Bartowsky E J, Attridge S R, Thomas C J, Mayrhofer G, Manning P A
Department of Microbiology and Immunology, University of Adelaide, South Australia.
Infect Immun. 1990 Sep;58(9):3129-34. doi: 10.1128/iai.58.9.3129-3134.1990.
The conjugative plasmid P of Vibrio cholerae has been shown to have a suppressive effect on the virulence of hypertoxigenic strains like 569B. In this study, we have sought to analyze this phenomenon. Utilizing the infant mouse cholera model, we have demonstrated that the presence of P increases the 50% lethal dose of V. cholerae classical Inaba 569B by more than 300-fold. No effect of P on cholera toxin (CT) production, whether measured by GM1 enzyme-linked immunosorbent assay, by CT activity in ligated rabbit ileal loops, or by transcription from the CT promoter, could be discerned. Colonization of the intestine by P+ derivatives was dramatically reduced although only a minor effect could also be demonstrated on in vitro attachment to intestinal strips. Electron microscopic examination suggested that the P plasmid was affecting the production of the TCP pilus. Another conjugative plasmid, V, has also been examined, but it had no effect on virulence.
霍乱弧菌的接合质粒P已被证明对569B等超产毒菌株的毒力有抑制作用。在本研究中，我们试图分析这一现象。利用幼鼠霍乱模型，我们证明P的存在使霍乱弧菌古典生物型稻叶569B的50%致死剂量增加了300多倍。无论是通过GM1酶联免疫吸附测定、结扎兔回肠袢中的CT活性，还是通过CT启动子的转录来测量，均未发现P对霍乱毒素（CT）产生有影响。P+衍生物在肠道的定殖显著减少，尽管对体外附着于肠条也有轻微影响。电子显微镜检查表明，P质粒影响TCP菌毛的产生。另一种接合质粒V也已被检测，但它对毒力没有影响。
