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Katsunori Furuhata

Publications and source records attributed to Katsunori Furuhata.

11 recordsLinked to original sources
PubMed2006

Neutralizing activity of bovine colostral antibody against verotoxin derived from enterohemorrhagic Escherichia coli O157:H7 in mice.

The neutralization efficacy of bovine colostral antibody against verotoxin (VT) 1 and 2 was investigated. Cows were immunized with VT1 or VT2 fourteen times at 7-day intervals. A colostral antibody exhibiting high titers was obtained from immunized cows. Survival rates were evaluated in mice administered VT1 or VT2, and those infected with Escherichia coli (E. coli) O157:H7 producing VT1 or VT2. Survival rates after VT1 administration were 100% in the single-administration group, 90% in the repeat-administration group, and 78.6% in the control group. Survival rates after VT2 were 75.0% in the single-administration group, and 100% in the repeat-administration group. All mice in the control group died. Colostral antibody and fosfomycin (FOM) in the colostral antibody group and FOM and skim milk in the control group were administered three times per day for 5 days to mice infected with E. coli O157:H7 producing VT1 or VT2. Survival rates after inoculation with E. coli O157:H7 producing VT1 were 80.0% in the colostral antibody group, and 63.6% in the control group. Survival rates after inoculation with E. coli O157:H7 producing VT2 were 83.3% in the colostral antibody group, and 20.0% in the control group. The survival rate in mice without treatment following inoculation with E. coli O157:H7 producing VT2 was 88.2%. The survival rates in mice infected with E. coli O157:H7 strains producing VT1 or VT2 improved after administration of this colostral antibody, which exhibited neutralization efficacy against VT.

Animals↗
PubMed2006

Isolation and identification of methylobacterium species from the tap water in hospitals in Japan and their antibiotic susceptibility.

Contamination of tap water by Methylobacterium species has become a serious concern in hospitals. This study was planned to examine the distribution of Methylobacterium species inhabiting tap water used in Japanese hospitals and antibiotic sensitivity of the isolates in 2004. Species identification of 58 isolates was performed based on the homology of a partial sequence of 16S rDNA. The dominant Methylobacterium species in hospital water were M. aquaticum and M. fujisawaense. To examine the biochemical properties of these isolates, a carbon source utilization was tested using an API50CH kit. The phenotypic character varied widely, and was not necessarily consistent with the results of phylogenic analysis based on the partial 16S rDNA sequence, suggesting that the biochemical properties are not suitable for identification of Methylobacterium species. The isolates were also subjected to antibiotic sensitivity tests. They were resistant to 8 antibiotics, but highly sensitive to imipenem (MIC90 = 1 microg/ml) and tetracycline (MIC90 = 8 microg/ml). These findings concerning the isolates revealed the presence of Methylobacterium species with resistance to multiple antibiotics in hospital tap water.

Anti-Bacterial Agents↗
PubMed2005

[Drug susceptibility and analysis using pulsed-field gel electrophoresis of Streptococcus pyogenes strains isolated from the patients with streptococcal toxic shock syndrome (STSS) in Japan].

Previously, we have performed T typing of Streptococcus pyogenes strains isolated from patients with streptococcal toxic shock syndrome (STSS) in Japan, and streptococcal pyrogenic exotoxin (SPE) typing for epidemiological examination. In this study, we conducted a drug sensitivity test using these strains, and investigated the results of gene analysis by pulse-field gel electrophoresis (PFGE) of S. pyogenes strains derived from patients with STSS, the patient's family, and patients other than those with STSS. To clarify the relationship between the host and bacterial factors, we investigated the association between clinical symptoms and T typing of the isolated strains/production of streptococcal pyrogenic exotoxin. There were no strains resistant to beta-lactams, and only 1 strain was resistant to multiple agents other than beta-lactams. The PFGE pattern of T1 type strains was classified into 2 ; the pattern was consistent between the strains derived from patients with STSS and those derived from the patient's family. The PFGE pattern of T3 type strains was classified into 5 (IV) ; Pattern I, which was most frequently observed, was detected in both the strains derived from patients with STSS/non-STSS. However, Patterns II and III were detected only in the strains derived from patients with non-STSS. Patterns IV and V were detected only in the strains derived from patients with STSS. When examining the association between clinical symptoms and bacterial factors, disseminated intravascular coagulation (DIC) was associated with T1-SPE B-producing strains, and pharyngitis was associated with T3-SPE A-producing strains. In the future, the relationship between the host and bacterial factors should be further investigated.

Anti-Bacterial Agents↗
PubMed2004

[Distribution of Legionella spp. in hot spring baths in Japan].

We investigated the inhabitation of Legionella spp. in hot spring water in various regions in Japan. The following results were obtained. 1) Of 710 hot spring water samples nationwide, Legionella spp. was isolated from 204 samples (28.7%), covering all 47 prefectures. By region, the isolation rate was the highest at 31.0% in the Chugoku district, while the isolation rates in Hokkaido, Kinki, and Kyushu were low, ranging from 25.0 to 26.2%. The rate in Tohoku, Kanto, Chubu, and Shikoku districts was 28.6-30.7%. Regarding the isolation rate by pH of hot spring water, the isolation rate was 4.9% at pH 3 or lower, but 34.8% at pH 3.1-7.5. When pH was 7.6 or higher, the isolation rate was 24.8%. 2) Most frequently, the number of bacteria detected was below 10(2) CFU/100ml (98 samples, 48.0%). The count was between 10(2) and 10(3) CFU/100ml in 71 samples (34.8%), and between 10(3) and 10(4) CFU/100ml in 29 samples (14.2%). In 6 samples (2.9%), the count was higher than 10(4) CFU/100 ml. 3) Among the isolates identified, L. pneumophila was the predominant species, and particularly, serogroups 1 and 5 were frequently isolated. The above findings clarified that although the number of the bacteria is low, Legionella spp. inhabits hot spring water throughout Japan.

Baths↗
PubMed2004

[A basic study of Vibrio vulnificus infection: serotyping and drug sensitivity test of environment-derived strains and human clinical isolates].

In attempt to elucidate the route and source of Vibrio vulnificus infection. serotyping and drug sensitivity tests of environment-derived strains and human clinical isolates were performed. 1) Serotyping of isolates from the two types of source were determined. Of environment-derived strains, 72.5% were classified into 18 types, and O7 was the most frequent type, accounting for 73.1%, and the second frequent type was O4, accounting for 6.1%. Of human clinical isolates, 87.1% were classified into eight types, and O4 was the most frequent, accounting for 73.5%, and O7 was the secondly most frequent, accounting for 12.9%. 2) Serotypes were investigated by regions. In eastern Japan, 69.2% were classified into 18 types, and O7 and O4 accounting for 44.6% and 5.7%, respectively. In western Japan, 64.8% were classified into eight types, and O7 was the most frequent, accounting for 20.4%, and secondly frequent type was O4, accounting for 11.1%. 3) Regarding the relationship between biotypes and serotypes, environment-derived biotype-I strains were widely distributed in the serotypes, but most biotype-I human clinical isolates were distributed in serotypes O1-O7, showing a difference between the two types of sources. However, many biotype-II strains from the two types of sources included in the serotype O7 group. 4) Drug sensitivity was compared based on MIC90 between strains from the two types of sources. Environment-derived strains were sensitive to ABPC, PIPC, CPZ, CTX, LMOX, MEPM, GM, EM, TC, DOXY, MINO, CP, NA and CPFX, but some strains were resistant to CER, CET, CTX, CMZ, KM and LCM. Human clinical isolates were sensitive to EM, TC, DOXY, MINO, CP, NA and CPFX, but some strains were resistant to ABPC, PIPC, CER, CET, CPZ, CTX, CMZ, LMOX, MEPM, KM, GM, AMK and LCM.

Bacterial Typing Techniques↗
PubMed2003

[Fundamental studies on legionellosis--the growth with in Acanthamoeba sp. and antibiotics susceptibility of Legionella spp. isolated from soil samples in Japan].

As part of an epidemiological study of legionellosis, we investigated the growth within Acanthamoeba sp. and antibiotic susceptibility of 62 strains of Legionella spp. isolated from surface soils nationwide in 2001. 1) All strains tested grew in Acanthamoeba sp., suggesting that the strains were pathogenic. The minimum bacterial number required for the growth in the amoeba was 10(3)-10(8) CFU/ml and there were differences between the strains. 2) Susceptibility to 10 drugs was investigated using the Etest. The MIC90 values of imipenem, as a beta-lactam, and rifampicin, as an antitubercular agent, were 0.047 microgram/ml and 0.064 microgram/ml, respectively, showing high sensitivity. In contrast, sensitivity to minocycline, as a tetracycline, and piperacillin, as a beta-lactam, was low and the MIC90 values were 12 micrograms/ml and 16 micrograms/ml, respectively. Sensitivity to minocycline was particularly low, with a MIC value of 32 micrograms/ml, in two strains. The above findings suggested that all soil-derived strains were pathogenic, and susceptibility of the strains tended to be slightly lower than that of clinical isolates.

Acanthamoeba↗
PubMed2002

First isolation of urease-positive thermophilic Campylobacter (UPTC) from crows (Corvus levaillantii) in Japan.

Two strains of urease-positive thermophilic Campylobacter (UPTC), designated YC98-1 and YC98-2, were identified by biochemical characterization after isolation from the intestinal contents of crows around Yokohama City, Japan, in 1998. The biochemical characteristics of these strains were identical to those of strains described previously. Pulsed-field gel electrophoresis (PFGE) after separate digestion with ApaI, SalI, and SmaI of the genomic DNA from the two strains indicated that respective PFGE profiles were distinctly different and distinguishable from each other. This is the first report of the isolation of UPTC from crows (Corvus levaillantii).

Animals↗
PubMed2002

[Basic studies on Vibrio vulnificus infection: isolation of V. vulnificus from sea water, sea mud, and oysters].

To clarify the environmental distribution of Vibrio vulnificus, sea water, sea mud, and oysters were examined at 13 sites, i.e. 4 sites in the Tokyo Bay (eastern Japan) and 9 sites (5 sites for oysters) in Tokushima Prefecture (western Japan). 1. V. vulnificus was isolated from 80 (54.8%) of the 146 samples of sea water examined. It was isolated from 19 (41.3%) of the 46 samples from western Japan and 61 (61.0%) of the 100 samples from eastern Japan. 2. It was isolated from 40 (40.8%) of the 98 samples of sea mud obtained in eastern Japan. 3. It was isolated from 655 (30.3%) of the 2,165 samples of oysters. They were 30 (9.7%) of 309 samples from western Japan and 625 (33.7%) of 1,856 samples from eastern Japan. 4. The density of V. vulnificus was 0.3-1.1 x 10(6) MPN/L in seawater, 0.3-1.1 x 10(5) MPN/100 g in sea mud, and 0.3-1.1 x 10(7) MPN/100 g in oysters. 5. Seasonally, V. vulnificus was isolated from 44 (6.2%) of the 713 samples in spring, 450 (72.6%) of the 620 samples in summer, 264 (51.8%) of the 510 samples in fall, and 17 (3.0%) of the 56 samples in winter. Thus, the isolation rates of V. vulnificus from sea water and oysters tended to be higher in eastern Japan than in western Japan and to be highest in summer, then, in fall.

Animals↗
PubMed2002

[Antibacterial activity of new-quinolone and macrolide antibiotics against oral bacteria].

Minimum Inhibitory Concentration (MIC) of 4 new-quinolone antibacterial reagents and 4 macrolide antibiotics against periodontopathic bacteria 21 species 24 strains of standard strains including oral related bacteria and clinical isolated (1993-1999) 20 strains of Porphyromonas gingivalis, 7 strains of Actinobacillus actinomycetemcomitans were determined. Minocycline HCl was used as the comparative reagent. Macrolide showed moderate antibacterial activity against standard strains of oral related bacteria except Fusobacterium nucleatum. New-quinolone showed excellent activity against Eikenella corrodens and Actinobacillus actinomycetemcomitans. Concerning to the clinical isolated strains, Clarithromycin effected P. gingivalis (MIC90 0.1 microgram/ml) and Levofloxacin and Ciprofloxacin showed high-potency antibacterial activity against clinical isolated Actinobacillus actinomycetemcomitans (MIC90 0.013-0.025 microgram/ml).

4-Quinolones↗
PubMed2002

[Identification of chemical structure of antibacterial components against Legionella pneumophila in a coffee beverage].

We previously reported that certain constituents in brewed coffee exhibited antibacterial activities against a strain of Legionella pneumophila. The constituents showing antibacterial activities were included only in extracts cold with water or hot water. To determine the antibacterial substances in coffee extract, the extract was fractionated by HPLC using a UV/photodiode array detector. The optimum HPLC conditions for analysis were UV wavelength of 250 nm and eluents of methanol/acetic acid (10/90), pH 3.0. When several fractions separated by HPLC were investigated for antibacterial activities against L. pneumophila, it was found that three peak fractions exhibited strong antibacterial activities. Each product from these fractions was analyzed by NMR and LC-mass spectrometry, and the chemical structure of each was determined. It was shown that the antibacterial substances was were protocatechuic acid (3,4-dihydroxy benzoic acid), chlorogenic acid, and caffeic acid.

Beverages↗