Roles of the surface layer proteins of Campylobacter fetus subsp fetus in ovine abortion
Roles of the surface layer proteins of Campylobacter fetus subsp fetus in ovine abortion
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DOI：
10.1128/iai.68.3.1687-1691.2000
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发表时间：
2000-03-01
影响因子：
3.1
通讯作者：
Newell, DG
中科院分区：
文献类型：
--
作者：
Grogono-Thomas, R;Dworkin, J;Newell, DG
胎儿弯曲杆菌胎儿亚种的表面（S）层蛋白的作用已经使用绵羊流产模型进行了研究。野生型菌株23 D诱导高达90%的皮下攻毒妊娠母羊流产。从母鼠和胎儿中回收的分离株表达分子量可变的S层蛋白，自发的S层阴性变异株23 B既不定植也不引起妊娠精灵流产。在该模型中还研究了一系列源自23 D的同基因sapA和recA突变体，A突变体（501 [sapA recA（+）]）在5只攻击动物中的一只中引起流产，并从第二只动物的胎盘中回收。另一种无S层蛋白表达的突变体（502 [sapA recA]）在激发动物中未引起定殖或流产，但在胎盘内给药时引起流产。突变体600（2）和600（4）（均为recA）分别具有97和127 kDa S层蛋白的固定表达。用突变体600（4）攻击的6只动物中有2只被定殖，但没有流产。正如预期的那样，回收的所有五种菌株均表达127 kDa的S层蛋白。相反，突变体600（2）从所有5只攻毒动物的胎盘中回收，并导致2只动物流产。出乎意料。16个分离物中的一个表达127-kDa而不是97-kDa的S-层蛋白。因此，这些研究表明，S-层蛋白出现必不可少的殖民和/或易位到胎盘，但不需要介导胎儿损伤和S-层变异可能发生在recA菌株。
The role of the surface (S)-layer proteins of Campylobacter fetus subsp, fetus has been investigated using an ovine model of abortion. Wild type strain 23D induced abortion in up to 90% of pregnant ewes challenged subcutaneously. Isolates recovered from both dams and fetuses expressed S-layer proteins with variable molecular masses, The spontaneous S-layer-negative variant, strain 23B, neither colonized nor caused abortions in pregnant elves. A series of isogenic sapA and recA mutants, derived from 23D, also were investigated in this model, A mutant (501 [sapA recA(+)]) caused abortion in one of five challenged animals and was recovered from the placenta of a second animal. Another mutant (502 [sapA recA]) with no S-layer protein expression caused no colonization or abortions in challenged animals but caused abortion when administered intraplacentally, Mutants 600(2) and 600(4), both recA, had fixed expression of 97- and 127-kDa S-layer proteins, respectively. Two of the six animals challenged with mutant 600(4) were colonized, but there were no abortions. As expected, all five strains recovered expressed a 127-kDa S-layer protein. In contrast, mutant 600(2) was recovered from the placentas of all five challenged animals and caused abortion in two. Unexpectedly. one of the 16 isolates expressed a 127-kDa rather than a 97-kDa S-layer protein. Thus, these studies indicate that S-layer proteins appear essential for colonization and/or translocation to the placenta but are not required to mediate fetal injury and that S-lager variation may occur in a recA strain.