ter Huurne A A, Muir S, van Houten M, Koopman M B, Kusters J G, van der Zeijst B A, Gaastra W
Department of Bacteriology, Faculty of Veterinary Medicine, University of Utrecht, Netherlands.
Zentralbl Bakteriol. 1993 Apr;278(2-3):316-25. doi: 10.1016/s0934-8840(11)80848-0.
Serpulina (Treponema) hyodysenteriae, an anaerobic beta hemolytic spirochaete, is the etiologic agent of swine dysentery. Not much is known at present about the virulence factors of S. hyodysenteriae. However, the hemolysin production of this bacterium is generally accepted to be a virulence factor. To study the exact role of hemolysin production in the pathogenesis of swine dysentery, the gene encoding a hemolysin, tly, was cloned and its nucleotide sequence determined. After inactivation of this gene, the virulence of a tly-minus mutant in mice was tested. The mutant had reduced hemolysis indicating that the tly-encoded hemolysin was not the only hemolysin produced by S. hyodysenteriae. Mice infected with the tly-minus mutant had fewer cecal lesions than mice infected with the wild-type S. hyodysenteriae. It was concluded that the tly-encoded hemolysin might be an important virulence factor, but not the only one. Since it was demonstrated that spirochaetes can be transformed through electroporation, this has made a genetic approach to elucidate the pathogenesis of spirochaetal infections possible.
猪痢疾密螺旋体（密螺旋体属）是一种厌氧的β溶血螺旋体，是猪痢疾的病原体。目前对猪痢疾密螺旋体的毒力因子了解不多。然而，这种细菌产生溶血素通常被认为是一种毒力因子。为了研究溶血素产生在猪痢疾发病机制中的确切作用，克隆了编码溶血素的基因tly并确定了其核苷酸序列。该基因失活后，测试了tly缺失突变体在小鼠中的毒力。该突变体的溶血作用减弱，表明tly编码的溶血素不是猪痢疾密螺旋体产生的唯一溶血素。感染tly缺失突变体的小鼠盲肠病变比感染野生型猪痢疾密螺旋体的小鼠少。得出的结论是，tly编码的溶血素可能是一种重要的毒力因子，但不是唯一的毒力因子。由于已证明螺旋体可通过电穿孔转化，这使得通过遗传学方法阐明螺旋体感染的发病机制成为可能。
