We investigated antimicrobial activities of meropenem and other antibiotics against 164 isolates (41 Escherichia coli, 16 Klebsiella pneumoniae, 7 Enterobacter cloacae, 21 Pseudomonas aeruginosa, 14 methicillin-susceptible Staphylococcus aureus (MSSA), 18 methicillin-resistant Staphylococcus aureus (MRSA), 47 Staphylococcus epidermidis) from blood of the patients admitted to Keio University Hospital between January and October in 2010. Meropenem showed the potent antibacterial activity against Gram-negative bacteria especially and it maintained good broad spectrum antimicrobial activity including resistant strains through 13 years since when we started the investigation. These results indicated the validity of choosing meropenem as a first line antimicrobial agent for serious infectious diseases.

The antimicrobial activity of 18 antimicrobial agents were measured for the 500 Pseudomonas aeruginosa strains that had been isolated from various clinical specimens in 17 medical institutions in the Kinki district from April to July of 2008. The antimicrobial activity was excellent in the order of tobramycin (TOB), arbekacin (ABK), doripenem (DRPM), gentamicin (GM) and amikacin (AMK). Susceptible rate that was interpreted by Clinical and Laboratory Standards Institute (CLSI) was high in the order of AMK, TOB, tazobactam/piperacillin (TAZ/PIPC), DRPM, ABK. Also, the difference in susceptible rate was observed between departments, materials and institutions. Multidrug resistant strains were only 12 (2.4%) but strains that had resistance to 2 agents were 48 (9.6%), therefore, implementation of further surveillance should be continued.

The clinical effect of peramivir was examined retrospectively in 30 children aged 23 days to 8 years; they had been treated with peramivir at our hospital within 48 hours after the onset of influenza from November 2010 to April 2011. Intravenous dripping of peramivir at a dose of 10mg/kg was performed only once for 15 to 30 minutes. To examine the clinical effect of peramivir, the time from dosing to defervescence (body temperature ～37.5°C) was evaluated. To compare the clinical effects of peramivir and oseltamivir, the time required for the defervescence was evaluated in a similar manner in 30 children aged 7 months to 8 years who had been treated for influenza with oseltamivir at a dose of 4mg/kg/day. The influenza type was type A (n=25) and type B (n=5) in the peramivir group and type A (n=26) and type B (n=4) in the oseltamivir group. In the peramivir group, 5 (16.7%), 16 (53.3%), and 24 (80.0%) patients achieved defervescence within 6, 12, and 24 hours, respectively. In the oseltamivir group, 3 (10.0%) and 6 (20.0%) patients had defervescence within 12 and 24 hours, respectively. The difference between these groups was statistically significant (p～0.05). An increase in the levels of AST and ALT was observed as an adverse reaction in 1 patient. Thus, peramivir was determined to be effective to influenza in children.

Infective endocarditis caused by methicillin-resistant Staphylococcus aureus (MRSA) is a serious disease and sometimes leads to poor prognosis. We should have several therapeutic options. Arbekacin is one of the aminoglycoside antibiotics, which is more active against MRSA and less nephrotoxic than gentamicin. Here we presented a successfully treated case of severe MRSA endocarditis without any adverse effect by monitoring therapeutic level of vancomycin and arbekacin.