腸管出血性大腸菌O157に用いる抗生物質の検討  [in Japanese] Evaluation of Antibiotics Used for Enterohemorrhagic Escherichia coil O157 Enteritis : Effect of Various Antibiotics on Extracellular Release of Verotoxin  [in Japanese]

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Abstract

腸管出血性大腸菌O157感染症患者に投与する最も適切な抗菌剤を検討するため, MIC及び抗菌剤存在下でのベロ毒素の放出を測定した. 供試薬剤として経口剤ABPC, CCL, CFDN, FOM, NFLX, NA, KM, MINO, DOXY, TCを用いた. 11株中2株が, ABPC, TC耐性であったほかは, いずれの薬剤にも感受性を示し, MIC値の上では, 殆どすべての薬剤が有効であった. 薬剤存在下でのベロ毒素の放出を測定した所, 薬剤の添加により毒素の著しい放出をもたらすグループ (ABPC, CCL, CFDN, FOM, NFLX, NA) と, 殆ど無添加の場合と変わらないグループ (KM, MINO, DOXY, TC) に大別された. 細胞壁合成阻害剤 (ABPC, CCL, CFDN, FOM) の場合は殺菌に伴ってVT1, VT2ともに菌体より放出された. キノロン系薬剤 (NFLX及びNA) の場合は, VT2のみ菌体より放出された. これに対して蛋白合成阻害剤 (KM, MINO, DOXY, TC) の場合は, VT1は薬剤無添加の場合と同様に, 測定に用いた逆受身ラテックス凝集反応の検出限界以下であり, VT2も薬剤無添加の場合と同等, あるいはそれ以下であった. この結果は, 蛋白合成阻害剤を使用すれば, 腸管出血性大腸菌O157感染症に於て, 毒素を放出させることなく, 殺菌あるいは増殖を抑制することができることを示唆している

We tested antimicrobial activities of ten oral antibiotics; ampicillin (ABPC), cefdinir (CFDN), cefaclor (CCL), fosfomycin (FOM), norfloxacin (NFLX), nalidixic acid (NA), kanamycin (KM), minocycline (MINO), doxycycline (DOXY), and tetracycline (TC) against eleven enterohemorrhagic <I>Esherichia coli</I> (EHEC) O157 clinical strains. Two strains were resistant to ABPC and TC. Other strains were sensitive to all the ten antibiotics. To investigate the effect of antibiotics on extracellular release of verotoxin (VT), strain EHEC TT10 was grown in 10 ml of LB containing various concentrations of the antibiotics for 2 h. Number of viable cells were counted and the amounts of VT1 and VT2 released in the supernatants were measured with reverse passive latex agglutination (RPLA) using serially diluted sterilized culture supernatants. The amount of VT1 and VT2 was evidently increased with ABPC, CFDN, CCL, and FOM, the inhibitors of cell wall biosynthesis. In the case of quinolons, VT2 was markedly increased, but VT1 was not released to the supernatant. KM killed the bacteria efficiently, but no release of VT1 or VT2 was observed in the supernatant. Tetracyclines (MINO, DOXY, and TC) did not make the bacteria release either VT1 or VT2, but could not kill the bacteria appreciably. These results indicated that the inhibitors of protein synthesis (KM, MINO, DOXY, TC) are the safe antibiotics not causing the release of verotoxin from the cells and thus preventing development of hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpra (TTP), the important sequelae of the enteritis.

Journal

  • Kansenshogaku Zasshi

    Kansenshogaku Zasshi 71(2), 130-135, 1997-02-20

    The Japanese Association for Infectious Diseases

References:  11

Cited by:  15

Codes

  • NII Article ID (NAID)
    10008720308
  • NII NACSIS-CAT ID (NCID)
    AN00047715
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    03875911
  • NDL Article ID
    4151877
  • NDL Source Classification
    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 Call No.
    Z19-193
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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