The annual changes of antibacterial activities of β-lactam antibiotics, mainly carbapenem antibiotics, were investigated against 5 bacterial species, S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, which had been isolated from the clinical materials at Toho University Omori Hospital during the period of 1995 to 1997. In addition, antibacterial activities against other main bacterial strains isolated from the clinical materials during 1997 were also determined.
The five bacterial species on which annual changes of the sensitivity were investigated did not show any remarkable trend to increase in resistance to the carbapenem antibiotics tested. The antibacterial activities of the carbapenem antibiotics against MRSA were weak, and MIC90 values were between 25 and 50μg/ml.
In S. marcescens and P. aeruginosa on which high resistance by the production of metallo-β-lactamase has become a problem in recent years, there were no remarkable changes in annual changes of sensitivities. Especially, MIC90 valuses of the carbapenem antibiotics against P. aeruginosa were between 12.5 and 25μg/ml, 4 to 8 times better than that of PIPC, like the case of CAZ.
Furthermore, the carbapenem antibiotics showed strong antibacterial activities against clinically important 16 bacterial species, from Gram-positive to Gram-negative bacteria.

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The injectable cephalosporin cefpirome(CPR)was launched in Japan in 1993. It has widely been used in the various infectious diseases. We therefore studied the clinical and bacteriological efficacy of CPR against infections caused by Bacteroides species, Prevotella species and Porphyromonas species frequently isolated from the obstetric and gynecologic infections. Thirteen institutions were involved in this study which ran from March 1994 to January 1999. The administration dosage of CPR was 2 to 4 gram per day administered by drip infusion or intravenous infusion. The duration of treatment was from 3 to 15days. The evaluations were performed before and after the treatment. CPR was administered to 194 patients with obstetric and gynecologic infections, and 146 of 194 cases were acceptable for the evaluation of drug efficacy.
Bacteroides species were identified in 102 patients. Clinical efficacy in 146 cases was excellent in 12 patients, good in 110, fair in 9 and poor in 15 patients. The eradication rate for Bacteroides species could be in 37 cases out of 54 evaluable cases; Prevotella species in 38 out of 49; and Porphyromonas species in 5 out of 5. The overall assessment of bacteriological efficacy was “eradicated” in 91 cases out of 133(68.4%).
Adverse reactions including abnormal findings in laboratory tests were seen in 8 patients(4.76%).
Based on these results, CPR promises efficacy and safety in the treatment of obstetric and gynecologic infections due to Bacteroides species.

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Clinical isolates collected from clinical facilities across Japan in 1998 were tested against five aminoglycosides and three β-lactams. The resistance of 50 strains each of methicillin sensitive Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, Enterobacter sp., Serratia sp., Pseudomonas aeruginosa and Proteus sp.(P. mirabilis 25 strains and P. vulgaris 25 strains) to the aminoglycosides isepamicin (ISP), amikacin (AMK), gentamicin, tobramycin and dibekacin, and to the β-lactams imipenem, ceftazidime and piperacillin (all three known to be effective against P. aeruginosa) were investigated using a micro liquid dilution method with the following results:
1. ISP was effective against all strains except for 14% of MRSA, 2% of Proteus sp., and 4% of P. aeruginosa.
2. Six strains of MRSA were resistant to all eight drugs; however, in these cases ISP exhibited a relatively low minimum inhibitory concentration (MIC) compared to the other compounds.
3. Four strains of MRSA were resistant to all drugs except ISP. MRSA was the only isolate to demonstrate a resistance to seven or more drugs.
4. Twenty-one strains of MRSA and 1 strain of P. aeruginosa were resistant to six drugs; however, all of these were susceptible to both ISP and AMK.
5. Against all strains tested, ISP generally exhibited a lower MIC compared to AMK.
These results suggest that, even ten years after its entering the market, ISP is still an aminoglycoside having a high anti-bacterial activity against a wide range of clinical isolates.

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