迟缓爱德华氏菌对Hep-2细胞的侵袭特性

用细胞裂解计数法及超薄切片电镜观察法分析了迟缓爱德华氏菌侵袭ＨＥｐ－２细胞的基本特性。在１５株来源各异的迟缓爱德华氏菌中，有６株细菌具有对ＨＥｐ－２细胞的侵袭能力。细菌侵入细胞后，主要位于空泡内。侵入细胞内的迟缓爱德华氏菌不仅可在细胞内增殖，而且可从细胞内释放出来。用细胞松弛素破坏微丝后可抑制其侵袭作用，而且表现出剂量依赖关系，而在秋水仙素破坏微管后不影响其侵袭力。这表明在迟缓爱德华氏菌对ＨＥｐ－

INTERNALIZATION AND REPLICATION OF EDWARDSIELLA TARDA IN HEp-2 CELLS

It is demonstrated that Edwardsiella tarda possesses the ability to invade cultured epithelial HEp-2 cells by both lysis-counting assay and thin-section electron microscopy. Among fifteen strains of E. tarda, 6 strains internalized into HEp-2 cells and located mainly in vesicles. After internalization, the bacteria replicated in the host cells and then released into medium. Pretreatment of the HEp-2 cells with various concentration of cytochalasin D (0.1-5.0 micrograms/ml) or cytochalasin B (2.5-10.0 micrograms/ml) significantly reduced the amount of internalized bacteria in a dose-dependent manner. While pretreatment of HEp-2 cells with 0.25-100 mumol/L colchicine did not show any effect on the invasiveness of E. tarda. This strongly indicates that microfilaments are required for the internalization of E. tarda into HEp-2 cells and that microtubules are not involved in the entrance of E. tarda into HEp-2 cells.