Methicillin-resistant Staphylococcus aureus (MRSA) was identified by various methods, including the disk diffusion test, to predict mecA-mediated resistance by Staphylococcus with a cefoxitin disk, which was newly described in NCCLS (at present CLSI) M100-S14 (2004), among 79 strains of borderline oxacillin-resistant Staphylococcus aureus (BORSA) whose oxacillin MIC values were 1, 2, 4 and 8μg/mL.
The results of the susceptibility testing of strains containing mecA did not agree with the oxacillin MIC values, and mecA (+) was present in 1 of the 30 strains and in 5 of the 30 strains that were susceptible to oxacillin at 1 and 2μg/mL, respectively. There were 12 PBP2'-producing strains among the 54 mecA (-) strains, and since the reaction of 7 of these strains to latex particles was weak, their susceptibility to oxacillin was judged to be weakly positive. However, since these 12 strains were susceptible to oxacillin and cefoxitin, the results of the PBP2' test were presumed to be due to a nonspecific reaction. The test results with the cefoxitin disk indicated that 53 of the 60 strains susceptible to oxacillin were also susceptible to cefoxitin, but the remaining 7 strains were resistant to cefoxitin, and the diameters of the inhibition zone were around the borderline values for identification. The frequency of errors in the cefoxitin susceptibility test were low, i. e., 1.3% for very major error and 8.9% for major error, but since the diameters of the inhibition zone in case of BORSA may be around the borderline values for identification, it is concluded that it is necessary to confirm the susceptibility of these strains to oxacillin by other methods in addition.

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Carbapenems antibiotics [imipenem/cilastatin (IPM/CS), meropenem (MEPM), biapenem (BIPM) and doripenem (DRPM)] were compared in terms of their antimicrobial activity against Pseudomonas aeruginosa, their growth inhibition ring during incubation, their bactericidal effect in the presence or absence of serum, morphological changes, their binding affinity to penicillin-binding proteins (PBPs), and the influence of human serum and the inducibility of AmpC β-lactamase. The MIC₅₀ and MIC₉₀ values of IPM/CS, MEPM, BIPM and DRPM against 50 strains of P. aeruginosa clinically isolated in 2003 were 2 and 16, 1 and 16, 1 and 16 and 1 and 8 7mu;g/mL, respectively. The 1-hour bactericidal activity of carbapenem antibiotics that did not induce the formation of a double inhibition ring (IPM/CS and BIPM) was stronger than that of the drugs that induced a double ring formation (MEPM and DRPM). At the MIC of each drug, the bactericidal effect of IPM/CS and BIPM increased in the presence of human serum, but no increase was observed for MEPM or DRPM. This bactericidal activity was well reflected in the microbial conglobation (spherical forms) and bacteriolytic images observed in association with IPM/CS and BIPM. On the other hand, numerous microbes became filamentous after treatment with DRPM and MEPM, but no bacteriolytic images were seen. IPM/CS and BIPM exhibited the strongest binding affinity for PBP4, followed by 2, 1A÷3 and 1B. MEPM exhibited the strongest binding affinity for PBP4, followed by 3, 2, and 1A÷1B, and DRPM showed the strongest affinity for PBP4, followed by 3, 2, 1A and 1B. From the aspect of enzyme inducibility strong activity was observed for IPM/CS and BIPM, compared with MEPM and DRPM. These findings suggested that carbapenem antibiotics can be divided into two types: those with a strong bactericidal activity (IPM/CS, BIPM and perhaps panipenem) and those with a weak bactericidal activity (MEPM and DRPM).

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Background: Japan's nursing-home population is mushrooming. The mortality of residents is usually related to pulmonary infection, including aspiration pneumonia.
Objective: We clarified the impacts of initial antibiotic therapy in the elderly with aspiration pneumonia institutionalized in nursing homes.
Patients and Methods: Subjects were 104 patients (114 episodes) with a mean aging of 85.8 years old, with aspiration pneumonia and transferred from nursing homes to a care mixed hospital. Aspiration pneumonia was diagnosed based on the diagnostic criteria of the Japanese Aspiration Pneumonia Research Conference.
Results: Among patients 59.6% and 35.1% were transferred from nursing home and own house, respectively. Only 32.5% of patients have had more than 37.5°C, and 33.3% did have more than 9, 000/μL of peripheral white blood cell. A positive bacterial culture was found in 54 of 114 episodes in sputa or tracheobronchial secretion. A Gram-negative bacterium was found in 25 cases (46.3%) and MRSA in 21 cases (38.9%). The initial antibiotic was chosen from piperacillin (PIPC), meropenem (MEPM) and cefazolin (CEZ). Response to PIPC was 50%, 80.0% to MEPM and 61.9%, to CEZ. In 27 cases, initial antibiotic therapy was changed, but 22 of 27 died.
Risk factors for poor outcome appear to be comorbidity, the degree of pulmonary involvement, slight fever, increased CRP, hypoalbuminemia, and lowered arterial blood oxygen saturation.
Conclusion: Although prospective validation is required, we were able to clarify the clinical characteristics and prognostic indices in advanced aged people with aspiration pneumonia.

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As the special surveys on gatifloxacin (GFLX), a fluoroquinolone oral antimicrobial agent, we planned to collect 6, 000 patients in order to confirm the safety and efficacy and detect the new problems under conditions of actual use of this product. The target sample size in the first survey was 3, 000 patients.(The second survey is scheduled to be conducted from 2006 to collect 3, 000 patients.) The data collected from 3, 384 patients at 607 sites was compiled to prepare an interim report.
The results showed that 56 (1.66%) of 3, 369 patients eligible for the safety evaluation had experienced a total of 70 adverse reactions. The commonest ADRs were diarrhoea (8 cases), nausea (6 cases) and exanthem (5 cases). At the same time, the new problems were not detected.
The efficacy rate of GFLX in the 3, 212 patients eligible for the efficacy evaluation was 95.3%(observed in 3, 060/3, 212 natients)

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