Metallo-β-lactamase（MBL）producing Serratia marcescens isolate was recovered from a study patient in September, 2007 in whom MBL non-producing S. marcescens had been isolated 2 months previously. Two S. marcescens isolates recovered from the study patient showed the same pulsed-field gel electrophoresis （PFGE）pattern. Seven S. marcescens isolates were recovered from other patients in our hospital during August, 2007 and November, 2007. Five of the seven isolates produced MBL. All of the MBL-producing isolates showed the same PFGE pattern and harbored plasmids of the same size and bla_IMP genes. The bla_IMP genes were easily transferred to Escherichia coli DH5α by transformation of a plasmid purified from the MBL-producing isolate. Those transformation experiments suggested that bla_IMP genes were encoded by the plasmid. From these observations, it was speculated that the MBL non-producing S. marcescens isolate recovered from the study patient had acquired the plasmid which encoded bla_IMP genes and a monoclone of MBL-producing S. marcescens spread horizontally in our hospital.

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We examined the efficacy and safety of inactivated influenza vaccine when the amount of HA influenza vaccination in children was increased to the dose recommended by the WHO. The purpose of this study was to obtain basic evidence to review the vaccination dose in Japanese children. HA influenza vaccine produced by the Research Foundation for Microbial Diseases of Osaka University（Biken）licenced in Japan was administered through vaccination at the international dose, and split HA influenza vaccine produced by Sanofi Pasteur corp.（Sanofi）was used as control. Children from 6 months to less than 13 years of age were registered, and vaccinated with doses of 0.25mL or 0.5mL. Clinical symptoms during the influenza season were monitored to investigate vaccine efficacy, and information on adverse reactions was collected to evaluate safety profile. Paired serum HI and NT antibody titers were measured at pre first dose and post second dose of vaccination. Both HI and NT antibody titers for H1N1 subtype were satisfactory elevated after administration of both vaccines. Elevation of the NT antibody titer for the H3N2 subtype was observed for both vaccines, but the H3N2 HI antibody titer for the Biken vaccine was not so high. For the subtype B virus, the NT titer had a better response than the HI titer for both vaccines. As only the H1N1 virus was prevalent in the area during the study period, we performed factor analysis concerning influenza contraction only for the H1N1 antibody titer. An HI titer of 1：40 or more at post-vaccination was a significant factor to lower the risk of influenza contraction. The relative risk for fever among children with an HI titer of 1：20 or less was significantly higher than those with an HI titer of 1：40 or more. Children with a higher HI titer had better prevention against fever, so that both vaccines were considered to be effective. As for the appearance of adverse reactions, both vaccines were considered to be safe. From the above-mentioned results, vaccination with the Japanese Biken vaccine at an international dose was thought to be an effective and safe procedure.

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Kingella species including K. kingae are non-motile coccobacilli or short straight rods, and their normal habitats appear to be the upper respiratory and oropharyngeal tracts of humans. In recent years, K. kingae strains have been in creasingly recognized as common causes of invasive infections in children at the age of less than 4 years. In Japan, however, invasive K. kingae infections including osteomyelitis have rarely been described. We incidentally encountered isolation of a K. kingae strain from intraoperatively obtained specimens from a previously healthy 44-month-old boy. He first consulted a nearby medical facility and a suspected diagnosis of osteomyelitis was made, after which the patient was then transferred to our Nagano Childrenʼs hospital. There was evidence of inflammation in his right calcaneus and toe walking was noted. He was treated with surgical drainage. An isolate grown on sheep blood agar with positive oxidase and negative catalase was biochemically characterized with the ID-Test HN20（Nissui Pharmaceutical Co., Ltd., Tokyo, Japan）kit system together with genetic examinations involving sequencing the 16S rRNA gene, and the infection was finally identified as K. kingae. The patient was successfully treated with cefotiam（CTM）for the first 7 days followed by the administration of trimethoprim-sulfamethoxazole（ST）for an additional 2 months. The K. kingae isolate was confirmed as a sure causative pathogen by observing that the serum showed high agglutinin titers against the isolate. Accumulation of the case reports in Japan with the isolation of this species is essential for clarifying invasive infections due to K. kingae. Our case report is a noteworthy and useful piece of information.

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We report on a previously healthy 56-year-old woman who was referred to our hospital with fever and progressive left foot pain. She had been bitten by a cat 7 days previously, and cephalosporins had been prescribed for treatment. However, her clinical symptoms deteriorated, and physical examination on admission was compatible with necrotizing fasciitis. Treatment with ampicillin-sulbactam and clindamycin was initiated. In addition, immediate surgical debridement was performed, resulting in therapeutic success. Culture of the necrotizing tissue grew multiple organisms, including Pasteurella multocida and Bacteroides caccae. Administration of appropriate antibiotics after a cat bite is essential for the prevention of potentially fatal complications.

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