bacteria in UTIs with or without surgery, E. coli was more frequently isolated in the patients without surgery, while P aeruginosa was more in the patients with surgery in any UTIs. E. faecalis was more frequently isolated in the patients with surgery in uncomplicated and complicated UTIs without indwelling catheter and in the patients without surgery in complicated UTIs with indwelling catheter.

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Combinede ffectso f arbekacin (A BK) with biapenem (BIPM) w eree xaminedo n both i n vitro and in vivo model of a mixtureo f MRSA and Pseudomonaase ruginosa As a result, significan etffect in vitrow aso bserved in combined use of ABK (1/2 MIC) with BIPM (1/4 and 1/2 MIC) against MRSA as compared with ABK or BIPM alone. Against P aeruginosa combined effect was also observed, showing reduction of viable cells to the limitation of detection within 2 hours. Moreover, with respect to the protective effect on mixed systemic infection of MRSA and P aeruginosa, the combined treatment with ABK and BIPM showed more excellent efficacy as compared with the single use of each drug.

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[in Japanese]

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