埃尔托霍乱弧菌感染棘阿米巴原虫的实验研究

Intracellular survival and multiplication of El Tor biotype V. cholerae inside Acanthamoeba

目的探讨埃尔托霍乱弧菌能否在棘阿米巴原虫内生存繁殖,并观察棘阿米巴原虫对埃尔托霍乱弧菌存活的影响。方法采用埃尔托霍乱弧菌与棘阿米巴共培养的方法,通过倒置显微镜和电镜切片观察霍乱弧菌在阿米巴滋养体内的生长情况。结果共培养8h后可见埃尔托霍乱弧菌已进入棘阿米巴滋养体的细胞质中。随着共培养时间的延长,吉曼尼兹染色下可见埃尔托霍乱弧菌在棘阿米巴滋养体的空泡中的数量增多。共培养液经成囊培养待95%棘阿米巴转化为包囊后,使用盐酸处理的包囊传代实验能再分离培养出埃尔托霍乱弧菌。与棘阿米巴共培养的霍乱弧菌的活菌数在15d内维持在(1.02～9.77)106CFU/mL;而单独培养的埃尔托霍乱弧菌的活菌数量2d后下降了3个数量级,在后续13d内基本保持(1.40～3.07)×103CFU/mL;对每一时间段两者作t检验比较,差异在统计学上都有显著性意义(P<0.01)。结论埃尔托霍乱弧菌能在棘阿米巴的滋养体和包囊内生存繁殖,棘阿米巴能提高埃尔托霍乱弧菌的存活数量。

Objective To investigate the survival and multiplication of E1 Tor biotype V. cholerae cocultured with the Acanthamoeba polyphaga, to determine whether Acanthamoeba could affect the survival of E1 Tor biotype V. cholerae. Methods Survival and replication of E1 Tot biotype V. cholerae which was co-cultured with A. polyphaga were observed with inverted microscope, electron microscopic section and viable count in passage cultures in the presence or absence of amoebae. Results E1 Tor biotype V. cholerae was found present in the trophozoites and grew within the vacuoles after 8-hour coculture together with A. polyphaga. The germs could be re-isolated from the excystmen of A. polyphaga. The V. cholerae could maintain in a high concentration co-cultured with amooebae according to the survival count of them, but it decreased from 1.02 × 10^6 CFU/mL to 1.60 × 10^3 CFU/mL in the absence of amoeba after two-day incubation. Conclusions El Tot biotype V. cholerae can survive and multiply within A. polyphaga and it can maintain in a high concentration in the presence of amooebae. These results suggest that Acantharnoebae might provide one of environmental reservoirs of E1 Tor biotype V. cholerae.