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Kazufumi Hiramatsu

Publications and source records attributed to Kazufumi Hiramatsu.

At least 19 recordsLinked to original sources

The prophylactic effectiveness of various antifungal agents against the progression of trichosporonosis fungemia to disseminated disease in a neutropenic mouse model.

Neutropenic mice with latent trichosporonemia were given various antifungal agents (amphotericin B, fluconazole, itraconazole) or saline to determine which antifungal agent could be useful for prophylaxis. The 3-week-survival rate was 80% in the fluconazole group, 50% in the amphotericin B group, 45% in the itraconazole group, and 30% in the saline group. Compared with the other antifungal agents, fluconazole offered superior prophylaxis against the progression of trichosporonosis fungemia to disseminated disease (P<0.05). These results suggest that clinical studies are warranted to investigate fluconazole prophylaxis of trichosporonosis progression in neutropenic patients, such as people receiving chemotherapy and patients who have received solid organ transplants.

Amphotericin B↗

Intratracheal immunization with pili protein protects against mortality associated with Pseudomonas aeruginosa pneumonia in mice.

We examined the protective effect of intratracheal immunization with Pseudomonas aeruginosa pili protein against respiratory infection caused by P. aeruginosa. Mice were immunized intratracheally or subcutaneously with purified pili protein or bovine serum albumin as a control. Intratracheally but not subcutaneously pili protein-immunized mice showed significant improvement of survival after intratracheal challenge with the PAO1 strain. Furthermore, bacterial cell counts in pili protein-immunized murine lungs were significantly decreased compared to controls at 18 h after the challenge. Antipili protein antibody titers in bronchoalveolar lavage fluid of intratracheally pili protein-immunized mice were higher than in bovine serum albumin immunized mice. However, antipili antibody titers were not increased in bronchoalveolar lavage fluid of subcutaneously pili protein-immunized mice, despite the high serum antipili antibody titers. Inoculation of P. aeruginosa induced immediate increases in interleukin-12 and interferon-gamma in bronchoalveolar lavage fluid of pili protein-immunized mice, reflecting an adequate and rapid immune response against P. aeruginosa respiratory tract infection. Our findings suggest that intratracheal pili protein immunization is effective against respiratory tract infection caused by P. aeruginosa in mice.

Animals↗

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2004)].

From October 2004 to September 2005, we collected the specimen from 319 patients with lower respiratory tract infections in 12 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 383 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 381 strains were examined. The breakdown of the isolated bacteria were: Staphylococcus aureus 87, Streptococcus pneumoniae 80, Haemophilus influenzae 78, Pseudomonas aeruginosa (non-mucoid) 35, P. aeruginosa (mucoid) 9, Klebsiella pneumoniae 15, Moraxella subgenus Branhamella catarrhalis 30, etc. Of 87 S. aureus strains, those with 2 microg/mL or less of MIC of oxacillin (methicillin-sensitive S. aureus: MSSA) and those with 4 microg/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were 40 (46.0%) and 47 (54.0%) strains, respectively. Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all the strains at 0.063 microg/mL. Against MRSA, vancomycin showed the most potent activity and inhibited the growth of all the strains at 1 microg/mL. Arbekacin (ABK) also showed the potent activity and its MIC90 was 2 microg/mL. Carbapenems showed the most potent activities against S. pneumoniae and inhibited the growth of all the strains at 0.25-0.5 microg/mL. Cefozopran (CZOP) also had a preferable activity (MIC90: 1 microg/mL) and inhibited the growth of all the strains at 2 microg/mL. In contrast, there were high-resistant strains (MIC: 128 microg/mL or more) for ABK (2.5%), erythromycin (37.5%), and clindamycin (38.8%). Against H. influenzae, levofloxacin showed the most potent activity and inhibited the growth of all the strains at 0.125 microg/mL. Meropenem showed the most potent activity against P. aeruginosa (mucoid) and inhibited the growth of all the strains at 2 microg/mL. Against P. aeruginosa (non-mucoid), amikacin (AMK) had the most potent activity and its MIC90 was 4 microg/mL. The activity of CZOP against the non-mucoid type also was preferable and its MIC90 was 8 microg/mL. Against K. pneumoniae, CZOP, cefmenoxime, cefpirome, flomoxef were the most potent activity and inhibited the growth of all the strains at 0.063 microg/mL. Also, all the agents generally showed a potent activity against M. (B.) catarrhalis and the MIC90 of them were 4 microg/mL or less. The approximately half the number (57.0%) of the patients with respiratory infection were aged 70 years or older. Bacterial pneumonia and chronic bronchitis accounted for 50.8% and 23.8% of all the respiratory infection, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. aureus (21.6%), S. pneumoniae (24.7%) and H. influenzae (20.1%). S. aureus (20.9%), S. pneumoniae (16.1%), and H. influenzae (16.1%) also were relatively frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from the patients were S. pneumoniae (22.3%) and H. influenzae (25.1%). The bacteria relatively frequently isolated from the patients treated with macrolides were P. aeruginosa and the isolation frequency was 43.5%.

Aged↗

[Evaluation of the new detectable method of the specimen mix-up in a microbiological examination].

To date, it has been difficult to detect a mix-up of specimens for microbiological examinations. We developed and evaluated a computer program that detects specimen mix-up during the examinations. Once some bacterial species such as Pseudomonas aeruginosa and MRSA are detected in an examination, it is not easy for these bacteria to disappear on subsequent examinations. It is possible to speculate that there has been a specimen mix-up when there are differences in the existence of bacterial species between the results of the past and current examinations. In this study, 1379 false mix-up specimens were created and evaluated for the detection of specimen mix-ups using this method and 417 of the 1379 specimens were detected as mix-ups (sensitivity; 30.2%). Furthermore, when 1486 real specimens were evaluated for the detection of mix-ups, 114 samples were judged to have been mixed-up. Three of these samples were mixed up during the examinations (specificity; 92.5%). These findings suggest that this method is useful for the detection of specimen mix-up during microbiological examinations.

Bacteriological Techniques↗

[In vitro susceptibilites to levofloxacin and various antibacterial agents of 11,475 clinical isolates obtained from 52 centers in 2002].

The susceptibilities of bacteria to fluoroquinolones (FQs), especially levofloxacin, and other antimicrobial agents were investigated using 11,475 clinical isolates collected in Japan during 2002. Methicillin susceptible staphylococci, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis, the family of Enterobactericeae, Haemophilus influenzae and Acinetobacter spp. exhibited stable and high susceptibilities to FQs. The rate of FQs-resistant MRSA was 80 approximately 90%, being markedly higher than that of FQs-resistant MSSA. The FQs-resistance rate of MRCNS was also higher than that of MSCNS, however, it was lower than that of MRSA. No FQs-resistant clinical isolates of Salmonella spp. were detected in any of the surveys. Thirteen of Escherichai coli 696 isolates, 8 of Klebsiella pneumoniae 630 isolates and 33 of Proteus mirabilis 373 isolates produced extended-spectrum beta-lactamase (ESBL), furthermore 6 of 13 in E. coli, 1 of 8 in K. pneumoniae and 14 of 31 ESBL-producing isolates, and in P. mirabilis were FQs resistant. Attention should be focused in the future on the emergence of ESBL in relation to FQs resistance. The rate of FQs-resistant P. aeruginosa isolated from urinary tract infection (UTI) was 40 approximately 60%, while 15 approximately 25% of isolates from respiratory tract infection (RTI) were resistant. IMP-1 type metallo beta-lactamase producing organisms were found in 49 of P. aeruginosa 1,095 isolates, 7 of S. marcescens 586 isolates and 4 of Acinetobacter spp. 474 isolates, respectively. Glycopeptide-resistant enterococci or S. aureus was not found.

Anti-Bacterial Agents↗

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2003)].

From October 2003 to September 2004, we collected the specimen from 399 patients with lower respiratory tract infections in 12 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 474 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 469 strains were examined. The breakdown of the isolated bacteria were: Staphylococcus aureus 76, Streptococcus pneumoniae 81, Haemophilus influenzae 84, Pseudomonas aeruginosa (non-mucoid) 56, P. aeruginosa (mucoid) 11, Klebsiella pneumoniae 36, Moraxella subgenus Branhamella catarrhalis 24, etc. Of 76 S. aureus strains, those with 2 microg/ml or less of MIC of oxacillin (methicillin-susceptible S. aureus: MSSA) and those with 4 microg/ml or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) were both 38 strains (50.0%). Against MSSA, imipenem had the most potent antibacterial activity and inhibited the growth of all the strains at 0.063 microg/mL. Against MRSA, vancomycin showed the most potent activity and inhibited the growth of all the strains at 2 microg/mL. Arbekacin also showed the potent activity and inhibited the growth of all the strains at 4 microg/mL. Carbapenems showed the most potent activities against S. pneumoniae and inhibited the growth of all the strains at 0.125-0.5 microg/mL. Cefozopran (CZOP) also had a preferable activity (MIC90:2 microg/ mL) and inhibited the growth of all the strains at 4 microg/mL. In contrast, there were high-resistant strains (MIC: 128 microg/mL or more) for cefaclor (11.1%), erythromycin (43.2%), and clindamycin (40.7%). Against H. influenzae, levofloxacin showed the most potent activity and inhibited the growth of 83 of all the strains (98.8%) at 0.063 microg/mL. Tobramycin showed the most potent activity against P. aeruginosa (both mucoid and non-mucoid) and its MIC90 was 2 microg/mL. The activity of CZOP also was preferable and its MIC90 was 4 microg/mL for the mucoid-type and 8 microg/mL for the non-mucoid type. CZOP was the most potent activities against K. pneumoniae and inhibited the growth of all the strains at 0.125 microg/mL. Also, all the agents generally showed potent activities against M. (B.) catarrhalis and the MIC90 of them were 4 microg/mL or less. The approximately half the number (54.1%) of the patients with respiratory infection were aged 70 years or older. Bacterial pneumonia and chronic bronchitis accounted for 46.1% and 30.6% of all the respiratory infection, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. aureus (18.6%) and H. influenzae (18.1%). In contrast, S. aureus (16.9%) and S. pneumoniae (14.9%) were frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from the patients were S. pneumoniae (20.6%) and H. influenzae (21.5%). The bacteria relatively frequently isolated from the patients treated with cephems or macrolides were P. aeruginosa, and S. aureus was relatively frequently isolated from the patients treated with quinolones.

Aged↗

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2004].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 907 strains of Gram-positive bacteria, 1790 strains of Gram-negative bacteria, and 192 strains of anaerobic bacteria obtained from 30 medical institutions during 2004 was measured. The results were as follows; 1. MIC90 of MEPM for almost all of enterobacteriaceae and Haemophilus influenzae were 4-fold to 32-fold lower than those of other carbapenems. MEPM was more active than other carbapenem antibiotics against Gram-negative bacteria, especially against enterobacteriaceae and H. influenzae. MEPM were active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus. 2. As for Pseudomonas aeruginosa, imipenem (IPM) showed high cross-resistant rate againt meropenem-resistant P. aeruginosa (87.9%). MEPM showed low cross-resistant rate both againt IPM-resistant P. aeruginosa (49.2%) and ciprofloxacin-resistant P. aeruginosa (38.0%). 3. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (4 strains) in Escherichia coli, 8.0% (2 strains) in Citrobacter koseri, 2.5% (3 strains) in Klebsiella pneumoniae, 2.5% (2 strains) in Enterobacter cloacae, 0.9% (1 strains) in Serratia marcescens, and 2.2% (2 strains) in Proteus mirabilis. The proportion of metallo-beta-lactamase strains was 1.6% (5 strains) in P. aeruginosa. 4. Of all species tested, Peptostreptococcus spp. was the only species, which MIC90 of MEPM was more than 4-fold higher than that in our previous study using clinical isolates during 2002 (0.25 microg/ml --> 1 microg/ml). Therefore, there is almost no siginificant decrease in susceptibility of clinical isolates to meropenem. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem at present, 9 years after available for commercial use.

Anti-Infective Agents↗

Antimicrobial susceptibilities and analysis of genes related to penicillin or macrolide resistance in Streptococcus pneumoniae.

One hundred and seventy-seven strains of Streptococcus pneumoniae derived from respiratory specimens between 1987 and 2001 were evaluated for their antimicrobial susceptibilities and distribution of genes related to penicillin and macrolide resistance. Resistance rates tended to be higher for the 1996-2001 isolates than for the 1987-1995 isolates for all beta-lactams tested. For benzylpenicillin the MIC(90) value of the isolates derived between 1996 and 2001 was 1.56 mg/L, while that of strains isolated between 1987 and 1990 was 0.05 mg/L. Furthermore, the number of strains susceptible to macrolides also decreased, but only two strains isolated in 1993 were resistant to levofloxacin of the 177 S. pneumoniae strains tested. When of genes relating to penicillin resistance were analysed using PCR with primers specific to susceptible alleles, although more than 50% of strains from 1987 to 1990 and 1991 to 1995 revealed no mutations in the pbp 1a, 2x and 2b genes, only 30.0% of strains derived between 1996 and 2001 showed no mutations in the pbp gene. Strains having mutations in all three pbp genes (1a, 2x and 2b) by the PCR method increased from only 2.2% in the 1987-1990 derived strains to 27.5% in the 1996-2001 strains. Furthermore, 64.1 and 60.0% of the isolates from 1987 to 1990 and 1991 to 1995, respectively, did not possess either the mefA or ermB by PCR analysis. Conversely, 75.0% of isolates from 1996 to 2001 possessed mefA and/or ermB. These genetic changes may explain the increase in the number of penicillin and macrolide resistant strains. We believe that it is important to evaluate changes in MIC as well as genetic mutations in order to select the most appropriate therapy for S. pneumoniae infections.

Anti-Bacterial Agents↗

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2002].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 899 strains of Gram-positive bacteria, 1500 strains of Gram-negative bacteria, and 158 strains of anaerobic bacteria obtained from 28 medical institutions during 2002 was measured. The results were as follows; 1. MEPM was more active than other carbapenem antibiotics against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MIC90 of MEPM against Pseudomonas aeruginosa was the lowest of the drugs tested. MEPM showed low cross-resistant rate against both imipenem-resistant P. aeruginosa and ciprofloxacin-resistant P. aeruginosa. MEPM was active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE). 2. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (4 strains) in Escherichia coli and 1.9% (2 strains) in Klebsiella pneumoniae. Carbapenems including MEPM were active against these ESBL strains. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem; at present, 7 years after available for commercial use.

Bacteria↗

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2002)].

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, Moraxella subgenus Branhamella catarrhalis 29, etc. Of 77 S. aureus strains, those with 2 microg/ml or less of MIC of oxacillin (MPIPC) [methicillin-susceptible S. aureus: MSSA] was 34 strains (44.2%) and those with 4 microg/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 0.25 microg/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 1 microg/ml without the low sensitive strains. Against MRSA, vancomycin (VCM) showed the most potent activity and inhibited the growth of all the strains at 2 microg/ml. Arbekacin (ABK) also showed the relatively potent activity and inhibited the growth of all the strains at 4 microg/ml. Carbapenems showed the most potent activities against S. pneumoniae and inhibited the growth of all the strains at 0.25-0.5 microg/ml. Cefozopran (CZOP) also had a preferable activity (MIC90: 1 microg/ml) and inhibited the growth of all the strains at 2 microg/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 microg/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 2 microg/ml. The antibacterial activity of CZOP was good and its MIC90 against mucoid and non-mucoid strains was 8 and 16 microg/ml, respectively. CZOP and cefpirome (CPR) were the most potent against K. pneumoniae with 0.125 microg/ml of MIC90. Also, all the agents generally showed potent activities against M. (B.) catarrhalis and the MIC90 of all drugs were 4 microg/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.

Anti-Bacterial Agents↗

Treatment with rokitamycin suppresses the lethality in a murine model of Escherichia coli O157:H7 infection.

The effects of rokitamycin (ROK) and levofloxacin (LEVX) were investigated in a murine model of enterohaemorrhagic Escherichia coli (EHEC) infection. After C3H/HeN mice were inoculated intragastrically with E. coli O157:H7, ROK (20mg/kg) or LEVX (1.2 mg/kg) was administered intragastrically. The death rate of the mice was noted and the faeces were collected to determine viable cell counts of EHEC and for Shiga-like toxins (SLTs) assays. After the mice were sacrificed, the kidneys and colons of some of the mice were removed for histopathological examination. The death rate of mice administered ROK (19%) was significantly lower than that of the control and LEVX-treated groups (80, 93%, respectively). Viable cell counts of EHEC in the faeces of the control and ROK-treated groups were 10(7) and 10(6) CFU/g at day 5 after the infection, respectively. LEVX reduced the bacterial count by less than 100 CFU/g at day 5. The level of SLTs in the faeces from the ROK group were lower than the LEVX-treated and control groups at day 5. The histopathological findings in the kidneys treated with LEVX showed necrotic tubular epithelial cells and those in the colon, inflammatory infiltrates. These were not seen in the ROK-treated group. These results suggested that ROK suppressed release of SLTs from the EHEC and could be useful in the treatment of EHEC infection.

Animals↗

Clindamycin modulates inflammatory-cytokine induction in lipopolysaccharide-stimulated mouse peritoneal macrophages.

We investigated the mechanism by which clindamycin (CLI) modulates cytokine induction after lipopolysaccharide (LPS) stimulation. Although CLI decreased the intracellular expression levels of tumor necrosis factor alpha and interleukin 1beta (IL-1beta) and increased IL-6 expression in macrophages, cytokine mRNA expression levels were similar in CLI-treated and untreated groups. Our findings suggest that CLI modulates cytokine production in LPS-stimulated macrophages.

Animals↗

[Activities of antimicrobial agents against 8,474 clinical isolates obtained from 37 medical institutions during 2000 in Japan].

A survey was conducted to determine the antimicrobial activity of fluoroquinolones and other antimicrobial agents against 8,474 clinical isolates obtained from 37 Japanese medical institutions in 2000. A total of 25 antimicrobial agents were used, comprising 4 fluoroquinolones, 13 beta-lactams, minocycline, chloramphenicol, clarithromycin, azithromycin, gentamicin, amikacin, sulfamethoxazole-trimethoprim, and vancomycin. A high resistance rate of over 85% against fluoroquinolones was exhibited by methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium. Isolates showing resistance to fluoroquinolones among methicillin-resistant coagulase-negative Staphylococci, Enterococcus faecalis, and Pseudomonas aeruginosa from UTI accounted for 30-60%. However, many of the common pathogens were still susceptible to fluoroquinolones, such as Streptococcus pneumoniae (including penicillin-resistant isolates), Streptococcus pyogenes, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible coagulase-negative Staphylococci, Moraxella catarrhalis, the Enterobacteriaceae family, and Haemophilus influenzae (including ampicillin-resistant isolates). About 85% of P. aeruginosa isolated from RTI were susceptible to fluoroquinolones. In conclusion, this survey of sensitivity to antimicrobial agents clearly indicated trend for increasing resistance to fluoroquinolones among MRSA, Enterococci, and P. aeruginosa isolated from UTI, although fluoroquinolones are still effective against other organisms and P. aeruginosa from RTI as has been demonstrated in previous studies.

Anti-Bacterial Agents↗

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2001)].

From October 2001 to September 2002, we collected the specimen from 370 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of the isolated bacteria to various antibacterial agents and antibiotics and patients' characteristics. Of 458 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 456 strains were investigated. The breakdown of the isolated bacteria were: Staphylococcus aureus 69, Streptococcus pneumoniae 72, Haemophilus influenzae 85, Pseudomonas aeruginosa (non-mucoid) 44, P. aeruginosa (mucoid) 13, Klebsiella pneumoniae 32, Moraxella subgenus Branhamella catarrhalis 32, and others. Of 69 S. aureus strains, those with 4 micrograms/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) occupied 43.5%. Vancomycin and arbekacin showed the most potent activities against MRSA as observed in 2000. The frequency of S. pneumoniae exhibiting low sensitivity to penicillin (penicillin-intermediate S. pneumoniae: PISP + penicillin-resistant S. pneumoniae: PRSP) was 59.7% and both rates of PISP and PRSP were the highest after 1992. Carbapenems had strong activities against S. pneumoniae. Especially, panipenem and imipenem inhibited the growth of all 72 strains at 0.125 and 0.5 microgram/mL, respectively. Generally, all drugs had strong activities against H. influenzae with MIC90s of 16 micrograms/mL or less. The drug that had the strongest activity against H. influenzae was levofloxacin, which inhibited the growth of 80 of the 85 strains at 0.063 microgram/mL. Against P. aeruginosa mucoid strain, meropenem had a strong activity with MIC90 of 0.5 microgram/mL while, against non-mucoid strain, tobramycin had a strong activity with MIC90 of 2 micrograms/mL. K. pneumoniae showed good susceptibilities to all drugs except ampicillin and minocycline, and the MIC90s were 4 micrograms/mL or less. Particularly, cefmenoxime, cefpirome, and imipenem had the strongest activity (MIC90: 0.125 microgram/mL), and cefozopran had a strong activity, inhibiting the growth of all strains at 0.25 microgram/mL. Also, all drugs generally had strong activities against M. (B.) catarrhalis. MIC90s of all drugs were 4 micrograms/mL or less. The drug that had the strongest activity was minocycline and levofloxacin inhibiting all 32 strains at 0.063 microgram/mL. Most of the patients with respiratory infection were aged 70 years or older, accounting for approximately a half of the total (40.5%). As for the incidence by the diseases, bacterial pneumonia and chronic bronchitis were the highest, being noted in 39.2% and 37.3% of all the patients, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. aureus (19.3%) and S. pneumoniae (19.9%). In contrast, H. influenzae (22.0%) were frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from the patients were S. pneumoniae (20.8%) and H. influenzae (21.5%). S. pneumoniae and H. influenzae decreased after the initiation of drug administration while S. aureus increased. The isolation frequency of P. aeruginosa was higher after than before the initiation of drug administration. The bacteria were frequently isolated from the patients who had already treated with cephems were S. aureus and P. aeruginosa. From the patients who had already treated with macrolides, S. pneumoniae was the most frequently isolated while S. aureus was the most frequently isolated from the patients pre-treated with quinolones.

Adult↗