コーチゾン投与による易感染化マウス膀胱内での Escherichia coli の増殖様式 Colonization Types of Escherichia coli in Experimental Urinary Tract Infection in Compromised Mice Treated with Hydrocortisone

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著者

    • 角野 洋一 KAKUNO Yoichi
    • 麻布大学環境保健学部衛生学講座 Laboratory of Hygiene and Public Health, College of Environmental Health Azabu University
    • 本田 政幸 HONDA Masayuki
    • 麻布大学環境保健学部衛生学講座 Laboratory of Hygiene and Public Health, College of Environmental Health Azabu University
    • 高倉 剛二 TAKAKURA Koji
    • 麻布大学環境保健学部衛生学講座 Laboratory of Hygiene and Public Health, College of Environmental Health Azabu University

抄録

尿路感染病原因菌としての<I>Escherichia coli</I>の尿路での増殖様式を知るために, 菌株 (3株), コーチゾン投与量 (0, 2, 4, 8mg/mouse), 経過時間 (菌液接種後3, 6, 24時間) の3種類の要因を取り上げ72匹のマウスを用いた3元配置の要因実験を行った. 菌株は先に我々が30株を用いて行った尿路感染実験で増殖部位に比較的傾向のみられた3菌株を用いた. 即ち, 株H70は尿路上皮細胞内での増殖 (細胞内増殖型) が多く, 株H99は膀胱腔内での増殖 (腔内増殖型) が, また株K88は高度に両部位 (混合型) で増殖がみられたものである.<BR>菌株H70, H99, K88を接種されたマウスでの菌の検出された割合はそれぞれ25.0, 41.7, 79.2%であった. コーチゾン0, 2, 4, 8mg/mouse投与群での検出率は, それぞれ38.9, 55.6, 55.6, 44.4%であった.<BR>菌液接種3, 6, 24時間後での, 腔内増殖型の検出率は45.8, 20.8, 20.8%で, 混合型は4.2, 16.7, 4.2%, 細胞内増殖型は4.2, 16.7, 12.5%で, 3種のいずれかが検出されたものは54.2, 54.2, 37.5%であった. これは感染当初は膀胱腔内での菌の増殖が優勢で, その後, 細胞内への侵入が起こり, 腔内の菌が排除された後も細胞内の菌は留まるためと考えられた.<BR>しかし, 菌株により増殖部位と程度が異なり, 特に, 検出率の低いH70株で細胞内増殖型が検出されたのに対し, 検出率がそれより高いH88株では細胞内増殖型は観察されなかったこと, またコーチゾン処理による影響や経過時間による増殖様式の推移にも菌株で違いがみられたことから, 尿路感染症の機序が単一ではなく, 菌株や宿主性状により異なると結論された.

We studied the experimental urinary tract infections (UTIs) on compromised mice with <I>Esherichia coli</I> to elucidate the effects of three factors (bacterial strains, doses of hydrocortisone, infectious periods) on the bacterial colonization in the bladders.<BR>We selected three strains from the stock of <I>E. coli</I> isolated from the urine or feces of patients with lower UTI, because each of the three strains showed a tendency in colonization in previous experiments: One strain, which was named H70, showed a relative slight and intracellular colonization; the H99, an extracellular and the K88, both intracellular and extracelluar growths which were large.<BR>The rate of bacterial microscopic recovery from the bladders of mice inoculated strains H70, H99 and K88 were 25.0, 41.7 and 79.2% respectively. And the recovery from the mice inoculated cortisone 0, 2, 4 and 8 mg/mouse were 38.9, 55.6, 55.6 and 44.4% respectively. The detections of various colonizations at 3, 6 and 24 hr after the bacterial inoculation were that extracellular types were 45.8, 20.8 and 20.8%, intracellular types were 4.2, 16.7 and 12.5%, simultaneous colonizations were 4.2, 16.7 nad 4.2% and the detections of at least one of them were 54.2, 54.2 and 37.5% respectively.<BR>Thus, the global findings were that extracellular growth of the bacteria were predominant at first, then the bacteria invaded the mucosal cells and the intracellular bacteria stayed after the voiding of extracellular bacteria. Intracellular colonizations seemed more strongly interacting with hosts than extracelluar types, because cortisone enhanced the intracellular colonizations more strongly than the others.<BR>However, it seemed that urinary tract infections were not simple events but the results of the interactions of the bacterial strains and hosts, because the locations and degrees of the bacterial colonization and the effects of hydrocortisone on them were different in each bacterial strain and infectious period.

収録刊行物

  • 感染症学雑誌 : 日本伝染病学会機関誌 : the journal of the Japanese Association for Infectious Diseases

    感染症学雑誌 : 日本伝染病学会機関誌 : the journal of the Japanese Association for Infectious Diseases 71(7), 652-658, 1997-07-20

    The Japanese Association for Infectious Diseases

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各種コード

  • NII論文ID(NAID)
    10008721196
  • NII書誌ID(NCID)
    AN00047715
  • 本文言語コード
    JPN
  • 資料種別
    ART
  • ISSN
    03875911
  • NDL 記事登録ID
    4268912
  • NDL 雑誌分類
    ZS9(科学技術--医学--病理学・微生物学・寄生虫学・感染・免疫学・血清学・アレルギー)
  • NDL 請求記号
    Z19-193
  • データ提供元
    CJP書誌  NDL  J-STAGE 
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